The possible influence of LuxS in the in vivo virulence of rabbit enteropathogenic Escherichia coli

Chengru Zhu, Shuzhang Feng, Venessa Sperandio, Zhuolu Yang, Timothy E. Thate, James B. Kaper, Edgar C. Boedeker

Research output: Contribution to journalArticlepeer-review

13 Scopus citations

Abstract

Attaching and effacing (A/E) organisms, such as rabbit enteropathogenic Escherichia coli (EPEC), human EPEC or enterohemorrhagic E. coli (EHEC) share attaching and effacing phenotype and LEE pathogenicity island responsible for A/E. The present study was undertaken to investigate the impact of the LuxS quorum sensing (QS) signaling system in vitro and in vivo pathogenicity of A/E organisms using rabbit EPEC (rEPEC) strain E22 (O103:H2). Analysis of the bioluminescence indicated abolished production of the QS signal AI-2 by luxS mutant (E22ΔluxS). Strain E22Δlux also exhibited impaired expression of several normally secreted proteins and reduced adherence to cultured HeLa cells. Complementation of the intact luxS gene to E22ΔluxS restored secreted protein expression comparable to the WT type but not adherence to HeLa cells. In experimentally infected rabbits, the isogenic luxS mutant induced clinical illness and intimate adherence to the intestinal mucosa, albeit to a less extent, comparable to that seen with the parent virulent strain. It is worth noting that reduced fecal bacterial shedding, mucosal adherence and improved cumulative weight gain were seen for the mutant strain complemented with luxS when compared to the WT. It appears that the luxS gene is not essential for in vivo pathogenicity by rEPEC where exogenous QS signals are present in the gut. The impact of AI-2 provided by multicopy plasmid on bacterial virulence is discussed.

Original languageEnglish (US)
Pages (from-to)313-322
Number of pages10
JournalVeterinary Microbiology
Volume125
Issue number3-4
DOIs
StatePublished - Dec 15 2007

Keywords

  • Autoinducer
  • LEE
  • Quorum sensing
  • Regulation

ASJC Scopus subject areas

  • Microbiology
  • veterinary(all)

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