Occurrence of Toxigenic Clostridium difficile in Louisiana Oysters (iCrassostrea virginica/i) and Environmental Waters

摘要

Clostridium difficile infection (CDI) was generally considered as a hospital-associated disease;however, recent community-acquired CDI has raised the concerns regarding the transmission of the pathogen through environmental sources. Limited data are available regarding the presence of C. difficile in food and water. In this study, oysters (Crassostrea virginica) and the harvest water collected from the commercial harvesting areas along the Louisiana Gulf Coast as well as the influent and effluent of a municipal treatment plant in New Orleans, LA were analyzed for toxigenic C. difficile. The bacterium was isolated from 47.37% (9/19) of oysters and 37.5% (3/8) of harvest water samples. Toxigenic C. difficile were also detected in all the wastewater influent and effluent samples. All the isolates harbored the gene tcdB encoding the virulence factor toxin B. Further PCR-ribotyping showed that the C. difficile isolated from the oysters and harvest water differed from the wastewater isolates. However, similar ribotypes were found in oysters and the surrounding harvest water. We found that oysters growing in contaminated water could bioaccumulate toxigenic C. difficile and pose a health risks by serving as a vehicle for the transmission of the pathogen to humans.