Kingella kingae septic arthritis with endocarditis in an adult.

Kingella kingae is part of the nonpathogenic flora normally found in the oral cavity and pharynx. Recent reports have established that K. kingae can cause invasive infections in pediatric patients. Few cases have been described in adults, however. We report a case of K. kingae arthritis of the knee followed by endocarditis in a 59-year-old woman. Physicians and microbiologists should be alert to the possibility of K. kingae infection. K. kingae is easy to detect provided its specific culture requirements are taken into account. Synovial fluid inoculation into blood culture vials considerably increases the likelihood of K. kingae recovery in patients with septic arthritis.