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: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:To characterize the differentially expressed genes between pathogenic avian E. coli and human E. coli ATCC 25922, Abstract Escherichia coli (E. coli) is a harmless common bacterium of poultry intestine, but with a wide range of genomic flexibility, is also causative agent of many poultry diseases collectively called colibacillosis that is blamed for high economic loss in poultry sector worldwide. Numerous studies have been conducted to check the prevalence of pathogenic E. coli in poultry and poultry products, however limited data are available regarding their resistance and virulence associated genes expression profile. This study examined the pathogenomic content of poultry E. coli by antibiotic susceptibility, biofilm formation and adhesion, invasion and intracellular survivability assays in Caco-2 and Raw 264.7 cell lines along with the determination of median lethal dose in two-day old chickens. A clinical pathogenic multidrug resistant (MDR) isolate, E. coli 381, isolated from broilers was found to be highly virulent in cell culture and in chicken model. Transcriptome analysis has been skewed towards bacterial pathogens because of the prioritization of poultry diseases. Comparative gene expression profile of MDR E. coli 381 and the reference human strain E. coli ATCC 25922 was done using Illumina HiSeq2500 transcriptome and results were verified by RT-qPCR analyses. A number of resistant encoding genes including multidrug transporters, multidrug resistance proteins, porins and autotransporters were identified. We also noticed overexpression of very important virulent genes (fimA, fimC, fimH and fimI) encoding the type-1 fimbrial proteins, curli fimbriae genes , invasin genes, toxin-encoding genes and biofilm forming regulatory genes . In addition, many types of stress and metal homeostasis controlling genes were among up-regulated genes in E. coli 381 as compared to reference strain. GO and KEGG pathway analysis results revealed that genes controlling secondary metabolism, drug transport, adhesion and invasion proteins, and mobile genetic elements were over-expressed in E. coli 381. Several genes involved in cellular and metabolic processes such as carbohydrate metabolism were responsible for stress tolerance. Seminal description of the transcriptomic results and other unique features of E. coli 381 confirmed that it is highly virulent and MDR strain of poultry origin. This comparative study provides new avenues for further work on molecular mechanisms to prevent resistance development in bacteria and to ensure public health.
Project description:The antibiotic fosfomycin is widely recognized for treatment of lower urinary tract infections caused by Escherichia coli and lately gained importance as a therapeutic option to combat multidrug resistant bacteria. Still, resistance to fosfomycin frequently develops through mutations reducing its uptake. Whereas the inner membrane transport of fosfomycin has been extensively studied in E. coli, its outer membrane (OM) transport remains insufficiently understood. While evaluating minimal inhibitory concentrations in OM porin-deficient mutants, we observed that the E. coli ΔompCΔompF strain is five times more resistant to fosfomycin than the wild type and the respective single mutants. Continuous monitoring of cell lysis of porin-deficient strains in response to fosfomycin additionally indicated the relevance of LamB. Furthermore, the physiological relevance of OmpF, OmpC and LamB for fosfomycin uptake was confirmed by electrophysiological and transcriptional analysis. This study expands the knowledge of how fosfomycin crosses the OM of E. coli.
Project description:Gene expression profiles of Escherichia coli, grown anaerobically, with or without Acacia mearnsii (Black wattle) extract were compared to identify tannin-resistance strategies. The cell envelope stress protein, spy, and the multidrug transporter-encoding mdtABCD, both under the control of the BaeSR two-component regulatory system, were significantly up-regulated in the presence of tannins. BaeSR mutants were more tannin-sensitive than their wild-type counterparts. Keywords: tannin resistance
Project description:The intention of this study is to analyse the effect of antibiotics on the gene expression of Escherichia coli. Shaking-flask cultivations of Escherichia coli K12GFP-UTL2 were carried out with a medium containing nalidixic acid. Cultures with antibiotic-free medium, which were run in an identical way, served as reference. Samples were taken at different times during the cultivations, the RNA was isolated and hybridised on whole genome yeast microarrays. Keywords: Influence of toxins on gene expression in E. coli