北京地区社区获得性单纯性泌尿系感染病原菌对常用抗菌药物的体外活性分析

In vitro susceptibility of commonly used antibiotics on community-acquired uncomplicated urinary tract infection pathogens in Beijing

目的了解北京地区社区获得性单纯性泌尿系感染病原菌的分布及其对常用抗菌药物的体外抗菌活性。方法随机收集首都医科大学附属北京朝阳医院、北京大学人民医院和北京协和医院2010年1月1日至2011年3月31日300株社区获得性单纯性泌尿系感染的所有病原菌，用肉汤稀释法检测阿米卡星、头孢克洛、头孢吡肟、头孢哌酮／舒巴坦、环丙沙星、左氧氟沙星、庆大霉素、呋喃妥因8种抗生素对病原菌的体外抗菌活性；用琼脂稀释法检测磷霉素氨丁三醇对病原菌的体外抗菌活性；用双纸片协同法检测产超广谱p．内酰胺酶（extended-spectrump—lactamase，ESBLs）的病原菌。结果肠杆菌科细菌仍是单纯性泌尿系感染的主要病原菌（232株，77．3％）。300株分离的病原菌中，大肠埃希菌分离率最高（195株，65．0％），其余依次为肠球菌（35株，11．7％）、葡萄球菌（19株，6．3％）、肺炎克雷伯菌（16株，5．3％）、奇异变形杆菌（14株，4．7％）、铜绿假单胞菌（9株，3．0％）等。242株革兰阴性菌对阿米卡星、头孢哌酮／舒巴坦、呋喃妥因和磷霉素氨丁三醇的敏感率分别为92．1％、92．1％、88．4％、87．9％，对环丙沙星和左氧氟沙星的敏感率分别为34．7％和38．4％；葡萄球菌对阿米卡星、头孢哌酮／舒巴坦和呋喃妥因的敏感率分别为100．0％、94．7％和100．0％，对环丙沙星和左氧氟沙星的敏感率均为47．4％；肠球菌对呋喃妥因和磷霉素氨丁三醇的敏感率分别为91．4％和90．O％，对环丙沙星和左氧氟沙星的敏感率均为31．4％。232株肠杆菌科细菌中，111株（47．8％）产ESBLs，其中大肠埃希菌102株，肺炎克雷伯菌7株，奇异变形杆菌2株。结论北京地区社区获得性单纯性泌尿系感染病原菌对喹诺酮类药物的敏感率较低，对阿米卡星、头孢哌酮／舒巴坦、呋喃妥因和磷霉素氨丁三醇的敏感性较高，上述4种药物可作为治疗单纯性泌尿系感染的经验抗菌药物。

Objective To investigate the distribution and susceptibility patterns of common uropathogens causing community-acquired urinary tract infection （UTI） in Beijing. Methods A total of 300 non-duplicate isolates were randomly collected from 3 hospitals in Beijing between Jan, 1 2010 and Mar, 31 20ll. Minimal inhibitory concentrations （MICs） were determined by the broth microdilution methods, which were performed and interpreted according to the guidelines established by the Clinical and Laboratory Standards Institute （CLSI）. A panel of 8 antimicrohial agents were tested： amikacin, cefaclor, cefepime, cefoperazone/sulbactam, ciprofloxacin, levofloxacin, gentamicin and nitrofurantoin. Fosfomycin trometamol MICs were determined by the agar-dilution method in cation-adjusted MH agar supplemented with glucose 6- phosphate at a concentration of 25 mg/L as detailed in the guidelines issued by 2010 CLSI. All the Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis strains were screened and confirmed by double,disk synergy test for extended-spectrum 13-1aetamase （ESBLs）. Results Among the organisms cultured, E. coli was the predominant pathogen （65. 0% ）, followed by Enterococcus （11. 7% ）, Staphylococcus （ 6.3% ） , Klebsiella pneumoniae （ 5. 3% ） , Proteus mirabilis （ 4. 7% ） , and Pseudomonas aeruginosa （3.0%）. Lower susceptibility rates to ciprofloxacin and levofloxacin （31.4% - 47.4% ） were observed among all the stains. Amikaein, cefoperazone/sulbactam, nitrofurantoin and fosfomyein trometamol were the most active drugs （92.1% , 92. 1% , 88.4% and 87.9% susceptible strains, respectively） among the Gram-negative strains. Isolates of Staphylococctts were highly sensitive to amikacin （ 100.0% ） , cefoperazone/sulbactam （94.7%） , nitrofurantoin （ 100.0% ）. Higher susceptibility rates to nitrofurantoin （91.4%） and fosfomycin trometamol （90.0%） were observed in Enterococcus. ESBLs-producing strains accounted for 52.3% （102/195） in E. coli, 43.8% （7/16） in K. pneumoniae and 14.3% （2/14） in P. mirabilis, respectively. Conclusions Resistance is most common to ciprofloxacin and levo-floxaein of all the stains. Currently, the most appropriate agents for the empirical management of uncomplicated UTI seems to be amikacin, cefoperazone/sulbactam, nitrofurantoin and fosfomycin trometamol.