Multilocus sequence typing and rtxA toxin gene sequencing analysis of Kingella kingae isolates demonstrates genetic diversity and international clones.

Background: Kingella kingae, a normal component of the upper respiratory flora, is being increasingly recognized as an important invasive pathogen in young children. Genetic diversity of this species has not been studied.

Methods: We analyzed 103 strains from different countries and clinical origins by a new multilocus sequence-typing (MLST) schema.