Native joint septic arthritis with Veillonella species.

Septic arthritis usually presents as subacute monoarticular inflammation. Majority of the cases in healthy adults are caused by methicillin-resistant Staphylococcus aureus, streptococci and certain gram-negative organisms, mostly in the setting of extremes of ages, trauma or immunosuppression. This is a case of a healthy adult with a sudden onset of inflammation of the knee joint, being diagnosed with septic arthritis of the left knee with Veillonella sp. growing from the joint aspirate on two successive cultures. The patient was treated with 6 weeks of oral metronidazole and 4 weeks of intravenous ceftriaxone in addition to arthroscopic drainage and irrigation. Rare causes of septic arthritis should be considered even in healthy adults with native joints. Closer follow-up might be needed to ensure successful treatment.