Inoue S, Ohue T, Yamagishi J, Nakamura S, Shimizu M
Antimicrob Agents Chemother. 1978 Aug;14(2):240-5. doi: 10.1128/AAC.14.2.240.
Spontaneous mutants with various patterns of resistance to pipemidic acid (PPA), piromidic acid (PA), and nalidixic acid (NAL) were isolated from Escherichia coli K-12. Most mutants were less resistant to PPA than to PA and NAL, and some mutants resistant to PA and NAL were hypersusceptible to PPA. As for the mutants tested, resistance to the drugs was conferred by mutations at nalA and new nal genes designated as nalC and nalD, both of which were located at about 82 min on the recalibrated map. Resistance to PA and NAL was due to decreased sensitivity of the bacterial DNA synthesizing system to them and insufficient drug transport, whereas resistance to PPA was only due to the former.
从大肠杆菌K-12中分离出了对吡哌酸(PPA)、吡咯米酸(PA)和萘啶酸(NAL)具有不同耐药模式的自发突变体。大多数突变体对PPA的耐药性低于对PA和NAL的耐药性,一些对PA和NAL耐药的突变体对PPA高度敏感。对于所测试的突变体,对这些药物的耐药性是由nalA以及新的nal基因(命名为nalC和nalD)的突变赋予的,这两个基因在重新校准的图谱上都位于约82分钟处。对PA和NAL的耐药性是由于细菌DNA合成系统对它们的敏感性降低以及药物转运不足,而对PPA的耐药性仅归因于前者。