Kingella kingae is a fastidious gram-negative bacillus that is being increasingly recognized as pathogen in both children and adults. It is the second most frequent germ involved in arthritis affecting young children, and with the help of polymerase chain reaction (PCR) is currently being described as the first germ involved in arthritis affecting infants under two years old. Other unusual septic localizations have been described, such as endocarditis, or meningitis.
Case report Patient A was a previously healthy, immunocompetent 10-month-old female. She was admitted with a sudden left hemiplegia. No event except an isolated fever since five days was reported. The brain MRI showed a recent right temporo-parieto-occipital and left occipital stroke with embolic occlusion of the right middle artery and of the left posterior cerebral artery. Clinical examination revealed a cardiac systolic murmur not previously heard. The echocardiogram showed normal cardiac anatomy with good left ventricular function but highlighted an aortic endocarditis. Blood sample cultures were positive in three days for K kingae.
Discussion and Conclusion This unusual case of K kingae endocarditis with cerebral emboli in a young infant with no congenital heart defect emphasizes the pathogenicity of this microorganism. This story can suggest that endocarditis must be systematically checked in children presenting with K kingae arthritis. K kingae must be searched for by specific PCR in cases of negative blood culture endocarditis in children under two years old. Probabilistic anti-infectious treatment has to be discussed.