铜绿假单胞菌临床分离株gyrA基因突变与喹诺酮类耐药关系研究

目的：了解铜绿假单胞菌临床分离株gyrA基因突变与喹诺酮类药物耐药的关系。研究其临床意义。方法：通过PCR HinfⅠ酶切分析，PCR－单链构象多态性分析（SSCP）等方法检测铜绿假单胞菌ATCC27853及36株铜绿假单胞菌临床分离株的gyrA基因突变情况。结果HinfⅠ酶切结果显示，所有13株环丙沙星耐药株，3株环丙沙星中介株中的2株，20株环丙沙星敏感株中的1株存在gyrA基因HinfⅠ酶切酶点突；SSCP分析结果显示，所有耐药菌株和中介菌株的gyrA基因基因HinfⅠ酶切位点突变密切相关，但gyrA基因突变不局限于该位点，在常规药敏试验的基础上开展gyrA基因突变检测有重要的临床意义。

Studies on relationship between gyrA gene mutation and quinolone resistance of Pseudomonas aeruginosa

Objective To observe the relationship between gyrA gene mutations and quinolone resistance of Pseudomonas aeruginosa and explore its clinical significance.Methods Mutations of gyrA gene were analysed with PCR RFLP and PCR SSCP in 36 clinical Pseudomonas aeruginosa strains and strain ATCC27853.Results The results of PCR RFLP showed that all 13 quinolone senstive strains,2 quinolone intermediate resistant strains and 1 quinolone sensitive strains exhibited gyrA gene mutations in Hinf I digestion.PCR SSCP showed that the genotype of all quinolone resistant strains and strain ATCC27853 were different from the standard strain.Conclusions There is a close relationship between quinolone resistance and the mutation of restriction site of gyr A gene by Hinf I digestion in Pseudomonas aeruginosa ,but the mutations do not be just limited in gyrA gene Hinf I digestion site.The findings in this study has important significance in detection of the gyrA gene mutations on the basis of routine drug susceptibility test of antibiotics.