Ontology highlight
ABSTRACT:
PROVIDER: PRJEB19893 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:The seventh pandemic of cholera in Europe revisited by microbial genomics
| PRJEB38484 | ENA
Project description:Seventh pandemic Vibrio cholerae O1 El Tor, Algeria
| PRJEB48258 | ENA
Project description:Genomic study of seventh pandemic Vibrio cholerae El Tor isolates from the Democratic Republic of Congo
| PRJEB47296 | ENA
Project description:Transcriptional response to overexpressing Vibrio Seventh Pandemic -II island encoded genes
| PRJNA727981 | ENA
Project description:The history of click-speaking Khoe-San, and African populations in general, remains poorly understood. We genotyped ~2.3 million SNPs in 220 southern Africans and found that the Khoe-San diverged from other populations at least 100,000 years ago, but structure within the Khoe-San dated back to about 35,000 years ago. Genetic variation in various sub-Saharan populations did not localize the origin of modern humans to a single geographic region within Africa, instead, it indicated a history of admixture and stratification. We found evidence of adaptation targeting muscle function and immune response, potential adaptive introgression of UV-light protection, and selection predating modern human diversification involving skeletal and neurological development. These new findings illustrate the importance of African genomic diversity in understanding human evolutionary history .220 samples were analysed with the Illumina HumanOmni2.5-Quad BeadChip and are described herein.
2012-09-22 | E-MTAB-1259 | biostudies-arrayexpress
Project description:Using a combination of ChIP-seq and RNA-seq we show that ToxT regulates expression of the small RNA TarB. TarB modulates the expression level of the transcriptioanl repressor VC0177. VC0177 controls expression of several genes including VC0179. The function of the Vibrio 7th pandemic island-1 (VSP-1) in cholera pathogenesis has remained obscure. Utilizing ChIP-seq and RNA-seq to map the regulon of the master virulence regulator ToxT, we identify a TCP island encoded small RNA that reduces the expression of a previously unrecognized VSP-1 encoded transcription factor termed VspR. VspR modulates the expression of several VSP-1 genes including one that encodes a novel class of di-nucleotide cyclase (DncV), which preferentially synthesizes a previously undescribed hybrid cyclic AMP-GMP molecule. We show that DncV is required for efficient intestinal colonization and down-regulates V. cholerae chemotaxis, a phenotype previously associated with hyperinfectivity. This pathway couples the actions of previously disparate genomic islands, defines VSP-1 as a pathogenicity island in V. cholerae and implicates its occurrence in 7th pandemic strains as a benefit for host adaptation through the production of a regulatory cyclic di-nucleotide.
2012-04-13 | E-GEOD-36373 | biostudies-arrayexpress
Project description:Pandemic and endemic strains of Vibrio cholerae arise from toxigenic conversion by the CTXφ bacteriophage, a process by which CTXφ infects non-toxigenic strains of V. cholerae. CTXφ encodes the cholera toxin, an enterotoxin responsible for the watery diarrhea associated with cholera infections. Despite the critical role of CTXφ during infections, signals that affect CTXφ-driven toxigenic conversion or expression of the CTXφ-encoded cholera toxin remain poorly characterized, particularly in the context of the gut mucosa. Here, we identify mucin polymers as potent regulators of CTXφ-driven pathogenicity in V. cholerae. Our results indicate that mucin-associated O-glycans block toxigenic conversion by CTXφ and suppress the expression of CTXφ-related virulence factors, including the toxin co-regulated pilus and cholera toxin, by interfering with the TcpP/ToxR/ToxT virulence pathway. By synthesizing individual mucin glycan structures de novo, we identify the Core 2 motif as the critical structure governing this virulence attenuation. Overall, our results highlight a novel mechanism by which mucins and their associated O-glycan structures affect CTXφ-mediated evolution and pathogenicity of V. cholerae, underscoring the potential regulatory power housed within mucus.
2022-12-01 | GSE213598 | GEO
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:Purpose: to characterize the regulatory targets of an AraC-like transcriptional regulator (VC0513) encoded on the Vibrio Seventh Pandemic Island -II (VSP-II) in V. cholerae O1 El Tor N16961 Methods: RNA was isolated from a wild-type N16961 carrying an IPTG-inducible copy of vc0513, vc0515, or an empty vector control Results: vc0513 induction significantly increased expression of other VSP-II encoded genes relative to the empty vector control Conclusions: our study represents the first analysis of a transcriptional regulator encoded on the VSP-II island
2021-05-08 | GSE174028 | GEO
Project description:Origin and relationships of the current Cholera El Tor pandemic Clone
| PRJDB2103 | ENA