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Internal Medicine

Training Level

Resident PGY 1


Henry Ford Hospital


Actinomyces pyogenes is a gram positive bacillus known to cause pyogenic infections in animals with rare reports in humans with farm animal exposure. A 52-year-old male who was an active injection drug user presented to the emergency department with right-sided weakness, expressive aphasia, and altered mental status. He was found to be tachycardic and febrile. The patient was admitted two weeks prior for bilateral pneumonia and blood cultures grew Actinomyces pyogenes. Infectious Diseases was not consulted during that admission. On this admission, CT head showed a large left MCA ischemic stroke. Further imaging was concerning for septic emboli to the lungs and kidney. Blood cultures again grew Actinomyces pyogenes. TEE showed severe mitral valve regurgitation with numerous vegetations. Panorex showed multiple dental caries, but otherwise unremarkable. HIV was non-reactive. The patient denied licking his needles before injecting drugs or any animal contacts. Antibiotic management was guided by treatment of other Actinomyces infections. That included gentamicin and ampicillin, and was switched to IV penicillin G for a total duration of 12 weeks, followed by PO amoxicillin twice daily for 3 months. On outpatient follow-up, his focal deficits had improved, his aphasia resolved and he was ambulating. There are only two case reports of A. pyogenes infective endocarditis (IE) in the literature. One includes a patient with no reported animal exposure with multiple embolic complications who eventually succumbed to the infection. It is important for A. pyogenes to be considered in patients with IE, even with no history of typical exposures.

Presentation Date


An Unusual Case of Urban Actinomyces Pyogenes Infective Endocarditis