The aim of this study consisted in evaluating MALDI-TOF MS as a tool for the identification of the genus Brachyspira (B.) and its relevant species for the pig industry. First, a database was created with 30 control strains, and superspectra for five different porcine Brachyspira species were calculated. In a second step, 67 field isolates were investigated using MALDI-TOF MS, and results were compared to those obtained using nox gene-based RFLP (reference method) and biochemical tests. Among the 67 field isolates, five different Brachyspira species were detected using nox gene-based RFLP analysis. MALDI-TOF MS analysis correctly assigned all isolates to the genus Brachyspira and identified all isolates from B. hyodysenteriae (29/29), B. pilosicoli (11/11), B. intermedia (4/4) and B. innocens (11/11). In terms of B. murdochii, MALDI-TOF MS assigned one of 12 isolates ambiguously as B. innocens/B. murdochii. The results of this study indicate that MALDI-TOF MS facilitates the diagnosis of swine dysentery and porcine intestinal spirochaetosis.
Significance and impact of the study: Current methods for the discrimination of pathogenic Brachyspira hyodysenteriae and Brachyspira pilosicoli from Brachyspira species with low pathogenic potential have proven to be laborious and time-consuming and are therefore not suitable for routine diagnostics. This study describes the evaluation of MALDI-TOF MS for the identification of different porcine Brachyspira species in routine diagnostic laboratories. The results suggest that MALDI-TOF MS is an effective method for the identification of porcine Brachyspira spp. and accelerates diagnosis of swine dysentery and porcine intestinal spirochaetosis.
Keywords: Brachyspira; MALDI-TOF MS; pigs; porcine intestinal spirochaetosis; swine dysentery.
© 2013 The Society for Applied Microbiology.