BARBER M
J Clin Pathol. 1961 Jul;14(4):385-93. doi: 10.1136/jcp.14.4.385.
Eighteen strains of Staph. pyogenes (nine penicillin-sensitive and nine penicillin-destroying) were passaged 40 to 50 times on Celbenin(1) ditch plates. All strains developed an increase in resistance to Celbenin and eight strains (four penicillin-sensitive and four penicillin-destroying) were able to grow in 100 mug/ml. or more Celbenin. Resistance was of the drug-tolerant type and none of the cultures inactivated Celbenin. There was an associated increase in tolerance to benzyl penicillin. The highly Celbenin-resistant cultures isolated from penicillin-destroying staphylococci were in sharp contrast to those from penicillin-sensitive strains, as well as to penicillin G-tolerant staphylococci isolated in vitro, because they retained the cultural characteristics, coagulase and haemolytic activity, and mouse virulence of the parent strains, and the degree of resistance remained stable after repeated passage in the absence of Celbenin. Three naturally occurring Celbenin-resistant strains of Staph. pyogenes isolated from infective processes were also studied. All three strains grew luxuriantly in concentrations of Celbenin up to 12.5 mug/ml. but very poorly in higher concentrations. The possible significance of these findings is discussed.
18株化脓性葡萄球菌（9株对青霉素敏感，9株能破坏青霉素）在氯苯吩嗪（1）平板上传代40至50次。所有菌株对氯苯吩嗪的耐药性均有所增加，8株（4株对青霉素敏感，4株能破坏青霉素）能够在100微克/毫升或更高浓度的氯苯吩嗪中生长。耐药性属于耐药类型，且所有培养物均未使氯苯吩嗪失活。对苄青霉素的耐受性也相应增加。从能破坏青霉素的葡萄球菌中分离出的高度耐氯苯吩嗪的培养物，与从对青霉素敏感的菌株中分离出的培养物以及体外分离出的耐青霉素G的葡萄球菌形成鲜明对比，因为它们保留了亲本菌株的培养特性、凝固酶和溶血活性以及对小鼠的毒力，并且在无氯苯吩嗪的情况下反复传代后耐药程度保持稳定。还研究了从感染过程中分离出的3株天然耐氯苯吩嗪的化脓性葡萄球菌菌株。所有3株菌株在浓度高达12.5微克/毫升的氯苯吩嗪中生长旺盛，但在更高浓度下生长很差。讨论了这些发现的可能意义。
