Etiological characteristics of Streptococcus pyogenes isolated from children with Scarlet fever in Guangdong province, China
KE Bi-xia, LI Bai-sheng, TAN Hai-ling, KE Chang-wen, HE Dong-mei, CHEN Jing-diao, LIU Mei-zhen
Published 2013-05-30
Cite as Chin J Microbiol Immunol, 2013,33(05): 360-363. DOI: 10.3760/cma.j.issn.0254-5101.2013.05.011
Abstract
Objective To investigate the etiological characteristics of Streptococcus pyogenes that caused scarlet fever in different periods in Guangdong province.Methods 22 isolates from different periods were analyzed through emm typing,PCR detection for super antigen genes,antibiotic susceptibility test and pulsed-field gel electrophoresis (PFGE).Results All isolates were susceptible to cefotaxim,levofloxacin and penicillin.Streptococcus pyogenes isolated after the year 2000 were 100% resistant to erythrocin and clindamycin,but the resistant rate for strains isolated before the year 2000 was 9.1% (1/11).There were 3 emm types indentified from 22 isolates including emm12.0 (59.09%,13/22),emm6.0 (36.36%,8/22) and emm1.0 (4.55%,1/22),which were detected in the isolates from the year 1997 and 2011,from 1978 and 1986,and from 2008,respectively.The positive rates for speA,speB,speC,speF,speG,speH,smeZ,and ssa genes detected by PCR were 54.55%,100%,100%,100%,100%,54.55%,0%,and 86.36% respectively.Among all strains,95.45% of the isolates carried 6 superantigen genes simultaneously.Three clusters of 10 PFGE subtypes were identified in 22 isolates.Cluster Ⅰ consisted of all strains from 1997 and one strain from 2011.Cluster Ⅱ consisted of strains isolated from 1978 and 1986.Cluster Ⅲ consisted of nine strains from 2011 and one from 2008.Conclusion S.pyrogenes isolates in Guangdong province were susceptible to penicillin but resistant to erythrocin.emm 12.0 accounted for the majority of the three types and there was a high frequency of super antigen genes.
Key words:
Scarlet fever; Streptococcus pyogenes; Etiological characteristics
Contributor Information
KE Bi-xia
Center for Disease Control and Prevention of Guangdong Province, Guangzhou 511430, China
LI Bai-sheng
Center for Disease Control and Prevention of Guangdong Province, Guangzhou 511430, China
TAN Hai-ling
Center for Disease Control and Prevention of Guangdong Province, Guangzhou 511430, China
KE Chang-wen
Center for Disease Control and Prevention of Guangdong Province, Guangzhou 511430, China
HE Dong-mei
Center for Disease Control and Prevention of Guangdong Province, Guangzhou 511430, China
CHEN Jing-diao
Center for Disease Control and Prevention of Guangdong Province, Guangzhou 511430, China
LIU Mei-zhen
Center for Disease Control and Prevention of Guangdong Province, Guangzhou 511430, China