Laboratoire de Recherche Résistance aux Antimicrobiens, Faculté de Médecine de Tunis, Tunisie.
Clin Microbiol Infect. 2011 Jan;17(1):63-8. doi: 10.1111/j.1469-0691.2010.03174.x.
To further understand the epidemiology of Streptococcus pyogenes or group A streptococcus (GAS) infections in Tunisia, phenotypic and genomic markers of GAS isolates, including antibiotic susceptibility, biotypes, T and emm types and toxin gene profiles, have been characterized. A total of 103 isolates, collected between 2000 and 2006, were investigated; 47 were recovered from invasive infections, and 56 from non-invasive infections. Rates of resistance to tetracycline, erythromycin, clindamycin and rifampin were 70.8%, 4.8%, 4.8% and 0.9%, respectively. High levels of resistance to streptomycin and kanamycin were observed in 1.9% and 4.8% of isolates, respectively. Biotype 3 was most common. Twenty different T patterns were observed, with a predominance of T3/13/B3264, and 38 different emm types. In both invasive and non-invasive isolates, emm118 (9.7%), emm42 (8.7%), emm1 (7.8%), st432 (6.8%), emm28 (5.8%) and emm76 (5.8%) were the most prevalent types; emm1, emm76 and emm18 were mainly observed among invasive infections, whereas emm118 (12.5%), emm42 (10.7%) and emm28 (8.9%) were predominant among non-invasive infections. The speB gene was detected in all isolates, but there were variable frequencies of speA, speC and ssa (20.3%, 32% and 25.2% respectively). Significant associations of emm1, emm18 and emm3 with speA and of emm4 and st432 with ssa were found. This first report from Tunisia revealed a unique emm distribution of GAS that differs from those of other regions. This information on the distribution of such emm types will be useful for the development of an appropriate vaccine in a country where the incidence of rheumatic fever remains high.
为了进一步了解突尼斯化脓性链球菌或 A 组链球菌（GAS）感染的流行病学，对 GAS 分离株的表型和基因组标记，包括抗生素敏感性、生物型、T 和 emm 型以及毒素基因谱进行了特征分析。共调查了 103 株分离株，其中 47 株来自侵袭性感染，56 株来自非侵袭性感染。对四环素、红霉素、克林霉素和利福平的耐药率分别为 70.8%、4.8%、4.8%和 0.9%。1.9%和 4.8%的分离株对链霉素和卡那霉素表现出高水平耐药。生物型 3 最为常见。观察到 20 种不同的 T 型，以 T3/13/B3264 为主，38 种不同的 emm 型。在侵袭性和非侵袭性分离株中，emm118（9.7%）、emm42（8.7%）、emm1（7.8%）、st432（6.8%）、emm28（5.8%）和 emm76（5.8%）是最常见的类型；emm1、emm76 和 emm18 主要见于侵袭性感染，而 emm118（12.5%）、emm42（10.7%）和 emm28（8.9%）在非侵袭性感染中占主导地位。所有分离株均检测到 speB 基因，但 speA、speC 和 ssa 的检出率存在差异（分别为 20.3%、32%和 25.2%）。发现 emm1、emm18 和 emm3 与 speA 显著相关，而 emm4 和 st432 与 ssa 显著相关。这是突尼斯的第一份报告，揭示了 GAS 的独特 emm 分布，与其他地区不同。在风湿热发病率仍然很高的国家，了解这些 emm 型的分布情况将有助于开发合适的疫苗。
