Background: Clostridium difficile (Clostridioides difficile) is known as one of the main causes of pseudomembranous colitis and is considered an important enteropathogen in humans. Antibiotic use has been introduced as one of the most significant risk factors contributing to the prevalence and incidence of “Clostridium difficile nosocomial infection”. The aim of this study is to investigate the prevalence, antibiotic resistance, and genetic diversity of Clostridium difficile in semi-cooked ready-to-eat products in stores of Isfahan Province in Iran.
Methods: A total of 240 samples of semi-cooked ready-to-eat products, including potato kuku, herb kuku, cordon bleu, and chicken nuggets (each 60 samples), were randomly collected from stores of Isfahan Province between July 2020 and February 2021. Clostridium difficile was identified by culturing the samples in Clostridium difficile moxalactam norfloxacin. To determine the characteristics of the toxins, tcdA and tcdB genes were detected through multiplex polymerase chain reaction (M-PCR). The antibiotic sensitivity of the isolates was determined based on the minimum inhibitory concentration (MIC) test. The results were analyzed using chi-square test in SPSS software and P-value was considered significant at 0.05.
Findings: 37 samples were infected with Clostridium difficile. The contamination rate was 13.3%, 20.0%, 11.6%, and 16.6% in potato kuku, herb kuku, cordon bleu, and chicken nugget, respectively. The highest contamination was related to the semi-cooked herb kuku product. TcdA and tcdB gene toxins were identified in 15 and 17 isolates of Clostridium difficile, respectively. Among Clostridium difficile strains, the highest level of resistance was seen for ampicillin and penicillin antibiotics, and the highest sensitivity was related to chloramphenicol and metronidazole.
Conclusion: Semi-cooked ready-to-eat products can be considered as potential sources of antibiotic-resistant Clostridium difficile. Thus, complete cooking process of semi-cooked ready-to-eat foods at appropriate temperature and time (85° C and 30 minutes) and following hygiene principles in food processing plants can prevent the probable gastrointestinal infections caused by strains of Clostridium difficile in consumers.
