Increased high-level gentamicin resistance in invasive Enterococcus faecium is associated with aac(6′)Ie-aph(2")Ia-encoding transferable megaplasmids hosted by major hospital-adapted lineages
Increased high-level gentamicin resistance in invasive Enterococcus faecium is associated with aac(6′)Ie-aph(2")Ia-encoding transferable megaplasmids hosted by major hospital-adapted lineages
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DOI：
10.1111/j.1574-695x.2012.00997.x
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发表时间：
2012-11-01
影响因子：
--
通讯作者：
Pedersen, Torunn
中科院分区：
文献类型：
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作者：
Rosvoll, Torill C. S.;Lindstad, Belinda L.;Pedersen, Torunn
庆大霉素在与细胞壁剂协同杀菌治疗严重肠球菌感染中是重要的。2003 - 2008年期间，挪威抗菌素耐药性监测系统报告，屎肠球菌血培养分离株中高水平庆大霉素耐药性（HLGR）的患病率增加了10倍，达到50%以上。一个具有代表性的国家收集入侵E。通过多水平方法检查来自2008年的屎肠菌分离物（n = 99）。基因分型显示多克隆人群主要由主要的医院相关谱系（主要是ST 203、ST 17、ST 18、ST 202和ST 192）主导。aac（6 '）-Ie-aph（2？）-编码双功能氨基糖苷类修饰酶的Ia在98%的HLGR分离株中被发现（56/57）。此外，与其他序列类型相比，在属于主要医院相关谱系的分离株中，潜在毒力基因、毒素-抗毒素基因座以及pRE 25和普鲁姆型复制子的患病率显著较高。pLG 1复制子型（200 - 330 kb）的大质粒存在于90%的分离株。共杂交分析表明aac（6 '）-Ie-aph（2？）与此复制子类型的关系。HLGR编码质粒的转移仅限于E.屎室总之，HLGR在侵袭性大肠杆菌中的患病率增加。挪威的屎肠菌与携带aac（6 '）-Ie-aph（2？）-编码Ia的pLG 1复制子类型的可转移大质粒。
Gentamicin is important in synergistic bactericidal therapy with cell wall agents for severe enterococcal infections. During 20032008, a 10-fold increase in the prevalence of high-level gentamicin resistance (HLGR), to above 50%, in blood culture isolates of Enterococcus faecium, was reported by the Norwegian Surveillance System for Antimicrobial Resistance. A representative national collection of invasive E. faecium isolates (n = 99) from 2008 was examined by a multilevel approach. Genotyping revealed a polyclonal population dominated by major hospital-associated lineages (mainly ST203, ST17, ST18, ST202 and ST192). The presence of aac(6')-Ie-aph(2?)-Ia, encoding the bi-functional aminoglycoside-modifying enzyme, was found in 98% of HLGR isolates (56/57). Furthermore, a significantly higher prevalence of potential virulence genes, toxin-antitoxin loci as well as pRE25 and pRUM type replicons was demonstrated in isolates belonging to major hospital-associated lineages compared to other sequence types. Megaplasmids of pLG1 replicon type (200330 kb) were present in 90% of the isolates. Co-hybridization analyses revealed genetic linkage of aac(6')-Ie-aph(2?)-Ia to this replicon type. Transfer of HLGR-encoding plasmids was restricted to E. faecium. In conclusion, the increased prevalence of HLGR in invasive E. faecium in Norway is associated with hospital-adapted genetic lineages carrying aac(6')-Ie-aph(2?)-Ia-encoding transferable megaplasmids of the pLG1 replicon type.