摘要
【目的】研究解脲脲原体(Uu)编码Ⅱ型拓扑异构酶的基因喹诺酮耐药决定区(QRDR)突变与环丙沙星耐药的关系。【方法】对喹诺酮类药物敏感的Uu临床分离株用环丙沙星进行耐药诱导培养,产生第一代和第二代耐药突变株。检测环丙沙星对Uu标准株、临床分离株、第一代和第二代耐药突变株的最低抑菌浓度(MIC),并对这些菌株的QRDR进行基因测序。【结果】第一代耐药突变株均在编码拓扑异构酶Ⅳ的基因的QRDR上发生了点突变;第二代耐药突变株则在继承了前代的点突变之后,均在编码DNA促旋酶的基因的QRDR上发生了额外的点突变。【结论】QRDR突变可导致Uu对环丙沙星产生耐药;环丙沙星对Uu的首要靶酶是拓扑异构酶Ⅳ。
【Objective】To research the correlation between mutations of the quinolone resistance-determining regions（QRDRs） of gene that encodes type Ⅱ topoisomerase of Ureaplasma urealyticum with resistance to ciprofloxacin.【Methods】Clinical isolate of Ureaplasma urealyticum sensitive to quinolones was induced by ciprofloxacin,then the first and the second generations of resistant mutants were got.The MICs of ciprofloxacin against Ureaplasma urealyticum reference strain,the clinical isolate and the resistant mutants were determined,and QRDRs of these Ureaplasma urealyticum were sequenced.【Results】Each of the first generation of resistant mutants had a mutation in the QRDR of gene that encoded topoisomerase Ⅳ.Both of the second generation of resistant mutants not only inherited the mutation of their previous generations,but also had an additional mutation in the QRDR of gene that encoded DNA gyrase.【Conclusion】The mutations of QRDRs can result in the resistance to ciprofloxacin in Ureaplasma urealyticum.The primary target of ciprofloxacin in Ureaplasma urealyticum is topoisomerase Ⅳ.
出处
《医学临床研究》
CAS
2007年第6期898-901,共4页
Journal of Clinical Research
