Detection of the enterococcal oxazolidinone/phenicol resistance gene optrA in Campylobacter coli
Detection of the enterococcal oxazolidinone/phenicol resistance gene optrA in Campylobacter coli
复制标题
大肠杆菌弯曲杆菌中肠球菌恶唑烷酮/苯酚耐药基因 optrA 的检测
DOI：
10.1016/j.vetmic.2020.108731
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发表时间：
2020-07-01
影响因子：
3.3
通讯作者：
Wang, Yang
中科院分区：
文献类型：
--
作者：
Liu, Dejun;Yang, Dawei;Wang, Yang
可转移的optrA基因编码ABC-F蛋白，其赋予对恶唑烷酮和酚类的抗性，并且迄今为止仅在革兰氏阳性细菌中检测到，包括肠球菌、葡萄球菌和链球菌。在这里，我们第一次确定了optrA在天然存在的革兰氏阴性细菌中的存在。2017-2018年，从中国广东省（n = 1，鸡）和山东省（n = 6，鸭）的563株动物源弯曲杆菌分离株中鉴定出7株optrA阳性弯曲杆菌。检测到的optrA基因功能活跃，并介导利奈唑胺、氟苯尼考和氯霉素在相应C.分离物。optrA基因与其他可转移的耐药基因如fexA、catA 9、泰特（O）、泰特（L）、tetA-like、spc或aadE一起位于两个不同的染色体携带的多药耐药基因组岛（MDRGIs）中。在两种MDRGIs中，optrA附近存在插入序列IS 1216 E的完整或截短拷贝。optrA的IS 1216 E-括号内的遗传环境与肠球菌质粒上的optrA区域几乎相同，表明弯曲杆菌中的optrA可能起源于肠球菌属。此外，通过重组IS 1216 E形成携带optrA的可转位单元，表明该IS元件可能在弯曲杆菌中optrA的水平转移中起重要作用。optrA虽然只在少数C.杆菌分离物，需要加强监测以监测弯曲杆菌属中optrA的分布和潜在出现。
The transferable optrA gene encodes an ABC-F protein which confers resistance to oxazolidinones and phenicols, and has so far been detected exclusively in Gram-positive bacteria, including enterococci, staphylococci and streptococci. Here, we identified for the first time the presence of optrA in naturally occurring Gram-negative bacteria. Seven optrA-positive Campylobacter coll. were identified from 563 Campylobacter isolates of animal origin from Guangdong (n = 1, chicken) and Shandong (n = 6, duck) provinces of China in 2017-2018. The detected optrA genes were functionally active and mediated resistance or elevated minimal inhibitory concentrations of linezolid, florfenicol and chloramphenicol in the respective C. coll. isolates. The optrA gene, together with other transferable resistance genes, such as fexA, catA9, tet(O), tet(L), erm(A)-like, spc, or aadE, was located in two different chromosome-borne multidrug resistance genomic islands (MDRGIs). In both MDRGIs, complete or truncated copies of the insertion sequence IS1216E were present in the vicinity of optrA. The IS1216E-bracketed genetic environment of optrA was almost identical to the optrA regions on enterococcal plasmids, suggesting that the optrA in Campylobacter probably originated from Enterococcus spp.. Moreover, the formation of an optrA-carrying translocatable unit by recombination of IS1216E indicated that this IS element may play an important role in the horizontal transfer of optrA in Campylobacter. Although optrA was only found in a small number of C. coli. isolates, enhanced surveillance is needed to monitor the distribution and the potential emergence of optrA in Campylobacter.