Actinomyces israeli

Actinomyces israelii is a species of bacteria that can cause a chronic infection called actinomycosis in humans and cattle. These bacteria are typically found as normal flora in the oral cavity, gastrointestinal tract, and female genital tract.1

Actinomycosis is characterized by the formation of abscesses and draining sinus tracts that exude sulfur granules. While rare in humans, it most commonly affects the jaws, neck, and face (cervicofacial actinomycosis), but can also impact the chest, abdomen, and pelvis. The infection can occur when the integrity of mucous membranes is compromised, allowing the bacteria to invade tissues. Treatment involves antibiotics, and sometimes surgical drainage or removal of lesions.1