Comparison of API ZYM system with API AN-Ident, API 20A, Minitek Anaerobe II, and RapID-ANA systems for identification of Clostridium difficile.

The API ZYM system was compared with four anaerobe identification systems for the definitive identification of Clostridium difficile by using 88 cultures of C. difficile grown on Mueller-Hinton blood agar medium. The API ZYM system yielded a distinct and consistent enzyme profile for all test strains, whereas the sensitivities of the other systems in identifying C. difficile ranged from 78 to 96% (AN-Ident, 77.9%; RapID-ANA, 88.6%; Minitek Anaerobe II, 90.9%; and API 20A, 95.5%). The API ZYM system is highly reliable in identifying C. difficile accurately, is rapid, and is relatively simple to use.