title: Alteration of the Microbiota and Virulence Gene Expression in E. coli O157:H7 in Pig Ligated Intestine with and without AE Lesions.
abstract: BACKGROUND
  Previously we found that E. coli O157:H7 inoculated into ligated pig intestine formed attaching and effacing (AE) lesions in some pigs but not in others. The present study evaluated changes in the microbial community and in virulence gene expression in E. coli O157:H7 in ligated pig intestine in which the bacteria formed AE lesions or failed to form AE lesions.
  
  
  RESULTS
  The intestinal microbiota was assessed by RNA-based denaturing gradient gel electrophoresis (DGGE) analysis. The DGGE banding patterns showed distinct differences involving two bands which had increased intensity specifically in AE-negative pigs (AE- bands) and several bands which were more abundant in AE-positive pigs. Sequence analysis revealed that the two AE- bands belonged to Veillonella caviae, a species with probiotic properties, and Bacteroides sp. Concurrent with the differences in microbiota, gene expression analysis by quantitative PCR showed that, compared with AE negative pigs, E. coli O157:H7 in AE positive pigs had upregulated genes for putative adhesins, non-LEE encoded nleA and quorum sensing qseF, acid resistance gene ureD, and genes from the locus of enterocyte effacement (LEE).
  
  
  CONCLUSIONS
  The present study demonstrated that AE-positive pigs had reduced activities or populations of Veillonella caviae and Bacterioides sp. compared with AE-negative pigs. Further studies are required to understand how the microbiota was changed and the role of these organisms in the control of E. coli O157:H7.
authors.affiliation: College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi Province, P. R. China.
authors.forename: Bianfang
authors.initials: B
authors.lastname: Liu
authors.affiliation: Guelph Food Research Centre, Agriculture and Agri-Food Canada, Guelph, Ontario, Canada.
authors.forename: Xianhua
authors.initials: X
authors.lastname: Yin
authors.affiliation: Guelph Food Research Centre, Agriculture and Agri-Food Canada, Guelph, Ontario, Canada.
authors.forename: Hai
authors.initials: H
authors.lastname: Yu
authors.affiliation: College of Animal Science and Technology, Qingdao Agricultural University, Qingdao, P. R. China.
authors.forename: Yanni
authors.initials: Y
authors.lastname: Feng
authors.affiliation: China National Cereals, Oils and Foodstuff s Corporation, Beijing, P. R. China.
authors.forename: Xin
authors.initials: X
authors.lastname: Ying
authors.affiliation: Guelph Food Research Centre, Agriculture and Agri-Food Canada, Guelph, Ontario, Canada.
authors.forename: Joshua
authors.initials: J
authors.lastname: Gong
authors.affiliation: Department of Pathobiology, Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada.
authors.forename: Carlton L
authors.initials: CL
authors.lastname: Gyles
mesh_terms: D018830:Adhesins, Escherichia coli / Q000235:genetics / Q000378:metabolism; D000818:Animals; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004927:Escherichia coli Infections / Q000382:microbiology*; D019453:Escherichia coli O157 / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism; D005260:Female; D015870:Gene Expression; D015964:Gene Expression Regulation, Bacterial; D007082:Ileum / Q000382:microbiology* / Q000473:pathology; D008026:Ligation; D064307:Microbiota; D034421:Sus scrofa; D015854:Up-Regulation; D014774:Virulence
chemical_list: D018830:Adhesins, Escherichia coli; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C540352:QseF protein, E coli