Impact of sigB mutation on Staphylococcus aureus oxacillin and vancomycin resistance varies with parental background and method of assessment.
Impact of sigB mutation on Staphylococcus aureus oxacillin and vancomycin resistance varies with parental background and method of assessment.
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DOI：
10.1016/s0924-8579(02)00359-x
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发表时间：
2003-03
影响因子：
10.8
通讯作者：
V. Singh;Jennifer L. Schmidt;R. Jayaswal;B. Wilkinson
中科院分区：
文献类型：
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作者：
V. Singh;Jennifer L. Schmidt;R. Jayaswal;B. Wilkinson
先前对金黄色葡萄球菌转座子插入突变体的研究显示，甲氧西林或替考拉宁耐药性降低，表明RNA聚合酶替代因子SigB在表达对这些抗生素的耐药性中发挥作用。在S.金黄色葡萄球菌菌株COL sigB基因及其对苯唑西林和万古霉素耐药性的影响进行了研究。通常，甲氧西林耐药菌株的sigB突变体的苯唑西林最低抑菌浓度（MIC）的一半，其亲本菌株。sigB突变的影响似乎更显着时，通过人口分析概况或在摇瓶中的液体培养物中的生长比MIC测定进行评估。通过常规测定，COL和COLΔsigB突变体的苯唑西林MIC分别为400和200 mg/l，根据群体分析曲线，分别为800和100-200 mg/l。在摇瓶培养中，COLΔsigB突变株比COL株更明显地受到一系列苯唑西林浓度的抑制。sigB突变导致两种实验室衍生的糖肽中间体S中万古霉素抗性的降低。金黄色葡萄球菌结果表明，一些表达受SigB控制的蛋白质产物在对细胞壁活性抗生素的抗性中起作用。
Previous studies of Staphylococcus aureus transposon insertion mutants showing decreased methicillin or teicoplanin resistance have suggested a role for the RNA polymerase alternative sigma factor SigB in the expression of resistance to these antibiotics. A knockout mutation was created in the S. aureus strain COL sigB gene and its influence on oxacillin and vancomycin resistance was studied in a variety of parental backgrounds. Typically, sigB mutants of methicillin-resistant strains had oxacillin minimum inhibitory concentrations (MICs) one-half of their parent strains. The effect of the sigB mutation appeared to be more dramatic when assessed by population analysis profiles or by growth in liquid culture in shaking flasks than by MIC determinations. Oxacillin MICs of COL and the COLΔsigB mutant were 400 and 200 mg/l, respectively, by conventional determination and 800 and 100–200 mg/l from population analysis profiles. The COLΔsigB mutant strain was significantly more inhibited by a range of oxacillin concentrations in a shake flask culture than strain COL. Mutation of sigB caused a decrease in vancomycin resistance in two laboratory derived glycopeptide-intermediate S. aureus strains. The results suggest that some protein products whose expression is controlled by SigB play a role in resistance to cell wall-active antibiotics.