National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Zhunan, Taiwan.
J Clin Microbiol. 2014 Feb;52(2):508-16. doi: 10.1128/JCM.02383-13. Epub 2013 Dec 4.
Our multicenter nationwide surveillance data indicated that erythromycin (ERY) resistance among group A Streptococcus (GAS) isolates in Taiwan declined from 53.1% in 1998 and 2000 to 14.6% in 2002 and 2004 and 10.7% in 2006 to 2010 (P < 0.01). The present study aimed to assess the epidemiology of GAS in Taiwan and identify factors associated with ERY resistance. All 127 ERY-resistant (ERY(r)) isolates and 128 randomly selected ERY-susceptible (ERY(s)) isolates recovered from 1998 to 2010 were emm typed. ERY(r) isolates were also characterized by ERY resistance phenotype and mechanisms and pulsed-field gel electrophoresis (PFGE). Multilocus sequence typing was performed on selected ERY(r) isolates. The predominant emm types in ERY(r) isolates were emm22 (n = 33, 26.0%), emm12 (n = 24, 18.9%), emm4 (n = 21, 16.5%), and emm106 (n = 15, 11.8%). In ERY(s) isolates, emm12 (n = 27, 21.9%), emm1 (n = 18, 14.1%), emm106 (n = 16, 12.5%), and emm11 (n = 9, 7.1%) predominated. The most common ERY resistance phenotype was the M phenotype (resistant to macrolides) (70.9%), with all but one isolate carrying mef(A), followed by the constitutive macrolide-lincosamide-streptogramin B resistance (cMLSB) phenotype (26.8%), with isolates carrying erm(B) or erm(TR). ERY(r) isolates of the emm12-sequence type 36 (ST36) lineage with the cMLSB phenotype were mostly present before 2004, while those of the emm22-ST46 lineage with the M phenotype predominated in later years. Recovery from respiratory (throat swab) specimens was an independent factor associated with ERY resistance. emm1 and emm11 GAS isolates were significantly associated with ERY(s), while emm22 was detected only in ERY(r) GAS. In addition, emm106 isolates were prevalent among the abscess/pus isolates, whereas emm12 isolates were strongly associated with a respiratory (throat) origin. In addition to identifying factors associated with ERY resistance in GAS, our study provides helpful information on the changing GAS epidemiology in Taiwan.
我们的多中心全国性监测数据表明，台湾地区 A 组链球菌（GAS）分离株对红霉素（ERY）的耐药性从 1998 年和 2000 年的 53.1%下降到 2002 年和 2004 年的 14.6%，以及 2006 年至 2010 年的 10.7%（P < 0.01）。本研究旨在评估台湾地区 GAS 的流行病学，并确定与 ERY 耐药相关的因素。从 1998 年至 2010 年期间共分离出 127 株红霉素耐药（ERY(r)）和 128 株随机选择的红霉素敏感（ERY(s)）分离株。对所有 ERY(r)分离株进行emm 型分型。ERY(r)分离株还通过红霉素耐药表型和机制以及脉冲场凝胶电泳（PFGE）进行了特征描述。对选定的 ERY(r)分离株进行多位点序列分型。ERY(r)分离株中主要的 emm 型为 emm22（n = 33，26.0%）、emm12（n = 24，18.9%）、emm4（n = 21，16.5%）和 emm106（n = 15，11.8%）。ERY(s)分离株中，emm12（n = 27，21.9%）、emm1（n = 18，14.1%）、emm106（n = 16，12.5%）和 emm11（n = 9，7.1%）最为常见。最常见的红霉素耐药表型为 M 表型（对大环内酯类耐药）（70.9%），除 1 株外，所有分离株均携带 mef(A)，其次是组成型大环内酯-林可酰胺-链阳菌素 B 耐药（cMLSB）表型（26.8%），分离株携带 erm(B)或 erm(TR)。emm12-序列型 36（ST36）谱系的 cMLSB 表型 ERY(r)分离株主要存在于 2004 年之前，而 emm22-ST46 谱系的 M 表型则主要存在于后期。从呼吸道（咽喉拭子）标本中分离出的菌株是与 ERY 耐药相关的独立因素。emm1 和 emm11 GAS 分离株与 ERY(s)显著相关，而 emm22 仅在 ERY(r) GAS 中检测到。此外，emm106 分离株在脓肿/脓液分离株中较为常见，而 emm12 分离株与呼吸道（咽喉）来源密切相关。除了确定与 GAS 中 ERY 耐药相关的因素外，我们的研究还提供了有关台湾地区 GAS 不断变化的流行病学的有用信息。
