Development of Clostridium difficile R20291ΔPaLoc model strains and in vitro methodologies reveals CdtR is required for the production of CDT to cytotoxic levels

T.W Bilverstone,N.L Kinsmore,N.P Minton,S.A Kuehne

doi:10.1016/j.anaerobe.2017.01.009

T.W Bilverstone, N.L Kinsmore + Show 2 more

Open Access

https://doi.org/10.1016/j.anaerobe.2017.01.009

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Abstract

Assessing the regulation of Clostridium difficile transferase (CDT), is complicated by the presence of a Pathogenicity locus (PaLoc) which encodes Toxins A and B. Here we developed R20291ΔPaLoc model strains and cell-based assays to quantify CDT-mediated virulence. Their application demonstrated that the transcriptional regulator, CdtR, was required for CDT-mediated cytotoxicity.

Highlights

Assessing the regulation of Clostridium difficile transferase (CDT), is complicated by the presence of a Pathogenicity locus (PaLoc) which encodes Toxins A and B
The main virulence factors of C. difficile are Toxin A (TcdA) and Toxin B (TcdB) whose genes reside on a 19.6 Kb pathogenicity locus (PaLoc) [2]
Some hypervirulent strains responsible for outbreaks and severe cases of disease, in particular BI/NAP1/027 strains including the archetypal strain R20291, produce an additional toxin, the binary toxin or Clostridium difficile transferase (CDT) [3]

Summary

Introduction

Assessing the regulation of Clostridium difficile transferase (CDT), is complicated by the presence of a Pathogenicity locus (PaLoc) which encodes Toxins A and B. We developed R20291DPaLoc model strains and cell-based assays to quantify CDT-mediated virulence. A gene encoding the transcriptional regulator CdtR belonging to the LytTR family, was discovered upstream of cdtA and cdtB (for locus arrangement see Fig. S1b), and was shown to be required for the maximal expression of CDT [5].

Results

Conclusion