High prevalence of Clostridium difficile in soil, mulch and lawn samples from the grounds of Western Australian hospitals

Abstract

Despite being considered a major hospital-associated pathogen for many years, Clostridium difficile has been isolated increasingly from people without hospital contact. In this study, we investigated the prevalence of C. difficile in the immediate outdoor environment of several hospitals in Perth, Western Australia, to provide further insight into potential sources of community-acquired C. difficile infection. Over 6 months, a total of 159 samples consisting of soil, mulch, lawn and sand were collected from outdoor surroundings of four different old (age>50 years) and new (age<10 years) hospitals. Samples were cultured in a C. difficile selective enrichment broth. Toxin gene profiling using PCR, and PCR ribotyping, was performed on all C. difficile recovered. C. difficile was isolated from 96 of the 159 samples (60.4%). Of the 112 isolates, 33 (29.5%) were toxigenic and 49 (43.8%) were identified as novel strains. Ribotypes (RTs) 014/020 (14.3%) and 010 (13.4%) constituted the highest proportion of isolates. Interestingly, RT 017, a strain endemic to the Asia-Pacific region (but not Australia), was found in a newly laid lawn. This study adds to existing knowledge of potential sources of C. difficile in Western Australia. More research is required to determine the route of transmission of C. difficile from community sources into the hospital.