Amount of enterotoxigenic Clostridium perfringens in meat detected by nested PCR.

The incidence and quantity of enterotoxigenic Clostridium perfringens in beef, pork, and chicken meat were determined and compared with that of the total enterotoxigenic and nonenterotoxigenic C. perfringens. The method for the detection and quantification of enterotoxigenic C. perfringens consisted of a combination of the most probable number (MPN) method and a nested polymerase chain reaction after culturing of the sample. The results obtained by this method for inoculated meat samples were significantly correlated with those obtained by the plate count method. When the method was applied to the detection and quantification of enterotoxigenic C. perfringens found in randomly selected meat samples, the organism was found in 2% of the beef pieces (< 10(2) MPN/100 g) and 12% of the chicken pieces (< 10(2)-4.3 x 10(2) MPN/100 g) out of the 50 pieces of each meat tested. No enterotoxigenic C. perfringens was found in pork. Total C. perfringens was found in 16% of the beef (< 10(2)-4.3 x 10(2) MPN/100 g), 10% of the pork (< 10(2) MPN/100 g), and 84% of the chicken (< 10(2)-9.3 x 10(3) MPN/100 g) when 50 pieces of each meat was tested by the conventional MPN method. As shown in the above methods, the majority of cells were not enterotoxigenic cells in the population of C. perfringens. A small number of enterotoxigenic cells of C. perfringens co-existed with a large number of nonenterotoxigenic cells in the same meat sample.