Zhou Shan, Zhou Ke, Yang Peihong, Kong Meijuan, Liu Hao, Zhang Rui, Hou Zheng, Liu Jiayun
Department of Clinical Laboratory, Xijing Hospital, Air Force Medical University, Xi'an, Shanxi, 710032, People's Republic of China.
Institute of Medical Research, Northwestern Polytechnical University, Xi'an, Shanxi, 710129, People's Republic of China.
Infect Drug Resist. 2025 Jun 12;18:2987-2996. doi: 10.2147/IDR.S508027. eCollection 2025.
This study examines the distribution of pathogens and the characteristics of linezolid-resistant (LRSA) in osteoarticular infections (OAIs) over an 11-year period.
Identification and initial antimicrobial susceptibility testing were conducted using the VITEK2 compact system. Broth microdilution method (BMD) to confirm linezolid-resistant isolates. The results were interpreted according to the Clinical and Laboratory Standards Institute (CLSI) guideline. Polymerase chain reaction (PCR) screening identified linezolid-resistance-related genes and molecular typing loci.
From 2012 to 2022, 2049 clinical isolates were collected, with identified as the leading pathogen, constituting 38.90% (797/2049) of cases. Among the 797 isolates, eight strains were initially identified as LRSA through VITEK2; however, only one isolate was confirmed as LRSA by BMD. For the eight strains, molecular typing revealed four spa types (t030, t037, t002, t437) and three MLST types, with ST239-t030 as the dominant clone. No transferable resistance genes () were detected, but a G2576T mutation, associated with reduced linezolid sensitivity, was identified in two isolates (included the isolate confirmed as LRSA by BMD) subjected to extended linezolid therapy.
Our findings highlight the importance of accurate susceptibility testing and proactive monitoring of LRSA in the treatment of chronic OAIs to mitigate potential therapeutic challenges.
本研究考察了11年间骨关节炎感染（OAIs）中病原体的分布及耐利奈唑胺金黄色葡萄球菌（LRSA）的特征。
使用VITEK2紧凑型系统进行鉴定和初始药敏试验。采用肉汤微量稀释法（BMD）确认耐利奈唑胺菌株。结果依据临床和实验室标准协会（CLSI）指南进行解读。聚合酶链反应（PCR）筛查鉴定耐利奈唑胺相关基因和分子分型位点。
2012年至2022年共收集2049株临床分离株， 被确定为主要病原体，占病例的38.90%（797/2049）。在797株 分离株中，通过VITEK2最初鉴定出8株为LRSA；然而，经BMD确认仅1株为LRSA。对这8株菌株进行分子分型，发现有4种spa型（t030、t037、t002、t437）和3种多位点序列分型（MLST）型，其中ST239 - t030为优势克隆。未检测到可转移耐药基因（ ），但在接受延长疗程利奈唑胺治疗的2株分离株（包括经BMD确认为LRSA的分离株）中鉴定出与利奈唑胺敏感性降低相关的G2576T突变。
我们的研究结果凸显了在慢性OAIs治疗中准确进行药敏试验和对LRSA进行主动监测以应对潜在治疗挑战的重要性。
