Genomic and Phenotypic Characterization of subsp. Strains.

The pathogenesis mechanisms of subsp. (), the etiologic agent of Bovine Genital Campylobacteriosis remain elusive. This study evaluated the virulence potential and biovar characteristics of isolates ( = 13) by PCR screening of putative virulence-factor (VF) genes, Multilocus Sequence Typing (MLST) analysis, antimicrobial susceptibility to tetracycline, penicillin, enrofloxacin and streptomycin testing and whole-genome sequencing (WGS; = 5), also comparing the latter with 26 other whole-genome sequences of strains. The putative VF genes encoding type IV secretion system of (-/) were absent in 92% of isolates, including isolates from aborted foetuses, evidencing that these VF genes are not essential for pathogenicity. The gene, used as a diagnostic molecular target, was detected in only 3 of 13 isolates, invalidating its use for diagnosis purposes. Three novel sequence types were identified by MLST. Although no in vitro antimicrobial resistance was detected, WGS identified antimicrobial resistance-related genes, including those encoding the multidrug efflux pumps CmeABC and YkkCD, indicating that their presence is not enough to provide antimicrobial resistance. The SNP and accessory protein families analysis segregated the and biovar intermedius () strains into different clusters. In conclusion, this study evidenced virulence potential and biovar characteristics of and , which are of relevance for the control of Bovine Genital Campylobacteriosis.