Kingella organisms colonize the human respiratory tract. They cause skeletal infections, endocarditis, and bacteremia and, rarely, pneumonia, epiglottitis, meningitis, abscesses, and ocular infections.
(See also Introduction to Neisseriaceae.)
Kingella, which belong to the family Neisseriaceae, are short, nonmotile, gram-negative coccobacilli that occur in pairs or short chains. The organisms are slow-growing and fastidious. Kingella are recovered from the human respiratory tract and are a rare cause of human disease.
Among Kingella species, K. kingae is the most frequent human pathogen; these organisms frequently colonize the respiratory mucous membranes. Children aged 6 mo to 4 yr have the highest rates of colonization and invasive disease from this respiratory tract pathogen. K. kingae is transmitted from child to child through close personal contact (eg, at day care centers). Infection has a seasonal distribution, with more cases in fall and winter.
The most common manifestations of K. kingae disease are
Rare manifestations include pneumonia, epiglottitis, meningitis, abscesses, and ocular infections.
The most common skeletal infection is septic arthritis, which most frequently affects large, weight-bearing joints, especially the knee and ankle. Osteomyelitis most frequently involves bones of the lower extremities. Onset is insidious, and diagnosis is often delayed. Hematogenous invasion of intervertebral disks can occur, most commonly in the lumbar intervertebral spaces.
Kingella endocarditis has been reported in all age groups. Endocarditis may involve native or prosthetic valves. Kingella is a component of the so-called HACEK group (Haemophilus aphrophilus and H. parainfluenzae, Aggregatibacter, Cardiobacterium, Eikenella, Kingella), which includes fastidious gram-negative bacteria capable of causing endocarditis.
Diagnosis of Kingella infections requires laboratory isolation from fluids or tissues thought to be infected.
Kingella organisms are generally susceptible to various penicillins and cephalosporins. However, antimicrobial susceptibility testing is needed to guide therapy. Other useful drugs include aminoglycosides, trimethoprim/sulfamethoxazole, tetracyclines, erythromycin, and fluoroquinolones.