MOLECULAR ANAYSES OF FLUOROQUINOLONE RESISTANCE MECHANISAMS IN FLUOROQUINOLONE-RESISTANT CLINICAL ISOALTES RECOVERED FROM PATIENTS WITH GRNITOURINARY TRACT INFECTIONS

我们检测了从泌尿生殖道感染患者中回收的表皮葡萄球菌临床分离株对氟喹诺酮类药物的敏感性。我们阐明了氟喹诺酮耐药与gyrA和parC基因突变之间的关系，并检测了从复杂性尿路感染患者中分离的铜绿假单胞菌和粪肠球菌临床分离株中gyrA和parC基因突变的患病率。在40%的铜绿假单胞菌临床分离株中发现了基因突变;对于粪肠球菌，30%的临床分离株中发现了基因突变。在选择的氟喹诺酮耐药突变体中，我们发现gyrA和parC基因突变，这与临床氟喹诺酮耐药分离株中观察到的突变相似。我们用氟喹诺酮治疗由沙眼衣原体或生殖支原体引起的非淋菌性尿道炎（NGU）男性。我们成功地治疗了所有沙眼衣原体阳性NGU患者，但我们观察到一些生殖支原体阳性NGU患者治疗失败。在氟喹诺酮治疗后生殖支原体仍然阳性的患者中，我们检查了治疗前后检测到的支原体gyrA和parC基因突变。我们发现突变的parC基因，这表明出现的氟喹诺酮耐药菌株生殖支原体。

We examined clinical isolates of Staphylococcus epidermidis that were recovered from patients with genitourinary tract infections for susceptibility to fluoroquinolones. We clarified the association between fluoroquinolone resistance and mutations in the gyrA and parC genes.We examined clinical isolates of Pseudomonas aeruginosa and Enterococcus faecalis that were recovered from patients with complicated urinary tract infections for the prevalence of mutations in the gyrA and parC genes. In 40% of clinical isolates of P.aeruginosa, mutations in the genes were found ; for E.faecalis, 30% of clinical isolates had mutations in the genes .We selected fluoroquinolone-resistant strains of Neisseria gonorrhoeae by in vitro exposure of a fluoroquinolone-susceptible strain to norfloxacin. In the selected mutants with fluoroquinolone resistance, we found mutations in the gyrA and parC genes, which were analogous to those observed in clinical fluoroquinolone-resistant isolates.We treated the men with non-gonococcal urethritis (NGU) caused by Chlamydia trachomatis or Mycoplasma genitalium with fluoroquinolones. We successfully treated all the men with C.trachomatis-positive NGU, but we observed treatment failure in some cases with M.genitalium-positive NGU.In the men that remained positive for M.genitalium after fluoroquinolone treatment, we examined the mycoplasma, which were detected before and after the treatment, for mutations in the gyrA and parC genes. We found mutations in the parC gene, suggesting the emergence of fluoroquinolone-resistant strains of M.genitalium.