Affiliation:
1. Laboratory of Bacteriology and Medical Mycology, Istituto Superiore di Sanità, Rome, Italy
Abstract
ABSTRACT
The pathogenicity locus (PaLoc) of
Clostridium difficile
contains toxin A and B genes and three accessory genes, including
tcdD
and
tcdC
, which are supposed to code for the positive and negative regulators of toxin expression, respectively. Different studies have described variations in
C. difficile
toxin A and B genes, but little is known about
C. difficile
variants for the accessory genes. The PaLoc of several
C. difficile
clinical isolates was investigated by three different PCR methods with the aim to identify variant strains. Of the toxinogenic
C. difficile
strains examined, 25% showed variations. No correlation between
C. difficile
variant strains and key patient groups was found. Interestingly, all of these strains showed a variant
tcdC
gene. Three different
tcdC
alleles were identified, and one of these had a nonsense mutation which reduced the TcdC protein from 232 to 61 amino acids. It is possible that different TcdC variants affect toxin production differently, a hypothesis with important implications for the pathogenic potential of variant
C. difficile
strains.
Publisher
American Society for Microbiology
Cited by
250 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献