【摘要】 目的探讨嗜麦芽窄食单胞菌的DNA解旋酶和拓扑异构酶Ⅳ与氟喹诺酮类抗菌药物的耐药关系。方法选择氟喹诺酮类抗菌药物耐药且主动外排表型机制阴性的临床分离菌株19株和氟喹诺酮类抗菌药物敏感株10株,对其gyrA和parC的喹诺酮决定区域的基因进行PCR扩增,扩增产物进行测序,BLAST比对分析其氨基酸序列。采用SPSS软件进行统计学分析。结果 19株耐药菌的gyrA和parC基因各有7株菌核苷酸发生了碱基替换改变但均为同义突变,有2株菌在gyrA基因中124位氨基酸发生了突变由谷氨酸变为天冬氨酸(GAA→GAC),在氟喹诺酮类抗菌药物敏感组中也同样有1株发生同样的突变,两组比较差异无统计学意义(P>0.05)。结论嗜麦芽窄食单胞菌对氟喹诺酮类抗菌药物耐药与主动外排泵、外膜的通透性降低有关,但与解旋酶和拓谱异构酶Ⅳ的靶位点改变无显著关系。更多还原

【Abstract】 Objective To research the relationship between DNA gyrase,topoisomerase Ⅳ and Stenotrophomonas maltophilia to fluoroquinolone resistance.Methods 19 resistant strains with negative for efflex mechanism and 10 sensitive strains were selected to amplify their quinolone resistence determining regions of gyrA and parC,and to analyze the nucleotide sequence.The data were analyzed by SPSS software.Results Of 19 strains of Stenotrophomonas maltophilia to fluoroquinolone resistance strains of gyrA gene and parC gene,7 strains were observed the nucleoside changes in each,while those base subtitutions were same sense mutation.2 strains showed amino acid changes in position 124 leading to substitution Glu by Asp(GAA→GAC),the same amino acid mutation was found in the controls.No significant difference was found between 2 groups(P>0.05).Conclusions Fluoroquinolone resistance in Stenotrophomonas maltophilia is related to active effax pump,and it may be correlated with a low level of permeability,but not asscociatad with gyrase and topoisomerase Ⅳ.更多还原