Helcococcus ovis

Helcococcus ovis is a catalase-negative, facultatively anaerobic, opportunistic, gram-positive coccus belonging to the Peptostreptococcaceae family.

Hosts
H. ovis is frequently found in domestic sheep, cows and humans. H. ovis is found in the uterus of healthy cows. When disease manifests,
H. ovis is often associated with metritis, mastitis, hepatic abscesses, and septic arthritis in cows. In humans, it is associated with peritoneal effusion, vaginal infections, and endometrial neoplasms.

Cases in Chickens
In 2017, a 7-year-old rooster in California developed valvular vegetative endocarditis, myocarditis and hepatitis resulting from infection with H. ovis. Prior to this case, Helcococcus was never reported in avian species before.

Diagnosis
H. ovis is likely underdiagnosed since it evades clinical detection due to the unique conditions needed for its isolation in culture media. H. ovis was first isolated from samples of lung, liver, and spleen of domestic sheep after they died from milk associated with subclinical mastitis. It is frequently paired with Trueperella pyogenes or Staphylococcus spp due to its reliance on pyridoxal.

Most H. ovis strains have been found to be tetracycline resistant.