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:Avian Pathogenic Escherichia coli (APEC) are a group of extra-intestinal E. coli that infect poultry, and are able to cause a variety of diseases, systemic or localized, collectively designated as colibacillosis. Colibacillosis is the most common bacterial illness in poultry production, resulting in significant economic losses world-wide. Despite of its importance, pathogenicity mechanisms of APEC strains remain not completelly elucidated and available vaccines are not fully effectives. In order to better understand which genes could be related to pathogenicity in different APEC isolated, a microarray analyses of two APEC strains representing: Swollen Head Syndrome and Omphalitis was carried out.
Project description:Avian Pathogenic Escherichia coli (APEC) are a group of extra-intestinal E. coli that infect poultry, and are able to cause a variety of diseases, systemic or localized, collectively designated as colibacillosis. Colibacillosis is the most common bacterial illness in poultry production, resulting in significant economic losses world-wide. Despite of its importance, pathogenicity mechanisms of APEC strains remain not completelly elucidated and available vaccines are not fully effectives. In order to better understand which genes could be related to pathogenicity in different APEC isolated, a microarray analyses of two APEC strains representing: Swollen Head Syndrome and Omphalitis was carried out. We used the microarray methodology to evaluate the expression profile of two different APEC strains
Project description:Avian pathogenic Escherichia coli strains frequently cause extra-intestinal infections and are responsible for significant economic losses in the poultry industry worldwide. APEC isolates are closely related to human extraintestinal pathogenic E.coli strains and may also act as pathogens for humans. In this work, three type VI secretion systems were deleted to analyze which pathogenicity characteristics would change in the mutants, compared to wild type strain (SEPT 362). Four Avian Pathogenic Escherichia coli strains (one wild type and three deleted mutants) were grown at 37°C in Dulbecco´s Modified Eagle´s Media (DMEM) media until reach O.D 600 = 0.8, for RNA extraction and hybridization on Affymatrix microarrays.
Project description:Campylobacter jejuni is a common cause of diarrheal disease worldwide. Human infection typically occurs through the ingestion of contaminated poultry products. We previously demonstrated that an attenuated Escherichia coli live vaccine strain expressing the C. jejuni N-glycan on its surface reduces the Campylobacter load in more than 50% of vaccinated leghorn and broiler birds to undetectable levels (responder birds), whereas the remainder of the animals were still colonized (non-responders). To understand the underlying mechanism, we conducted 3 larger scale vaccination and challenge studies using 135 broiler birds and found a similar responder/non responder effect. The submitted data were used for a genome-wide association study of the chicken responses to glycoconjugate vaccination against Campylobacter jejuni.
Project description:Avian pathogenic Escherichia coli strains frequently cause extra-intestinal infections and are responsible for significant economic losses in the poultry industry worldwide. APEC isolates are closely related to human extraintestinal pathogenic E.coli strains and may also act as pathogens for humans. In this work, three type VI secretion systems were deleted to analyze which pathogenicity characteristics would change in the mutants, compared to wild type strain (SEPT 362).
Project description:Pathogens that cause respiratory diseases in poultry are very complicated, and co-infections with multiple pathogens are prevalent. The H9N2 strain of avian influenza virus (AIV) and Escherichia coli (E. coli) are common poultry pathogens that limit the development of the poultry industry. This study aimed to clarify the interaction between these two pathogens and their pathogenic mechanism using a mouse model. Co-infection with H9N2 AIV and E. coli significantly increased the mortality rate of mice compared to single viral or bacterial infections. It also led to the development of more severe lung lesions compared to single viral or bacterial infections. Co-infection further causes a storm of cytokines, which aggravates the host’s disease by regulating the STAT/SOCS and ERK1/2 pathways. Moreover, co-infection mutually benefited the virus and the bacteria by increasing their multiplication rates. Importantly, nitric oxide synthase 2 (NOS2) expression was also significantly enhanced by the co-infection. It played a key role in the rapid proliferation of E. coli in the presence of the coinfecting H9N2 virus. Therefore, our study underscores the role of NOS2 as a determinant for bacteria growth and illustrates its importance as an additional mechanism that enhances influenza virus-bacteria synergy. It further provides a scientific basis for investigating the synergistic infection mechanism between viruses and bacteria.
Project description:Primary objectives: The study investigates whether a Escherichia coli Nissle-suspenison has a (preventive) antidiarrheal effect in patients with tumors who are treated with chemotherapeutic schemes which are associated with increased occurances of diarrhea. Diarrhea caused by treatment are thought to be reduced in intensity and/or frequency by the treatment with Escherichia coli Nissle-Suspension.
Primary endpoints: Common toxicity criteria (CTC) for diarrhea
Project description:Reed2003 - Genome-scale metabolic network of
Escherichia coli (iJR904)
This model is described in the article:
An expanded genome-scale
model of Escherichia coli K-12 (iJR904 GSM/GPR).
Reed JL, Vo TD, Schilling CH,
Palsson BO.
Genome Biol. 2003; 4(9): R54
Abstract:
BACKGROUND: Diverse datasets, including genomic,
transcriptomic, proteomic and metabolomic data, are becoming
readily available for specific organisms. There is currently a
need to integrate these datasets within an in silico modeling
framework. Constraint-based models of Escherichia coli K-12
MG1655 have been developed and used to study the bacterium's
metabolism and phenotypic behavior. The most comprehensive E.
coli model to date (E. coli iJE660a GSM) accounts for 660 genes
and includes 627 unique biochemical reactions. RESULTS: An
expanded genome-scale metabolic model of E. coli (iJR904
GSM/GPR) has been reconstructed which includes 904 genes and
931 unique biochemical reactions. The reactions in the expanded
model are both elementally and charge balanced. Network gap
analysis led to putative assignments for 55 open reading frames
(ORFs). Gene to protein to reaction associations (GPR) are now
directly included in the model. Comparisons between predictions
made by iJR904 and iJE660a models show that they are generally
similar but differ under certain circumstances. Analysis of
genome-scale proton balancing shows how the flux of protons
into and out of the medium is important for maximizing cellular
growth. CONCLUSIONS: E. coli iJR904 has improved capabilities
over iJE660a. iJR904 is a more complete and chemically accurate
description of E. coli metabolism than iJE660a. Perhaps most
importantly, iJR904 can be used for analyzing and integrating
the diverse datasets. iJR904 will help to outline the
genotype-phenotype relationship for E. coli K-12, as it can
account for genomic, transcriptomic, proteomic and fluxomic
data simultaneously.
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Project description:To understand the mechanism of isopropanol tolerance of Escherichia coli for improvement of isopropanol production, we performed genome re-sequencing and transcriptome analysis of isopropanol tolerant E. coli strains obtained from parallel adaptive laboratory evolution under IPA stress.