What type of infections does Actinomyces israelii commonly cause?

Actinomyces israelii is a bacterium that is part of the normal flora of the human mouth and gastrointestinal tract. This organism is primarily known for causing cervicofacial and thoracic infections, which often occur in individuals with poor oral hygiene or those who have experienced trauma to the mouth or face, such as after dental procedures. The infection can manifest as a chronic, suppurative disease that progresses slowly, leading to the formation of abscesses and draining sinuses.

Cervicofacial actinomycosis typically presents as a hard, swollen mass in the jaw region, which can sometimes be mistaken for a malignancy or a dental abscess. Thoracic actinomycosis can occur after aspiration of oral secretions, leading to pneumonia and abscess formation in the lungs. Treating these infections generally requires prolonged antibiotic therapy, often with penicillin, due to the tendency of Actinomyces species to be resistant to certain antibiotics.

In contrast, the other options such as urinary tract infections, skin infections, and intestinal infections are not commonly associated with Actinomyces israelii, as this organism does not typically colonize those areas or cause infections therein.