Exploring the MALDI Biotyper for the Identification of Corynebacterium pseudotuberculosis biovar Ovis and Equi

Abstract

Biochemical, serological, and molecular methods have been developed for the laboratory diagnosis of diseases caused by C. pseudotuberculosis (CP), but the identification of the pathogen and biovars differentiation may be time-consuming, expensive, and confusing compared with other bacteria. This study aimed to evaluate MALDI Biotyper and Overall Genome Relatedness Index (OGRI) analysis to optimize the identification and differentiation of biovars of C. pseudotuberculosis. Out of 230 strains isolated from several hosts and countries, 202 (87.8%) were precisely classified using MALDI Biotyper and the BioNumerics platform. The classification accuracies for the Ovis and Equi biovars were 80 (88.75%) and 82 (92.68%), respectively. When analyzing a sampling of these strains by Average Nucleotide Identity based on BLAST and TETRA analyses using genomic sequence data, it was possible to differentiate 100% of the strains in Equi and Ovis. Our data show that MALDI Biotyper and OGRI analysis help identify C. pseudotuberculosis at the species and biovar levels.

Bacteria, yeasts, and fungi associated with larval food of Brazilian native stingless bees

“…The bacteria were plated on BHI for taxonomic identification and incubated at 37ºC ± 1 for 24 h. An isolated colony of each strain was collected from the agar using an inoculation loop and inactivated with absolute ethanol. Bacterial preparation was performed following the manufacturer's protocol 88 . Spectra were acquired using a Flex Control Microflex LT mass spectrometer (Bruker Daltonics) with a 60 Hz nitrogen laser.…”

“…Spectra were acquired using a Flex Control Microflex LT mass spectrometer (Bruker Daltonics) with a 60 Hz nitrogen laser. The spectra of each sample were processed using MALDI Biotyper software version 3 (Bruker Daltonics) and assembled to generate a Master Spectral Library (MSP) for strains using the BioTyper MSP breeding standard 88 , 89 .…”

Proteomics of Toxigenic Corynebacteria

“…However, at least the already described specific spectral peaks may allow the standard identification of C. rouxii also by means of MALDI-TOF MS in combination with commercially available databases in the near future [ 31 , 32 ]. A mass spectrometric demarcation was also achieved for the newly described C. silvaticum [ 78 ] and as shown recently, in case of C. pseudotuberculosis , MALDI-TOF MS can contribute not only to the identification at species level but can additionally support biovar differentiation [ 79 , 80 ].…”