• Pediatric Infection and Vaccine
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• v.12 no.1
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• pp.52-60
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• 2005

Purpose : The aim of this study is to know seasonal distribution of group A streptococci obtained from one center using emm genotyping and T serotyping in Masan from 2003 through 2004. Methods : Among children who visited the Changwon Fatima Hospital at Masan, Korea from June 2003 through February 2004, 100 patients who had clinical findings of acute pharyngitis, scarlet fever, and cellulitis were confirmed as GAS by culture, and were enrolled in our study. All obtained GAS were sent to the WHO Collaborative Center for Reference and Research on Streptococci, University of Minnesota, Minneapolis for T serotyping and emm genotyping. We classified these results again according to seasonal and disease's entities. Results : 19 different T serotypes was typed. T4(27.5%), T1(17.6%), T6(13.7%), and T12(13.7%) serotypes were relatively common in summer, while T4(28.3%), T12(15.2%), and T12/B3264(8.7%) were common in winter. T4 and T12 were persistent all year around. Distribution of T serotypes in 89 patients with pharyngotonsillitis were T4(26.7%), T12(14.0%), T1(12.8%), and T6(11.6%) in order of frequency. 15 different emm genotypes was typed. The number of emm 1, emm 6, emm 9, and emm 44 genotypes decreased or disappeared in winter, and the number of emm 3, emm 12, and emm 89 genotypes increased or reappeared in winter. Conclusion : Because T serotyping and emm genotyping are useful tools for evaluating epidemiology and pathogenesis of group A streptococci, we should monitor these strains every year, and should serotype and genotype GAS obtained from the invasive streptococcal infections.

• Pediatric Infection and Vaccine
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• v.10 no.2
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• pp.178-185
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• 2003

Purpose : Group A streptococci(GAS) was isolated from the patients with acute pharyngitis. Epidemiological studies using T typing and emm genotyping was performed for GAS and compared with the results of the carriers. Methods : Throat cultures were taken from 246 children(123 boys, 123 girls) from November, 2001 to May, 2002 who visited a pediatrician's office located in Jinju, Gyeongnam province. T types were identified with slide agglutination and emm genotypes were identified with DNA sequencing after amplification of emm genes. Results : One hundred thirty(52.8%) out of 246 children yielded beta-hemolytic streptococci, of which 96.1% were group A. Children from 4 to 7 years old comprised 70.4% of the GAS positive group. T12 were the most common(35.2%) and T non-typeable strains were the next(30.4%). emm12 was most frequent(28.5%), and emm75(18.7%), emm22(13.0%), emm2(12.2%), and emm8(8.1%) were relatively common. Conclusion : Since GAS is so highly prevalent in acute pharyngitis, indeed being half of the population, good clinical practice dictates the systematic employment of throat culture for acute pharyngitis before prescribing antibiotics in a pediatric setting. The distribution of the T antigens and emm genes showed similar pattern between the acute pharyngitis and the carriers.