Purpose: The objective of this study was to investigate the prevalence of C. perfringens in South Korea and the biofilm formation ability by toxin type.
Methods: Raw beef (n=74), pork (n=82) and poultry (chicken, n=62; duck, n=8) were collected from food service facilities in three different regions of Gyeongsangnam-do in South Korea. Clostridium perfringens were isolated by cooked-meat medium incubated for 24 h at 37°C under anaerobic condition and transferred to tryptose sulphite cycloserine with D-cycloserine and egg yolk emulsion. Colonies with lecithinase positive and black color were selected as positive. PCR was performed for toxin typing with specific primers to toxin genes (cpe, cpa, cpb, cpb2, etx, iap). Crystal violet assay was performed to evaluate the biofilm formation abilities of the isolates and their correlations with toxin type and sampling region.
Results: Out of 226 samples, 60 samples were positive (24.3% in raw beef, 12.2% in pork, 41.9% in chicken and 75% in duck) and the average concentration in raw meat was 176 CFU/g. All isolates were positive in cpa to be toxin type A and enterotoxin gene cpe and beta2 gene cpb2-positive isolates were confirmed among the isolates. The contamination level and toxin type were closely related to geography of the samples. Also, biofilm formations of the isolates were relatively weak while few isolates showed strong biofilm forming abilities that were more resistant to disinfectants.
Significance: The results showed the most prevalent toxin type of C. perfriengens and their correlation between biofilm formation and toxin types to control in the food processing environment.