Co-existence of the oxazolidinone resistance genes cfr and optrA on two transferable multi-resistance plasmids in one Enterococcus faecalis isolate from swine
Co-existence of the oxazolidinone resistance genes cfr and optrA on two transferable multi-resistance plasmids in one Enterococcus faecalis isolate from swine
复制标题
恶唑烷酮抗性基因 cfr 和 optrA 在猪粪肠球菌分离株的两个可转移多抗性质粒上共存
DOI：
10.1016/j.ijantimicag.2020.105993
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发表时间：
2020-07-01
影响因子：
10.8
通讯作者：
Zeng, Zhenling
中科院分区：
文献类型：
--
作者：
Chen, Lin;Han, Dongdong;Zeng, Zhenling
目的：鉴定肠球菌分离株中恶唑烷酮耐药基因cfr和optrA。方法：采用聚合酶链反应法对293株分离肠球菌进行cfr和optrA检测。通过偶联法考察了cfr和optrA的可转移性。利用S1核酸酶脉冲场凝胶电泳和Southern blotting鉴定cfr和optrA的位置。对一株同时携带cfr和optrA的粪肠球菌分离株进行了全序列测序。结果：检出cfr 16株（5.5%），检出optrA 170株（58.0%）。16株肠球菌（粪肠球菌13株，鸟肠球菌2株，蒙氏肠球菌1株）同时携带cfr和optrA。质粒p4中res和theta之间的cfr携带片段与耐万古霉素屎肠球菌质粒pEF120805对应区域的同源性为98.9%。质粒p1中携带optrA的tnpB和optrA片段与E. faecalis A101基因组DNA对应区域的同源性为99.9%。质粒p4和质粒p1同时与粪肠杆菌JH2-2结合。结论：从猪和猪场环境分离的293株肠球菌中检出170株optra阳性肠球菌。cfr和optrA在E. avium和E. mundtii中共存已被证实。从一株粪肠杆菌分离物中鉴定出cfr和optrA两个新的共轭质粒。最初报告了携带optra的片段（IS1216E-optrA-IS1216E）。在不同类型的肠球菌质粒中，ISEnfa5和IS1216E元件可能分别在cfr和optrA的传播中发挥重要作用。(c) 2020 Elsevier B.V.和国际化学疗法学会。版权所有。
Objectives: To identify and characterize oxazolidinone resistance genes cfr and optrA in enterococcal isolates.Methods: Two hundred and ninety-three enterococcal isolates were screened for the presence of cfr and optrA by polymerase chain reaction. The transferability of cfr and optrA was examined by conjugation. S1 nuclease pulsed-field gel electrophoresis and Southern blotting were used to identify the location of cfr and optrA. One Enterococcus faecalis isolate carrying both cfr and optrA was sequenced in full.Results: cfr and optrA were detected in 16 (5.5%) and 170 (58.0%) enterococcal isolates, respectively. Sixteen enterococcal isolates (E. faecalis n=13, Enterococcus avium n=2, Enterococcus mundtii n=1) carried both cfr and optrA. The cfr-carrying fragment between res and theta in plasmid p4 showed 98.9% identity to the corresponding region of plasmid pEF120805 from vancomycin-resistant Enterococcus faecium. The optrA-carrying segment between tnpB and optrA in plasmid p1 showed >99.9% identity to the corresponding region of genomic DNA from E. faecalis A101. Plasmid p4 and plasmid p1 were simultaneously conjugated to E. faecalis JH2-2.Conclusions: One hundred and seventy optrA-positive enterococci were identified in 293 enterococcal isolates from swine and the farm environment. The co-existence of cfr and optrA in E. avium and E. mundtii has been identified previously. cfr and optrA were identified on two new conjugative plasmids from one E. faecalis isolate. The optrA-carrying segment (IS1216E-optrA-IS1216E) was reported initially. Among different types of enterococcal plasmids, ISEnfa5 and IS1216E elements may play a vital role in the dissemination of cfr and optrA, respectively. (c) 2020 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.