放射性^(125)碘标记阿莫西林研究临床分离MRSA青霉素结合蛋白

Studies of (125)~I-radioIabeIed Amoxycillinfor Penicillin-binding Proteins, of Clinincal Isolated MRSA

目的:本文以放射性125碘标记阿莫西林研究-临床分离MRSA青霉素结合蛋白(PBPs),探讨高耐药及低耐药不产酶MRSA青霉素结合蛋白的改变。方法:用125I-阿莫西林与ATCC25923、临床分离MRSA及MSSA结合,SDS-PAGE分离检测PBPs的改变。结果:SDS-PAGE分离检测PBPs,高耐药株在78KDa处有放射性,低耐药株放射性低于敏感株。结论:125I-阿莫西林与MRSA结合降低,高耐药株产生低亲和力的PBP2a,低耐药株PBPs与阿莫西林结合下降。

125I-radiolabeled amoxycillin is used to study for the penicillin-binding proteins (PBPs) of clinical isolated MRSA. The resistsnt strains did not produce detectable β-lactamase activity. Penicillin-binding proteins was separated by SDS-PAGE. The samples of PBPs were obtained using whole organisms treated with 125I-amoxycillin. High-level resistant strains produced a new PBP fraction (PBP2a), which was low binding affinities for β-lactam antibiotics. In low-level resistant strains, the binding of amoxycillin was decreased.