Evaluation of Minitec and API as rapid diagnostic methods for anaerobic bacteria

The performance of the miniaturized biochemical differentiation systems API 20 anaerobe System and Minitek was compared with pH reactions in PRAS media of 58 anaerobic or capno-aerophilic bacterial strains from recent clinical specimens. The overall correlation of the Minitek reactions was 87% and of the API reactions 85%. The reactions of acid formation from carbohydrates was slightly higher for Minitek. This resulted in a correct diagnosis in 90% after Minitek and 86% after API. If corrected for 3 strains of Clostridium perfringens for which double haemolysis would have prevented reporting of another diagnosis, 95% of the strains would have been correctly identified by Minitek compared to 91% with API. The errors were mostly due to lack of sensitivity of the reactions of the test kits.