Abstract:

Objective　To retrospectively analyze the identification process of strain 1304 in external quality assessment, and to evaluate the application of Vitek 2 Compact automatic microorganism analyzer system（Vitek 2 Compact system） to identify clinical rare bacteria. Methods　Strain 1304 was identified comprehensively by traditional microscopic morphology, manual biochemical reaction and Vitek 2 Compact system, simultaneously. The final result was confirmed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry（MALDI-TOF MS）. Results　Strain 1304 was Gram-negativebacilli. The result of oxidase test was positive.The first result wasBordetella bronchiseptica（identification probability was 99%）. The second result was low discrimination（51%Alcaligenes faecalis and 49%Pseudomonas pseudoalcaligenes） by Vitek 2 Compact system. The result of supplementary test（NO₃） was negative. The final identification result wasAlcaligenes faecalis, and MALDI-TOF MS got the same result with a score value of 2.158.Conclusions　It exists some limitations in the identification of rare bacteria by Vitek 2 Compact system. Comprehend means should be used to decrease wrong identification rate.

Key words: Vitek 2 Compact automatic microorganism analyzer system, Identification, Rare bacterium