Genetic characterization of the natural SigB variants found in clinical isolates of Staphylococcus aureus
Genetic characterization of the natural SigB variants found in clinical isolates of Staphylococcus aureus
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DOI：
10.2323/jgam.52.259
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发表时间：
2006-10-01
影响因子：
1.2
通讯作者：
Ohta, Toshiko
中科院分区：
文献类型：
--
作者：
Inose, Yumiko;Takeshita, Sayaka L.;Ohta, Toshiko
测量金黄色葡萄球菌临床分离株中的 SigB 浓度，以检查其与抗生素耐药性的相关性。耐甲氧西林金黄色葡萄球菌 (MRSA) 中的 SigB 浓度高于对照菌株 N315 和许多甲氧西林敏感金黄色葡萄球菌 (MSSA)。 sigB 基因的测序分析表明，表现出高 SigB 浓度的菌株在 SigB 中具有三个氨基酸取代：I11V、D141N 和 Q256K。使用同基因突变体的进一步分析表明，D141N（或 D141N 和 Q256K）对于维持高 SigB 浓度至关重要。这些取代影响了紫外线耐受性，但对抗生素耐药性没有影响。 SigB 活性受到这些对固定相的取代的影响，但在瞬态热激响应期间不受影响。
The SigB concentrations in clinical isolates of Staphylococcus aureus were measured to examine their correlation with the antibiotic resistance. The SigB concentrations in methicillin-resistant S. aureus (MRSA) were higher than in the control strain, N315, and many of methicillin-susceptible S. aureus (MSSA). Sequencing analyses of the sigB genes revealed that the strains exhibiting the high SigB concentrations have three amino acid substitutions in SigB: I11V, D141N, and Q256K. Further analysis using isogenic mutants demonstrated that D141N (or both D141N and Q256K) is essential to maintain the high SigB concentration. These substitutions affected the UV tolerance, but had no effect on the antibiotic resistance. The SigB activity was affected by these substitutions toward the stationary phase, but not during the transient heat shock response.