MALDI ‐ TOF MS for identification of porcine B rachyspira species

The aim of this study consisted in evaluating MALDI ‐ TOF MS as a tool for the identification of the genus B rachyspira ( B .) and its relevant species for the pig industry. First, a database was created with 30 control strains, and superspectra for five different porcine B rachyspira 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 B rachyspira species were detected using nox gene‐based RFLP analysis. MALDI ‐ TOF MS analysis correctly assigned all isolates to the genus B rachyspira 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 B rachyspira hyodysenteriae and B rachyspira pilosicoli from B rachyspira 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 B rachyspira species in routine diagnostic laboratories. The results suggest that MALDI ‐ TOF MS is an effective method for the identification of porcine B rachyspira spp. and accelerates diagnosis of swine dysentery and porcine intestinal spirochaetosis.