Characteristics of Streptococcus pyogenes strains isolated from Chinese children with scarlet fever
Article first published online: 7 AUG 2008
©2008 The Author(s)/Journal Compilation ©2008 Foundation Acta Pædiatrica/Acta Pædiatrica
Volume 97, Issue 12, pages 1681–1685, December 2008
How to Cite
Liang, Y., Shen, X., Huang, G., Wang, C., Shen, Y. and Yang, Y. (2008), Characteristics of Streptococcus pyogenes strains isolated from Chinese children with scarlet fever. Acta Paediatrica, 97: 1681–1685. doi: 10.1111/j.1651-2227.2008.00983.x
- Issue published online: 6 NOV 2008
- Article first published online: 7 AUG 2008
- Received 4 April 2008; revised 7 July 2008; accepted 11 July 2008.
- Antibiotic resistance;
- scarlet fever;
- Streptococcus pyogenes
Aim: To analyse the characteristics of Streptococcus pyogenes isolates from Chinese children with scarlet fever.
Methods: Minimal inhibitory concentration with nine antibiotics was performed on 145 Streptococcus pyogenes isolates acquired from Beijing and Shanghai in 2007. Their macrolide-resistant genes (mefA, ermB and ermA– a subclass of ermTR), superantigens (speA and speC), and en-coding mature M protein gene (emm gene) were amplified by PCR.
Results: A total of 97.9% of the isolates exhibited resistance to the macrolides, while 96.6% manifested resistance to tetracycline. All isolates were sensitive to chloramphenicol, penicillin, cefradine, and ofloxacin. Moreover, 94.5% exhibited a cMLSB phenotype, while 90.3% had the ermB gene. Five emm types (emm1.0, emm4.0, emm12.0, emm22.0 and st5240) were discovered, of which 9.7% carried the superantigen speA, 35.9% carried the speC, 42.8% carried both speA and speC and 11.7% carried neither speA nor speC. Finally, 85.5% of emm1.0 and 15.5% of emm12.0 isolates carried speA, while 79.0% of emm1.0 and 75.9% of emm12.0 isolates carried speC.
Conclusion: The Streptococcus pyogenes isolates had high resistance rates against macrolides and tetracycline. They mainly expressed the ermB gene type and cMLSB phenotype. Their common emm types are emm1.0 and emm12.0, which have different frequencies of speA and speC.