Controlled multiplex PCR of enterotoxigenic Clostridium perfringens strains in food samples

A controlled multiplex polymerase chain reaction (PCR) for the detection of Clostridium (C.) perfringens enterotoxin gene (cpe) was established and co mpared with an in vitro antigenic detection method. The cpe PCR and the cla ssical method of electric immunodiffusion gave identical results. The predi cted specific amplicon of the cpe gene was generated from all of the tested enterotoxigenic C. perfringens strains. In contrast, cultures of any other Clostridium species tested by PCR were negative (100% sensitivity, 100% sp ecificity). Addition of an alphatoxin (plc) gene specific PCR as an in proc ess control reaction was performed in order to prevent false negative PCR r esults. The PCR detection limit was 0.5 ng of genomic C. perfringens DNA pe r mi of bouillon culture. By contaminating minced meat with C. perfringens reference strains, the multiplex PCR was established as a tool for routine diagnostic laboratories. The detection limit was approximately 3.0 x 10(5) C. perfringens cells per gram meat. The results demonstrate the multiplex PCR as an easy, specific, sensitive a nd time saving diagnostic procedure. Application of this improved method sh ould enhance the knowledge concerning epidemiological aspects of food borne diseases caused by enterotoxigenic C. perfringens. (C) 1998 Academic Press .