Presence of Clostridioides difficile in fresh mushrooms at retail stores.

Clostridioides difficile (C. difficile) is an opportunistic spore-forming intestinal pathogen, mainly associated with nosocomial infections. The ecological niche of the bacterium are soils, and therefore C. difficile spores are often found in animals and foods, suggesting a potential for foodborne transmission. The use of contaminated composted products with C. difficile spores during farming practices along with the ability of the spores to survive the composting process are probably the main factors implicated in frequent contamination of fresh vegetables and crops. Microbiological studies in cultivated mushrooms are scarce and none of them have been focused on the presence of toxigenic C. difficile. The aim of this study was to investigate for the first time the prevalence of C. difficile in fresh mushrooms in Spain, and to characterize phenotypically and genotypically the C. difficile isolates in terms of toxin production, PCR-ribotyping and antimicrobial resistant rates. Mushrooms are an important ingredient in the Mediterranean diet, which are often eaten fresh without cooking in salads and side dishes. The findings of this study reveal a low contamination of fresh mushrooms sold in retail markets in Spain. However, the isolates obtained were toxigenic and exhibited resistances to antibiotics, underlaying the need of a general recommendation ”to wash properly before consumption” in the product label.