Identification of Clostridium Botulinum with API 20 A, Rapid ID 32 A and RapID ANA II

Three commercially available test systems for the identification of anaerobic bacteria were evaluated for the identification of 18 proteolytic group I and 69 non-proteolytic group II Clostridium botulinum, four Clostridium sporogenes and 18 non-toxigenic group II C. botulinum-like strains. All proteolytic C. botulinum strains were misidentified by the Rapid ID 32 A and RapID ANA II, while 14 strains and all C. sporogenes strains were identified as C. botulinum or C. sporogenes by the API 20 A. Reversely, all non-proteolytic C. botulinum strains were misidentified by the API 20 A while the Rapid ID 32 A recognized 67 and RapID ANA II 68 strains. All C. sporogenes strains were recognized by the RapID ANA II, while the Rapid ID 32 A recognized one strain. All non-proteolytic non-toxigenic strains were identified as C. botulinum group II by the Rapid ID 32 A, 17 strains by the RapID ANA II, and one strain by the API 20 A. The results show that these test systems do not provide a reliable method for identification of C. botulinum.