High genetic similarity between Clostridioides difficile isolates from a woman with community-acquired infection and her dog

Clostridioides difficile infection is a leading cause of diarrhea associated with healthcare settings, but its incidence in the community has increased substantially in recent years, raising questions about possible non-hospital reservoirs. We report a case of community-acquired C. difficile infection in a woman and the concurrent isolation of a toxigenic strain from her dog, which also presented diarrhea. Both isolates showed the same ribotype and differed by only four single-nucleotide polymorphisms in whole-genome sequencing analysis, indicating a high degree of genetic similarity. These findings suggest the possibility of shared exposure or transmission between the patient and her dog and highlight the need to further investigate companion animals as potential sources of community-acquired C. difficile.