Survey of Clostridium difficile in retail seafood in College Station, Texas

Abstract

The incidence and severity of disease associated with toxigenic Clostridium difficile have increased in hospitals in North America with the emergence of newer, more virulent strains. Toxigenic C. difficile has been isolated from food animals and retail meat with potential implications of transfer to humans. The objective of the present study was to investigate the prevalence of C. difficile in retail seafood from grocery stores in College Station, Texas. C. difficile was found in 4.5% (3/67) of shellfish and finfish samples. The positive samples included one each from fresh mussel, frozen salmon and frozen shrimp. The mussel and salmon isolates were characterized as toxinotype V and pulsed-field gel electrophoresis (PFGE) type-NAP7. The shrimp isolate was identified as toxinotype XII, but had an unknown PFGE type. Susceptibilities to 11 antimicrobial agents were identical for the mussel and salmon isolates and were sensitive to eight of 11 antimicrobials (including ampicillin) and intermediate to clindamycin. However, the shrimp isolate was resistant to clindamycin and ampicillin. This study demonstrates that seafood, like other food commodities, can be contaminated by C. difficile.

Keywords:

• Clostridium difficile
• finfish
• retail grocers
• shellfish
• toxinotype

Acknowledgements

Proprietary or brand names are necessary to report factually on available data; however, the US Department of Agriculture (USDA) neither guarantees nor warrants the standard of the product, and the use of the name by the USDA implies no approval of the product, or exclusion of others that may be suitable. The authors declared no potential conflicts of interest with respect to the research, authorship, publication and/or financial support for this article.