Abstract:
Objective To identify an unknown strain, whose clone was similar to Clostridium difficile (C. difficile) by sequencing and phylogenetic analysis of 16S rDNA and test its antimicrobial susceptibility. Methods C. difficile selective medium was used to isolate the strains from fecal samples of healthy pet dogs. To identify unknown strains, a C. difficile latex agglutination rapid test kit was used and the detection of triosephosphate isomerase (tpi) gene by PCR was performed. S equencing of 16S rDNA was used to identify the unknown strain sample and phylogenetic tree was constructed to analyze its evolution. Agarose dilution method was used to evaluate the sensitivity pattern of Clostridium sordelli (C. sordelli). Results The unknown strain was isolated by using C. difficile selective medium. Neither tpi gene nor C. difficile antigen was found, which showed that the unknown strain was not C. difficile. Sequencing and analysis of its 16S rDNA showed that it was C. sordelli. Phylogenetic tree showed that the strain had a relative close evolutionary relationship with C. difficile and it was sensitive to ampicillin, clindamycin and moxifloxacin. Conclusions The unknown strain isolated from a healthy pet dog was C. sordelli. Although phylogenetic tree showed that the strain had a relative close evolutionary relationship with C. difficile, its sensitivity pattern was differed from C. difficile