广州淋球菌基因特征及其多抗原序列分型与环丙沙星耐药相关性研究  

Genetic characteristics of Neisseria gonorrhoeae isolates from Guangzhou city and relationship between their multi-antigen sequence typing sequence types and ciprofloxacin resistance

作　　者：陈霄霄[1] 梁景耀[1] 曹文苓[2] 黎小东[2] 杨娟[1] 薛如君[1] 张锡宝[2] 

机构地区：[1]广州医科大学,510182 [2]广州医科大学皮肤性病研究所广州市皮肤病防治所

出　　处：《中华皮肤科杂志》2016年第5期353-356,共4页Chinese Journal of Dermatology

基　　金：广州市卫生局重点项目（201102A212016）

摘　　要：目的探讨2014年广州市97株淋球菌环丙沙星耐药株的基因特征及其多抗原序列分型（NG～MAST）与淋球菌耐环丙沙星的相关性。方法用琼脂稀释法测定淋球菌对环丙沙星的最低抑菌浓度（MIC），PCR分别扩增淋球菌的gyrA、parC基因和NG—MAST分型基因porB、tbpB基因并测序，获取耐药菌株的sT型别。结果97株淋球菌中95株（97．9％）对环丙沙星耐药。95株环丙沙星耐药菌株均在gyrA基因对应丝氨酸的第91和95位点上发生了突变，其中93株菌出现了parC基因突变。41株高水平耐药株（MIC≥16m∥L）中35株（85．4％）出现了parC基因87位点突变，54株低水平耐药株中32株（59．3％）出现此突变，差异有统计学意义（Z：7．64，P〈O．05）。96株淋球菌分离株配对后，50株为网站已编号型别，共35个不同的ST型，其中10个ST型含有2—4个不同的分离株，sT型别中最常见ST5309。对淋球菌菌株系统进化树分析，淋球菌流行株可分为两群，第1群84株中MIC≥16mg／L的菌株39株占46．4％，第2群12株中只有1株MIC值为16mg／L，差异有统计学意义（r=6．27，P=0．012）。结论淋球菌对环丙沙星的高水平耐药主要与parC基因87位点突变相关。NG—MAST分型与环丙沙星耐药程度高低可能存在相关性。Objective To investigate genetic characteristics of Neisseria gonorrhoeae （N.gonorrhoeae） isolates from Guangzhou city in 2014,and to analyze the relationship of N.gonorrhoeae multi-antigen sequence typing （NGMAST） sequence types （STs） with ciprofloxacin resistance.Methods An agar dilution method was used to determine the minimal inhibitory concentration （MIC） of ciprofloxacin in 97 N.gonorrhoeae isolates from Guangzhou city.PCR was performed to amplify the gyrA,parC,porB and tbpB genes from these isolates,followed by gene sequencing and determination of NG-MAST STs.Results Of the 97 N.gonorrhoeae isolates,95 （97.9%） were resistant to ciprofloxacin,including 41 high-level （MIC ≥ 16 mg/L） and 54 low-level （1 mg/L ≤ MIC 〈 16 mg/L） resistant strains.Mutations were detected at codons 91 and 95 encoding serine in the gyrA gene of all the 95 ciprofloxacin-resistant strains,and in the parC gene of 93 resistant strains.The frequency of the mutation at codon 87 in the parC gene was 85.4% （35/41） in high-level resistant strains,significantly higher than that in low-level resistant strains （59.3%[32/54],x2 =7.64,P 〈 0.05）.MAST STs were successfully determined for all the 97 N.gonorrhoeae isolates except 1 isolate with incorrect PCR amplicons.Of the 96 genotyped isolates,50 were assigned to 35 known STs by using the NG-MAST website （www.ngmast.net）,among which,10 STs each contained 2 to 4 isolates.The most common ST was ST5309.Phylogenetic tree analysis revealed that the 96 genotyped N.gonorrhoeae isolates could be classified into 2 groups,and the proportion of isolates with MIC ≥ 16 mg/L is 46.4% （39/84） in group 1,but only 1/12 in group 2 （x2 =6.27,P=0.012）.Conclusions High-level resistance of N.gonorrhoeae to ciprofloxacin may be mainly associated with the mutation at codon 87 in the parC gene.NG-MAST STs may be related to the degree of ciprofloxacin resistance.

关 键 词：淋病奈瑟球菌 环丙沙星 抗药性 细菌 NG—MAST分型 

分 类 号：R440[医药卫生—诊断学]