1Department of Clinical Microbiology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, 197 Ruijin 2nd Road, Shanghai, 200025 China.
2Department of Clinical Laboratory, Shanghai Pudong Hospital, Fudan University Pudong Medical Center, 2800 Gongwei Road, Huinan Town, Pudong, Shanghai, 201399 China.
Antimicrob Resist Infect Control. 2019 Jul 15;8:117. doi: 10.1186/s13756-019-0563-x. eCollection 2019.
Clindamycin is a lincosamide antibiotic used to treat staphylococcal and streptococcal infections. Reports of clinical isolates with the rare lincosamide resistance/macrolide susceptibility (L/M) phenotype are increasing worldwide. In this study, we characterised three clinical strains with the unusual L phenotype from China.
Three clinical strains, Sag3, Sag27 and Sag4104, with the L phenotype were identified from 186 isolates collected from 2016 to 2018 in Shanghai, China. The MICs of clindamycin, erythromycin, tetracycline, levofloxacin, and penicillin were determined using Etest. PCR for the gene was conducted. Whole genome sequencing and sequence analysis were carried out to investigate the genetic context of . Efforts to transfer lincomycin resistance by conjugation and to identify the circular form by inverse PCR were made.
Sag3, Sag27, and Sag4104 were susceptible to erythromycin (MIC ≤0.25 mg/L) but resistant to clindamycin (MIC ≥1 mg/L). was found to be responsible for the L phenotype. in Sag3 and Sag27 were chromosomally located in an resistance gene cluster adjacent to an upstream 7-kb resistance gene cluster. Two resistance gene clusters were flanked by the IS6-like element, IS1216. Sag4104 only contained partial genes of resistance gene cluster and was also flanked by IS1216.
These results established the presence of the L phenotype associated with in clinical isolates in China. The -containing multi-resistance gene cluster possibly acts as a composite transposon flanked by IS1216 and as a vehicle for the dissemination of multidrug resistance among .
克林霉素是一种林可酰胺类抗生素，用于治疗葡萄球菌和链球菌感染。全球范围内越来越多的报告显示，临床分离株出现罕见的林可酰胺耐药/大环内酯类药物敏感性（L/M）表型。在本研究中，我们对来自中国的三株具有不寻常 L 表型的临床菌株进行了特征描述。
从 2016 年至 2018 年在中国上海收集的 186 株分离株中鉴定出三株具有 L 表型的临床菌株，分别为 Sag3、Sag27 和 Sag4104。使用 Etest 测定克林霉素、红霉素、四环素、左氧氟沙星和青霉素的 MIC。进行 PCR 检测 基因。进行全基因组测序和序列分析，以研究 的遗传背景。通过接合转移尝试传递林可霉素耐药性，并通过反向 PCR 鉴定环形形式。
Sag3、Sag27 和 Sag4104 对红霉素敏感（MIC≤0.25mg/L），但对克林霉素耐药（MIC≥1mg/L）。发现 负责 L 表型。Sag3 和 Sag27 中的 位于与上游 7kb 耐药基因簇相邻的耐药基因簇中。两个耐药基因簇被 IS6 样元件 IS1216 所包围。Sag4104 仅含有 耐药基因簇的部分基因，也被 IS1216 所包围。
这些结果证实了中国临床分离株中存在与 相关的 L 表型。含有 耐药基因簇的 - 可能作为一个复合转座子，由 IS1216 侧翼，并作为多药耐药性在 中传播的载体。
