淋球菌对头孢克肟等6种抗生素敏感性及耐药质粒分型研究

In Vitro Susceptibility to 6 Antimicrobial Agents and the Resistance Plasmids Genotype of Neisseria gonorrhoeae Isolates from 4 Cities in Guangdong

目的:检测2011年广东省广州、佛山、江门、肇庆四市临床分离的淋球菌流行株对青霉素、四环素、环丙沙星、头孢克肟、头孢曲松和大观霉素等6种抗生素的敏感性,对质粒介导的产β-内酰胺酶淋球菌(PPNG)和四环素高水平耐药淋球菌(TRNG)进行耐药质粒TEM-1和tetM基因分型。方法:采用琼脂稀释法测定菌株对6种抗菌药物的最小抑菌浓度(MIC),判断敏感性按WHO西太区淋球菌耐药性监测统一标准,其中头孢克肟敏感性试验和判断标准按美国临床和实验室标准化研究所(CLSI)判断。用纸片酸度法检测产β-内酰胺酶淋球菌(PPNG)菌株,多重PCR方法鉴定β-内酰胺酶质粒并进行TEM-1和TRNG tetM基因分型。结果:来自四市429株淋球菌中检出青霉素耐药364株(84.8%),四环素和环丙沙星耐药株(率)分别为389株(90.7%)和418株(97.4%),未发现对大观霉素、头孢克肟和头孢曲松耐药菌株,但头孢曲松低敏率达到34.0%(146/429),头孢克肟低敏只有1株(0.2%)。青霉素、四环素和环丙沙星的MIC50及MIC90均已超过耐药标准。检出PPNG株156株(36.4%),TRNG株201株(46.9%)。耐药质粒TEM-1基因分型以亚洲型为主(94.9%,148/156),只有8株携带非洲型质粒;tetM基因分型均为荷兰型。结论:四市淋球菌对青霉素、四环素和环丙沙星耐药率较高,对大观霉素、头孢克肟和头孢曲松的敏感性较高,TEM-1基因质粒分型以亚洲型为主,tetM基因分型均为荷兰型。

Objective：To assess the in vitro susceptibility to 6 antimicrobial agents and TEM-1, tetM genotypes of clinical isolates of Neisseria gonorrhoeae from 4 cities in Guangdong province in 2011. Methods ：The agar dilution method was used to determine the minimum inhibitory concentrations （MICs） to six antibiotics, penicillin G, tetracycline, ciprofloxaein, cefixime, ceftriaxone and spectinomycin. The susceptibility of all strains to five antibiotics was interpreted according to criteria adopted in the project of surveillance of gonococcal antibiotic susceptibility in the WHO Western Pacific Region and cefixime susceptibility was interpreted as Clinical and Laboratory Standards Institute （CLSI）. Penicillinase （β-lactamase） -producing N. gonorrhoeae （PPNG） was analysed by the paper acidometric method. A multi-PCR was used to distinguish subtypes of TEM-1 and tetM. Results： 429 strains of N. gonorrhoeae collected from Guangzhou, Foshan, Jiangmen and Zhaoqin in Guangdong province were studied. 364 isolates （84. 8% ） showed resist, ance to penicillin. The prevalence of tetracycline- and ciprofloxacin-resistance was 90. 7% and 97.4%, while none of the strains appeared to be resistant to spectinomycin, cefixime and ceftriaxone, respectively, but 146（34.0% ） and 1 （0. 2% ） showed reduced sensitivity to ceftriaxone and cefixime. MIC50 and MIC90 of penicillin, tetracycline and ciprofloxacin were significantly higher than resistant standards. 156（36.4% ） strains were PPNG and 201 （46.9%） strains were TRNG. Subtyping of TEM-1 gene in β-lactamase plasmids of PPNG showed that 148 （94. 9% ） PPNGs carried the Asian-type plasmids while African-type plasmid was found in only 8 strains. Subtyping of tetM gene showed that all 201 TRNGs were Dutch variant. Conclusion：Resistance to penicillin, tetracycline and ciprofloxacin spreads seriously in four cities of Guangdong province. The isolates of N. gonorrhoeae show better susceptibility to spectiomycin, cefixime and ceftriaxone. The Asian-type β - lactamase plasmids are dominant in PPNG, while African-type plasmid is sporadic. All of the TRNGs carry the Dutch variant plasmid.