Analysis of VanA vancomycin-resistant Enterococcus faecium isolates from Saudi Arabian hospitals reveals the presence of clonal cluster 17 and two new Tn1546 lineage types
Analysis of VanA vancomycin-resistant Enterococcus faecium isolates from Saudi Arabian hospitals reveals the presence of clonal cluster 17 and two new Tn1546 lineage types
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DOI：
10.1093/jac/dkn173
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发表时间：
2008-08-01
影响因子：
5.2
通讯作者：
Hays, John P.
中科院分区：
文献类型：
--
作者：
Khan, Mushtaq A.;van der Wal, Martin;Hays, John P.
目的：本研究的目的是表征从沙特阿拉伯两家医院获得的34株万古霉素耐药VanA粪肠球菌，并评估这些分离株中Tn1546的变异。方法：检测PFGE和多位点序列分型（MLST）基因型、抗生素敏感性、肠球菌表面蛋白（esp）和透明质酸酶（hyl）基因的存在及偶联频率。此外，还对Tn1546元素进行了表征。结果：PFGE和MLST分析分别发现31个和6个不同的基因型。此外，还发现了三种新的ST类型。97%（33/34）的分离株与克隆复合物17 （CC17）相关，除1株外，其余分离株均对氨苄西林耐药，所有分离株均对利奈唑胺敏感。esp和hyl基因分别占44%（15/34）和53%（18/34）。Tn1546分析显示，分离物属于5个不同的类群，包括2个新谱系。所描述的is元素插入并没有消除VanA抵抗的转移。结论：从沙特阿拉伯医院获得的万古霉素耐药粪肠杆菌分离株包括CC17 MLST型，这是一种与全世界粪肠杆菌医院感染相关的克隆聚集型。新型粪肠杆菌MLST型和新型Tn1546型在沙特阿拉伯流行。CC17粪肠杆菌分离株可能分布在整个中东以及欧洲、美洲、非洲和澳大利亚。
Objectives: The aim of this study was to characterize 34 vancomycin-resistant VanA Enterococcus faecium isolates obtained from two hospitals in Saudi Arabia and to assess Tn1546 variation within these isolates.Methods: PFGE and multilocus sequence typing (MLST) genotypes, antibiotic susceptibility patterns, the presence of enterococcal surface protein (esp) and hyaluronidase (hyl) genes and conjugation frequencies were determined. In addition, Tn1546 elements were characterized.Results: PFGE and MLST analysis revealed the presence of 31 and 6 different genotypes, respectively. Further, three new ST types were discovered. Ninety-seven percent (33/34) of the isolates were associated with clonal complex 17 (CC17), with all isolates but one being resistant to ampicillin and all isolates being susceptible to linezolid. The esp and hyl genes were found in 44% (15/34) and 53% (18/34) of the isolates, respectively. Tn1546 analysis revealed that the isolates belonged to five different groups, including two new lineages. The IS-element insertions described did not abolish the transfer of VanA resistance.Conclusions: VanA vancomycin-resistant E. faecium isolates obtained from Saudi Arabian hospitals include CC17 MLST types, a clonal cluster associated with E. faecium nosocomial infection worldwide. Novel E. faecium MLST types are circulating in Saudi Arabia, as well as novel Tn1546 types. It seems likely that CC17 E. faecium isolates may be distributed throughout the Middle East as well as Europe, America, Africa and Australia.