An adult case of oral infection with Kingella kingae.

An exceptional case of microbiologically confirmed oral infection with Kingella kingae in an immunocompetent adult (30-year-old woman) is presented and the pathogenesis is discussed and related to known literature data.K. kingae is a rather common but yet relatively unknown commensal corroding bacterium from the oro- and nasopharynx in healthy children, which might turn into a human pathogen causing osteomyelitis, arthritis, spondylitis, endocarditis and intervertebral diskitis in young children and rarely endocarditis, septic arthritis, meningitis, epiglottitis, diskitis and bacteraemia in adults. Sofar K. kingae associated stomatitis was reported in children and a few adults, however, with concomitant herpes simplex virus infections, and without microbiological confirmation. In the described case no viral infection was found. The proven K. kingae stomatitis represents an extension of the pathogenic spectrum and suggests that the breach of the oral mucosal barrier can be caused by the bacterial pathogen itself. Whether a concomitant viral infection is necessary forK. kingae to actually invade the bloodstream remains to be considered.