Content area
Full Text
Kingella kingae was initially isolated by Elizabeth O. King in 1960 during her tenure at the Center for Disease Control10. She sent two strains to Bovre and Henriksen at the University of Oslo, Norway, asking if they thought the new isolate was a member of the genus Moraxella and, if so, if it was a member of an existing species. She died before the species could be fully described, but ? kingae is now recognized as an important pediatric pathogen. Improvements in culture and identification methods have led to K. kingae being detected more frequently. It is now known to be the leading cause of pediatric osteoarticular infections (OAI), infection of bone or joint, for which a causative agent has been determined4.
Though a cause of endocarditis, bacteremia, and lower respiratory infection, ? kingae is most commonly seen as a causative agent of OAI. Its role in endocarditis led to ? kingae being included in the HACEK (Haemophilus, Aggregatibacter, Cardiobacterium, Eikenella, and Kingella) grouping of organisms. As Kingella 's growing importance is recognized, it is critical to understand the organism's presentation, pathogenesis, epidemiology, identification, and treatment.
Taxonomy
Bovre and Henriksen initially reported on Kingella kingae in 1968. They named it Moraxella kingii, as it had a similar appearance to other Moraxella species and was isolated from similar body sites10. Further study showed that unlike other Moraxella species, M. kingae was catalase negative. Attempts to transform Moraxella species with DNA from M. kingae were unsuccessful, suggesting that the two were not closely related. Analysis of fatty acid composition showed that M kingae was most related to members of the family Neisseriaceae, though it was distinct from previously identified members of that family13.
After further study, Bovre and Henriksen renamed the species Kingella kingae and placed it in the family Neisseriaceae, which also contains the genus Neisseria and the genus Eikenella. Three other species of the genus Kingella have since been discovered: Kingella oralis, Kingella denitrificans, and Kingella potus (Table 1). Analysis of 16S RNA sequencing suggests that K. kingae, K. oralis, and K. potus are very closely related, while K. denitrificans is more closely related to Eikenella cor rodens 619.
Clinical Significance and Disease
Kingella kingae has been implicated in a variety of diseases, including...