The Past, Present, and Future of Kingella kingae Detection in Pediatric Osteoarthritis

Abstract

As a result of the increasing use of improved detection methods, Kingella kingae, a Gram-negative component of the pediatric oropharyngeal microbiota, is increasingly appreciated as the prime etiology of septic arthritis, osteomyelitis, and spondylodiscitis in children aged 6 to 48 months. The medical literature was reviewed to summarize the laboratory methods required for detecting the organism. Kingella kingae is notoriously fastidious, and seeding skeletal system samples onto solid culture media usually fails to isolate it. Inoculation of synovial fluid aspirates and bone exudates into blood culture vials enhances Kingella kingae recovery by diluting detrimental factors in the specimen. The detection of the species has been further improved by nucleic acid amplification tests, especially by using species-specific primers targeting Kingella kingae’s rtxA, groEL, and mdh genes in a real-time PCR platform. Although novel metagenomic next-generation technology performed in the patient’s plasma sample (liquid biopsy) has not yet reached its full potential, improvements in the sensitivity and specificity of the method will probably make this approach the primary means of diagnosing Kingella kingae infections in the future.

Is the emergency MRI protocol for acute pediatric osteoarticular infection a luxury or an absolute priority?

“…MRI first made its place in the pediatric OAIs workup as an adjunctive exam for the determination of their extent and topography, especially for delayed, complicated or atypic cases (1)(2)(3)(4). During the first decade of the new millennium, referral centers have claimed its early use in the workup for both osteomyelitis, septic arthritis, and spondylodiscitis, to facilitate the surgical decisionmaking process (5)(6)(7)(8)(9)(10)(11). During these last years, it has become evident that the quality of care for children with OAIs is significantly impacted by processes that improve the efficiency and accuracy of diagnosis as well as the rapidity and efficacy of treatment.…”

Laboratory diagnostics for primary spinal infections in pediatric and adult populations: a narrative review

“…When mNGS is performed using plasma (known as “liquid biopsy”), this method detects not only the pathogens circulating in the bloodstream but also those causing focal infections. Sequences of a pathogen's DNA leak from infected sites such as bones, joints, or the spine into the patient's blood, potentially allowing clinicians to dispense with the need for source sample collection using costly, invasive surgical procedures [ 106 ].…”

“…In a recent interesting multicenter study, mNGS performed using plasma detected K. kingae in 10 young children (median age 16.5 months; range 10–23 months) with spondylodiscitis [ 106 ]. Despite negative blood cultures in all 10 patients, detecting K. kingae using mNGS from plasma enabled narrow antimicrobial coverage for 9 patients and established diagnoses without a biopsy for 8 of them.…”

“…The benefits to patients include avoiding invasive diagnostic procedures and the identification of both common and novel pathogens that would otherwise remain undetected by culture or NAAA methods. However, the mNGS approach has yet to fulfill all of its theoretical potential [ 106 ] ( Tables 1 and 2 ).…”

Reflection on osteoarticular infections in children

“…We could expect there to be continuous improvements in nucleic acid amplification processes, probably leading to faster bacterial identification and eventually to real-time diagnosis. This was the case of K. kingae , whose identification was dramatically improved using NAAAs ( 23 ).…”