Global_population_genomics_of_Campylobacter_fetus

The species Campylobacter fetus has gained renown due to its incidence in the reproductive health of cattle and sheep to a lesser extent, causing significant socioeconomic burden worldwide. This organism has been historically subdivided in C. fetus subsp. fetus (Cff), C. fetus subsp. venerealis (Cfv) and C. fetus subsp. venerealis biovar. intermedius (Cfvi), based on their biochemical behaviours (growth in 1% glycine medium and H2S production) and clinical presentations. Recently, a new subspecies named C. fetus subsp. testudinum (Cft) has been proposed based on the discovery of genetically divergent strains of reptilian origin. Strains biochemically characterized as Cfv are believed to be cattle-specific and restricted to colonize the genital epithelium, however strains characterized as Cff not only cause genital infections in cattle but also are natural inhabitants of reptiles gut and are the main Campylobacter species isolated from human bacteremia, posing an emerging zoonotic risk. The epidemiological features of Cfvi and Cft are mostly unknown to date.