TY - JOUR
T1 - Multilocus sequence typing and rtxA toxin gene sequencing analysis of kingella kingae isolates demonstrates genetic diversity and international clones
AU - Basmaci, Romain
AU - Yagupsky, Pablo
AU - Ilharreborde, Brice
AU - Guyot, Kathleen
AU - Porat, Nurith
AU - Chomton, Marilyn
AU - Thiberge, Jean Michel
AU - Mazda, Keyvan
AU - Bingen, Edouard
AU - Bonacorsi, Stéphane
AU - Bidet, Philippe
PY - 2012/5/31
Y1 - 2012/5/31
N2 - 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. Putative virulence gene rtxA, encoding an RTX toxin, was also sequenced, and experimental virulence of representative strains was assessed in a juvenile-rat model. Results: Thirty-six sequence-types (ST) and nine ST-complexes (STc) were detected. The main STc 6, 14 and 23 comprised 23, 17 and 20 strains respectively, and were internationally distributed. rtxA sequencing results were mostly congruent with MLST, and showed horizontal transfer events. Of interest, all members of the distantly related ST-6 (n = 22) and ST-5 (n = 4) harboured a 33 bp duplication or triplication in their rtxA sequence, suggesting that this genetic trait arose through selective advantage. The animal model revealed significant differences in virulence among strains of the species. Conclusion: MLST analysis reveals international spread of ST-complexes and will help to decipher acquisition and evolution of virulence traits and diversity of pathogenicity among K. kingae strains, for which an experimental animal model is now available.
AB - 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. Putative virulence gene rtxA, encoding an RTX toxin, was also sequenced, and experimental virulence of representative strains was assessed in a juvenile-rat model. Results: Thirty-six sequence-types (ST) and nine ST-complexes (STc) were detected. The main STc 6, 14 and 23 comprised 23, 17 and 20 strains respectively, and were internationally distributed. rtxA sequencing results were mostly congruent with MLST, and showed horizontal transfer events. Of interest, all members of the distantly related ST-6 (n = 22) and ST-5 (n = 4) harboured a 33 bp duplication or triplication in their rtxA sequence, suggesting that this genetic trait arose through selective advantage. The animal model revealed significant differences in virulence among strains of the species. Conclusion: MLST analysis reveals international spread of ST-complexes and will help to decipher acquisition and evolution of virulence traits and diversity of pathogenicity among K. kingae strains, for which an experimental animal model is now available.
UR - http://www.scopus.com/inward/record.url?scp=84861712498&partnerID=8YFLogxK
U2 - 10.1371/journal.pone.0038078
DO - 10.1371/journal.pone.0038078
M3 - Article
C2 - 22693588
AN - SCOPUS:84861712498
SN - 1932-6203
VL - 7
JO - PLoS ONE
JF - PLoS ONE
IS - 5
M1 - e38078
ER -