Project description:The transcriptome of Escherichia coli K-12 has been widely studied over a variety of conditions for the past decade while such studies involving E. coli O157:H7, its pathogenic cousin, are just now being conducted. To better understand the impact of intracellular life within a ruminant and environmental protozoan on E. coli O157:H7, global transcript levels of strain EDL933 cells inside Acanthamoeba were compared to cell grown in the protozoan media (ATCC PYG712) by microarray.
Project description:The transcriptome of Escherichia coli K-12 has been widely studied over a variety of conditions for the past decade while such studies involving E. coli O157:H7, its pathogenic cousin, are just now being conducted. To better understand the impact of an anaerobic environment on E. coli O157:H7, global transcript levels of strain EDL933 cells grown aerobically were compared to cells grown anaerobically using microarrays.
Project description:Transcript abundance in Escherichia coli O157:H7 was determined in the presence or absence of pulsed expression of the small RNA, AsxR.
Project description:The transcriptome of Escherichia coli K-12 has been widely studied over a variety of conditions for the past decade while such studies involving E. coli O157:H7, its pathogenic cousin, are just now being conducted. To better understand the impact of heat shock on E. coli O157:H7, global transcript levels of strain EDL933 cells shifted from 37°C to 50°C for 15 min were compared to cells left at 37°C using microarrays. Keywords: Stress Response
Project description:The transcriptome of Escherichia coli K-12 has been widely studied over a variety of conditions for the past decade while such studies involving E. coli O157:H7, its pathogenic cousin, are just now being conducted. To better understand the impact of rumen fluid on E. coli O157:H7, global transcript levels of strain EDL933 cells resuspended in heat clarified rumen fluid for 15 min were compared to cells resuspended in fresh LB using microarrays.
Project description:Multiple infection sources for enterohemorrhagic Escherichia coli O157:H7 are known, including food of animal origin and produce. The ecology of this pathogen outside its human host is largely unknown. One third of its annotated genes still are hypothetical. To identify genetic determinants expressed under environmental factors, we applied strand-specific RNA-sequencing of strain E. coli EDL933 under 11 different biotic and abiotic conditions: LB medium at pH4, pH7, pH9, or at 15°C; LB with nitrite or trimethoprim-sulfamethoxazole; LB-agar surface, M9 minimal medium, spinach leaf juice, surface of living radish sprouts, and cattle feces. Of 5379 annotated genes, only 144 are transcriptionally completely inactive under all conditions. Of 1,771 hypothetical genes, 1,672 exhibit significant transcriptional signals under at least one condition. The pathogenicity island LEE showed highest transcriptional activity in LB medium, minimal medium, and after treatment with antibiotics. Unique sets of genes, including many hypothetical genes, are highly up regulated on radish sprouts, cattle feces, or in the presence of antibiotics. For instance, azoR is biotechnologically important, but its environmental function has been elusive. This gene is highly active on radish sprouts. Further, we observed induction of the shiga-toxin carrying phages by antibiotics and confirmed active biofilm related genes on radish sprouts, in cattle feces, and on agar plates. Thus, environmental transcriptomics uncovers hitherto unknown gene functions and regulatory patterns of Escherichia coli O157:H7.
Project description:Pathogenic biofilms have been associated with persistent infections due to their high resistance to antimicrobial agents. To identify non-toxic biofilm inhibitors for enterohemorrhagic Escherichia coli O157:H7, indole-3-acetaldehyde was used and reduced E. coli O157:H7 biofilm formation. Global transcriptome analyses revealed that indole-3-acetaldehyde most repressed two curli operons, csgBAC and csgDEFG, and induced tryptophanase (tnaAB) in E. coli O157:H7 biofilm cells. Electron microscopy showed that indole-3-acetaldehyde reduced curli production in E. coli O157:H7. Together, this study shows that Actinomycetales are an important resource of biofilm inhibitors as well as antibiotics.
