Project description:Enterotoxigenic Escherichia coli (ETEC) is a globally prevalent cause of diarrhea. We report the first gene expression analysis of the human host response to experimental challenge with ETEC.
Project description:The purpose of this study is to determine whether the presence of pathogenic Escherichia coli in colon is associated with psychiatric disorders.
Project description:Enterotoxigenic Escherichia coli (ETEC) is a major cause of diarrhoea in children in resource-limited countries and of travellers diarrhoea. The ileal proteomics change after ETEC challenge is less characterised. Here in this study changes of ileal proteins post ETEC challenge in weaned pigs are studied. In total, 5151 ileal proteins were successfully annotated and 9 proteins had significantly different abundance between the ETEC and CON pigs.
Project description:Despite the characterization of many aetiologic genetic changes. The specific causative factors in the development of sporadic colorectal cancer remain unclear. This study was performed to detect the possible role of Enteropathogenic Escherichia coli (EPEC) in developing colorectal carcinoma.
Project description:The most commonly used genome annotation processes are to a great extent based on computational methods. However, those can only predict genes that have been described earlier or that have sequence signatures indicative of a gene function. We reported a synonymous proteogenomic approach for experimentally improving microbial genome annotation based on label-free quantitative MS/MS. The approach was exemplified by analysis of cell extracts from in vitro cultured enterotoxigenic Escherichia coli (ETEC) strain TW10598, as part of an effort to create a new reference ETEC genome sequence. The proteomic analysis yielded identification of 2,060 proteins, out of which 274 proteins were originally described as hypothetical. For 84% of the identified proteins we have provided description of their relative quantitative levels, among others, for 20 abundantly expressed ETEC virulence factors. Proteogenomic mapping supported the existence of four protein-coding genes that had not been annotated, and led to correction of translation start positions of another nine.
Project description:Purpose: In this work, we evaluated the role of two indicative species, Citrobacter werkmanii (CW) and Escherichia albertii (EA), in the virulence of two DEC pathotypes, Shiga toxin-producing (STEC) and enteroaggregative (EAEC) Escherichia coli. Methods: To determine the effect of supernatant obtained from CW and EA cultures in STEC strain 86-24 and EAEC strain 042 gene expression, a RNA-seq analysis was performed. T84 cells were infected with DEC strains in the presence or absence of supernatant from EA and IL-8 secretion was evaluated. The effect of supernatant from EA on the growth and adherence of STEC and EAEC to T84 cells was also evaluated. Finally, we studied the participation of long polar fimbriae (Lpf) in STEC and plasmid-encoded toxin (Pet) in EAEC during DEC infection in the presence of supernatant from EA. Results: RNA-seq analysis revealed that several virulence factors in STEC and EAEC were up-regulated in the presence of supernatants from CW and EA. Interestingly, an increase in the secretion of IL-8 was observed in T84 cells infected with STEC or EAEC in the presence of a supernatant from EA. Similar results were observed with the supernatants obtained from clinical strains of E. albertii. Supernatant from EA had no effect on the growth of STEC and EAEC, or on the ability of these DEC strains to adhere to intestinal epithelial cells. Finally, we found that Pet toxin in EAEC was up-regulated in the presence of a supernatant from EA. In STEC, using mutant strains for Lpf fimbriae, our data suggested that these fimbriae might be participating in the increase of IL-8 induced by STEC on intestinal epithelial cells in the presence of a supernatant from EA. Conclusion:Supernatant obtained from an indicative species of DEC-positive diarrhea could modulate gene expression in STEC and EAEC, and IL-8 secretion induced by these bacteria. These data provide new insights into the effect of gut microbiota species in the pathogenicity of STEC and EAEC.
Project description:Enterotoxigenic Escherichia coli (ETEC) infections are a common cause of diarrheal illness in low- and middle-income countries. The live-attenuated ACE527 vaccine, adjuvanted with double mutant LT (dmLT), affords clear but partial protection against ETEC challenge inhuman volunteers. Comparatively, initial wild-type ETEC challenge completely protects against severe diarrhea on homologous re-challenge...To investigate molecular determinants of protection, vaccine antigen content was compared to wild-type ETEC, and proteome microarrays were used to assess immune responses following vaccination and ETEC challenge... Although molecular interrogation of the vaccine confirmed expression of targeted canonical antigens, relative to wild-type ETEC, vaccine strains were deficient in production of flagellar antigens, immotile, and lacked production of the EtpA adhesin. Similarly, vaccination ± dmLT elicited responses to targeted canonical antigens, but relative to wild-type challenge, vaccine responses to some potentially protective non-canonical antigens including EtpA were diminished or absent...These studies highlight important differences in vaccine and wild-type ETEC antigen content and call attention to distinct immunologic signatures that could inform investigation of correlates of protection, and guide vaccine antigen selection for these pathogens of global importance.