A modified multilocus sequence typing protocol to genotype Kingella kingae from oropharyngeal swabs without bacterial isolation

Nawal El Houmami, Janek Bzdrenga, Jean Christophe Pons, Philippe Minodier, Guillaume André Durand, Anis Oubraham, Dimitri Ceroni, Pablo Yagupsky, Didier Raoult, Philippe Bidet, Pierre Edouard Fournier

Research output: Contribution to journalArticlepeer-review

10 Scopus citations


Background: Outbreaks of Kingella kingae infection are an emerging public health concern among daycare attendees carrying epidemic clones in the oropharynx. However, genotyping of such epidemic clones from affected cases is limited by the low performance of current methods to detect K. kingae from blood samples and lack of specimens available from infected sites. We aimed at developing a modified multilocus sequence typing (MLST) method to genotype K. kingae strains from oropharyngeal samples without prior culture. We designed in silico MLST primers specific for K. kingae by aligning whole nucleotide sequences of abcZ, adk, aroE, cpn60, recA, and gdh/zwf genes from closely related species belonging to the Kingella and Neisseria genera. We tested our modified MLST protocol on all Kingella species and N. meningitidis, as well as 11 oropharyngeal samples from young children with sporadic (n = 10) or epidemic (n = 1) K. kingae infection. Results: We detected K. kingae-specific amplicons in the 11 oropharyngeal samples, corresponding to sequence-type 6 (ST-6) in 6 children including the epidemic cases, ST-25 in 2 children, and 3 possible novel STs (ST-67, ST-68, and ST-69). No amplicon was obtained from other Kingella species and N. meningitidis. Conclusions: We herein developed a specific MLST protocol that enables genotyping of K. kingae by MLST directly from oropharyngeal samples. This discriminatory tool, with which we identified the first K. kingae outbreak caused by ST-6 in Europe, may be used in further epidemiological investigations.

Original languageEnglish
Article number200
JournalBMC Microbiology
Issue number1
StatePublished - 21 Sep 2017
Externally publishedYes


  • Bone and joint infections
  • Kingella kingae
  • MLST
  • Outbreaks
  • Pediatrics

ASJC Scopus subject areas

  • Microbiology
  • Microbiology (medical)


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