Berger-Bächi B, Strässle A, Kayser F H
Eur J Clin Microbiol. 1986 Dec;5(6):697-701. doi: 10.1007/BF02013308.
A low affinity penicillin binding protein (PBP2') present in methicillin resistant strains but absent in isogenic sensitive strains of Staphylococcus aureus is responsible for the phenotypic expression of the methicillin resistance. An additional factor controlling methicillin resistance is known to map on the chromosome at the insertion site omega 2003 (chr::Tn551). The influence of this factor on PBP2' synthesis was analysed. Isogenic methicillin sensitive and resistant mutants derived from a Staphylococcus aureus strain carrying methicillin resistance factors and the omega 2003 (chr::Tn551) insertion were characterized by population analysis and restriction analysis of the DNA surrounding the Tn551 insertion site, and their PBP2' content was determined. Both methicillin resistant and sensitive mutants produced levels of PBP2' similar to those of the original methicillin resistant parent. The mere presence of this PBP2' could therefore not be solely responsible for the phenotypic expression of methicillin resistance. The nature and site of action of the additional factor determined by the omega 2003 (chr::Tn551) site controlling expression of methicillin resistance still remains unknown.
一种低亲和力青霉素结合蛋白（PBP2'）存在于耐甲氧西林的金黄色葡萄球菌菌株中，而在同源敏感菌株中不存在，它负责耐甲氧西林表型的表达。已知另一个控制耐甲氧西林的因素定位于染色体上的ω2003插入位点（chr::Tn551）。分析了该因素对PBP2'合成的影响。通过对Tn551插入位点周围DNA的群体分析和限制性分析，对携带耐甲氧西林因子和ω2003（chr::Tn551）插入的金黄色葡萄球菌菌株衍生的同源耐甲氧西林和敏感突变体进行了表征，并测定了它们的PBP2'含量。耐甲氧西林和敏感突变体产生的PBP2'水平与原始耐甲氧西林亲本相似。因此，仅这种PBP2'的存在不能单独导致耐甲氧西林表型的表达。由ω2003（chr::Tn551）位点决定的控制耐甲氧西林表达的额外因素的性质和作用位点仍然未知。
