Native joint infections caused by Parvimonas micra.

Parvimonas micra is an anaerobic, fastidious, gram positive organism commonly found in the oral cavity and gastrointestinal tract. It has been increasingly reported as the cause of septic arthritis of native joints, often times with delayed diagnosis leading to increased morbidity. Risk factors include immunosuppression, inflammation of the joint, and recent dental procedures or infections. It has been a historically difficult organism to culture. However, the development of and increasing use of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) has led to increased identification of P. micra. Common antibiotic susceptibilities, as well as data regarding susceptibilities in specific situations, have been reported, but susceptibility testing is required in all cases. Common treatments include clindamycin, penicillin, and metronidazole for six to ten weeks.