Selecting out of virulent strains of C. perfringens by the preparation process of meat curries possess a public health threat: evidence from a retrospective study

Heat resistant spore formation is favourable for selecting out of C. perfringens virulent strains by the preparation process of meat curries. When heat resistance coupled with enterotoxin production it possesses a public health threat. Hence, this study was conducted using a representative sub sample of stored 15 meat curry isolates of C.perfringens from a large sample based on a previous descriptive cross sectional study to compare heat-resistant spore (HRS) formation, C. perfringens enterotoxin (CPE) production, and combined HRS - CPE abilities of meat curry isolates of this bacterium obtained from eating houses within Colombo city. Representative subsample (12 chicken and 03 beef) of preserved C. perfringens cultures after complete confirming retrieved from the cold room. Stored culture was vortex mixed prior to inoculation. Subsequently, 20ml of freshly steamed thioglycollate medium was inoculated with 2ml of stored culture (preserved in cooked meat medium and they were incubated anaerobically at 37 0 C for 24hrs. Sporulation endeavoured using 3 media: Duncan and Strong, Modified Duncan and Strong, and Sporulation Broth as described previously. Heat resistance was tested at 100 0 C for 1 h in distilled water and the production of enterotoxin was evaluated with a PET-RPLA kit as detailed previously. The differences in selected virulent factors by the variety of meat curry were statistically significant ( p<0.05). Selecting out of virulent strains due to the process of curry preparation was evident from this retrospective study. This evidence needs to confirm with a large sample size refining methodologies.