Mouse gut metagenome
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA1087316 | ENA |
REPOSITORIES: ENA
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Project description:We report the transcriptome of Burkholderia pseudomallei type VI secretion regulator TctR mutant grown in rich media compared to wild type. The RNA-seq studies confirmed the role of TctR as a negative regulator of T6SS-2, a positive regulator of T6SS-6 and suggest a potential role in regulation of the T6SS-3 and T6SS-4 gene clusters.
2017-10-09 | GSE104716 | GEO
Project description:Melioidosis is a disease caused by the Gram-negative bacillus Burkholderia pseudomallei (Bpm), commonly found in soil and water of endemic areas. Naturally acquired human melioidosis infections can result from either exposure through percutaneous inoculation, inhalation, or ingestion of soil-contaminated food or water. Our prior studies recognized Bpm as an effective enteric pathogen, capable of establishing acute or chronic gastrointestinal infections following oral inoculation (Sanchez-Villamil, Tapia et al. 2020). However, the specific mechanisms and virulence factors involved in the pathogenesis of Bpm during intestinal infection are unknown. In our current study, we standardized an in vitro intestinal infection model using mouse primary intestinal epithelial cells (mIECs) and demonstrated that Bpm requires a functional T6SS for full virulence. Further, we performed dual RNA-seq analysis on Bpm-infected mIECs to evaluate differentially expressed host and bacterial genes in the presence or absence of a T6SS. Our results showed a dysregulation in the TNF- signaling via NF-B pathway in the absence of the T6SS, with some of the genes involved in inflammatory processes and cell death also affected. Analysis of the bacterial transcriptome identified virulence factors and regulatory proteins playing a role during infection, with association to the T6SS. By using a Bpm transposon mutant library and isogenic mutants, we showed that deletion of the bicA gene, encoding a putative T3SS/T6SS regulator, ablated intracellular survival and plaque formation by Bpm and impacted survival and virulence when using murine models of acute and chronic gastrointestinal infection. Overall, these results highlight the importance of the type 6 secretion system in the gastrointestinal pathogenesis of Bpm.
2022-08-15 | GSE201263 | GEO
Project description:The mammalian gastrointestinal tract harbors a diverse microbiota residing in intimate contact with the host immune system. Though most associations are symbiotic or commensal, some resident bacteria (termed pathobionts) have the potential to induce disease in immunocompromised hosts. Type VI secretion systems (T6SSs) have recently emerged as a novel mechanism for forging microbial-host interactions during infection. We reveal here a unique protective role for the T6SS of Helicobacter hepaticus, a Gram-negative bacterium of the murine intestinal microbiota. The T6SS of H. hepaticus targets effector substrates to intestinal epithelial cells (IECs). Mutants in T6SSs display higher intracellular and cell-associated numbers upon incubation with IECs, and exhibit increased bacterial colonization of the gastrointestinal tract compared to wild-type bacteria. The T6SS accordingly directs an anti-inflammatory gene expression profile in IECs co-cultured with H. hepaticus. Remarkably, T6SS mutants induce an exacerbated pro-inflammatory response in an experimental model of colitis. CD4+ T cells isolated from T6SS mutant-colonized animals produce increased T-helper 17 (Th17) cytokines in response to IECs presenting H. hepaticus antigens. These data demonstrate that H. hepaticus intimately interacts with IECs and employs type VI secretion to establish a balanced host relationship by limiting microbial colonization and intestinal inflammation. We propose that altering host-bacterial equilibriums that lead to dysbiosis of the microbiota contributes to human disorders such as inflammatory bowel disease and colon cancer.
2010-06-01 | GSE20434 | GEO
Project description:Vibrio species are recognized for their role in food- and water-borne diseases in humans, fish, and aquatic invertebrates. We screened bacterial strains isolated from raw food shrimp for those that are bactericidal to Vibrio strains. Here we identify and characterize Aeromonas dhakensis strain A603 which shows robust bactericidal activity specifically towards Vibrio and related taxa but less potency toward other Gram-negative species. Using the A603 genome and genetic analysis, we show that two antibacterial mechanisms account for its vibriocidal activity -- a highly potent Type Six Secretion System (T6SS) and biosynthesis of a vibriocidal phenazine-like small molecule, named here as Ad-Phen. Further analysis indicates coregulation between Ad-Phen and a pore-forming T6SS effector TseC, which potentiates V. cholerae to killing by Ad-Phen.
2024-07-05 | GSE270023 | GEO
Project description:Secretion systems are used as weapons by a variety of Gram-negative bacteria. Among them the Type VI Secretion System (T6SS) gained more interest throughout the last years. The system functions as a molecular nano-weapon: it is used in inter-kingdom competition by various bacteria to deliver toxic effectors in target cells. Here we describe the role of the T6SS in Photorhabdus laumondii subsp. laumondii strain DJC, an entomopathogenic biocontrol agent able to live in different environmental niches, such as in symbiosis with nematodes and in the rhizosphere on plant roots. Using bioinformatic and protein motif analyses we identified four T6SS gene clusters (T6SS-1, T6SS-2, T6SS-3 and T6SS-4) and multiple orphan T6SS related genes in the genome of P. laumondii. Furthermore, we highlighted 11 T6SS effector-immunity pairs, including three undescribed membrane disrupting effectors, each with putatively different antibacterial activities. By label-free mass spectrometry of P. laumondii wild type cells and respective T6SS-deficient strains, we could point out a cross-link between T6SS and other Photorhabdus’ virulence related mechanisms such as PVCs, T3SS and pyocins. Furthermore, a change in motility as well as in the secondary metabolism was observed upon T6SS-deficiency. Here, we shed light on the T6SS in P. laumondii DJC and suggesting a cross-link of various virulence mechanisms, which could help to gain knowledge on T6SS and better figure out the Photorhabdus ability to live in polymicrobial environments.
2024-04-05 | PXD035720 | Pride
Project description:Characterization of a metagenomic regulatory sequence library derived from M. xanthus, E. coli, and O. urethralis genomes in strains expressing different RpoD ortholog variants. Targeted DNA and RNA seq used to profile relative DNA and RNA abundances, respectively of each regulatory sequence construct in the library.
2022-06-07 | E-MTAB-9111 | biostudies-arrayexpress
Project description:We recently demonstrated that colistin resistance in Acinetobacter baumannii can result from mutational inactivation of genes essential for lipid A biosynthesis. Consequently, strains harboring these mutations are unable to produce the major Gram negative bacterial surface component, lipopolysaccharide (LPS). To understand how A. baumannii compensates for the lack of LPS, we compared the transcriptional profile of the A. baumannii type strain ATCC19606, to that of an isogenic, LPS-deficient, lpxA mutant strain. Analysis of the expression profiles indicated that the LPS-deficient strain showed increased expression of many genes involved in cell envelope and membrane biogenesis. In particular, up-regulated genes included those involved in the Lol lipoprotein transport system and the Mla-retrograde phospholipid transport system. In addition, genes involved in the synthesis and transport of poly-beta-1,6-N-acetylglucosamine (PNAG) were also up-regulated and a corresponding increase in PNAG production was observed. The LPS-deficient strain also exhibited reduced expression of genes predicted to encode the fimbrial subunit FimA and a type VI secretion system (T6SS). The reduced expression of genes involved in T6SS correlated with the detection of the T6SS-effector protein, AssC, in culture supernatants of the A. baumannii wild-type strain, but not in the LPS-deficient strain. Taken together, these data show that, in response to total LPS loss, A. baumannii alters the expression of critical transport and biosynthesis systems associated with modulating the composition and structure of the bacterial surface. Comparison of a gene expression in biological duplicate samples derived from parent bacterial strain to an isogenic mutant strain.
2011-08-11 | E-GEOD-31206 | biostudies-arrayexpress
Project description:Bacteria of the genus Achromobacter are environmental germs, with an unknown reservoir, which can become opportunistic pathogens in immunocompromised patients, and be responsible for bacteremia, meningitis, pneumonia and peritonitis. Achromobacter xylosoxidans is an emerging pathogenic bacterium frequently isolated in the context of cystic fibrosis (CF). Recent studies show that A. xylosoxidans is involved in the degradation of the respiratory function of CF patients. The respiratory ecosystem of CF patients is colonized by bacterial species that constantly fight for space and access to nutrients. In particular, these bacteria use an antagonism system, a type VI secretion nanomachine (T6SS), which represents a virulence factor in many pathogenic bacteria. This study aimed to investigate the prevalence of the T6SS genes in Achromobacter xylosoxidans isolated in cystic fibrosis patient. We also evaluated clinical and molecular characteristics of T6SS-positive A. xylosoxidans strains. We have shown that A. xylosoxidans possesses a T6SS-encoded gene cluster and that some environmental and clinical isolates assemble a functional T6SS nanomachine. The A. xylosoxidans T6SS is used to target competitor bacteria, including other CF-specific pathogens. We gathered some evidences pointing toward a role of T6SS in CF-lung colonization: i, CF mimicking conditions trigger the activation of A. xylosoxidans T6SS; ii, we detected Hcp in the sputum of CF patient and iii, the T6SS helps internalization of A. xylosoxidans in lung epithelial cells. Our study highlights a new clinical determinant of the virulence of A. xylosoxidans as well as new diagnostic and therapeutic options in cystic fibrosis.
2024-02-01 | PXD031682 | Pride
Project description:To determine whether the Vibrio cholerae type VI secretion system (T6SS) is functional during animal infection, derivatives of V52 were used to infect infant mice. In this infection model, a diarrheal response occurred and effector translocation could be detected. These host responses were dependent on a functional T6SS and on the actin cross-linking effector domain of VgrG-1. Gene expression and histological studies showed innate immune activation and immune cell infiltration in the intestinal lumen.
2010-01-20 | GSE19946 | GEO