Comparison of rapid perfringens medium and lactose sulfite medium for detection of Clostridium perfringens.

Two tubed media, lactose sulfite (LS) and rapid perfringens medium (RPM), were evaluated and compared for their ability to detect and enumerate Clostridium perfringens in inoculated and naturally contaminated samples. In a 3-tube most probable number system, the number of organisms recovered from spiked samples was several-fold higher with RPM than with LS and was close to the numbers inoculated. Levels detected in 15 naturally contaminated samples were also higher with RPM. Only 13 of the samples were positive for C. perfringens with LS medium. These results indicate that RPM is a more effective medium than LS; therefore, its use is recommended.