Division of Infectious Diseases, School of Medicine, Universidad Nacional de Rosario, Rosario, Argentina.
Curr Opin Pharmacol. 2010 Oct;10(5):516-21. doi: 10.1016/j.coph.2010.06.006. Epub 2010 Jul 1.
Methicillin-resistant Staphylococcus aureus (MRSA) with decreased susceptibility to glycopeptides can be categorized as first, heteroresistant to vancomycin (hVISA); second, with intermediate susceptibility to vancomycin (VISA); and third, fully resistant to vancomycin (VRSA). Whereas the hVISA and VISA isolates are characterized by increased cell wall thickness, activated cell wall synthesis and reduced autolysis, VRSA harbor the vanA gene cluster resulting in a remodeled peptidoglycan. Nonsusceptibility to daptomycin has been associated with changes in the structure and function of the cell envelope and surface charge. Linezolid resistance in MRSA is often associated with mutations in the 23S rRNA, although resistance mediated by an acquired gene (cfr encoding a 23S rRNA methyltransferase) has now been documented in several continents and in outbreak settings.
耐甲氧西林金黄色葡萄球菌(MRSA)对糖肽类药物的敏感性降低可分为以下三种类型:第一,对万古霉素表现为异质性耐药(hVISA);第二,对万古霉素的敏感性为中间程度(VISA);第三,对万古霉素完全耐药(VRSA)。hVISA 和 VISA 分离株的特征是细胞壁增厚、细胞壁合成激活和自溶减少,而 VRSA 则携带 vanA 基因簇,导致肽聚糖结构重塑。对达托霉素的不敏感性与细胞包膜结构和表面电荷的变化有关。MRSA 对林可酰胺类药物的耐药性通常与 23S rRNA 发生突变有关,尽管现在已经在几个大洲和爆发环境中记录到由获得性基因(编码 23S rRNA 甲基转移酶的 cfr 基因)介导的耐药性。