Division of Immunity and Infection, The Medical School, University of Birmingham, and Health Protection Agency West Midlands Public Health Laboratory, Heart of England NHS Foundation Trust, Birmingham, UK.
Clin Microbiol Infect. 2009 Dec;15 Suppl 7:2-9. doi: 10.1111/j.1469-0691.2009.03094.x.
Vancomycin resistance in Staphylococcus aureus has emerged over the last ten years due to varying mechanisms and giving variable levels of resistance to vancomycin. The most resistant strains (fortunately rare) bear the vanA gene cluster and these are generally recognisable as MICs of vancomycin are usually found to be in the range 32-64mg/L. It should be noted that some automated systems have failed to detect these isolates. The much more commonly encountered GISA and hGISA vancomycin resistant strains of MRSA and methicillin sensitive Staph. aureus (MSSA) exhibit lower levels of resistance and difficulty is encountered in reliably defining and identifying these strains in clinical laboratories. No single completely reliable, convenient test either phonotypical genetic currently exists which can be readily applied in the clinical laboratory for the detection of hGISA/GISA. The population analysis profile (PAP) method is currently regarded as the reference method but is slow and tedious to perform on a large number of isolates. This enables the differentiation of hGISA and GISA from fully vancomycin sensitive strains. In the clinical laboratory the use of Meuller-Hinton agar with 5mg/L teicoplanin and a 10microL innoculum of MacFarland 0.5 incubated for 48h represents the most reliable and economical screening test. Further confirmation would be required using either macrodilution Etest methodology using an MIC >or= 8mg/L of vancomycin and/or teicoplanin as the cut off for hGISA or the newer GRD (glycopeptide resistance detection) strip.
耐万古霉素的金黄色葡萄球菌在过去十年中出现，其耐药机制各不相同，对万古霉素的耐药程度也不同。耐药程度最高的菌株（幸运的是比较少见）携带 vanA 基因簇，这些菌株通常被认为 MIC 值为万古霉素通常在 32-64mg/L 范围内。值得注意的是，一些自动化系统未能检测到这些分离株。更为常见的万古霉素中介金黄色葡萄球菌（hGISA）和万古霉素中介耐甲氧西林金黄色葡萄球菌（MRSA）和甲氧西林敏感金黄色葡萄球菌（MSSA）菌株表现出较低的耐药性，在临床实验室中可靠地定义和鉴定这些菌株存在困难。目前，没有一种完全可靠、方便的表型或遗传测试方法可以在临床实验室中用于检测 hGISA/GISA。群体分析谱（PAP）方法目前被认为是参考方法，但在大量分离物上进行操作既缓慢又繁琐。这使得能够区分 hGISA 和 GISA 与完全对万古霉素敏感的菌株。在临床实验室中，使用含 5mg/L 替考拉宁的 Mueller-Hinton 琼脂和 10μL MacFarland 0.5 的接种物孵育 48h 是最可靠和经济的筛选试验。需要进一步使用 MIC>or=8mg/L 万古霉素和/或替考拉宁作为 hGISA 的截止值的微量稀释 Etest 方法学，或者使用新的 GRD（糖肽耐药检测）条进行确认。
