Nationwide Surveillance Study of Clostridium difficile in Australian Neonatal Pigs Shows High Prevalence and Heterogeneity of PCR Ribotypes

Abstract

ABSTRACTClostridium difficileis an important enteric pathogen of humans and the cause of diarrhea and enteritis in neonatal pigs. Outside Australia, prevalence in piglets can be up to 73%, with a single PCR ribotype (RT), 078, predominating. We investigated the prevalence and genotype ofC. difficilein Australian pig herds. Rectal swabs (n= 229) were collected from piglets aged <7 days from 21 farms across Australia. Selective culture forC. difficilewas performed and isolates characterized by PCR for toxin genes and PCR ribotyping.C. difficilewas isolated from 52% of samples by direct culture on chromogenic agar and 67% by enrichment culture (P= 0.001). No association betweenC. difficilerecovery or genotype and diarrheic status of either farm or piglets was found. The majority (87%; 130/154) of isolates were toxigenic. Typing revealed 23 different RTs, several of which are known to cause disease in humans, including RT014, which was isolated most commonly (23%; 36/154). RT078 was not detected. This study shows that colonization of Australian neonatal piglets withC. difficileis widespread in the herds sampled.