Clinical Laboratory Center, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China.
Department of Gynecology and Obstetrics, Hua Zhong University of Science and Technology Union Shenzhen Hospital, Shenzhen 518000, China.
Diagn Microbiol Infect Dis. 2024 Mar;108(3):116180. doi: 10.1016/j.diagmicrobio.2024.116180. Epub 2024 Jan 4.
The use of glycopeptide medications may decline in line with the annual decline in methicillin-resistant Staphylococcus aureus (MRSA) detection rates in China. The rate of heterogeneous vancomycin-intermediate Staphylococcus aureus (hVISA)detection may be impacted by this. However, there is currently a dearth of information on the incidence of hVISA in China. This study aims to analyze the recent epidemiology and molecular characteristics of hVISA strains in Beijing, China. A total of 175 non-duplicate MRSA strains from various infection sites were collected from a medical center between January 2018 and May 2023 and underwent molecular typing and susceptibility testing (Vitek2). Vancomycin and teicoplanin MICs were also evaluated by standard broth microdilution method and agar dilution method, respectively. Isolates growing on screening agar (BHIV4 and BHIT5, brain heart infusion agar containing 4 μg/ml vancomycin and 5 μg/ml teicoplanin, respectively) were characterized further by analysis of macro-Etest (MET) and population analysis profiling with area under the curve (PAP-AUC). The proportion of hVISA among MRSA isolates was 8.6 %. BHIT5 could select all hVISA strains while BHIV4 and MET only selected two hVISA strains. Compared with vancomycin- susceptible Staphylococcus aureus (VSSA), hVISA isolates were less susceptible to erythromycin and clindamycin. In addition, hVISA frequency was MIC-independent despite using different detection methods. In total, 11 types of STs, 28 types of spa typing, four types of SCCmec typing, and two types of agr typing were identified and the predominant type in both MRSA and hVISA isolates was ST239-t030-SCCmecIII-agr I. The analysis of biofilm formation, growth, and virulence genes in hVISA strains revealed sparse information. The dataset presented in this study provided the prevalence and molecular characteristics of hVISA in hospital settings and the combination of BHIT5 and PAP-AUC may identify hVISA efficiently. The result of genotyping suggested the genotype of hVISA was mainly consistent with that of local MRSA. Additional studies on the characteristics of hVISA strains were necessary.
糖肽类药物的使用可能会随着中国耐甲氧西林金黄色葡萄球菌 (MRSA) 检出率的逐年下降而减少。这可能会影响异质性万古霉素中介金黄色葡萄球菌 (hVISA) 的检出率。然而，目前中国关于 hVISA 发病率的信息还很匮乏。本研究旨在分析中国北京地区 hVISA 菌株的近期流行病学和分子特征。从 2018 年 1 月至 2023 年 5 月，从一家医疗中心采集了来自不同感染部位的 175 株非重复 MRSA 菌株，进行了分子分型和药敏试验（Vitek2）。还通过标准肉汤微量稀释法和琼脂稀释法分别评估了万古霉素和替考拉宁的 MIC 值。在筛选琼脂（BHIV4 和 BHIT5，分别含有 4μg/ml 万古霉素和 5μg/ml 替考拉宁的脑心浸液琼脂）上生长的分离物通过宏检测（MET）和面积下曲线的种群分析轮廓（PAP-AUC）分析进一步表征。MRSA 分离株中 hVISA 的比例为 8.6%。BHIT5 可以选择所有 hVISA 菌株，而 BHIV4 和 MET 仅选择两株 hVISA 菌株。与万古霉素敏感金黄色葡萄球菌 (VSSA) 相比，hVISA 分离株对红霉素和克林霉素的敏感性较低。此外，尽管使用不同的检测方法，但 hVISA 频率与 MIC 无关。总共鉴定出 11 种 ST 型、28 种 spa 型、4 种 SCCmec 型和 2 种 agr 型，MRSA 和 hVISA 分离株的主要类型均为 ST239-t030-SCCmecIII-agr I。hVISA 菌株生物膜形成、生长和毒力基因分析的结果信息稀疏。本研究提供了医院环境中 hVISA 的流行率和分子特征，BHIT5 和 PAP-AUC 的结合可能有效地识别 hVISA。基因分型结果表明，hVISA 的基因型主要与当地的 MRSA 一致。需要进一步研究 hVISA 菌株的特征。
