Ying Yuanyuan, Wu Fei, Wu Chongyang, Jiang Yi, Yin Min, Zhou Wangxiao, Zhu Xinyi, Cheng Cong, Zhu Licheng, Li Kewei, Lu Junwan, Xu Teng, Bao Qiyu
School of Laboratory Medicine and Life Sciences/Institute of Biomedical Informatics, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China.
College of Medicine and Health, Lishui University, Lishui 323000, China.
Int J Genomics. 2019 Oct 1;2019:9828504. doi: 10.1155/2019/9828504. eCollection 2019.
Due to inappropriate use, florfenicol resistance is becoming increasingly serious among animal respiratory tract and gut bacteria. To detect the florfenicol resistance mechanism among Enterobacteriaceae bacteria, 292 isolates from animal feces were examined. The agar dilution method was conducted to determine the minimum inhibitory concentration (MIC) for florfenicol, and polymerase chain reaction (PCR) was performed to detect florfenicol resistance genes. To further explore the molecular mechanism of florfenicol resistance, the whole-genome R25 was sequenced. Of the strains tested, 61.6% (180/292) were resistant to florfenicol, 64.4% (188/292) were positive for , and 1.0% (3/292) for . The whole-genome sequence analysis of R25 revealed that the gene is carried by a transposon and located on a plasmid (pLA-64). Seven other resistance genes are also encoded on pLA-64, all of which were found to be related to mobile genetic elements. The sequences sharing the greatest similarities to pLA-64 are the plasmids p02085-tetA of and p234 and p388, both from . The resistance gene-related mobile genetic elements also share homologous sequences from different species or genera of bacteria. These findings indicate that mainly contributes to the high rate of florfenicol resistance among Enterobacteriaceae. The resistance gene-related mobile genetic elements encoded by pLA-64 may be transferred among bacteria of different species or genera, resulting in resistance dissemination.
由于使用不当，动物呼吸道和肠道细菌中氟苯尼考耐药性日益严重。为检测肠杆菌科细菌中的氟苯尼考耐药机制，对292株动物粪便分离株进行了检测。采用琼脂稀释法测定氟苯尼考的最低抑菌浓度（MIC），并进行聚合酶链反应（PCR）检测氟苯尼考耐药基因。为进一步探究氟苯尼考耐药的分子机制，对R25进行了全基因组测序。在所检测的菌株中，61.6%（180/292）对氟苯尼考耐药，64.4%（188/292） 呈阳性，1.0%（3/292） 呈阳性。R25的全基因组序列分析表明， 基因由转座子携带，位于质粒（pLA-64）上。pLA-64上还编码了其他7个耐药基因，所有这些基因均与可移动遗传元件有关。与pLA-64相似度最高的序列是 的质粒p02085-tetA以及来自 的p234和p388。与耐药基因相关的可移动遗传元件也共享来自不同细菌物种或属的同源序列。这些发现表明， 是肠杆菌科中氟苯尼考高耐药率的主要原因。pLA-64编码的与耐药基因相关的可移动遗传元件可能在不同物种或属的细菌之间转移，导致耐药性传播。
