Frimodt-Møller N, Rosdahl V T, Sørensen G, Hartzen S H, Bentzon M W
J Antimicrob Chemother. 1986 Jul;18(1):27-33. doi: 10.1093/jac/18.1.27.
A total of 157 strains of Staphylococcus aureus of different phage patterns and penicillinase production were investigated for their susceptibility to methicillin, oxacillin, cloxacillin, dicloxacillin, flucloxacillin and cephalothin by an agar dilution method. Only strains of the 52, 52A, 80, 81 complex had significantly higher IC-50 values than the rest of the strains. No correlation was found between penicillinase production and the IC-50 values. Penicillinase susceptibility divided the antibiotics into two groups: one including methicillin, oxacillin and cephalothin, and the other included dicloxacillin, cloxacillin and flucloxacillin. Nineteen strains of S. aureus which existed in both a penicillinase producing and a penicillinase non-producing form were examined for susceptibility to the six antibiotics. The difference between penicillinase positive and penicillinase negative variants was especially marked for flucloxacillin and cephalothin. Methicillin induction prior to susceptibility testing had only a minor influence on the results. Investigation of the stability of methicillin and the four isoxazolyl penicillins against penicillinase production by 37 strains of S. aureus showed methicillin to be the most stable antibiotic. This was followed by dicloxacillin, cloxacillin, flucloxacillin, and oxacillin in that order. The order of stability was identical and independent of phage pattern and quantitative penicillinase production.
采用琼脂稀释法，对157株具有不同噬菌体分型和青霉素酶产生情况的金黄色葡萄球菌进行了甲氧西林、苯唑西林、氯唑西林、双氯西林、氟氯西林和头孢噻吩敏感性研究。只有52、52A、80、81型复合菌株的半数抑制浓度（IC-50）值显著高于其他菌株。青霉素酶产生与IC-50值之间未发现相关性。根据对青霉素酶的敏感性，将这些抗生素分为两组：一组包括甲氧西林、苯唑西林和头孢噻吩，另一组包括双氯西林、氯唑西林和氟氯西林。对19株同时存在产青霉素酶和不产青霉素酶两种形式的金黄色葡萄球菌进行了这六种抗生素的敏感性检测。氟氯西林和头孢噻吩的青霉素酶阳性和阴性变体之间的差异尤为明显。药敏试验前的甲氧西林诱导对结果影响较小。对37株金黄色葡萄球菌产生的青霉素酶，研究了甲氧西林和四种异恶唑青霉素的稳定性，结果表明甲氧西林是最稳定的抗生素，其次依次为双氯西林、氯唑西林、氟氯西林和苯唑西林。稳定性顺序相同，且与噬菌体分型和青霉素酶定量产生无关。
