Sentinel surveillance study Shigella
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ABSTRACT:
PROVIDER: PRJEB56557 | ENA |
REPOSITORIES: ENA
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Project description:Background Compelling evidence indicates that Shigella species, the etiologic agents of bacillary dysentery, as well as enteroinvasive Escherichia coli, are derived from multiple origins of Escherichia coli and form a single pathovar. To further understand the genome diversity and virulence evolution of Shigella, comparative genomic hybridization microarray analysis was employed to compare the gene content of E. coli K-12 with those of 43 Shigella strains from all serotypes. Results For the 43 strains subjected to CGH microarray analyses, the common backbone of the Shigella genome was estimated to contain more than 1,900 open reading frames, with a mean number of 729 undetectable ORFs. The mosaic distribution of absent regions indicated that insertions and/or deletions have led to the highly diversified genomes of pathogenic strains. Conclusion These results support the hypothesis that by gain and loss of functions, Shigella species became successful human pathogens through convergent evolution from diverse genomic backgrounds. Moreover, we also found many specific differences between different lineages, providing a window into understanding bacterial speciation and taxonomic relationships. Keywords: comparative genomic hybridization
2007-07-01 | GSE5212 | GEO
Project description:Small regulatory RNAs (sRNAs) of Shigella dysenteriae and other pathogens are vital for the regulation of virulence-associated genes and processes. Here, we characterize RyfA1, one member of a sibling pair of sRNAs produced by S. dysenteriae. Unlike its nearly identical sibling molecule RyfA2, predicted to be encoded almost exclusively by non-pathogenic species, the presence of a gene encoding RyfA1, or a RyfA1-like molecule, is strongly correlated with virulence in a variety of enteropathogens. In S. dysenteriae, the over production of RyfA1 negatively impacts the virulence-associated process of cell-to-cell spread and the expression of ompC, a gene encoding a major outer membrane protein important for the pathogenesis of Shigella. Interestingly, the production of RyfA1 is controlled by a second sRNA, here termed RyfB1; the first incidence of one regulatory small RNA controlling another in S. dysenteriae or any Shigella species.
2017-04-17 | GSE87727 | GEO
Project description:to analyse the transcriptomic response of human intestinal tissue engrafted in SCID mice to Shigella infection Keywords: infection, Shigella, gene expression, intestinal cell
2008-06-23 | GSE8636 | GEO
Project description:We evaluated the transcriptome changes induced by infection of Hela 229 cells with Shigella flexneri. The sample set consists of a control (mock), total population of infected sample and infected sample sorted into Shigella positive and Shigella negative population.
2017-04-04 | GSE75746 | GEO
Project description:Shigella flexneri is historically regarded as the primary agent of bacillary dysentery, yet the closely-related Shigella sonnei is replacing S. flexneri, especially in developing countries. The underlying reasons for this dramatic shift are mostly unknown. Using a zebrafish (Danio rerio) model of Shigella infection, we discover that S. sonnei is more virulent than S. flexneri in vivo. Whole animal dual-RNAseq and testing of bacterial mutants suggest that S. sonnei virulence depends on its O-antigen oligosaccharide (which is unique among Shigella species). We show in vivo using zebrafish and ex vivo using human neutrophils that S. sonnei O-antigen can mediate neutrophil tolerance. Consistent with this, we demonstrate that O-antigen enables S. sonnei to resist phagolysosome acidification and promotes neutrophil cell death. Chemical inhibition or promotion of phagolysosome maturation respectively decreases and increases neutrophil control of S. sonnei and zebrafish survival. Strikingly, larvae primed with a sublethal dose of S. sonnei are protected against a secondary lethal dose of S. sonnei in an O-antigen-dependent manner, indicating that exposure to O-antigen can train the innate immune system against S. sonnei. Collectively, these findings reveal O-antigen as an important therapeutic target against bacillary dysentery, and may explain the rapidly increasing S. sonnei burden in developing countries.
2019-11-19 | GSE140544 | GEO
Project description:Trained immunity is a long-term memory of innate immune cells, generating an improved response upon re-infection. Shigella is an important human pathogen and inflammatory paradigm for which there is no effective vaccine. Using zebrafish larvae we demonstrate that after Shigella priming neutrophils are more efficient at bacterial clearance. We observe that Shigella-induced protection is non-specific and long-lasting, and is unlike training by BCG and β-glucan. Analysis of histone ChIP-seq on primed neutrophils revealed that Shigella training deposits the active H3K4me3 mark on promoter regions of 1612 genes, significantly changing the epigenetic landscape of neutrophils towards enhanced microbial recognition and mitochondrial ROS production. Finally, we demonstrate that mitochondrial ROS plays a key role in enhanced antimicrobial activity of trained neutrophils. It is envisioned that signals and mechanisms we discover here can be used in other vertebrates, including humans, to suggest new therapeutic strategies involving neutrophils to control bacterial infection.
2023-09-13 | GSE217063 | GEO
Project description:To explore what important role of PhoPQ TCS plays in Shigella virulence, the Agilent microarray technologies was used to compare the transcriptional profiles of Shigella flexneri 2a 301 and △phoPQ mutant strains at middle-log phase (6 h) or early-stationary phase (10 h) under LB growth conditions.
2017-11-28 | GSE107365 | GEO
Project description:Expression of type III secretion system (TTSS), a major determinant of virulence in Shigella, is markedly inhibited in a deletion mutant (cpxA) of the CpxAR two-component sensor at the level of post-transcriptional processing of the second TTSS regulator, InvE. A novel mutant of rodZ, which encodes a cytoskeletal protein involved in maintaining the rod-shaped morphology of bacilli, was isolated in a screen for mutations that restored TTSS expression in a cpxA mutant. The rodZ mutants of Shigella sonnei efficiently expressed InvE at 30°C, a temperature at which expression is normally repressed through temperature-dependent post-transcriptional regulation. Consistent with a marked increase in invE mRNA stability in the rodZ mutant, purified RodZ strongly bound to an invE RNA probe. Functional domain mapping indicated that the RNA binding activity of RodZ was dependent on a short basic region (KRRKKR) and multimer formation. Electron microscopy revealed that RodZ multimers formed filamentous superstructures, similar to another bacterial cytoskeletal protein, MreB. Our results indicate that RodZ functions as a novel membrane-bound RNA binding protein that provides a scaffold for post-transcriptional regulation. Phenotypic analysis of deletion mutant for RNA binding protein RodZ. The mutants analyzed in this study are further described in Jiro Mitobe, Itaru Yanagihara, Kiyouhisa Ohnishi, Akira Ishihama and Haruo Watanabe 2010. Bacterial cytoskeleton RodZ regulates post-transcriptional processing of Shigella type III secretion system. EMBO-J ( in submission). Four samples. Wild-type Shigella sonnei strain and the deletion mutant of rodZ gene, with or without rifampicin treatment for kinetics of mRNA stability.
2011-03-31 | E-GEOD-21051 | biostudies-arrayexpress
Project description:In this study, we probed factors that could influence Shigella pathogenesis. We show that in basic pH conditions, deoxycholate-induced biofilm formation and virulence of Shigella are attenuated. We utilized RNA-sequencing to investigate pathways enriched in bacterial cells in biofilms.
2021-09-09 | GSE183515 | GEO