Master of Science (MS)


School of Nutrition and Food Sciences

Document Type



Clostridium difficile (C. difficile) is regarded as the major cause of infectious diarrhea in humans after antimicrobial treatment. C. difficile has been reported to be widely isolated from food animals and meat. The main purpose of this study was to characterize C. difficile isolates from retail fresh vegetable (lettuce), test the antibiotic-resistance property using five common clinical-selected antibiotics (metronidazole, vancomycin, clindamycin, erythromycin, and cefotaxime). Lettuces (grown in California, Arkansas, and Louisiana) were purchased from retail stores. Toxigenic C. difficile was isolated from 13.8% (41/297) of the lettuce samples. Among the toxigenic isolates, 82.9% (34/41) only produce toxin B, and 17.1% (7/41) produced both toxin A and toxin B. Under the treatment of the five antibiotics, the virulence C. difficile isolates were identified as having antibiotic resistance to metronidazole, vancomycin, and erythromycin. The present study reports the highest toxigenic C. difficile yield rate from varieties of retail vegetables (lettuce) in the USA. The antibiotic resistance to metronidazole, vancomycin, and erythromycin of the isolated C. difficle from varieties of retail lettuces could lead to public health concerns.



Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Janes, E Marlene

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Life Sciences Commons