Cantacuzino National Institute for Research and Development of Microbiology and Immunology, Splaiul Independenţei 103, Sector 5, 050096, Bucharest, Romania.
Eur J Clin Microbiol Infect Dis. 2012 Sep;31(9):2301-10. doi: 10.1007/s10096-012-1569-y. Epub 2012 Feb 23.
One hundred and forty-eight colonizing isolates from adult Romanian women were conventionally serotyped and screened for antibiotic resistance. Capsular type assignment by multiplex polymerase chain reaction (PCR) was performed for nonserotypeable isolates. Tetracycline and macrolide resistance genes (tetM, tetO, tetL, ermA, ermB, and mefA) including tetM gene association with conjugative elements of the Tn916 family were searched. Molecular typing included PCR screening for major surface protein antigen genes (bac, bca, alp1, alp2/3, alp4, and rib), mobile genetic elements (GBSi1 and IS1548), and rapid detection of hypervirulent clone ST-17. Genetic diversity was assessed by pulsed field gel electrophoresis (PFGE) analysis of SmaI macrorestriction patterns. Among the colonizing isolates studied, serotypes V and III predominated and high rates of tetracycline and macrolide resistance were observed. The tetM gene occurred in 140 tetracycline-resistant isolates and was associated with the int-Tn916 gene in 94 of them. Most of the isolates displayed a constitutive MLS(B) phenotype (38/46 isolates) and harbored the ermB gene. rib, alp2/3, and alp1 were the most common surface protein genes detected. Either IS1548 or GBSi1 intron were detected in almost half of the isolates and nine serotype III isolates belonged to clone ST-17. PFGE analysis of SmaI macrorestriction patterns, obtained from 118 isolates, revealed an apparent genetic diversity.
从罗马尼亚成年女性中分离出的 148 株定植菌，通过常规血清分型和抗生素耐药性筛选进行了研究。对于不可分型的分离株，采用多重聚合酶链反应（PCR）进行荚膜型别赋值。检测了四环素和大环内酯类耐药基因（tetM、tetO、tetL、ermA、ermB 和 mefA），包括 tetM 基因与 Tn916 家族转座子的关联。分子分型包括针对主要表面蛋白抗原基因（bac、bca、alp1、alp2/3、alp4 和 rib）、移动遗传元件（GBSi1 和 IS1548）和超毒力克隆 ST-17 的快速检测的 PCR 筛选。通过 SmaI 宏观限制图谱的脉冲场凝胶电泳（PFGE）分析评估遗传多样性。在所研究的定植菌中，血清型 V 和 III 占主导地位，并且观察到四环素和大环内酯类耐药率较高。tetM 基因存在于 140 株四环素耐药分离株中，其中 94 株与 int-Tn916 基因相关。大多数分离株表现出组成型 MLS(B)表型（38/46 株），并携带 ermB 基因。rib、alp2/3 和 alp1 是最常见的检测到的表面蛋白基因。几乎一半的分离株中检测到 IS1548 或 GBSi1 内含子，9 株血清型 III 分离株属于克隆 ST-17。从 118 株分离株中获得的 SmaI 宏观限制图谱的 PFGE 分析显示出明显的遗传多样性。
