ARS | Publication request: A Rapid Method to Measure Heat-Induced Damage to DNA in Clostridium Perfringens

Submitted to: Food Control
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 1, 2004
Publication Date: January 1, 2005
Citation: Novak, J.S., Sommers, C.H., Juneja, V.K. 2005. A rapid method to measure heat-induced damage to dna in clostridium perfringens. Food Control. 16:399-404.

Interpretive Summary: Clostridium perfringens is a causative agent of food borne illness resulting from inadequate heating or refrigeration control during food preparation prior to consumption. The spores from enterotoxin producing strains enable the pathogens to survive elevated temperatures as high as 100 C for more than one hour. We have identified targets of heat damage in nspores. Pathogen destruction occurs due to the heat-induced injury to the genetic material. This study examines the thermal stability of DNA isolated from spores and vegetative cells of C. perfringens in an attempt to visually correlate DNA heat damage and cell death. The methods used enable facile detection of elevated temperature damage to these vital molecules. The findings should increase the knowledge base for improving thermal processing conditions for different foods. This information will be of use in establishing guidelines for food preparers, consumers, and regulatory agencies in the food industry.

Technical Abstract: DNA was isolated and purified from spores and vegetative cells of the foodborne pathogen, Clostridium perfringens H6, before and after 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 50 C, but not as severe as for unprotected DNA in Tris-EDTA buffer. A relationship was established between pathogen thermal viability and the electrophoretic stability of DNA. These findings may facilitate future testing of pathogen susceptibility to heat under different menstrum parameters ensuring food safety.