Isolation of Clostridioides difficile from a Large Animal Veterinary Teaching Hospital Environment

In veterinary hospitals, the risk of C. difficile nosocomial acquired infections remains largely unknown, and only a few studies surveyed the environmental prevalence of C. difficile in these facilities. The aim of this study was to determine the prevalence of C. difficile in the Ontario Veterinary College large animal hospital environment and to characterize the recovered isolates.

The environment of the large animal clinic of a university veterinary hospital was tested for the presence of C. difficile. Samples were collected from 157 surface sites and cultured using selective enriched broth and selective agar media. Multiplex PCR method for the detection of C. difficile toxin A (tcdA), toxin B (tcdB) binary toxin (cdtA⁄cdtB) genes; high-resolution capillary gel-based electrophoresis PCR-Ribotyping; multilocus sequence typing (MLST) and antimicrobial resistance predictions from sequenced genome were performed.

Thirteen isolates were recovered from 157 (8.3%) of multiple sampled sites of the main hospital. Ten distinct ribotypes, of which 7 were positive for toxin genes A and B, and all were negative for binary toxin genes. The two most common PCR ribotypes were 014 and 010. Isolates belong to the MLST Clade 1 and were further divided into 5 different sequence types. A high prevalence of AMR genes was observed in some isolates.

C. difficile is present in different areas of the large animal hospital environment, particularly areas of high traffic and surfaces difficult to clean. Active surveillance and biosecurity measures should be in place to maintain a low environmental contamination and prevent nosocomial infections.