Moraxella kingae

Moraxella kingae is a Gram-negative bacteria that is part of the Moraxellaceae family. It is named after American bacteriologist Elizabeth O. King, who first isolated it in 1960. Moraxella kingae is a commensal organism, meaning it normally lives in the human body without causing disease. However, it can cause infections, particularly in children.

Characteristics

Moraxella kingae is a small, aerobic, non-motile, oxidase-positive bacterium. It is coccobacillary in shape and is often found in pairs or short chains. It is capable of producing beta-lactamase, an enzyme that provides resistance to certain types of antibiotics.

Pathogenesis

While Moraxella kingae is a commensal organism, it can become pathogenic under certain conditions. It is a significant cause of bacteremia, septic arthritis, and osteomyelitis in young children. The bacterium is also associated with endocarditis and pneumonia, although these infections are less common.

Diagnosis and Treatment

Diagnosis of Moraxella kingae infection is typically made through blood culture or culture of the infected site. The bacterium can be difficult to grow in culture, so molecular methods such as polymerase chain reaction (PCR) may also be used.

Treatment for Moraxella kingae infection typically involves antibiotics. The bacterium is usually susceptible to a range of antibiotics, including penicillin, cephalosporins, and macrolides. However, resistance to these drugs can occur due to the production of beta-lactamase.

Epidemiology

Moraxella kingae is found worldwide and is most commonly isolated from the oropharynx of healthy children. The bacterium is most likely to cause disease in children under the age of 5, with the highest incidence in children aged 6 to 18 months.

Prevention

Currently, there is no vaccine available for Moraxella kingae. Prevention strategies primarily involve good hygiene practices to reduce the spread of the bacterium.