Kingella organisms colonize the human respiratory tract. They cause skeletal infections, endocarditis, and bacteremia and, rarely, pneumonia, epiglottitis, meningitis, abscesses, and ocular infections.

Kingella 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 and other respiratory tract pathogens such as Moraxella catarrhalis and Streptococcus pneumoniae. Infection has a seasonal distribution, with more cases in fall and winter.

Diseases Caused By Kingella

The most common manifestations of K. kingae disease are

• Skeletal infections
• Endocarditis
• Bacteremia

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, Actinobacillus, Cardiobacterium, Eikenella, Kingella—see Gram-Negative Bacilli: HACEK Infections), which includes fastidious gram-negative bacteria capable of causing endocarditis.

Diagnosis requires laboratory isolation from suspected fluids or tissues.

Treatment

• A penicillin or cephalosporin

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/sulfamethoxazoleSome Trade Names
BACTRIM
SEPTRA
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, tetracyclines, erythromycinSome Trade Names
ERY-TAB
ERYTHROCIN
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, and ciprofloxacinSome Trade Names
CILOXAN
CIPRO
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.

Last full review/revision September 2009 by Carlene A. Muto, MD, MS

Content last modified February 2012