Application analysis of MALDI-TOF MS in rapid identification of anaerobic bacteria

BACKGROUND: Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has been rapidly developed and widely used as an analytical technique in the clinical laboratories with high accuracy in the identification of microorganisms. METHOD: This study was designed to evaluate MALDI-TOF MS for identification of clinical pathogenic anaerobes. RESULT: Twenty-eight studies covering 6685 strains of anaerobic bacteria were included in this meta-analysis. Fixed-effects models based on the P-value and the I-squared were used for meta-analysis to consider the possibility of heterogeneity between studies. Statistical analyses were performed by using STATA 12.0. Results shown that the identification accuracy of MALDI-TOF MS at species was 84% (I2 = 98.0%, P < 0.1), genus was 92% (I2 = 96.6%, P < 0.1). Thereinto, the identification accuracy of Bacteroides was the highest at 96% with a 95% CI of 95% to 97%. Next were Lactobacillus spp., Parabacteroides spp., Clostridium spp., Propionibacterium spp., Prevotella spp., Veillonella spp. and Peptostreptococcus spp., and their correct identification rates were all above 90%, while the accuracy of rare anaerobic bacteria was lower. Meanwhile, the overall capabilitys of two MALDI-TOF MS systems were different. The identification accuracy rate of VITEK MS was 90%, compared to 86% by the MALDI biotyper system. CONCLUSON: In summary, our research showed that MALDI-TOF-MS was satisfactory in the identification of genus in clinical pathogenic anaerobic bacteria. However, this method still suffered from different drawbacks in the identification of the rare anaerobes and species levels of common anaerobic bacteria.