title: The BarA-UvrY two-component system regulates virulence in avian pathogenic Escherichia coli O78:K80:H9.
abstract: The BarA-UvrY two-component system (TCS) in Escherichia coli is known to regulate a number of phenotypic traits. Both in vitro and in vivo assays, including the chicken embryo lethality assay, showed that this TCS regulates virulence in avian pathogenic E. coli (APEC) serotype O78:K80:H9. A number of virulence determinants, such as the abilities to adhere, invade, persist within tissues, survive within macrophages, and resist bactericidal effects of serum complement, were compromised in mutants lacking either the barA or uvrY gene. The reduced virulence was attributed to down regulation of type 1 and Pap fimbriae, reduced exopolysaccharide production, and increased susceptibility to oxidative stress. Our results indicate that BarA-UvrY regulates virulence properties in APEC and that the chicken embryo lethality assay can be used as a surrogate model to determine virulence determinants and their regulation in APEC strains.
authors.affiliation: Virginia-Maryland Regional College of Veterinary Medicine, University of Maryland at College Park, 8075 Greenmead Drive, College Park, Maryland 20742-3711, USA.
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Herren
authors.forename: Arindam
authors.initials: A
authors.lastname: Mitra
authors.forename: Senthil Kumar
authors.initials: SK
authors.lastname: Palaniyandi
authors.forename: Adam
authors.initials: A
authors.lastname: Coleman
authors.forename: Subbiah
authors.initials: S
authors.lastname: Elankumaran
authors.forename: Suman
authors.initials: S
authors.lastname: Mukhopadhyay
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D002642:Chick Embryo / Q000382:microbiology*; D004926:Escherichia coli / Q000145:classification / Q000235:genetics / Q000378:metabolism / Q000472:pathogenicity*; D004927:Escherichia coli Infections / Q000382:microbiology / Q000401:mortality / Q000662:veterinary; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D005347:Fibroblasts / Q000382:microbiology; D015964:Gene Expression Regulation, Bacterial; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D010770:Phosphotransferases / Q000235:genetics / Q000378:metabolism*; D011201:Poultry Diseases / Q000382:microbiology* / Q000401:mortality; D015398:Signal Transduction; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014774:Virulence
chemical_list: D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D014157:Transcription Factors; C419603:UvrY protein, E coli; C074276:barA protein, E coli; D010770:Phosphotransferases