Wu Po-Chuang, Lo Wen-Tsung, Chen Shyi-Jou, Wang Chih-Chien
Department of Pediatrics, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, ROC.
Department of Pediatrics, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, ROC.
J Microbiol Immunol Infect. 2014 Aug;47(4):304-10. doi: 10.1016/j.jmii.2013.02.007. Epub 2013 Apr 30.
BACKGROUND/PURPOSE: Little information is available on the differences in frequency of pyrogenic exotoxin genes between strains of group A streptococci that cause scarlet fever and those that cause pharyngotonsillitis in children in Taiwan. This study retrospectively monitored the presence of pyrogenic exotoxin genes, the emm typing, and the susceptibility of macrolide drugs in Streptococcus pyogenes isolated from children diagnosed with scarlet fever and pharyngotonsillitis in northern Taiwan.
Isolates of S. pyogenes were recovered from children with scarlet fever (n = 21) and acute pharyngotonsillitis (n = 29) during 2000-2011. The isolates were characterized according to the presence of spe genes and emm typing. Antibiograms were determined by the disk diffusion method and agar dilution test. Polymerase chain reaction was used to detect the presence of erm genes in isolates that showed nonsusceptibility to erythromycin. All isolates underwent additional genotyping by pulsed-field gel electrophoresis.
In isolates from patients with scarlet fever, the frequencies of pyrogenic exotoxin genes were 9.5% for speA, 81.0% for speB, 4.8% for speC, and 71.4% for speF. In isolates from patients with pharyngotonsillitis, the frequencies were 17.2% for speA, 72.4% for speB, 13.8% for speC, and 69.0% for speF. There were no significant differences in frequencies of the exotoxin genes between the two groups of isolates. Eight emm sequence types were identified from all group A streptococci isolates. The most common types were emm12 followed by emm1 and emm4. The erythromycin resistant rate was 4/50 (8%). The ermB gene was detected in only one isolate from a patient with pharyngotonsillitis. Pulsed-field gel electrophoresis had a total of three sets of clustered strains, which showed >80% homology and belonged to the same emm type.
There were no significant differences in frequencies of the spe genes between S. pyogenes isolates from patients with scarlet fever and patients with pharyngotonsillitis. The most common emm type was emm12. Low erythromycin resistance in S. pyogenes was observed.
背景/目的：关于台湾地区儿童中引起猩红热的A组链球菌菌株与引起咽扁桃体炎的菌株之间致热外毒素基因频率的差异，目前可用信息较少。本研究回顾性监测了从台湾北部诊断为猩红热和咽扁桃体炎的儿童中分离出的化脓性链球菌中致热外毒素基因的存在情况、emm分型以及大环内酯类药物的敏感性。
在2000 - 2011年期间，从患有猩红热（n = 21）和急性咽扁桃体炎（n = 29）的儿童中分离出化脓性链球菌菌株。根据spe基因的存在情况和emm分型对分离株进行特征分析。通过纸片扩散法和琼脂稀释试验确定抗菌谱。采用聚合酶链反应检测对红霉素不敏感的分离株中erm基因的存在情况。所有分离株均通过脉冲场凝胶电泳进行额外的基因分型。
在猩红热患者的分离株中，致热外毒素基因的频率分别为：speA为9.5%，speB为81.0%，speC为4.8%，speF为71.4%。在咽扁桃体炎患者的分离株中，频率分别为：speA为17.2%，speB为72.4%，speC为13.8%，speF为69.0%。两组分离株的外毒素基因频率无显著差异。从所有A组链球菌分离株中鉴定出8种emm序列类型。最常见的类型是emm12，其次是emm1和emm4。红霉素耐药率为4/50（8%）。仅在一名咽扁桃体炎患者的分离株中检测到ermB基因。脉冲场凝胶电泳共有三组聚类菌株，其同源性>80%，且属于同一emm类型。
猩红热患者和咽扁桃体炎患者的化脓性链球菌分离株中spe基因频率无显著差异。最常见的emm类型是emm12。观察到化脓性链球菌对红霉素的耐药性较低。
