Presence of Clostridium difficile in pig faecal samples and wild animal species associated with pig farms

Abstract

Aims: To determine the presence of Clostridium difficile on fattening pig farms in north-eastern Spain.

Methods and results: Twenty-seven farms were sampled. Pools of pig faecal samples (n = 210), samples of intestinal content from common farm pest species (n = 95) and environment-related samples (n = 93) were collected. Isolates were tested for toxin genes of C. difficile, and typed by PCR-ribotyping and toxinotyping. The minimal inhibitory concentrations of six antimicrobial agents were determined using Etest. Thirty-four isolates were obtained from 12 farms, and 30 (88·2%) had toxin genes. Seven ribotypes were identified. Ribotype 078 and its variant 126 were predominant (52·9%). The same ribotypes were isolated from different animal species on the same farm. None of the isolates were resistant to metronidazole or vancomycin.

Conclusions: Clostridium difficile was common within the pig farm environment. Most of the positive samples came from pest species or were pest-related environmental samples.

Significance and impact of the study: Pest species were colonized with toxigenic and antimicrobial-resistant C. difficile strains of the same ribotypes that are found in humans and pigs. Rodents and pigeons may transmit toxigenic and antimicrobial-resistant C. difficile strains that are of the same ribotypes as those occuring in humans.

Keywords: Clostridium difficile; PCR-ribotyping; environment; pig; rodents; toxins; wildlife.