It is a commensal in the oral and nasal cavities, where it can give rise to dental and oral cavity abscesses. It is also a commensal in the bronchial and digestive as well as the female genital tracts of IUCD-wearers (often asymptomatic).
Infection (i.e. invasion) and abscess formation is most common in the oral cavity, typically associated with the teeth, but disease may occur in the other locations where it is a commensal, i.e. thoracic or abdominopelvic disease. Abdominopelvic disease may be seen in appendicitis, where presumbably the mucosal break allows the bacteria to disseminate into the peritoneum.
Usually penicillin sensitive.