Area de Bioquímica y Biología Molecular, Universidad de La Rioja, Logroño, Spain.
J Antimicrob Chemother. 2010 Aug;65(8):1570-5. doi: 10.1093/jac/dkq192. Epub 2010 Jun 2.
To characterize the Tn1546 structure and to perform the genetic typing of 51 PFGE-unrelated vanA-containing enterococci of different origin (clinical, food and faecal samples of healthy humans and healthy poultry).
Tn1546 structure was characterized by a PCR primer walking strategy and sequencing. Multilocus sequence typing (MLST) was performed for Enterococcus faecium and Enterococcus faecalis strains, and esp and hyl genes were detected by PCR.
Nine different Tn1546 structures were identified in the studied strains. Type I was the most prevalent structure (75%) (identical to GenBank M97297). Two new Tn1546 structures were identified (in three clinical and animal strains), containing two new insertion sequences (ISs; ISEfa11 disrupting vanS and ISEfa10 disrupting orf1). An additional new Tn1546 structure was found in one animal strain, containing ISEf1 interrupting vanY and IS1542 in the orf2-vanR region. A high diversity of sequence types (STs) was detected among clinical (6 ST/18 strains) and non-clinical E. faecium strains (18 ST/24 strains). STs associated with clonal complexes CC17 and CC9 were mainly detected among clinical and non-clinical E. faecium strains, respectively. Seven new STs were identified in non-clinical strains. The esp and hyl genes were only found among clinical E. faecium strains.
A moderate variability in Tn1546 structure has been detected among unrelated vanA-containing enterococci of different origins, showing three new structures including two new ISs. A high diversity of STs was detected among E. faecium strains, especially among non-clinical strains, and new STs have been identified.
对 Tn1546 结构进行特征描述，并对 51 株不同来源（临床、食品和健康人类及健康家禽粪便样本）、无 PFGE 相关性且携带 vanA 的肠球菌进行遗传分型。
采用 PCR 引物步行策略和测序对 Tn1546 结构进行特征描述。对屎肠球菌和粪肠球菌菌株进行多位点序列分型（MLST），并通过 PCR 检测 esp 和 hyl 基因。
在所研究的菌株中鉴定出 9 种不同的 Tn1546 结构。I 型是最常见的结构（75%）（与 GenBank M97297 相同）。在 3 株临床和动物分离株中鉴定出两种新的 Tn1546 结构，包含两个新的插入序列（ISs）；ISEfa11 破坏 vanS，ISEfa10 破坏 orf1。在 1 株动物分离株中还发现了另一种新的 Tn1546 结构，包含在 orf2-vanR 区中断 vanY 和 IS1542 的 ISEf1。在临床（18 株中有 6 种 ST）和非临床屎肠球菌菌株（24 株中有 18 种 ST）中检测到高度多样化的序列类型（ST）。与克隆复合体 CC17 和 CC9 相关的 ST 主要分别在临床和非临床屎肠球菌菌株中检测到。在非临床菌株中鉴定出 7 种新的 ST。esp 和 hyl 基因仅在临床屎肠球菌菌株中发现。
在不同来源的无 PFGE 相关性且携带 vanA 的肠球菌中，Tn1546 结构存在中等程度的变异性，其中包括 3 种新结构，包含 2 种新的 IS。在屎肠球菌菌株中检测到高度多样化的 ST，尤其是在非临床菌株中，并且鉴定出了新的 ST。
