Detection of Respiratory Colonization by Kingella kingae and the Novel Kingella negevensis Species in Children: Uses and Methodology

Abstract

The recognition of the role of as one of the main etiologic agents of skeletal system infections in young children and the recent discovery of the novel species have resulted in an increasing interest in these two emerging pediatric pathogens. Both bacteria colonize the oropharynx and are not detected in nasopharyngeal specimens, and the colonized mucosal surface is their portal of entry to the bloodstream. Although species-specific nucleic acid amplification assays have significantly improved the detection of kingellae and facilitated patients' management, the increasing use of this diagnostic approach has the potential drawback of neglecting culture recovery of these organisms. The isolation of species enables the thorough genotyping of strains for epidemiological purposes, the study of the dynamics of asymptomatic colonization and person-to-person transmission, the investigation of the pathogenesis of invasive infections, and the determination of antibiotic susceptibility patterns. The culture isolation of pharyngeal strains and their comparison with isolates derived from normally sterile body sites may also aid in identifying virulence factors involved in the transition from colonization to invasive disease which could represent potential targets for a future protective vaccine. The two species are notoriously fastidious, and their isolation from upper respiratory tract specimens requires a short transport time, plating on selective vancomycin-containing blood-agar medium, and incubation under capnophilic and aerobic conditions. The identification of and can be performed by a combination of the typical Gram stain and biochemical tests and confirmed and differentiated by molecular assays that target the and genes.

Kingella kingae and Osteoarticular Infections

“…42,43 K negevensis' DNA was also detected in an infant's hip joint fluid, indicating that this pathogen may also now be considered as responsible for OAIs in young infants. [44][45][46] Furthermore, although a rare occurrence in pediatric patients, some OAIs diagnosed as septic arthritis or septic osteomyelitis may have been the early manifestations of rheumatoid disease or related conditions or may even have been caused by viral pathogens.…”

Diagnostic Utility of Synovial Fluid Cell Counts and CRP in Pediatric Knee Arthritis: A 10-Year Monocentric, Retrospective Study

“…Hence, the synovial markers remain a laboratory element which is supportive for clinical decision making but is not determinant on its own. Although in the “other” (O) group we did not detect a causative pathogen in either the standard cultures of synovial fluid or in the PCR, we may have also included septic arthritis from other fastidious microorganisms involved in osteoarticular infections which have not yet been recognized as pathogens, and further efforts should be made to develop new molecular techniques to identify them [ 17 , 20 , 21 ].…”

Therapeutic target mapping from the genome of Kingella negevensis and biophysical inhibition assessment through PNP synthase binding with traditional medicinal compounds

“…Its colonization is known in respiratory tract and oropharynx, with carriage and colonization resembling K. kingae [ 2 , 3 ] . Its occurrence is known to increase from 6 to 24 month children and decrease thereafter [ 4 ]. Its role in the septic arthritis of an infant [ 2 , 4 , 5 ], endocarditis, pediatric osteomyelitis and bacteremia has been implicated [ 1 ], while the bacterial spread is through person to person contact [ 4 ].…”

“…Its genome has been sequenced, with genome size around 2 MB [ 6 ]. This bacterium has been reported to show heterogeneity in genetic makeup in different strains [ 4 ]. Among several key virulence factors, human epithelial binding through elements such as an exopolysaccharide, a polysaccharide capsule, an adhesin autotransporter, and a pili (type IV) are shared between K. negevensis and K. kingae [ 7 ].…”