tcrB, a gene conferring transferable copper resistance in Enterococcus faecium:: Occurrence, transferability, and linkage to macrolide and glycopeptide resistance
tcrB, a gene conferring transferable copper resistance in Enterococcus faecium:: Occurrence, transferability, and linkage to macrolide and glycopeptide resistance
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DOI：
10.1128/aac.46.5.1410-1416.2002
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发表时间：
2002-05-01
影响因子：
4.9
通讯作者：
Aarestrup, FM
中科院分区：
文献类型：
--
作者：
Hasman, H;Aarestrup, FM
一个新发现的基因，命名为tcrB，它位于接合质粒赋予获得性耐铜屎肠球菌，从猪分离物中鉴定。tcrB基因编码属于CPx型ATP酶家族的推定蛋白质，其与来自肠球菌的CopB蛋白质具有同源性（46%）。在大肠杆菌中发现了tcrB基因。从猪（75%）、肉鸡（34%）、小牛（16%）和人（10%）中分离的粪肠球菌，但从绵羊中分离的粪肠球菌中没有。耐药菌株，含有tcrB基因，生长在脑心输液琼脂板含有高达28 mM硫酸铜相比，只有4 mM的敏感菌株。铜抗性，因此存在的tcrB基因，是强烈相关的大环内酯类和糖肽类耐药的猪分离株，和tcrB基因被证明是位于同一接合质粒的基因负责这两种抗菌药物的耐药性。这种新的铜抗性基因在猪的分离物中频繁出现，其中硫酸铜被大量用作饲料添加剂，这表明铜的使用选择了抗性。
A newly discovered gene, designated tcrB, which is located on a conjugative plasmid conferring acquired copper resistance in Enterococcus faecium, was identified in an isolate from a pig. The tcrB gene encodes a putative protein belonging to the CPx-type ATPase family with homology (46%) to the CopB protein from Enterococcus hirae. The tcrB gene was found in E. faecium isolated from pigs (75%), broilers (34%), calves (16%), and humans (10%) but not in isolates from sheep. Resistant isolates, containing the tcrB gene, grew on brain heart infusion agar plates containing up to 28 mM CuSO4 compared to only 4 mM for the susceptible isolates. Copper resistance, and therefore the presence of the tcrB gene, was strongly correlated to macrolide and glycopeptide resistance in isolates from pigs, and the tcrB gene was shown to be located on the same conjugative plasmid as the genes responsible for resistance to these two antimicrobial agents. The frequent occurrence of this new copper resistance gene in isolates from pigs, where copper sulfate is being used in large amounts as feed additive, suggests that the use of copper has selected for resistance.