A role for the RNA chaperone Hfq in controlling adherent-invasive XXXX colonization and virulence.

@entity1 @entity2199 @entity29 @entity281 @entity30 @entity526
Adherent-invasive @entity526 (AIEC) has been linked with the onset and perpetuation of @entity29 . The AIEC strain LF82 was originally isolated from an ileal biopsy from a @entity1 with @entity30 . The pathogenesis of LF82 results from its abnormal adherence to and subsequent invasion of the intestinal epithelium coupled with its ability to survive phagocytosis by macrophages once it has crossed the intestinal barrier. To gain further insight into AIEC pathogenesis we employed the @entity2199 @entity2199 as an in vivo @entity281 model. We demonstrate that AIEC strain LF82 forms a persistent @entity281 in @entity2199 , thereby reducing the host lifespan significantly. This host killing phenotype was associated with massive bacterial colonization of the @entity2199 intestine and damage to the intestinal epithelial surface. @entity2199 killing was independent of known LF82 virulence determinants but was abolished by deletion of the LF82 hfq gene, which encodes an RNA chaperone involved in mediating posttranscriptional gene regulation by small non-coding RNAs. This finding reveals that important aspects of LF82 pathogenesis are controlled at the posttranscriptional level by riboregulation. The role of Hfq in LF82 virulence was independent of its function in regulating RpoS and RpoE activity. Further, LF82/\hfq mutants were non-motile, impaired in cell invasion and highly sensitive to various chemical stress conditions, reinforcing the multifaceted function of Hfq in mediating bacterial adaptation. This study highlights the usefulness of simple non- @entity1 @entity281 systems for the identification and analysis of bacterial virulence factors.
