• Review for Week 1

    Updated: 2010-01-31 18:27:28
    Course Basics You should be aware of how to negotiate the Vancko Web portions of Lecture and Lab.  This includes such things as Sending and receiving messages within Vancko Hall How to take and submit a quiz online Where the lecture outlines and practice quizzes are located. How to see your grades and Vancko Hall. You should have reviewed the course [...]

  • The genome of Pseudocowpoxvirus: comparison of a reindeer isolate and a reference strain.

    Updated: 2010-01-31 18:08:34
    : . . : Warning The NCBI web site requires JavaScript to function . more . Resources All Resources Literature Bookshelf Journals Database MeSH PubMed PubMed Central All Literature Resources… DNA RNA BankIt BLAST GenBank Genome Workbench Influenza Virus Nucleotide Database PopSet Reference Sequence RefSeq Sequence Read Archive SRA Trace Archive All DNA RNA Resources… Proteins BLAST BLAST Link BLink Conserved Domain Search Service CD Search GenBank Protein Protein Clusters Reference Sequence RefSeq All Proteins Resources… Sequence Analysis BLAST BLAST Stand-alone BLAST Link BLink GenBank Genome Workbench Influenza Virus All Sequence Analysis Resources… Genes Expression GenBank Gene Gene Expression Omnibus GEO Datasets Gene Expression Omnibus GEO Datasets Gene Expression Omnibus GEO Profiles Genome Workbench Map Viewer UniGene All Genes Expression Resources… Genomes GenBank Genome Genome Project Influenza Virus Map Viewer Nucleotide Database Sequence Read Archive SRA Trace Archive UniSTS All Genomes Resources… Maps Markers Genome Genome Workbench Map Viewer UniSTS All Maps Markers Resources… Domains Structures Cn3D Conserved Domain Database CDD Conserved Domain Search

  • Subcellular localisation and live cell imaging of the Helicoverpa armigera stunt virus 1 replicase in mammalian and Spodoptera frugiperda cells.

    Updated: 2010-01-31 18:08:34
    . : Warning The NCBI web site requires JavaScript to function . more . Resources All Resources Literature Bookshelf Journals Database MeSH PubMed PubMed Central All Literature Resources… DNA RNA BankIt BLAST GenBank Genome Workbench Influenza Virus Nucleotide Database PopSet Reference Sequence RefSeq Sequence Read Archive SRA Trace Archive All DNA RNA Resources… Proteins BLAST BLAST Link BLink Conserved Domain Search Service CD Search GenBank Protein Protein Clusters Reference Sequence RefSeq All Proteins Resources… Sequence Analysis BLAST BLAST Stand-alone BLAST Link BLink GenBank Genome Workbench Influenza Virus All Sequence Analysis Resources… Genes Expression GenBank Gene Gene Expression Omnibus GEO Datasets Gene Expression Omnibus GEO Datasets Gene Expression Omnibus GEO Profiles Genome Workbench Map Viewer UniGene All Genes Expression Resources… Genomes GenBank Genome Genome Project Influenza Virus Map Viewer Nucleotide Database Sequence Read Archive SRA Trace Archive UniSTS All Genomes Resources… Maps Markers Genome Genome Workbench Map Viewer UniSTS All Maps Markers Resources… Domains Structures Cn3D Conserved Domain Database CDD Conserved Domain Search

  • The HR motif in the RNA-dependent RNA polymerase L protein of Chandipura virus is required for unconventional mRNA capping activity.

    Updated: 2010-01-31 18:08:33
    . . : Warning The NCBI web site requires JavaScript to function . more . Resources All Resources Literature Bookshelf Journals Database MeSH PubMed PubMed Central All Literature Resources… DNA RNA BankIt BLAST GenBank Genome Workbench Influenza Virus Nucleotide Database PopSet Reference Sequence RefSeq Sequence Read Archive SRA Trace Archive All DNA RNA Resources… Proteins BLAST BLAST Link BLink Conserved Domain Search Service CD Search GenBank Protein Protein Clusters Reference Sequence RefSeq All Proteins Resources… Sequence Analysis BLAST BLAST Stand-alone BLAST Link BLink GenBank Genome Workbench Influenza Virus All Sequence Analysis Resources… Genes Expression GenBank Gene Gene Expression Omnibus GEO Datasets Gene Expression Omnibus GEO Datasets Gene Expression Omnibus GEO Profiles Genome Workbench Map Viewer UniGene All Genes Expression Resources… Genomes GenBank Genome Genome Project Influenza Virus Map Viewer Nucleotide Database Sequence Read Archive SRA Trace Archive UniSTS All Genomes Resources… Maps Markers Genome Genome Workbench Map Viewer UniSTS All Maps Markers Resources… Domains Structures Cn3D Conserved Domain Database CDD Conserved Domain Search

  • Cyclophilin A-Independent Recruitment of NS5A and NS5B Into HCV Replication Complexes.

    Updated: 2010-01-31 18:08:32
    Cyclophilin A-Independent Recruitment of NS5A and NS5B Into HCV Replication Complexes. J Gen Virol. 2010 Jan 27; Authors: Chatterji U, Bobardt M, Lim P, Gallay P The mechanisms by which cyclophilin A (CypA) governs HCV replication remain unknown. Since CypA binds two essential components of the HCV replication complex (RC) - the polymerase NS5B and the phosphoprotein NS5A, we asked in this study whether CypA regulates their RC association. We found that CypA, via its isomerase pocket, locates in a protease-resistant compartment similar to that where HCV replicates. CypA association with this compartment is not mediated by HCV. Moreover, CypA depletion of RC does not influence NS5A and NS5B RC association, arguing against a model where CypA governs HCV replication by recruiting NS5A or NS5B into RC. PMID: 20107018 [PubMed - as supplied by publisher]

  • Virologic footprint of CD4+ T cell responses during chronic HCV infection.

    Updated: 2010-01-31 18:08:31
    . . : Warning The NCBI web site requires JavaScript to function . more . Resources All Resources Literature Bookshelf Journals Database MeSH PubMed PubMed Central All Literature Resources… DNA RNA BankIt BLAST GenBank Genome Workbench Influenza Virus Nucleotide Database PopSet Reference Sequence RefSeq Sequence Read Archive SRA Trace Archive All DNA RNA Resources… Proteins BLAST BLAST Link BLink Conserved Domain Search Service CD Search GenBank Protein Protein Clusters Reference Sequence RefSeq All Proteins Resources… Sequence Analysis BLAST BLAST Stand-alone BLAST Link BLink GenBank Genome Workbench Influenza Virus All Sequence Analysis Resources… Genes Expression GenBank Gene Gene Expression Omnibus GEO Datasets Gene Expression Omnibus GEO Datasets Gene Expression Omnibus GEO Profiles Genome Workbench Map Viewer UniGene All Genes Expression Resources… Genomes GenBank Genome Genome Project Influenza Virus Map Viewer Nucleotide Database Sequence Read Archive SRA Trace Archive UniSTS All Genomes Resources… Maps Markers Genome Genome Workbench Map Viewer UniSTS All Maps Markers Resources… Domains Structures Cn3D Conserved Domain Database CDD Conserved Domain Search

  • Puumala hantavirus and Myodes glareolus in northern Europe: no evidence of co-divergence between genetic lineages of virus and host.

    Updated: 2010-01-31 18:08:31
    . . : Warning The NCBI web site requires JavaScript to function . more . Resources All Resources Literature Bookshelf Journals Database MeSH PubMed PubMed Central All Literature Resources… DNA RNA BankIt BLAST GenBank Genome Workbench Influenza Virus Nucleotide Database PopSet Reference Sequence RefSeq Sequence Read Archive SRA Trace Archive All DNA RNA Resources… Proteins BLAST BLAST Link BLink Conserved Domain Search Service CD Search GenBank Protein Protein Clusters Reference Sequence RefSeq All Proteins Resources… Sequence Analysis BLAST BLAST Stand-alone BLAST Link BLink GenBank Genome Workbench Influenza Virus All Sequence Analysis Resources… Genes Expression GenBank Gene Gene Expression Omnibus GEO Datasets Gene Expression Omnibus GEO Datasets Gene Expression Omnibus GEO Profiles Genome Workbench Map Viewer UniGene All Genes Expression Resources… Genomes GenBank Genome Genome Project Influenza Virus Map Viewer Nucleotide Database Sequence Read Archive SRA Trace Archive UniSTS All Genomes Resources… Maps Markers Genome Genome Workbench Map Viewer UniSTS All Maps Markers Resources… Domains Structures Cn3D Conserved Domain Database CDD Conserved Domain Search

  • Alliance for Regenerative Medicine Meets With Federal Multi-Agency Tissue Engineering Science Interagency Working Group (MATES IWG)

    Updated: 2010-01-30 11:40:31
    Home About Archives Science Bookstore Terms of Service Privacy Policy Contact Us ADVERTISMENT ADVERTISMENT Tags medicine member agencies patient groups principal purpose tissue engineering Alliance for Regenerative Medicine Meets With Federal Multi-Agency Tissue Engineering Science Interagency Working Group MATES IWG Posted on 30 January 2010 11:40 by Alfie VN:F 1.8.1_1037 please wait . Rating : 0.0 5 0 votes cast Story : Summary This was an important first step toward coalescing unified support around the cause of regenerative medicine . The Multi-Agency Tissue Engineering Science MATES Interagency Working Group IWG organized under the auspices of the Subcommittee on Biotechnology of the National Science and Technology Council NSTC was established in 2000. The principal purpose of the MATES IWG is to provide a platform across which member agencies can interact and exchange information on tissue engineering efficiently and effectively . It is the means by which Federal agencies involved in tissue engineering stay informed of each others activities and coordinate their efforts in a timely and efficient manner . ARM also works to increase public understanding of the field and its

  • Cold Spring Harbor Protocols Features Analysis Of Microbes, Immune Response

    Updated: 2010-01-29 15:57:31
    Story Summary: Improvements to cloning and sequencing techniques are allowing researchers to study microorganisms in environmental samples, and new knowledge of species interactions and community dynamics is emerging. The identification of microorganisms in these samples is of vital importance to interpreting the results of such studies. The method is highly sensitive, quantitative, easy to use, [...] Related posts:ChIP-Seq, Drosophila Targeted Mutagenesis Featured In Cold Spring Harbor Protocols ChIP-Seq, Drosophila Targeted Mutagenesis Featured In Cold Spring Harbor Protocols Cold Spring Harbor Protocols features RNA analysis methods

  • Corrigendum: Construction of a doramectin producer mutant from an avermectin-overproducing industrial strain of Streptomyces avermitilis

    Updated: 2010-01-29 15:14:35
    Xuejin Zhao, Yuanxin Wang, Shiwei Wang, Zhi Chen, Ying Wen, and Yuan Song - (Source: Canadian Journal of Microbiology)

  • Corrigendum: Identification and application of AFLP-derived genetic markers for quantitative PCR-based tracking of Bacillus and Paenibacillus spp. released in soil

    Updated: 2010-01-29 15:14:35
    Miguel A. Providenti, Melissa Begin, Samielle Hynes, Christine Lamarche, David Chitty, Jessica Rahn, Lee A. Beaudette, Rick Scroggins, and Myron L. Smith - (Source: Canadian Journal of Microbiology)

  • Nanofibers for Water Treatment

    Updated: 2010-01-29 13:13:00
    Electrospinning is a highly versatile technique that can be used to create ultrafine fibres of various polymers and other materials, with diameters ranging from a few micrometers down to tens of nanometres. The nonwoven webs of fibers formed through this process typically have high specific surface areas, nano-scale pore sizes, high and controllable porosity and extreme flexibility with regard to the materials used and modification of the surface chemistry of the fibres. A combination of these features is utilized in the application of electrospun nanofibres to a variety of water treatment applications, including filtration, solid phase extraction and reactive membranes read more ...References:Nanotechnology in Water Treatment ApplicationsLab-on-a-Chip TechnologyReal-Time PCR: Current Tech...

  • Potential Risks of Nanotechnology on Human Health

    Updated: 2010-01-29 13:13:00
    The risk assessment of nanoparticles and nanomaterials is of key importance for the continuous development in the new field of nanotechnology. Humans are increasingly being exposed to nanoparticles and nanomaterials, placing stress on the development and validation of reproducible toxicity tests. Tests currently used include genotoxicity and cytotoxicity tests, and in vivo toxicity models. The unique characteristics of nanoparticles and nanomaterials are responsible for their toxicity and interaction with biological macromolecules within the human body. This may lead to the development of diseases and clinical disorders. A loss in cell viability and structure can also occur in exposed tissues as well as inflammation and granuloma formation. The future of nanotechnology depends on the respo...MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.

  • Reverse Osmosis

    Updated: 2010-01-29 13:12:00
    The membrane separation technologies of reverse osmosis (hyperfiltration) and nanofiltration are important in water treatment applications. Reverse osmosis is based on the basic principle of osmotic pressure, while nanofiltration makes use of molecule size for separation. Recent advances in the field of nanotechnology are opening a range of possibilities in membrane technologies. These include: new membrane preparation and cleaning methods, new surface and interior modification possibilities, the use of new nanostructured materials, and new characterization techniques read more ...References:Nanotechnology in Water Treatment ApplicationsLab-on-a-Chip TechnologyReal-Time PCR: Current Technology and ApplicationsEnvironmental Molecular MicrobiologyPCR publicationsEnvironmental Microbiology pu...

  • Nanofiltration in Wastewater Treatment

    Updated: 2010-01-29 13:11:00
    Nanofiltration is a new type of pressure driven membrane process and used between reverse osmosis and ultrafiltration membranes. The most different speciality of nanofiltration membranes is the higher rejection of multivalent ions than monovalent ions. Nanofiltration membranes are used in softening water, brackish water treatment, industrial wastewater treatment and reuse, product separation in the industry, salt recovery and recently desalination as two pass nanofiltration system read more ...References:Nanotechnology in Water Treatment ApplicationsLab-on-a-Chip TechnologyReal-Time PCR: Current Technology and ApplicationsEnvironmental Molecular MicrobiologyPCR publicationsEnvironmental Microbiology publicationsBacteriologyFull range of books on microbiology at Microbiology Books (Source: ...

  • Nanobiocides in Water Purification

    Updated: 2010-01-29 13:09:00
    Electrospun nanofibers and nanobiocides show potential in the improvement of water filtration membranes. Biofouling of membranes caused by the bacterial load in water reduces the quality of drinking water and has become a major problem. Several studies showed inhibition of these bacteria after exposure to nanofibers with functionalized surfaces. Nanobiocides such as metal nanoparticles and engineered nanomaterials are successfully incorporated into nanofibers showing high antimicrobial activity and stability in water read more ...References:Nanotechnology in Water Treatment ApplicationsLab-on-a-Chip TechnologyReal-Time PCR: Current Technology and ApplicationsEnvironmental Molecular MicrobiologyPCR publicationsEnvironmental Microbiology publicationsBacteriologyFull range of books on microbi...

  • Nanozymes in Biofilm Removal

    Updated: 2010-01-29 13:09:00
    Sessile communities of bacteria encased in extracellular polymeric substances (EPS) are known as biofilms and causes serious problems in various areas, amongst other, the medical industry, industrial water settings, paper industry and food processing industry. Although various methods of biofilm control exist, these methods are not without limitations and often fail to remove biofilms from surfaces. Biofilms often show reduced susceptibility to antimicrobials or chemicals and chemical by-products may be toxic to the environment, whereas mechanical methods may be labour intensive and expensive due to down-time required to clean the system. This has led to a great interest in the enzymatic degradation of biofilms. Enzymes are highly selective and disrupt the structural stability of the biofi...

  • Nanobiotechnology for the Detection of Microbial Pathogens

    Updated: 2010-01-29 13:08:00
    An adequate supply of safe drinking water is one of the major prerequisites for a healthy life, but waterborne diseases is still a major cause of death in many parts of the world, particularly in young children, the elderly, or those with compromised immune systems. As the epidemiology of waterborne diseases is changing, there is a growing global public health concern about new and reemerging infectious diseases that are occurring through a complex interaction of social, economic, evolutionary, and ecological factors. An important challenge is therefore the rapid, specific and sensitive detection of waterborne pathogens. Presently, microbial tests are based essentially on time-consuming culture methods. However, newer enzymatic, immunological and genetic methods are being developed to repl...MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.

  • Nanotechnology in Water Treatment: Applications and Emerging Opportunities

    Updated: 2010-01-29 13:07:00
    Nanotechnology, the engineering and art of manipulating matter at the nanoscale (1-100 nm), offers the potential of novel nanomaterials for the treatment of surface water, groundwater and wastewater contaminated by toxic metal ions, organic and inorganic solutes and microorganisms. Due to their unique activity toward recalcitrant contaminants and application flexibility, many nanomaterials are under active research and development.References:Nanotechnology in Water Treatment ApplicationsLab-on-a-Chip TechnologyReal-Time PCR: Current Technology and ApplicationsEnvironmental Molecular MicrobiologyPCR publicationsEnvironmental Microbiology publicationsBacteriologyFull range of books on microbiology at Microbiology Books (Source: Microbiology Blog: The weblog for microbiologists.)

  • Design, Recombinant Expression, and Antibacterial Activity of the Cecropins-Melittin Hybrid Antimicrobial Peptides.

    Updated: 2010-01-28 23:00:00
    Authors: Cao Y, Yu RQ, Liu Y, Zhou HX, Song LL, Cao Y, Qiao DR In order to evaluate their antibacterial activities and toxicities, the cecropins-melittin hybrid antimicrobial peptide, CA(1-7)-M(4-11) (CAM) and CB(1-7)-M(4-11) (CBM), were designed by APD2 database. The recombinant hybrid antimicrobial peptides were successfully expressed and purified in Pichia pastoris. Antimicrobial activity assay showed that both of the two hybrid antimicrobial peptides had strong antibacterial abilities against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae, Bacillus subtilis, Bacillus thuringiensis, and Salmonella derby. The potency of CAM and CBM to E. coli 25922 were 0.862 and 0.849, respectively, slightly lower than Amp's 0.957. The hemolytic assays indicat...

  • Isolate-Specific Effects of Patulin, Penicillic Acid and EDTA on Biofilm Formation and Growth of Dental Unit Water Line Biofilm Isolates.

    Updated: 2010-01-28 23:00:00
    In this study, the effect of two quorum-sensing inhibitory compounds (patulin; PAT, penicillic acid; PA) and EDTA on planktonic growth, AI-2 signalling and in vitro biofilm formation of Pseudomonas aeruginosa, Achromobacter xylosoxidans and Achromobacter sp. was monitored. Vibrio harveyi BB170 bioassay and crystal violet staining methods were used to detect the AI-2 monitoring and biofilm formation in DUWL isolates, respectively. The V. harveyi BB170 bioassay failed to induce bioluminescence in A. xylosoxidans and Achromobacter sp., while P. aeruginosa showed AI-2 like activity suggesting the need of some pretreatments prior to bioassay. All strains were found to form biofilms within 72 h of incubation. The QSIs/EDTA combination have isolate-specific effects on biofilm formation and in som...

  • Plasmid Encoded AcrAB-TolC Tripartite Multidrug-Efflux System in Acidiphilium symbioticum H8.

    Updated: 2010-01-28 23:00:00
    This study is the first to report a multi-drug efflux system to be encoded on a plasmid of any Acidiphilium strain. PMID: 20111865 [PubMed - as supplied by publisher] (Source: Current Microbiology)

  • Identification of tomato plant as a novel host model for Burkholderia pseudomallei

    Updated: 2010-01-28 23:00:00
    Conclusions: The potential of B. pseudomallei as a plant pathogen raises new possibilities of exploiting plant as an alternative host for novel anti-infectives or virulence factor discovery. It also raises issues of biosecurity due to its classification as a potential bioterrorism agent. (Source: BMC Microbiology - Latest articles)

  • Proteomic comparison of the cytosolic proteins of three Bifidobacterium longum human isolates and B. longum NCC2705

    Updated: 2010-01-28 23:00:00
    Conclusion: These results showed that proteomic analysis can be valuable for investigating differences in bifidobacterial species and may provide a better understanding of the diversity of bifidobacteria and their potential use as probiotics. (Source: BMC Microbiology - Latest articles)

  • Characterization of the best anatomical sites in screening for methicillin-resistant Staphylococcus aureus colonization

    Updated: 2010-01-28 17:00:27
    Abstract nbsp;The purpose of this study was to identify differences in the sensitivity of anatomical sites sampling for methicillin-resistant Staphylococcus aureus (MRSA) colonization related to age, gender, clinical situation, and acquisition source as a base for screening protocols. We used a database that included all MRSA-positive cultures (Carmel Medical Center, 2003–2006) taken from nares, throat, perineum, and infection sites. The study population of 597 patients was divided into: “screening sample” (SS), which were cases of routine screening, and “clinical diagnostic sample” (CDS), which were patients with concurrent MRSA infection. MRSA acquisition sources were classified as internal medicine, surgical, referral patients, or intensive care unit (ICU). CDS pati...

  • Detection of multiple respiratory pathogens during primary respiratory infection: nasal swab versus nasopharyngeal aspirate using real-time polymerase chain reaction

    Updated: 2010-01-28 17:00:27
    In this study, we present the multiple detection of respiratory viruses in infants during primary respiratory illness, investigate the sensitivity of nasal swabs and nasopharyngeal aspirates, and assess whether patient characteristics and viral load played a role in the sensitivity. Healthy infants were included at signs of first respiratory tract infection. Paired nasopharyngeal aspirates and nasal swabs were collected. Real-time polymerase chain reaction (PCR) was carried out for 11 respiratory pathogens. Paired nasopharyngeal aspirates and nasal swabs were collected in 98 infants. Rhinovirus (n = 67) and respiratory syncytial virus (n = 39) were the most frequently detected. Co-infection occurred in 48% (n = 45) of the infants. The sensitivity of the nasal swab was lower...

  • Microbial community of salt crystals processed from Mediterranean seawater based on 16S rRNA analysis

    Updated: 2010-01-28 16:04:10
    Houda Baati, Sonda Guermazi, Neji Gharsallah, Abdelghani Sghir, and Emna Ammar - Phylogenetic analysis of 16S rRNA was used to investigate for the first time the structure of the microbial community that inhabits salt crystals retrieved from... (Source: Canadian Journal of Microbiology)

  • Iron in Yeasts

    Updated: 2010-01-28 12:52:00
    Yeasts take up iron by three main mechanisms. In the reductive uptake mechanism, specialized flavo-hemoproteins (Fre) dissociate extracellular ferric complexes by reduction involving trans-plasma membrane electron transfer. The resulting free iron is then imported by a high-affinity permease system (Ftr), coupled to a copper-dependent oxidase (Fet), which channels iron through the plasma membrane. As a consequence, iron uptake by this mechanism is dependent on the availability of copper. In the siderophore-mediated mechanism, siderophores excreted by the cells or produced by other bacterial or fungal species are taken up without prior dissociation, via specific, copper-independent high-affinity receptors. The iron is then dissociated from the siderophores intracellularly, probably by reduc...

  • Iron in Staphylococci

    Updated: 2010-01-28 12:51:00
    Staphylococcus aureus causes a significant amount of human morbidity and mortality. The ability of S. aureus to cause disease is dependent upon its acquisition of iron from the host. S. aureus can obtain iron from various sources during infection, including heme and transferrin. The most abundant iron source in humans is heme-iron bound by hemoglobin contained within erythrocytes. S. aureus is known to lyse erythrocytes through secretion of pore-forming toxins, providing access to host hemoglobin. Proteins of the iron-regulated surface determinant (Isd) system bind host hemoproteins, remove the heme cofactor, and shuttle heme into the cytoplasm for use as a nutrient iron source. Deletion of Isd system components decreases staphylococcal virulence, underscoring the importance of heme-iron a...MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.

  • Iron in Bacillus

    Updated: 2010-01-28 12:50:00
    Bacillus subtilis is a metabolically versatile soil microbe and Gram-positive model organism that displays a sophisticated adaptive response to conditions of iron limitation. The endogenous siderophore of B. subtilis is bacillibactin, a trimeric catecholate siderophore similar in structure to enterobactin. In addition to bacillibactin, B. subtilis can obtain iron from several xenosiderophores, ferric citrate, heme, and through a newly discovered elemental iron permease. The regulation of iron homeostasis in B. subtilis is complex and involves a ferric uptake regulator (Fur) protein as master regulator and at least two subsidiary regulatory systems. The most significant of these is an iron-sparing/prioritization response controlled by the small RNA FsrA and three auxiliary proteins (FbpABC)...

  • Iron in Campylobacter

    Updated: 2010-01-28 12:49:00
    Iron is known to catalyze a wide range of biochemical reactions essential for most living organisms, including Campylobacter jejuni. Paradoxically, this iron reactivity is also responsible for the generation of hydroxyl radicals (·OH), which are particularly biotoxic. In order to avoid iron toxicity, microorganisms must achieve an effective iron homeostasis by tightly regulating the expression of genes encoding the proteins involved in iron acquisition, metabolism and oxidative stress defences in response to iron availability. Interestingly, in addition to the classical ferric uptake regulator Fur, C. jejuni carries another member of the Fur family of metalloregulators, PerR. PerR is a peroxide-sensing regulator and typically regulates peroxide stress response in Gram-positive bacteri...

  • Iron in Cyanobacteria

    Updated: 2010-01-28 12:49:00
    Cyanobacteria are dependent on but can also be compromised by metals such as iron. On the one hand the demand for iron for photosystem functionality represents a challenge for the iron uptake machinery in iron limiting environments. On the other hand intoxication by iron causes a severe problem for growth and reproduction. To overcome this dilemma cyanobacteria have developed a regulatory network controlling iron uptake. They produce siderophores, which are distinct from that of other bacteria. Furthermore, the iron metabolism is linked to the nitrogen metabolism as documented for example in Anabaena sp. PCC 7120.Further reading: Iron Uptake and Homeostasis in MicroorganismsFull range of books on microbiology at Microbiology Books (Source: Microbiology Blog: The weblog for microbiologists....

  • Iron in Bacteroides

    Updated: 2010-01-28 12:48:00
    Bacteroides spp. have an essential requirement for heme and non-heme iron. They cannot synthesize the tetrapyrrole macrocycle ring due to a lack of genes for the heme biosynthetic pathway. It is remarkable that heme-dependent organisms outnumber heme-independent organisms in the lower intestinal tract suggesting that heme biosynthesis is not essential for colonization of the colonic environment. However, this colonization advantage may be due to the fact that under anaerobic conditions in the presence of heme, B. fragilis can generate nearly the double amount of ATP than Escherichia coli per mol of glucose. This high energy yield is linked to a rudimentary heme-induced fumarate reductase and cytochrome b-dependent electron transport energy metabolism pathway which uses fumarate as the term...

  • Iron in Francisella

    Updated: 2010-01-28 12:47:00
    Francisella tularensis is unusual among Gram-negative bacteria in that its genome does not encode orthologs for TonB, ExbB and ExbD that typically energize the uptake of iron across the outer membrane. This organism secretes however a siderophore similar in structure to rhizoferrin. The fsl operon of six genes encodes functions for biosynthesis and uptake of the siderophore. Two of these genes encode a siderophore synthetase belonging to the nonribosomal peptide synthetase (NRPS)-independent synthetase (NIS)-family and a protein belonging to the pyridoxyl phosphate-dependent decarboxylase family, and both are required for siderophore production. Siderophore utilization involves the product of the fslE gene, a protein unique to Francisella species that could function as a siderophore recept...MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.

  • Iron in Vibrio and Aeromonas

    Updated: 2010-01-28 12:46:00
    Vibrio and Aeromonas species are ubiquitous bacteria in aquatic environments worldwide. Many of the species are important pathogens for humans and/or aquatic animals. Several iron acquisition strategies have been developed by vibrios and aeromonads in order to get this essential element for surviving in their host and in aquatic habitats. All species studied so far have the ability to synthesize siderophores to sequester iron from the cell environment and transport it through their respective cognate outer membrane receptors. It has been demonstrated that this capacity is a relevant virulence factor for human and animal pathogens. Furthermore, all species studied can utilize exogenous siderophores, made by other bacteria. Another iron acquisition system described in both genera involves th...

  • Iron in Erwinia

    Updated: 2010-01-28 12:45:00
    The critical role of iron in host-pathogen relationships has been elucidated in infectious diseases of mammals, where the importance of siderophores in microbial pathogenesis has been demonstrated. Our group has established the role of iron and its ligands in the virulence of the plant pathogenic bacteria Dickeya dadantii (Erwinia chrysanthemi) and Erwinia amylovora. The genomes of the two pectinolytic enterobacterial species Pectobacterium atrosepticum SCRI1043 and D. dadantii 3937 have been sequenced and annotated. This review focuses on the functions involved in iron acquisition in both species. Besides the production and utilization of siderophores, P. atrosepticum and D. datantii have the capacity to use other iron sources. Indeed, both species are able to use haem iron, whereas only ...

  • Iron Shigella and E. coli

    Updated: 2010-01-28 12:43:00
    Shigella spp. and pathogenic E. coli are characterized by a variety and abundance of iron transport systems. Although members of this group of bacteria are closely related genetically, they differ widely in the iron transport systems they use. This may reflect the different niches occupied by different strains and the nature of the source of iron available in a specific environment. Only the ferrous iron transporter Feo is common to all the commensals and pathogens. All members of this group produce one or more siderophore, but no single siderophore is produced by all. Other iron transport systems include heme transporters and the ferrous iron transporters Sit and Efe. With the exception of the genes for enterobactin and the Feo system, the iron transport genes in the enterics are found wi...

  • Iron in Bordetella

    Updated: 2010-01-28 12:42:00
    Upon colonization of the mammalian respiratory epithelium by mucosal pathogens of the genus Bordetella, the host-pathogen interaction causes inflammatory changes, immune activation, and host cell injury. In this dynamic environment, Bordetella cells scavenge the nutritional iron necessary for growth. The three classical Bordetella species produce the siderophore alcaligin. In addition, they can utilize xenosiderophores that could be produced by commensals or other microbes that transiently inhabit the nasopharynx. As infection progresses, extravasation of immune cells, erythrocytes and serum to the mucosal surface can occur, exacerbated by the damaging action of Bordetella toxins, thus providing iron sources such as transferrin and heme compounds to the microbe. The three characterized Bor...

  • Iron in the Rhizobia

    Updated: 2010-01-28 12:41:00
    The rhizobia live as free-living soil bacteria or in symbiosis with leguminous plants. The success of these organisms in each milieu involves the ability to sense the environment to assess the availability of nutrients, and to optimize cellular systems for their acquisition. Iron in the rhizosphere is mostly inaccessible due to low solubility, and microorganisms must compete for this limited nutrient. Rhizobia belong to the alpha-Proteobacteria, a diverse taxonomic group that includes numerous species that form close or intracellular associations with eukaryotic hosts in a symbiotic or pathogenic context. Thus, in addition to their agricultural and economic importance, rhizobia are model organisms that have given new insights into related, but less tractable animal pathogens. In particular...MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.

  • Heme Uptake and Iron Extraction by Bacteria

    Updated: 2010-01-28 12:40:00
    Heme is ubiquitous, abundant and necessary for energy metabolism. Most bacteria have a heme biosynthesis pathway, but nevertheless, since heme is a major source of iron (an essential metal), microbes take up exogenous heme to retrieve iron. To grab heme, microbes extract it from host hemoproteins. This is achieved by two non-exclusive distinct pathways. One pathway involves proteins secreted by bacteria (hemophores) that scavenge heme from host hemoproteins. The second pathway involves microbial cell surface receptors that catch hemoproteins circulating in the vicinity of the cell surface. Both pathways lead to heme docking to cell surface receptors. In Gram-negative bacteria, docked heme is transported through the outer membrane by an energy-dependent process. In Gram-positive bacteria, d...

  • Iron Uptake and Homeostasis in Microorganisms

    Updated: 2010-01-28 12:39:00
    Iron is essential for almost all living organisms as it is involved in a wide variety of important metabolic processes. However, iron is not readily available and microorganisms therefore employ various iron uptake systems to secure sufficient supplies from their surroundings. There is considerable variation in the range of iron transporters and iron sources utilised by different microbial species. Pathogens, in particular, require efficient iron acquisition mechanisms to enable them to compete successfully for iron in the highly iron-restricted environment of the host's tissues and body fluids.Further reading: Iron Uptake and Homeostasis in MicroorganismsFull range of books on microbiology at Microbiology Books (Source: Microbiology Blog: The weblog for microbiologists.)

  • Lipoperoxidation affects ochratoxin A biosynthesis in Aspergillus ochraceus and its interaction with wheat seeds.

    Updated: 2010-01-27 23:26:06
    Authors: Reverberi M, Punelli F, Scarpari M, Camera E, Zjalic S, Ricelli A, Fanelli C, Fabbri AA In Aspergillus nidulans, Aspergillus flavus, and Aspergillus parasiticus, lipoperoxidative signalling is crucial for the regulation of mycotoxin biosynthesis, conidiogenesis, and sclerotia formation. Resveratrol, which is a lipoxygenase (LOX) and cyclooxygenase inhibitor, downmodulates the biosynthesis of ochratoxin A (OTA) in Aspergillus ochraceus. In the genome of A. ochraceus, a lox-like sequence (AoloxA; National Center for Biotechnology Information (NCBI) accession number: DQ087531) for a lipoxygenase-like enzyme has been found, which presents high homology (100 identities, 100 positives %, score 555) with a lox gene of Aspergillus fumigatus (NCBI accession number: XM741370). To study ...

  • Subunit-subunit interactions are weakened in mutant forms of acetohydroxy acid synthase insensitive to valine inhibition.

    Updated: 2010-01-27 23:00:00
    Authors: Kyselková M, Janata J, Ságová-Marečková M, Kopecký J In acetohydroxy acid synthase from Streptomyces cinnamonensis mutants affected in valine regulation, the impact of mutations on interactions between the catalytic and the regulatory subunits was examined using yeast two-hybrid system. Mutations in the catalytic and the regulatory subunits were projected into homology models of the respective proteins. Two changes in the catalytic subunit, E139A (alpha domain) and DeltaQ217 (beta domain), both located on the surface of the catalytic subunit dimer, lowered the interaction with the regulatory subunit. Three consecutive changes in the N-terminal part of the regulatory subunit were examined. Changes G16D and V17D in a loop and adjacent alpha-helix o...MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.

  • Diversity and Activity of PAH-Degrading Bacteria in the Phyllosphere of Ornamental Plants.

    Updated: 2010-01-27 23:00:00
    Authors: Yutthammo C, Thongthammachat N, Pinphanichakarn P, Luepromchai E Phyllosphere bacteria on ornamental plants were characterized based on their diversity and activity towards the removal of polycyclic aromatic hydrocarbons (PAHs), the major air pollutants in urban area. The amounts of PAH-degrading bacteria were about 1-10% of the total heterotrophic phyllosphere populations and consisted of diverse bacterial species such as Acinetobacter, Pseudomonas, Pseudoxanthomonas, Mycobacterium, and uncultured bacteria. Bacterial community structures analyzed by polymerase chain reaction-denaturing gradient gel electrophoresis from each plant species showed distinct band patterns. The uniqueness of these phyllosphere bacterial communities was partly due to the variation in leaf morphology...

  • Phage Resistance of a Marine Bacterium, Roseobacter denitrificans OCh114, as Revealed by Comparative Proteomics.

    Updated: 2010-01-27 23:00:00
    Authors: Huang C, Zhang Y, Jiao N Roseobacter is a dominant lineage in the marine environment. This group of bacteria is diverse in terms of both their phylogenetic composition and their physiological potential. Roseobacter denitrificans OCh114 is one of the most studied bacteria of the Roseobacter lineage. Recently, a lytic phage (RDJLPhi1) that infects this bacterium was isolated and a mutant strain (M1) of OCh114 that is resistant to RDJLPhi1 was also obtained. Here, we investigate the mechanisms supporting phage resistance of M1. Our results excluded the possibilities of several phage resistance mechanisms, including abortive infection, lysogeny, and the clustered regularly interspaced short palindromic repeats (CRISPRs) related mechanism. Adsorption kinetics assays revealed that a...

  • Characterization of Streptococcus pyogenes Isolated from Balanoposthitis Patients Presumably Transmitted by Penile-Oral Sexual Intercourse.

    Updated: 2010-01-27 23:00:00
    Authors: Minami M, Wakimoto Y, Matsumoto M, Matsui H, Kubota Y, Okada A, Isaka M, Tatsuno I, Tanaka Y, Hasegawa T Streptococcus pyogenes is indigenous to the human pharynx and causes acute pharyngitis. Balanoposthitis is an inflammatory disease of the glans and the foreskin. However, balanoposthitis caused by S. pyogenes is not widely recognized as a sexually transmitted disease. In addition, bacteriological features of the isolates causing balanoposthitis are unclear. The four S. pyogenes strains isolated from adult balanoposthitis were examined. We performed emm typing, T antigen typing, RAPD assay, PCR assay for the streptococcal pyrogenic exotoxin-related genes and antibiotic-resistant genes, and antibiotic susceptibility assay. All four strains were suspected to be transmitted by ...

  • The Regulator RamA Influences cmytA Transcription and Cell Morphology of Corynebacterium ammoniagenes.

    Updated: 2010-01-27 23:00:00
    In this study, we showed that the DeltaramA mutant constructed by a markerless knockout strategy possessed increased cell surface hydrophobicity, leading to the formation of aggregated cell masses in liquid media. In addition, the mutant exhibited an elongated cell shape as observed by SEM, suggesting that cell wall-associated proteins might be influenced. Furthermore, cell surface proteome analysis revealed that the expression of cmytA gene encoding corynomycoloyl transferase required for cell wall biosynthesis was down-regulated in the mutant, supporting the regulatory role of RamA in cell wall assembly. These studies support a novel regulatory role of RamA in inducing the expression of proteins required for cell wall assembly. PMID: 20107993 [PubMed - as supplied by publisher] (Sour...MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.

  • Impact of pneumococcal vaccines on invasive pneumococcal disease in Taiwan

    Updated: 2010-01-27 19:29:13
    Abstract nbsp;In Taiwan, the 23-valent pneumococcal polysaccharide vaccine (PPV23) and the 7-valent pneumococcal conjugate vaccine (PCV7) have been available since January 2001 and October 2005, respectively. A hospital-based surveillance of invasive pneumococcal disease (IPD) in a medical center was conducted from 2000 to 2008 to evaluate the epidemiologic changes after pneumococcal vaccination. A total of 337 episodes in 328 patients were identified. The cumulative coverage rate of PPV23 among persons of age ≥75 ears increased from 12% in 2007 to 41% in 2008, and that of PCV7 among children aged <5 ears was 0.7% in 2005 and 25.2% in 2008. The annual incidence of IPD decreased from 6.2 cases per 10,000 hospitalizations in 2000–2005 to 3.8 cases in 2006–200...

  • 14th Workshop of the International Study Group for Systems Biology 2010

    Updated: 2010-01-27 15:55:00
    September 6 - 10, 2010 14th Workshop of the International Study Group for Systems Biology 2010Vladimir, Russia Further informationThe International Study Group for Systems Biology is a collective of international researchers interested in advancing the biological sciences through exploring the interplay between theory and experiment. The general theme is theoretical approaches to understanding the behaviour of cell systems, particularly transport, metabolism and signal transduction.Suggested reading: Molecular Biology BooksFull range of books on microbiology at Microbiology Books (Source: Microbiology Blog: The weblog for microbiologists.)

  • 9th European Nitrogen Fixation Conference

    Updated: 2010-01-27 15:55:00
    September 6 - 10, 2010 9th European Nitrogen Fixation ConferenceGeneva, Switzerland Further informationTopics include: Applied aspects of biological nitrogen fixation; Evolution and diversity of diazotrophs and hosts; Genomics and post-genomics of diazotrophs and hosts; Interactions of proteobacteria with legumes; Interactions of diazotrophs with non-legume hosts; Novel tools and technologies to study diazotrophy; Physiology of free-living and symbiotic diazotrophs; Regulation of nitrogen fixation; Structure and function of nitrogenase.Suggested reading: Microbiology BooksFull range of books on microbiology at Microbiology Books (Source: Microbiology Blog: The weblog for microbiologists.)MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.

  • IMC9 The Biology of Fungi Conference

    Updated: 2010-01-27 15:54:00
    August 1 - 6, 2010 IMC9 The Biology of FungiEdinburgh, UK Further information9th International Mycological Congress hosted by the British Mycological SocietySuggested reading: Mycology BooksFull range of books on microbiology at Microbiology Books (Source: Microbiology Blog: The weblog for microbiologists.)

  • Advances in Plant Virology Conference

    Updated: 2010-01-27 15:54:00
    September 5 - 7, 2010 Advances in Plant VirologyWageningen, The Netherlands Further informationA conference organized by Association of Applied Biologists and the Dutch Society of Plant Virologists.Suggested reading: Virology BooksFull range of books on microbiology at Microbiology Books (Source: Microbiology Blog: The weblog for microbiologists.)

  • 46th Annual Meeting of British Society for Medical Mycology

    Updated: 2010-01-27 15:53:00
    April 18 - 20, 2010 46th Annual Meeting of British Society for Medical Mycology (BSMM)Exeter, UK Further informationThe meeting generally attracts 80-120 delegates and covers topics from many areas of Medical Mycology. A range of international experts are contributing to this year‚s meeting, including a Special Retirement lecture from Professor Frank Odds (Aberdeen University) and the President's lecture from Professor Joe Heitman (Duke University).Suggested reading: Mycology BooksFull range of books on microbiology at Microbiology Books (Source: Microbiology Blog: The weblog for microbiologists.)

  • Rabbit Hemorrhagic Disease Virus and Other Lagoviruses

    Updated: 2010-01-27 14:24:00
    Rabbit hemorrhagic disease virus (RHDV) is a pathogen of rabbits that causes major problems throughout the world where rabbits are reared for food and clothing, make a significant contribution to ecosystem ecology, and where they support valued wildlife as a food source. The high mortality caused by RHDV has driven research in protecting rabbits from infection. However, RHDV is an unusual calicivirus in that it has served also as an important model in the family Caliciviridae by providing a range of beneficial outcomes as diverse as the creation of virus-like particles (VLPs) for vaccine and therapeutics delivery, the elucidation of calicivirus replication and structural features at the molecular level, and the biological control of a vertebrate pest. Further reading: Caliciviruses: Molecu...

  • Murine Norovirus Translation, Replication and Reverse Genetics

    Updated: 2010-01-27 14:23:00
    Murine norovirus, currently the only norovirus that replicates efficiently in tissue culture, has offered scientists the first chance to study the entire norovirus life cycle in the laboratory. In addition, the development of reverse genetics for murine norovirus has provided the ideal opportunity for researchers to determine how variation at the genetic level affects pathogenicity in the natural host. Despite differences in the diseases caused by human and murine noroviruses, they possess a significant amount of genetic similarity; hence the general mechanisms of viral genome translation and replication are likely to be highly conserved. Further reading: Caliciviruses: Molecular and Cellular VirologyFull range of books on microbiology at Microbiology Books (Source: Microbiology Blog: The ...MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.

  • Murine Norovirus Pathogenesis and Immunity

    Updated: 2010-01-27 14:22:00
    The first murine norovirus, murine norovirus 1 (MNV-1), was discovered in 2003. Since then, numerous murine norovirus strains have been identified and they were assigned a new genogroup in the genus Norovirus. Murine noroviruses share pathogenic properties with human noroviruses. Specifically, they are infectious orally, they spread between mice, and at least one strain, MNV-1, causes mild diarrhea in wild-type hosts. Furthermore, primary MNV-1 infection fails to elicit protection from a secondary challenge with homologous virus in at least some situations, which is similar to the lack of long-term protective immunity elicited by primary human norovirus infection. Investigators have now begun to extend basic knowledge of norovirus infection and immunity using this system. In particular, st...

  • Feline Calicivirus

    Updated: 2010-01-27 14:21:00
    Feline calicivirus (FCV) represents an important pathogen of cats that has been studied extensively on the molecular level. FCV was the first calicivirus for which milestones like a reverse genetics system or the identification of a verified virus receptor were reached. Recently, great efforts were made to investigate unusual mechanisms of translation initiation driven by the RNA bound protein VPg or an RNA structure named TURBS.Further reading: Caliciviruses: Molecular and Cellular VirologyFull range of books on microbiology at Microbiology Books (Source: Microbiology Blog: The weblog for microbiologists.)

  • Caliciviruses in Swine

    Updated: 2010-01-27 14:21:00
    Viruses in three of the four established genera of the family Caliciviridae have been detected in pigs (Sapovirus, Norovirus and Vesivirus), making this animal species of particular interest in the study of calicivirus pathogenesis and host range. The Cowden strain of porcine enteric calicivirus (PEC), a sapovirus, was discovered in a diarrheic pig fecal sample in the US in 1980. Since then, sapoviruses have become recognized as a predominant calicivirus detected in pigs. The Cowden PEC strain grows efficiently in a unique cell culture system, and a reverse genetics system has been developed for elucidation of the mechanisms of replication and pathogenesis at the molecular level. Porcine noroviruses share genetic relatedness with those from humans, and recent studies have shown that pigs a...

  • Calicivirus Reverse genetics and Replicon Systems

    Updated: 2010-01-27 14:20:00
    Recently, reverse genetics and replicon systems have been developed and are starting to be used in the elucidation of the calicivirus replication and pathogenicity. Reverse genetics systems are available for feline calicivirus, porcine enteric calicivirus, murine norovirus, rabbit hemorrhagic disease virus and a rhesus monkey calicivirus. For uncultivable caliciviruses, such as human norovirus, cell-based replicon systems have been established. Norovirus replicon systems are used to screen potential antivirals and therapeutic options against norovirus infection. Replicon systems with reporter genes such as those encoding green fluorescent protein or luciferase allows quantitative analysis of cellular and viral factors that promote virus replication. Further studies with reverse genetics an...

  • Proteolytic Cleavage and Viral Proteins

    Updated: 2010-01-27 14:19:00
    Caliciviruses are icosahedral nonenveloped viruses with a positive-sense single strand RNA genome that does not exceed 8.6 kb. Despite its small size, the virus genome encodes a number of nonstructural proteins that successfully facilitate and regulate mechanisms required for efficient virus amplification. Although caliciviruses show significant genetic diversity, they share a common protein expression strategy. Recent findings have shown that the nonstructural proteins of caliciviruses are produced by autocatalytic cleavage of a polyprotein encoded by ORF1 of the virus genome. A single virus protease structurally similar to a class of viral chymotrypsin-like cysteine proteases mediates these cleavages, and in some caliciviruses, adds to a release of the virus capsid protein. The temporal ...MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.

  • Calicivirus Protein Structures

    Updated: 2010-01-27 14:19:00
    Sequence analysis and experimentally determined three-dimensional structures of structural and nonstructural proteins from a range of caliciviruses help to provide a molecular framework for understanding many aspects of their replication strategies. Structures of intact virions, virus-like particles and capsid fragments, as well as capsid-receptor complexes help to explain basic mechanisms of capsid assembly and receptor recognition. Structural studies of the recombinant viral proteinase and polymerase in complex with substrates and inhibitors provide a basis for understanding substrate recognition and enzymatic mechanisms, thus setting the stage for the design of new antiviral compounds.Further reading: Caliciviruses: Molecular and Cellular VirologyFull range of books on microbiology at M...

  • Virus-Host Interaction and Cellular Receptors of Caliciviruses

    Updated: 2010-01-27 14:19:00
    Caliciviruses are a diverse virus family with a wide range of host and tissue tropisms. Most calicivirus genera recognize a carbohydrate ligand for attachment, including the A, B, H and Lewis histo-blood group antigens (HBGAs) and heparan sulfate for the human noroviruses, the H type 2 antigen for the rabbit hemorrhagic disease virus (genus Lagovirus), the type B antigen for the Tulane virus (a potential new genus), and sialic acid for feline calicivirus (FCV; genus Vesivirus) and murine norovirus (MNV; genus Norovirus). Following attachment, FCV recognizes also a cell surface protein, the junctional adhesion molecule 1 (JAM-1), as a functional receptor or co-receptor potentially for penetration or entry into host cells. Some human noroviruses interact also with a 105 kDa membrane protein,...

  • Calicivirus Environmental Contamination

    Updated: 2010-01-27 14:18:00
    The virus family Caliciviridae contains four genera Norovirus, Sapovirus, Lagovirus and Vesivirus. Norovirus and sapovirus cause gastroenteritis in humans, while lagoviruses and vesiviruses mostly infect animals and cause a variety of diseases. Norovirus and sapoviruses can also infect a number of animals including cow and pig, respectively. Noroviruses are the dominant cause of human gastroenteritis around the world, infecting all age groups. Their low infectious dose and stability in the natural environment allows noroviruses to be easily spread. Contamination in food and water destined for human consumption has lead to numerous outbreaks of gastroenteritis. Noroviruses have been detected in shellfish, sandwiches, fruit, ice, drinking water and treated wastewater. Direct transmission fro...

  • Genome Organization and Recombination

    Updated: 2010-01-27 14:18:00
    Recombination was first described in the human caliciviruses in 1997. Since then naturally occurring recombinants have been detected for all four genera of the Caliciviridae and has become an important mechanism in the emergence of new calicivirus variants. Due to similarities in genome organization between the different genera, recombination predomoninantly occurs at the start of the major structural gene which encodes the capsid, VP1. Knowledge of the mechanisms of calicivirus recombination is important as new variants can emerge, with potentially different pathogenesis and virulence.Further reading: Caliciviruses: Molecular and Cellular VirologyFull range of books on microbiology at Microbiology Books (Source: Microbiology Blog: The weblog for microbiologists.)

  • Norovirus Epidemiology

    Updated: 2010-01-27 14:17:00
    Noroviruses are the dominant cause of outbreaks as well as sporadic community cases of viral gastroenteritis in the world. Their very low infectious dose, combined with high levels of shedding and long persistence in the environment make noroviruses extremely infectious. Although generally norovirus related illness is regarded as mild and self-limiting, more severe outcomes are increasingly described among elderly and immuno-compromised patients. The combination of large and difficult to control outbreaks and severe illness in some patients leads to major problems in healthcare settings, such as hospitals and nursing homes. Additionally, some large and diffuse, multi-national and even multi-continent, foodborne-outbreaks have been described for norovirus, affecting up to thousands of peopl...MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.

  • Caliciviruses

    Updated: 2010-01-27 14:15:00
    Members of the Caliciviridae family (caliciviruses) are positive-sense, single stranded RNA viruses containing four recognized genera: Norovirus, Sapovirus, Lagovirus and Vesivirus. They are ubiquitous in the environment and are a major cause of disease in humans and many animals. Examples include Norwalk virus, a norovirus, thought to be responsible for roughly 90% of epidemic, non-bacterial outbreaks of gastroenteritis in humans around the world. Lack of a suitable cell culture system for human caliciviruses limited studies in previous decades, however the recent application of modern genomic technologies has revolutionized the field, leading to an explosion in calicivirus publications.Further reading: Caliciviruses: Molecular and Cellular VirologyFull range of books on microbiology at M...

  • Virus Replication Seen On Video Is Faster Than Thought Possible

    Updated: 2010-01-27 08:34:13
    Story Summary: Previously, viruses were thought to spread by entering a cell, replicating there, and then being released to infect new cells, so that the rate of spread of a virus would be limited by how quickly it could replicate in each cell. However, a virus called vaccinia spreads in a different and much faster [...] Related posts:Video of virus in action shows viruses can spread faster than thought possible Visualizing Virus Replication In Three Dimensions New strategy for inhibiting virus replication

  • Mononuclear phagocytes and virus infection

    Updated: 2010-01-26 13:12:00
    By Howard E. Gendelman (University of Nebraska Medical Centre, USA) writing in Lentiviruses and Macrophages: Molecular and Cellular InteractionsFor chronic lentiviral infections mononuclear phagocytes remain an enigma. On the one hand they are among the first cells contacted by virus and, despite a virtual armada of immunological tools, still serve as means to both spread and contain infection. Virus particles can simultaneously assemble and hide in intracellular compartments, largely free from immune attack. Interestingly, the mononuclear phagocytes are not destroyed by the virus and throughout infection they still contribute to host immunity while at the same time perpetuating lentiviral dissemination. Infected mononuclear phagocytes are readily observed in lymph nodes and organs such as...

  • Acclaim for new Aspergillus book

    Updated: 2010-01-26 08:04:00
    "an overview of the forefront of Aspergillus genomics - from bioinformatics and systems biology to gene regulation, secondary metabolism, and novel industrial applications ... (the book starts) with a superb holistic overview of the genus by its doyenne Joan Bennett ... a most stimulating volume ... The editors and publishers can be proud of having put together a volume that is produced to the highest scientific standards."from David L. Hawksworth in Mycological Research 113: 1444-1445Further reading: Aspergillus: Molecular Biology and GenomicsFull range of books on microbiology at Microbiology Books (Source: Microbiology Blog: The weblog for microbiologists.)

  • Bacteraemia with Campylobacter jejuni: no association with the virulence genes iam, cdtB, capA or virB

    Updated: 2010-01-26 06:03:46
    Abstract nbsp;The role of bacterial genes in the determination of the clinical spectrum of Campylobacter jejuni infection is unclear. We compared clinical isolates from invasive blood-stream infection with stool isolates from gastroenteritis and found no association of the putative virulence genes iam, capA, virB and cdtB with clinical presentation. Content Type Journal ArticleCategory Brief ReportDOI 10.1007/s10096-009-0863-9Authors H. Nielsen, Aarhus University Hospital Departments of Infectious Diseases and Clinical Microbiology, Aalborg Hospital Aalborg DenmarkS. Persson, Statens Serum Institut Unit of Gastrointestinal Infections Copenhagen DenmarkK. E. P. Olsen, Statens Serum Institut Unit of Gastrointestinal Infections Copenhagen DenmarkT. Ejlertsen, Aarhus University Hos...MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.

  • Denitrification as an important taxonomic marker within the genus Halomonas.

    Updated: 2010-01-24 23:00:00
    Authors: González-Domenech CM, Martínez-Checa F, Béjar V, Quesada E We have made a comprehensive study of the denitrifying species of the genus Halomonas, evaluating both the phylogenetic and phenotypic relationships amongst them and other species of Halomonas. The phylogenetic analysis was based on the 16S rRNA gene sequence as well as those of the three genes essential to a complete denitrification process: narH, nirS and nosZ. The main aim of the phenotypic study was to improve our knowledge of some of the species in question. To this end we investigated the type strain of each species, although in the case of Halomonas cerina we also studied strains R53 and 15CR. In addition to this we investigated some other strains phylogenetically related to Halomonas ventosae, Ha...

  • Production of a class II two-component lantibiotic of Streptococcus pneumoniae using the class I nisin synthetic machinery and leader sequence.

    Updated: 2010-01-24 23:00:00
    Authors: Majchrzykiewicz JA, Lubelski J, Moll GN, Kuipers A, Bijlsma JJ, Kuipers OP, Rink R Recent studies showed that the nisin modification machinery can successfully dehydrate serines and threonines and introduce lanthionine rings in small peptides that are fused to the nisin leader sequence. This opens up exciting possibilities to produce and engineer larger antimicrobial peptides in vivo. Here, we demonstrate the exploitation of the class I nisin production machinery to generate, modify and secrete biologically active, previously not yet isolated and characterized class II two-component lantibiotics that have no sequence homology to nisin. The nisin synthesis machinery, composed of the modification enzymes NisB and NisC and the transporter NisT, was used to modify and secrete a pu...

  • High diversity of extended-spectrum {beta}-lactamases in Escherichia coli from Italian broiler flocks.

    Updated: 2010-01-24 23:00:00
    Authors: Bortolaia V, Guardabassi L, Trevisani M, Bisgaard M, Venturi L, Bojesen AM We characterized 67 Escherichia coli isolates with reduced susceptibility to cefotaxime or ceftiofur obtained from healthy broilers housed in five Italian farms. The blaCTX-M-1, blaCTX-M-32 and blaSHV-12 beta-lactamase genes were identified on IncI1, IncN or IncFIB plasmids. Considerable genetic diversity was detected among the ESBL-producing isolates, and we identified indistinguishable strains in unrelated farms and indistinguishable plasmids in genetically unrelated strains. The detection of highly mobile plasmids suggests a potential animal reservoir for beta-lactamase genes. PMID: 20100875 [PubMed - as supplied by publisher] (Source: Antimicrobial Agents and Chemotherapy)

  • Roles of calcineurin and Crz1 in antifungal susceptibility and virulence of Candida glabrata.

    Updated: 2010-01-24 23:00:00
    Authors: Miyazaki T, Yamauchi S, Inamine T, Nagayoshi Y, Saijo T, Izumikawa K, Seki M, Kakeya H, Yamamoto Y, Yanagihara K, Miyazaki Y, Kohno S A Candida glabrata calcineurin mutant exhibited increased susceptibility to both azole antifungal and cell-wall damaging agents, and was also attenuated in virulence. Although a mutant lacking the downstream transcription factor Crz1 displayed a cell wall-associated phenotype intermediate to that of the calcineurin mutant and was modestly attenuated in virulence, it did not show increased azole susceptibility. These results suggest that calcineurin regulates both Crz1-dependent and -independent pathways depending on the type of stress. PMID: 20100876 [PubMed - as supplied by publisher] (Source: Antimicrobial Agents and Chemotherapy)

  • In vitro activity of ceftaroline against 623 diverse strains of anaerobic bacteria.

    Updated: 2010-01-24 23:00:00
    Authors: Citron DM, Tyrrell KL, Merriam V, Goldstein EJ The in vitro activities of ceftaroline, a novel, parenteral, broad-spectrum cephalosporin, and 4 comparator antimicrobials were determined against anaerobic bacteria. Against gram-positive strains, the activity of ceftaroline was similar to that of amoxicillin/clavulanate and 4 to 8 times greater than ceftriaxone. Against gram-negative organisms, ceftaroline showed good activity against beta-lactamase-negative strains, but not against the Bacteroides fragilis group. Ceftaroline showed potent activity against a broad spectrum of anaerobes encountered in respiratory, skin, and soft-tissue infections. PMID: 20100877 [PubMed - as supplied by publisher] (Source: Antimicrobial Agents and Chemotherapy)

  • Activity of the Investigational Fluoroquinolone Finafloxacin Against Ciprofloxacin-Sensitive and -Resistant Acinetobacter baumannii.

    Updated: 2010-01-24 23:00:00
    This study compared the activity of finafloxacin, a novel fluoroquinolone which shows enhanced activity under acidic pH, and ciprofloxacin, against Acinetobacter baumannii under standard conditions (pH 7.2) and at a pH of 5.8. Overall, finafloxacin demonstrated superior activity to ciprofloxacin under acidic conditions. Furthermore, finafloxacin showed comparable activity to ciprofloxacin at pH 7.2. Hence, finafloxacin could be a promising new antimicrobial agent for the treatment of A. baumannii infections at acidic body compartments. PMID: 20100879 [PubMed - as supplied by publisher] (Source: Antimicrobial Agents and Chemotherapy)MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.

  • Tat pathway-mediated translocation of the Sec-pathway substrate protein, MexA, an inner membrane component of the MexAB-OprM xenobiotic extrusion pump in Pseudomonas aeruginosa.

    Updated: 2010-01-24 23:00:00
    Authors: Yoneyama H, Akiba K, Hori H, Ando T, Nakae T Pseudomonas aeruginosa is equipped with the Sec and Tat protein secretion systems, which translocate the xenobiotic transporter, MexAB-OprM, and the pathogenic factor, phospholipase C (PlcH), respectively. When the signal sequence of MexA was substituted with that of PlcH, the hybrid protein was successfully expressed and recovered from the periplasmic fraction, suggesting that the hybrid protein had been translocated across the inner membrane. MexA-deficient cells harboring the plasmid carrying the plcH-mexA fusion gene showed antibiotic resistance comparable to that of the wild-type cells. This result suggested that MexA secreted via the Tat-machinery was properly assembled and functioned as a subunit of the MexAB-OprM efflux pump...

  • Video of virus in action shows viruses can spread faster than thought possible

    Updated: 2010-01-24 14:38:29
    Story Summary: When further virus particles reach the infected cell, these proteins cause the host cell to push out snake-like projections called actin tails, which drive the virus particles away towards other cells that they can infect. The researchers believe that other viruses also employ rapid spreading mechanisms. For instance, herpes simplex virus (HSV-1), which [...] Related posts:Virus Replication Seen On Video Is Faster Than Thought Possible Earlier Flu Viruses Provided Some Immunity To Current H1N1 Influenza, Study Shows A global breakthrough in the study of a protein linked to the spread of viruses

  • Cholesterol-lowering drug shows promise against serious infections in sickle cell disease

    Updated: 2010-01-24 08:49:27
    Story Summary: The results provide the foundation for a possible future study to determine if statins, already widely used to lower cholesterol in adults, might protect children with sickle cell disease (SCD) from serious pneumococcal infection. In this study, scientists reported that statins prolonged the lives of mice with sickle cell disease following infection with [...] Related posts:New Approach To Sickle-Cell Disease Shows Promise In Mice Widely used cholesterol-lowering drug may prevent progression Breast cancer drug shows promise against serious infections

  • Modelling the bacterial communities associated with cystic fibrosis lung infections

    Updated: 2010-01-23 06:42:42
    This study outlines a novel methodology by which to generate and study bacterial biofilms communities. It is also hoped that the versatility of this in vitro approach, combined with its simplicity and high reproducibility, will make it an effective system to study CF sputum biofilm development and, in the longer term, serve as a means of assessing antibiotic susceptibilities. Content Type Journal ArticleCategory ArticleDOI 10.1007/s10096-009-0861-yAuthors T. Spasenovski, King’s College London Molecular Microbiology Research Laboratory, Pharmaceutical Science Division Franklin-Wilkins Building, 150 Stamford Street London SE1 9NH UKM. P. Carroll, Southampton University Hospitals NHS Trust Adult Cystic Fibrosis Unit Tremona Road Southampton SO16 6YD UKA. K. Lilley, King’s College L...

  • Mixture of endophytic Agrobacterium and Sinorhizobium meliloti strains could induce nonspecific nodulation on some woody legumes.

    Updated: 2010-01-22 23:00:00
    Authors: Liu J, Wang ET, Ren DW, Chen WX Agrobacterium sp. II CCBAU 21244 isolated from root nodules of Wisteria sinensis was verified as an endophytic bacterium by inoculation and reisolation tests. However, inoculation with a mixture of this strain and a Sinorhizobium meliloti strain could induce root nodules on W. sinensis and two other woody legumes, which do not form a symbiosis with S. meliloti alone. Rod-shaped and irregular nodules were found on the inoculated plants, in which the S. meliloti strain was detected in all of the nodules; while the Agrobacterium strain was inside of the rod-shaped nodules, or occupied only the nodule surface of the irregular globe-shaped nodules. These findings revealed novel interactions among the symbiotic bacteria, endophytic bacteria and the le...

  • Performance and microbial ecology of air-cathode microbial fuel cells with layered electrode assemblies.

    Updated: 2010-01-22 23:00:00
    Authors: Butler CS, Nerenberg R Microbial fuel cells (MFCs) can be built with layered electrode assemblies, where the anode, proton exchange membrane (PEM), and cathode are pressed into a single unit. We studied the performance and microbial community structure of MFCs with layered assemblies, addressing the effect of materials and oxygen crossover on the community structure. Four MFCs with layered assemblies were constructed using Nafion or Ultrex PEMs and a plain carbon cloth electrode or a cathode with an oxygen-resistant polytetrafluoroethylene diffusion layer. The MFC with Nafion PEM and cathode diffusion layer achieved the highest power density, 381 mW/m(2) (20 W/m(3)). The rates of oxygen diffusion from cathode to anode were three times higher in the MFCs with plain cathodes com...MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.

  • A Case Study for Assessment of Microbial Community Dynamics in Genetically Modified Bt Cotton Crop Fields.

    Updated: 2010-01-22 23:00:00
    Authors: Kapur M, Bhatia R, Pandey G, Pandey J, Paul D, Jain RK Bt cotton was the first genetically modified crop approved for use in India. However, only a few studies have been conducted to assess the feasibility of its commercial application. Bt cotton is genetically modified to express a proteinaceous endotoxin (Cry) encoded by cry gene of Bacillus thuringiensis that has specific insecticidal activity against bollworms. Therefore, the amount of pesticides used for growing Bt cotton is postulated to be considerably low as compared to their non-Bt counterparts. Alternatively, it is also speculated that application of a genetically modified crop may alter the bio-geochemical balance of the agriculture field(s). Microbial community composition and dynamics is an important descriptor fo...

  • Use of sustainable chemistry to produce an acyl amino acid surfactant.

    Updated: 2010-01-22 23:00:00
    In this report, we describe the engineering of a native nonribosomal peptide synthetase pathway (i.e., surfactin synthetase), to generate a Bacillus strain that synthesizes a highly water-soluble acyl amino acid surfactant, rather than the water insoluble lipopeptide surfactin. This novel product has a lower CMC and higher water solubility than myristoyl glutamate, a commercial surfactant. This surfactant is produced by fermentation of cellulosic carbohydrate as feedstock. This method of surfactant production provides an approach to sustainable manufacturing of new surfactants. PMID: 20094712 [PubMed - as supplied by publisher] (Source: Applied Microbiology and Biotechnology)

  • Epidemiology of invasive mycoses in north america.

    Updated: 2010-01-22 10:10:03
    Authors: Pfaller MA, Diekema DJ The incidence of invasive mycoses is increasing, especially among patients who are immunocompromised or hospitalized with serious underlying diseases. Such infections may be broken into two broad categories: opportunistic and endemic. The most important agents of the opportunistic mycoses are Candida spp., Cryptococcus neoformans, Pneumocystis jirovecii, and Aspergillus spp. (although the list of potential pathogens is ever expanding); while the most commonly encountered endemic mycoses are due to Histoplasma capsulatum, Coccidioides immitis/posadasii, and Blastomyces dermatitidis. This review discusses the epidemiologic profiles of these invasive mycoses in North America, as well as risk factors for infection, and the pathogens' antifungal susceptibilit...

  • Adaptation of enteropathogenic Yersinia to low growth temperature.

    Updated: 2010-01-22 10:10:03
    Authors: Palonen E, Lindström M, Korkeala H Yersinia enterocolitica and Yersinia pseudotuberculosis are important foodborne pathogens that cause infections through contaminated refrigerated food. Their cold tolerance mechanisms are therefore of special interest. Adaptation to cold involves changes in protein synthesis and in cell membranes to overcome diminished transcriptional and translational efficiency and reduced fluidity of cell membranes. Studies of low temperature adaptation mechanisms have mainly been performed on mesophilic bacteria, while most modern food hygiene risks are caused by psychrotrophs. Understanding low temperature adaptation of psychrotrophs would help to control these pathogens. This review demonstrates that more studies on cold tolerance mechanisms of psy...

  • The potential of nanofibers and nanobiocides in water purification.

    Updated: 2010-01-22 10:10:03
    Authors: Botes M, Eugene Cloete T Electrospun nanofibers and nanobiocides show potential in the improvement of water filtration membranes. Biofouling of membranes caused by the bacterial load in water reduces the quality of drinking water and has become a major problem. Several studies showed inhibition of these bacteria after exposure to nanofibers with functionalized surfaces. Nanobiocides such as metal nanoparticles and engineered nanomaterials are successfully incorporated into nanofibers showing high antimicrobial activity and stability in water. Research on the applications of nanofibers and nanobiocides in water purification, the fabrication thereof and recently published patents are reviewed in this article. PMID: 20088684 [PubMed - in process] (Source: Critical Reviews in ...MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.

  • Sponge-microbial interactions: Ecological implications and bioprospecting avenues.

    Updated: 2010-01-22 10:10:03
    Authors: Selvin J, Ninawe AS, Seghal Kiran G, Lipton AP Sponges are closely associated with microorganisms that occur either intracellularly and extracellularly. Sponges are soft-bodied sessile organisms appear to be defenseless in facing predation. Microbial symbionts supposed to have a functional role in the host defense against pathogens, predation and microfouling processes. Recently, the ubiquitous defense enzyme, phospholipase A2 (PLA2) detected in the sponge associated bacterium envisaged the possible functional role in the ecological succession of host sponge against predatory / fouling pressure in the habitat. In present review, we highlighted the possible functional interactions between associated microbes and host sponges and its potentials in bioprospecting approaches. ...

  • Phenotype MicroArray™ in the metabolic characterisation of Salmonella serotypes Agona, Enteritidis, Give, Hvittingfoss, Infantis, Newport and Typhimurium

    Updated: 2010-01-22 09:09:59
    Abstract nbsp;The Phenotype MicroArray™ (PM) technology was used to study the metabolic characteristics of 29 Salmonella strains belonging to seven serotypes of S. enterica spp. enterica. Strains of serotypes Typhimurium (six strains among definite phage types DTs 1, 40 and 104) and Agona (two strains) were tested for 949 substrates, Enteritidis (six strains of phage type PT1), Give, Hvittingfoss, Infantis and Newport strains (two of each) were tested for 190 substrates and seven other Agona strains for 95 substrates. The strains represented 18 genotypes in pulsed-field gel electrophoresis (PFGE). Among 949 substrates, 18 were identified that could be used to differentiate between the strains of those seven serotypes or within a single serotype. Unique metabolic differences bet...

  • First human isolates of methicillin-resistant Staphylococcus aureus sequence type 398 in Spain

    Updated: 2010-01-22 09:09:56
    Content Type Journal ArticleCategory Brief ReportDOI 10.1007/s10096-009-0860-zAuthors C. Potel, Complejo Hospitalario Universitario de Vigo Microbiology Laboratory Pontevedra SpainM. Álvarez-Fernández, Complejo Hospitalario Universitario de Vigo Microbiology Laboratory, Research Laboratory Pontevedra SpainL. Constenla, Complejo Hospitalario Universitario de Vigo Research Laboratory Pontevedra SpainP. Álvarez, Complejo Hospitalario de Pontevedra Microbiology Laboratory Pontevedra SpainS. Perez, Complejo Hospitalario Universitario de Vigo Microbiology Laboratory Pontevedra Spain Journal European Journal of Clinical Microbiology & Infectious DiseasesOnline ISSN 1435-4373Print ISSN 0934-9723 (Source: European Journal of Clinical Microbiology & Infectious Diseases)

  • CYP102 from Streptomyces coelicolor A3(2): a novel fatty acid hydroxylase encoded as a heme domain without a N-terminal redox partner.

    Updated: 2010-01-21 23:00:00
    Authors: Lamb DC, Lei L, Zhao B, Yuan H, Jackson CJ, Warrilow AG, Skaug T, Dyson PJ, Dawson ES, Kelly SL, Hachey DL, Waterman MR The gene encoding CYP102B1 from Streptomyces coelicolor A3(2), a recently discovered CYP102 subfamily which exists solely as a single P450 heme domain, has been cloned, expressed in Escherichia coli, purified and characterized and compared to its fusion protein family members. Purified reconstitution metabolism experiments with spinach ferredoxin, ferredoxin reductase and NADPH, revealed differences in the regio- and stereo-selective metabolism of arachidonic acid compared to CYP102A1, exclusively producing 11,12-epoxyeicosa-5,8,14-trienoic acid in addition to the shared metabolites 18-hydroxy arachidonic acid and 14,15- epoxyeicosa-5,8,11-trienoic acid. Cons...

  • Microbial community analysis of anodes from sediment microbial fuel cells powered by rhizodeposits of living rice plants.

    Updated: 2010-01-21 23:00:00
    Authors: De Schamphelaire L, Cabezas A, Marzorati M, Friedrich MW, Boon N, Verstraete W By placing the anode of a sediment microbial fuel cell in the rhizosphere of a rice plant, root excreted rhizodeposits can be microbially oxidized with concomitant current generation. Here, various molecular techniques were used to characterize the composition of bacterial and archaeal communities on such anodes, as influenced by electrical circuitry, sediment matrix and plant presence. Closed circuit anodes in potting soil were enriched with Desulfobulbus-like species, Geobacteraceae and as yet uncultured Archaea representatives. PMID: 20097806 [PubMed - as supplied by publisher] (Source: Applied and Environmental Microbiology)

  • The carnivorous Pale Pitcher Plant harbors diverse, distinct and temporally dependent bacterial communities.

    Updated: 2010-01-21 23:00:00
    Authors: Koopman MM, Fuselier DM, Hird S, Carstens BC The ability of American carnivorous Pitcher Plants (Sarracenia) to digest insect prey is facilitated by microbial associations. Knowledge of the details surrounding this interaction has been limited by our capability to characterize bacterial diversity in this system. To describe microbial diversity within and between pitchers of one species, S. alata, and to explore how these communities change over time as pitchers accumulate and digest insect prey we collected and analyzed environmental sequence tag (454-pyrosequencing) and genomic fingerprint (ARISA and T-rflp) data. Microbial richness associated with Pitcher Plant fluid is high; more than 1000 unique phylogroups were identified across at least seven phyla and 50 families. We do...

  • Development and application of a PCR-targeted gene disruption method to study CelR function in Thermobifida fusca.

    Updated: 2010-01-21 23:00:00
    In this study, we have developed an efficient procedure for creating precise chromosomal gene disruptions and demonstrate this procedure by generating a celR deletion strain. The celR deletion strain was then characterized using measurements for growth behavior, cellulase activity, and gene expression. The celR deletion strain of T. fusca exhibited a severely crippled growth phenotype with a prolonged lag phase and decreased cell yields for growth both on glucose and cellobiose. While the maximum endoglucanase activity and cellulase activity were not significantly changed, the endoglucanase activity and cellulase activity per cell was highly elevated. Measurements of mRNA transcript levels in both the celR deletion strain and the wild-type strain indicated that the CelR potentially acts as...

  • Girdling affects ectomycorrhizal fungal diversity and reveals functional differences of EMF community composition in a beech forest.

    Updated: 2010-01-21 23:00:00
    Authors: Pena R, Offermann C, Simon J, Naumann PS, Geßler A, Holst J, Dannenmann M, Mayer H, Kögel-Knabner I, Rennenberg H, Polle A The relationships between plant carbon resources, the soil carbon and nitrogen content, and ectomycorrhizal fungal (EMF) diversity in a mono-specific old-growth beech forest (Fagus sylvatica) were investigated by manipulating carbon flux by girdling. We hypothesized that disruption of the carbon supply would not affect diversity and EMF species numbers if EMF can be supplied by plant internal carbohydrate resources or would result in selective disappearance of EMF taxa because of differences in carbon demand of different fungi. Tree carbohydrate status, root demography, EMF colonisation and EMF taxa abundance were measured repeatedly during one y...MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.

  • Significance of Wall Structure, Macromolecular Composition, and Surface Polymers to the Survival and Transport of Cryptosporidium parvum Oocysts.

    Updated: 2010-01-21 23:00:00
    Authors: Jenkins MB, Eaglesham BS, Anthony LC, Kachlany SC, Bowman DD, Ghiorse WC The structure and composition of the oocyst wall are primary factors determining the survival and hydrologic transport of Cryptosporidium parvum oocysts outside the host. Microscopic and biochemical analyses of whole oocysts and purified oocyst walls was undertaken to better understand the inactivation kinetics and hydrologic transport of oocysts in terrestrial and aquatic environments. Results of microscopy showed an outer electron dense layer, a translucent middle layer, two inner electron dense layers, and a suture structure embedded in the inner electron dense layers. Freeze substitution showed an expanded glycocalyx layer external to the outer bilayer, and Alcian Blue staining confirmed its presence ...

  • Quantitative assessment of ammonia-oxidizing bacterial communities in the epiphyton of submerged macrophytes in shallow lakes.

    Updated: 2010-01-21 23:00:00
    Authors: Coci M, Nicol G, Pilloni GN, Schmid M, Kamst-van Agterveld MP, Bodelier PL, Laanbroek HJ In addition to the benthic and pelagic habitats, the epiphytic compartment of submerged macrophytes in shallow freshwater lakes offers a niche to bacterial ammonia-oxidizing communities. However the diversity, numbers and activity of epiphytic ammonia-oxidizing bacteria has long been overlooked. In the present study we analyzed quantitatively the epiphytic communities of three shallow lakes by a potential nitrification assay and by quantitative PCR of 16S rRNA genes. Based on m(2) lake surface, gene copy numbers of epiphytic ammonia oxidizers were not significantly different from those in the benthic and pelagic compartment. Potential ammonia-oxidizing activities measured in the epiphytic ...

  • Membrane topology of the outer membrane protein AlgE which is required for alginate production in Pseudomonas aeruginosa.

    Updated: 2010-01-21 23:00:00
    Authors: Hay ID, Rehman ZU, Rehm BH The ubiquitous opportunistic human pathogen Pseudomonas aeruginosa secretes a viscous extracellular polysaccharide, called alginate, as virulence factor during chronic infection of Cystic Fibrosis patients. Here it was demonstrated that the outer membrane protein AlgE is required for production of alginate in P. aeruginosa. An isogenic marker free algE deletion mutant was constructed. This strain was incapable of producing alginate but did secrete alginate degradation products, indicating that polymerization is occurring but the alginate chain is subsequently degraded during transit through the periplasm. Alginate production was restored by introducing the algE gene. The membrane topology of the outer membrane protein AlgE was assessed by site-specif...

  • Low Copy Number Plasmids are Widely Dispersed in Rickettsia Species Associated with Blood-feeding Arthropods and may have Multiple Origins.

    Updated: 2010-01-21 23:00:00
    We report existence of plasmids in Rickettsia (Rickettsiales; Rickettsiaceae) species including R. akari, R. amblyommii, R. bellii, R. rhipicephali and REIS, the rickettsial endosymbiont of Ixodes scapularis. All of the rickettsiae were isolated from humans or North and South American ticks. R. parkeri isolates from both continents did not possess plasmids. We have now demonstrated plasmids in nearly all Rickettsia species that we have surveyed from three continents and that represent three of the four major proposed phylogenetic groups associated with blood-feeding arthropods. Gel-based evidence consistent with existence of multiple plasmids in some species was confirmed by cloning plasmids with very different sequences from each of two R. amblyommii isolates. Phylogenetic analysis of ric...

  • Discrimination of Bacillus cereus T-strain Spores Grown on Different Media using Fatty Acid Methyl Ester (FAME) Profiles.

    Updated: 2010-01-21 23:00:00
    Authors: Ehrhardt CJ, Chu V, Brown T, Simmons TL, Swan BK, Bannan J, Robertson JM The goal of this study was to determine if cellular Fatty Acid Methyl Ester (FAME) profiling can be used to distinguish among spore samples from a single species (Bacillus cereus T-strain) that were prepared on ten different medium formulations. To analyze profile differences and identify FAME biomarkers diagnostic for the chemical constituents in each sporulation medium, a variety of statistical techniques were used including non-metric multidimensional scaling (nMDS), analysis of similarities (ANOSIM), and discriminant function analysis (DFA). Results showed that one FAME biomarker, oleic acid (18:1 omega9c), was exclusively associated with spores grown on Columbia Agar supplemented with sheep blood, an...MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.

  • Expanded MLST genotyping and comparative genomic hybridization of Campylobacter coli isolates from multiple hosts.

    Updated: 2010-01-21 23:00:00
    Authors: Lang P, Lefebure T, Wang W, Pavinski Bitar P, Meinersmann RJ, Kaya K, Stanhope MJ The purpose of this work was to evaluate the evolutionary history of Campylobacter coli isolates derived from multiple host sources and to use microarray comparative genomic hybridization to assess whether there are particular genes comprising the dispensable portion of the genome that are more commonly associated with certain host species. Genotyping and ClonalFrame analyses of an expanded 16 gene MLST dataset involving 85 isolates from 4 different hosts species tentatively supported the development of C. coli host preferred groups and suggested that recombination has played varying roles in their diversification, however, geography could not be excluded as a contributing factor underlying the h...

  • Structural effects on inhibition of planktonic growth and biofilm formation of Escherichia coli by Trp/Arg containing antimicrobial peptides.

    Updated: 2010-01-21 23:00:00
    Authors: Hou S, Liu Z, Young AW, Mark SL, Kallenbach NR, Ren D Biofilms are sessile microbial communities that cause serious chronic infections with high morbidity and mortality. In order to develop more effective approaches for biofilm control, a series of linear cationic antimicrobial peptides (AMPs) with varying arginine (Arg or R) and tryptophan (Trp or W) repeats ([RW]n-NH2, where n = 2, 3 or 4) were rigorously compared to correlate their structures with antimicrobial activities on the planktonic growth and biofilm formation of Escherichia coli. The chain length of AMPs appears to be important for inhibition of bacterial planktonic growth since the hexametric and octameric peptides significantly inhibited E. coli growth, while tetrameric peptide did not exhibit noticeable inhibiti...

  • Rapid Assessment of the Viability of Mycobacterium avium subsp. paratuberculosis Cells After Heating Using the Optimised Phage Amplification Assay.

    Updated: 2010-01-21 23:00:00
    This study has confirmed that the optimized phage assay could be employed in place of conventional culture on HEYM to speed up acquisition of results (48 h instead of minimum 6 weeks) in this kind of inactivation experiment involving M. avium subsp. paratuberculosis spiked samples. PMID: 20097817 [PubMed - as supplied by publisher] (Source: Applied and Environmental Microbiology)

  • Polymorphic mutation frequencies of clinical and environmental Stenotrophomonas maltophilia.

    Updated: 2010-01-21 23:00:00
    Authors: Turrientes MC, Baquero MR, Sánchez MB, Valdezate S, Escudero E, Berg G, Cantón R, Baquero F, Galán JC, Martínez JL Mutation frequencies were studied in 174 Stenotrophomonas maltophilia isolates from clinical and non-clinical environments by detecting spontaneous rifampin-resistant mutants in otherwise susceptible populations. The distribution of mutation frequencies followed a similar pattern to that found for other bacterial species, with a modal value of 1x10(-8). Nevertheless, the proportion of isolates showing mutation frequencies below modal value (hypomutators) was significantly higher for S. maltophilia that those so far reported in other organisms. Low mutation frequencies were particularly frequent among environmental S. maltophilia strains (58.3%)...

  • Genetic expansion of randomly mating founder populations of Alternaria brassicicola infecting Cakile maritima in Australia.

    Updated: 2010-01-21 23:00:00
    This study uses microsatellite markers in the interaction between Cakile maritima and the fungal pathogen Alternaria brassicicola to explore genetic expectations associated with such situations. The host, C. maritima was introduced to Australia approximately 100 years ago but it is unknown whether the pathogen was already present in Australia as it has a wide occurrence, or whether it has been introduced to Australia on brassicaceous hosts. Eleven A. brassicicola populations were studied and all show moderate levels of gene and genotypic diversity. Chi-square tests on frequencies of mating-type alleles, a large number of genotypes and linkage equilibrium among SSR loci, all suggest A. brassicicola reproduces sexually. Significant genetic differentiation was found among populations, but the...MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.

  • Characterization of wet heat inactivation of single spores of Bacillus species by dual-trap Raman spectroscopy and elastic light scattering.

    Updated: 2010-01-21 23:00:00
    Authors: Zhang P, Kong L, Setlow P, Li YQ Dual-trap laser tweezers Raman spectroscopy (LTRS) and elastic light scattering (ELS) were used to investigate dynamic processes during high temperature treatment of individual spores of Bacillus cereus, Bacillus megaterium and Bacillus subtilis in water. Major conclusions from these studies included the following. 1) After spores of all three species were added to water at 80-90 degrees C the level of the 1:1 complex of Ca(2+) and dipicolinic acid (CaDPA; approximately 25% of the dry wt of the spore core) in individual spores remained relatively constant during a highly variable lag time (Tlag) and then was released within 1-2 min. 2) The Tlag values prior to rapid CaDPA release and thus the times for wet-heat killing of individual spores of a...

  • D-xylose: repressor or inducer of xylanase expression in Hypocrea jecorina (Trichoderma reesei).

    Updated: 2010-01-21 23:00:00
    Authors: Mach-Aigner AR, Pucher ME, Mach RL In Hypocrea jecorina (anamorph Trichoderma reesei), a filamentous fungus used for hydrolase production in different industries, it is a long-term practice to use D-xylose as an inducing substance. We demonstrate in this study that the degree of xylanase-encoding gene induction strictly depends on the concentration of D-xylose, which was found to be optimal from 0.5 to 1 mM for 3 hours of cultivation. At higher concentrations of D-xylose a reduced level of xylanase gene expression was observed. In the present study, we also provide evidence that the D-xylose concentration-dependent induction is antagonized by the Carbon catabolite repressor 1. This repressor mediates its influence on D-xylose indirectly by reducing the expression of Xylanase r...

  • Bacterial symbionts in the brown planthopper, Nilaparvata lugens (Homoptera: Delphacidae).

    Updated: 2010-01-21 23:00:00
    In this study we examined the bacterial microbes in N. lugens, and identified in total 18 operational taxonomic units (OTUs), representing four phyla (Proteobacteria, Firmicutes, Actinobacteria and Bacteroidetes) by sequencing and analyzing 16S rRNA gene libraries obtained from three populations of N. lugens, which were maintained on rice varieties TN1, Mudgo and ASD7, respectively. Several of the OTUs were similar to previously reported secondary symbionts of other insects, including an endosymbiont of the psyllid Glycapsis brimblecombei, Asaia sp. found in the mosquito Anopheles stephensi and Wolbachia found in the mite Metaseiulus occidentalis. However, the species and numbers of the detected OTUs differed substantially among the N. lugens populations. Further, in situ hybridization ana...

  • Early stage of biofilm development by Salmonella Enteritidis on stainless steel is inhibited by the cell-free culture supernatant of Hafnia alvei.

    Updated: 2010-01-21 23:00:00
    Authors: Chorianopoulos NG, Giaouris ED, Kourkoutas Y, Nychas GJ Compounds present in Hafnia alvei cell-free culture supernatant cumulatively negatively influence the early stage of biofilm development by Salmonella enterica serovar Enteritidis on stainless steel, while they also reduce the overall metabolic activity of S. Enteritidis planktonic cells. Although, acylhomoserine lactones (AHLs) were detected among these compounds, the use of some synthetic AHLs was not able to affect the initial stage of biofilm formation by this pathogen. PMID: 20097823 [PubMed - as supplied by publisher] (Source: Applied and Environmental Microbiology)

  • Molecular Characterization of Sewage-borne Pathogens and Detection of Sewage Markers in an Urban Stream in Caracas, Venezuela.

    Updated: 2010-01-21 23:00:00
    This study reveals epidemiological features of human pathogens of worldwide distribution and the efficacy of molecular methods for accurate assessment of sewage pollution. PMID: 20097824 [PubMed - as supplied by publisher] (Source: Applied and Environmental Microbiology)MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.

  • Listeria monocytogenes EGD-e continuous flow biofilm formation is dependent on SOS response factor YneA.

    Updated: 2010-01-21 23:00:00
    Authors: van der Veen S, Abee T Listeria monocytogenes was previously shown to form biofilms composed of a network of knitted chains in continuous flow conditions. Here we show that the SOS response is activated under these conditions and that deletion of its regulon member yneA results in diminished biofilm formation in continuous flow conditions. PMID: 20097825 [PubMed - as supplied by publisher] (Source: Applied and Environmental Microbiology)

  • Agreement, Precision and Accuracy of Epifluorescence Microscopy Methods for Enumeration of Total Bacterial Number.

    Updated: 2010-01-21 23:00:00
    Authors: Seo EY, Ahn TS, Zo YG To assess interchangeability of estimates of bacterial abundance by different epifluorescence microscopy methods, total bacterial numbers (TBNs) determined by most widely-accepted protocols were statistically compared. Bacteria in a set of distinctive samples were stained with acridine orange (AO), 4'-6-diamidino-2-phenylindole (DAPI) and BacLight, and enumerated by visual counting (VC) and supervised-image analysis (IA). Model II regression and Bland-Altman analysis proved general agreements between IA and VC methods, albeit IA counts tended to be lower than VC counts by 7% on a logarithmic scale. Distributions of cells and latex beads on polycarbonate filters were best fitted to negative-binomial models rather than to Poisson or log-normal models. The f...

  • Improved Strains and Plasmid Vectors for Conditional Overexpression of His-tagged Proteins in Haloferax volcanii.

    Updated: 2010-01-21 23:00:00
    Authors: Allers T, Barak S, Liddell S, Wardell K, Mevarech M Research into archaea will not achieve its full potential until systems are in place to carry out genetics and biochemistry in the same species. Haloferax volcanii is widely regarded as the best-equipped organism for archaeal genetics, but the development of tools for expression and purification of H. volcanii proteins has been neglected. We have developed a series of plasmid vectors and host strains for conditional overexpression of halophilic proteins in H. volcanii. The plasmids feature the tryptophan-inducible p.tnaA promoter and a 6xHis-tag for protein purification by metal affinity chromatography. Purification is facilitated by host strains where pitA is replaced by the ortholog from Natronomonas pharaonis. The latter l...

  • Anaerobic digestion of renewable biomass - thermophilic temperature governs population dynamics of methanogens.

    Updated: 2010-01-21 23:00:00
    Authors: Krakat N, Westphal A, Schmidt S, Scherer P Beet silage and beet juice as representative energy crops were digested continuously in a thermophilic biogas fermenter for more than 7 years. Fluorescence microscopy of 15 samples covering a period of 650 days revealed, that a decrease in temperature from 60 degrees C to 55 degrees C converted a morphologically uniform archaeal population (rods) into a population of methanogens exhibiting different cellular morphologies (rods and coccoid cells). A subsequent temperature increase back to 60 degrees C re-established the uniform morphology of methanogens observed in the previous 60 degrees C period. In order to verify these observations, representative samples were investigated by Amplified "Ribosomal DNA" Restriction Analysis (ARDRA) a...

  • CoolProducts(TM) manage and standardize sample cooling, freezing, snap-freezing and thawing while ensuring sample integrity.

    Updated: 2010-01-20 00:36:18
    BioCision develops COOLPRODUCTSTM (CoolRackTM, CoolSinkTM, CoolBoxTM, CoolCellTM) - a line of novel modular tools that improve benchtop temperature management of biological samples. Our patent-pending products are used by researchers in the pharmaceutical, biotechnology, academic, and health care industries worldwide. CoolRacks and CoolSinks are patented highly ...

  • I have found a better way for treating cancer of the liver with Chinese medicine

    Updated: 2010-01-16 10:34:47
    It is found in my working.the man who has cancer of the liver is recovering while eating chinese medicine.he has eaten chinese medicine for three months.the lump in his liver is becoming small.first,the patient of the cancer refuse operation.but chemotherapy let his body drop! at last he selected eating chinese medicine . but the prescription let me someh...

  • Lessons from a pandemic: Nature

    Updated: 2010-01-15 11:00:26
    Jump to main content Jump to navigation nature.com homepage Publications A-Z index Browse by subject My account Submit manuscript Register Subscribe Login Search this journal all of nature.com Advanced search Journal home 0003E Archive 0003E Editorial 0003E Full Text Editorial Nature 463 135-136 14 January 2010 doi 10.1038 463135b Published online 13 January 2010 Lessons from a pandemic Top of page Abstract It is time to assess what worked , and what didn't , in the global efforts to cope with swine . flu The world's response to the H1N1 flu pandemic over the past ten months suggests that the lessons learned from dealing with severe acute respiratory syndrome SARS and the threat of H5N1 avian flu have paid off . Researchers worldwide freely shared and published data covering the genetics , virology and epidemiology of the H1N1 virus in almost real time . Most national and international health agencies reacted swiftly and generally communicated openly with the media and the public . But the response also revealed serious weaknesses . The sobering fact is that humans were lucky with this pandemic . Most cases have been mild , yet health services were still often stretched to capacity

  • UI Acquires Lasergene DNA Analysis Software License

    Updated: 2010-01-13 17:02:28
    The popular DNA sequence analysis software, Lasergene, is now available for use by all University of Iowa faculty, and staff using campus computers. The new license was acquired through American Reinvestment and Recovery Act funds secured by Robert Piper, PhD,  and W. Scott Moye-Rowley, both professors of molecular physiology and biophysics. Lasergene software is comprised of [...]

  • Research Week 2010 Call for Posters

    Updated: 2010-01-11 19:55:13
    Poster registrations are now being accepted for both poster sessions being held in conjunction with this year’s Health Sciences Research Week.  The Carver College of Medicine, College of Pharmacy, College of Public Health, Iowa City Veterans Affairs Medical Center and Iowa Institute for Clinical and Translational Science will again be participating in the sessions. Dates and [...]

  • Workshop Aims to Sharpen Poster Presentation Skills

    Updated: 2010-01-11 19:45:59
    The Carver College of Medicine is inviting individuals planning on presenting a poster during this year’s Research Week event to attend a poster presentation workshop.  The purpose of the workshop is to assist students and investigators make clear and effective presentations of their research. The workshop will be held Thursday, February 4 from 6-7:30 pm in [...]

  • Upcoming Biomedical Scholar Lectures Announced

    Updated: 2010-01-06 20:22:45
    The Carver College of Medicine, partnering with its departments, has announced the 2010 Distinguished Biomedical Scholars Lecture Series slate of speakers.  The series, still in its inaugural year, features top-tier scientists and physicians performing high impact research in a variety of areas.  Three investigators have presented seminars since the kick-off lecture in September.  These previous [...]

  • New Tissue Facility Available for Researchers

    Updated: 2010-01-06 19:32:12
    CCOM investigators utilizing human tissue in their research studies now have a new resource at their disposal.  The Carver College of Medicine Tissue Procurement Core Facility received Institutional Review Board (IRB) approval in late November and has begun the process of collecting, storing and logging tissue samples for use in current and future research.  The [...]

  • Registry Facilitates UI Senior Research

    Updated: 2010-01-06 19:00:52
    In 2007, The University of Iowa Center on Aging developed a registry of senior research volunteers to aid UI research studies involving participants from older populations.  Today, the Seniors Together in Aging Research (STAR) registry includes over 1,400 individuals age 50 and older and continues to recruit participants and facilitate clinical research. STAR matches research volunteers [...]

  • Grant Helps UI Research on Infantile Form of FSH Muscular Dystrophy

    Updated: 2010-01-06 17:35:26
    University of Iowa researchers will study the most prevalent type of muscular dystrophy, thanks to a one-year, $39,998 grant from the FSH Society, Inc. The organization focuses on raising awareness and advancing research on facioscapulohumeral muscular dystrophy (FSHD), which affects about one in 14,286 individuals worldwide and currently has no treatment or cure. A team led [...]

  • AAAS Names Donelson and Fritsch as Fellows

    Updated: 2010-01-06 16:19:52
    Two University of Iowa faculty members — one from the Roy J. and Lucille A. Carver College of Medicine and one from the College of Liberal Arts and Sciences — have been awarded the distinction of 2009 Fellow of the American Association for the Advancement of Science (AAAS), the world’s largest general scientific society and [...]

  • Rodent Surgery – The proper care of rodent surgical instruments

    Updated: 2010-01-05 18:49:56
    Normal 0 false false false MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0pt 5.4pt 0pt 5.4pt; mso-para-margin:0pt; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language...

Last Months Items