Biogeographic distribution and molecular epidemiology of () in Western Australian soils.

is a leading cause of infectious diarrhea in humans and production animals and can be found in a variety of environmental sources. The prevalence and diversity of multi-locus sequence type clade 5 strains of in Australian production animals suggest Australia might be the ancestral home of this lineage of One Health importance. To better understand the role of the environment in the colonization of humans and animals in Australia, it is important to investigate these endemic sources. This study describes the prevalence, molecular epidemiology, and biogeographic distribution of in soils of Western Australia. A total of 321 soil samples from remote geographical locations across the eight health regions of Western Australia were screened for and isolates characterized by PCR ribotyping and toxin gene profiling. was isolated from 31.15% of samples, with the highest prevalence in the Perth Metropolitan Health Region (49.25%, = 33/67). Overall, 52 different strains [PCR ribotypes (RTs)] were identified, with 14 being novel, and 38% (38/100) of isolates being toxigenic, the most common of which was RT014/020. Five unique novel isolates showed characteristics similar to clade 5. This is the first study of isolated from soils in Australia. The high prevalence and heterogeneity of strains recovered suggest that soils play a role in the survival and environmental dissemination of this organism, and potentially its transmission among native wildlife and production animals, and in community and hospital settings.IMPORTANCE is a pathogen of One Health importance. To better understand the role of the environment in human and animal colonization/infection, it is critical that autochthonous reservoirs/sources of be investigated. This is the first study of isolated from soils of Western Australia (WA). Here, the ecology of in WA is described by examining the geographic distribution, molecular epidemiology, and diversity of isolated from soils across WA.