A convenient method to detect potentially lethal heat-induced damage to DNA in Clostridium perfringens

A rapid method for determining the lethal effectiveness of heat on a food-borne spore-former based on the conversion of high molecular weight chromosomal DNA to lower molecular weight species was developed. DNA was isolated and purified from spores and vegetative cells of the food-borne pathogen, Clostridium perfringens, following exposure to 4, 50, 75, and 100 °C for 15 min. The DNA quality was subsequently analyzed electrophoretically on agarose gels. Spore DNA was most resistant to thermal damage up to 100 °C with minor hydrolysis. Vegetative cell DNA exhibited degradation at 75 °C. A relationship was established between pathogen thermal viability and the electrophoretic stability of DNA. This study describes a convenient method for evaluating heating efficiency based upon electrophoretic DNA stability. These findings may facilitate future testing of pathogen lethality to heat under different menstrum parameters ensuring food safety.