Project description:Investigation of whole genome gene expression level changes in a Vibrio cholerae O395N1 delta-nqrA-F mutant, compared to the wild-type strain. Total RNA recovered from wild-type cultures of VIbrio cholerae O395N1 and its nqrA-F mutant strain. Each chip measures the expression level of 3,835 genes from Vibrio cholerae O1 biovar eltor str. N16961 with twenty average probes/gene, with five-fold technical redundancy.
Project description:These experiments were performed to show serogroup conversion in Vibrio cholerae from O1 to O139 in a mixed communities / biofilms. For this purpose, V. cholerae O1 El Tor A1552 and VCO139-Kan strain (a MO10 derivative; O139 serogroup) were grown on crab shell fragments to induce natural competence for transformation. Transformants were selected on LB+Kan+Rif plates. O139 positive transformants have undergone a full exchange of the O1 region by the O139 region. This implies an exchange of an at least 32 kb spanning O1 genomic region by more than 42 kb of the O139 region. The transformation experiment was done at least five independent times; data from four experiments are shown; per experiment one to three clones were analysed by CGH with two experimental replicates each.
Project description:Environmental isolates of Vibrio cholerae from California coastal water compared to reference strain N16961. A genotyping experiment design type classifies an individual or group of individuals on the basis of alleles, haplotypes, SNP's. Keywords: genotyping_design; array CGH
Project description:Question Addressed: What is the level of expression of genes in Vibrio cholerae recovered from various conditions. These conditions include samples recovered directly from patients (O139 from stool samples from ICDDR,B and N16961 from stool samples from a vaccine trial held in Cincinnati) as well as standard logarithmic and stationary phase grown bacteria. Labeling reactions were performed in duplicate for each stool derived and in quadruplicate for each in vitro grown strain. A common reference was used for each slide, it was composed of RNA from the exponentially growing 92A1552 V. cholerae strain
Project description:In this study, we determined the TfoY regulon of V. cholerae using RNA-seq to better uderstand the protein's function. mRNA profiles of a WT V. cholerae O1 El Tor strain (A1552) and of a TfoY-producing derivative of the WT strain (A1552-TntfoY). 3 independent biological replicates are provided for each bacterial strain. The bacteria were grown to high cell density and in the presence of arabinose (to induce TfoY in strain A1552-TntfoY).
Project description:Investigation of whole genome gene expression level changes in a Vibrio cholerae O395N1 delta-nqrA-F mutant, compared to the wild-type strain.
Project description:This study is an analysis of changes in gene expression during stringent response in Vibrio cholerae. V. cholerae cells in mid-log were treated with serine hydroxamate and gene expression was compared to untreated cells. Keywords: Stress response, stringent response
Project description:These experiment were performed to show a serogroup conversion in Vibrio cholerae from O1 to O139. For this purpose, V. cholerae O1 WT = A1552 was grown on crab shell fragments to induce natural competence for transformation. Purified DNA (2 ug each) from strain VCO139-Kan was added after 24h and the cells grwon further for 24h. The VCO139-Kan strain is a MO10 derivative (both O139 serogroup) which harbors a Kanamycin cassette in the O139 region (as part of the operon between wbfA and wbfB w/o own promotor) for better selection. Transformants were selected on LB+Kan plates. Two groups of transformants were gained: Group I had a full exchange of the O1 region by the O139 region (clones serogroup-converted: SGC#1-3); the crossovers for the homologous recombination event had occurred within or upstream of the gmhD gene and in most instances within or downstream of the homolog gene of VC0271. This implies an exchange of an at least 33 kb spanning O1 genomic region by more than 42 kb of the O139 region. Group II had only half of the O139 region transfered and therefore half of the O1 region kept (clones HSGC#4-6). We analyzed their genotype and found that all of them had undergone a homologous recombination event with one crossover in or upstream of the gmhD gene and the second one inside the VC0254 and IS1358 gene. The transformation experiment was done three independent times (I - III). Three clones from group I and group II were selected from each experiment and analyzed by microarray hybridization (BioPrime. Array CGH Genomic Labeling from Invitrogen). Two microarray replicates were done per clone.
Project description:The PFGRC has developed a cost effective alternative to complete genome sequencing in order to study the genetic differences between closely related species and/or strains. The comparative genomics approach combines Gene Discovery (GD) and Comparative Genomic Hybridization (CGH) techniques, resulting in the design and production of species microarrays that represent the diversity of a species beyond just the sequenced reference strain(s) used in the initial microarray design. These species arrays may then be used to interrogate hundreds of closely related strains in order to further unravel their evolutionary relationships. Many infectious agents that cause emerging and re-emerging diseases appear to evolve from non-virulent forms. We still lack a clear understanding about the natural history of various microbial agents that cause human infectious diseases and the events leading to acquisition of their pathogenic potential. There have been seven pandemics of V. cholerae throughout the history of the mankind. To date, the world population is still experiencing the seventh one which started in the early 1960s. From almost 200 recognized V. cholerae serotypes, the majority of these epidemics are associated with primarily O1 serotype. However there is evidence that this species is undergoing some phenotypic changes during the last decades. Such examples include shifts in some metabolic pathways used for biotyping, phage sensitivity profiling and the acquisition of plasmids that carry multiple genes conferring antimicrobial resistance. Furthermore, the recent emergence of a non-O1 serotype (‘Bengal strain’, classified serologically as O139) has prompted the experts to think that perhaps this genotype will be the predominant one in the upcoming (eighth) pandemic. Besides the O1 and O139, the non-O1 and non-O139 V. cholerae stains are occasionally associated with other severe forms of gastrointestinal disease in humans. Interestingly, many of these non-canonical strains lack the genes encoding the typical virulence factors for this species such as the Cholera-toxin (ctx) and toxin co-regulated pilus (tcpA). Therefore it has been hypothesized that this group of non-canonical V. cholerae pathogens consist of several sub-clones that elicit disease via unknown virulence determinants and underlying mechanisms. The flow of genetic information within this group motivated us to identify novel genes for the purpose of creating a "species" DNA microarray to better understand the ancestral relationships among its members. Based on preliminary genotyping (MLST, and CGH using a single-genome-based array), 10 diverse V. cholerae and one V. mimicus were selected for sequencing. Sequence information obtained from this project, and from other publicly available sources, led to the development of a comprehensive species microarray for V. cholerae group members. The availability of the V. cholerae species DNA microarray has allowed us to carry out a collaborative CGH genotyping project to validate this microarray as well as understand the phylogenomic relationships among members of V. cholerae group.