Vibrio cholerae RC9
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA33553 | ENA |
REPOSITORIES: ENA
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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.
2009-11-25 | GSE19108 | GEO
Project description:Classical O1 serotype used in molecular research
| PRJNA15667 | ENA
Project description:Question Addressed: Does gene expression in V. cholerae change when samples are frozen at -80 degrees? An in vitro grown culture of O1 Inaba ICDDR,B (strain DSM-V999 described in Nature. 2002 Jun 6;417(6889):642-5) that had been grown to exponential phase (OD600 + 0.2) was placed in a 15 ml conical and then placed in a -80 degree freezer. A portion of the starting culture was harvested prior to freezing to serve as the control/reference for downstream hybridizations. RNA was recovered from the non-frozen sample as well as by prepping material directly from frozen samples. Labeling reactions were performed in quadruplicate for each sample. A replicate experimental design type is where a series of replicates are performed to evaluate reproducibility or as a pilot study to determine the appropriate number of replicates for a subsequent experiments.
2013-05-23 | GSE38179 | GEO
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).
2016-03-22 | E-GEOD-79467 | biostudies-arrayexpress
Project description:Question Addressed: Does gene expression in V. cholerae change when samples are frozen at -80 degrees? An in vitro grown culture of O1 Inaba ICDDR,B (strain DSM-V999 described in Nature. 2002 Jun 6;417(6889):642-5) that had been grown to exponential phase (OD600 + 0.2) was placed in a 15 ml conical and then placed in a -80 degree freezer. A portion of the starting culture was harvested prior to freezing to serve as the control/reference for downstream hybridizations. RNA was recovered from the non-frozen sample as well as by prepping material directly from frozen samples. Labeling reactions were performed in quadruplicate for each sample. A replicate experimental design type is where a series of replicates are performed to evaluate reproducibility or as a pilot study to determine the appropriate number of replicates for a subsequent experiments. replicate_design
2013-05-23 | E-GEOD-38179 | biostudies-arrayexpress
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.
2007-08-01 | E-SMDB-3574 | biostudies-arrayexpress