Isolation of toxigenic Clostridium difficile from ready-to-eat salads by multiplex polymerase chain reaction in Isfahan, Iran


1 Deparment of Food Science and Technology, Food Security Research Center, School of Nutrition and Food Sciences, Isfahan University of Medical Sciences, Isfahan, Iran

2 Deparment of Microbiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran

3 Department of Research and Development, Deputy of Food and Drug, Isfahan University of Medical Sciences, Isfahan, Iran


Background: Since 2003, the incidence of community associated Clostridium difficile infection (CA-CDI) has increased; different types of food have been supposed to be the vectors of C. difficile strains. The purpose of this study is to investigate the occurrence of C. difficile strains in ready-to-eat salads distributed in food services.
Materials and Methods: A total of 106 ready-made salad specimens were sampled from different restaurants and food services located in Isfahan, in the center of Iran. Positive isolates of Cdifficile were identified and confirmed for the existence of three genes including tpi, tcdA and tcdB by multiplex PCR.
Results: A total of six (5.66%) samples were positive for C. difficile strains. Of which, one strain (16.6%) was positive for A and B toxins.
Conclusion: The existence of toxigenic C. difficile in ready-made salads could be a caution for public health. Further investigation is required to assess the relationship between the isolated strains in our study and those from diarrheic patients through molecular typing.


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