全国27所医院多重耐药鲍曼不动杆菌及铜绿假单胞菌对12种抗菌药物的敏感性

目的研究医院感染相关多重耐药鲍曼不动杆菌(multi-drug resistant Acinetobacter baumannii,MDR-AB)及多重耐药铜绿假单胞菌(multi-drug resistant Pseudomonas aeruginosa,MDR-PA)对12种抗菌药物的敏感性。方法收集2011年8月至2012年7月全国27所教学医院分离的医院感染相关MDR-AB及MDR-PA菌株。所有菌株均分离自有明确感染意义的临床标本,严格排除痰及筛查性拭子。菌株收集后统一在微生物实验室采用微量肉汤稀释法,测定其对12种抗菌药物的最小抑菌浓度(minimum inhibitory concentration,MIC),并同时用CLSI M100-S24及M100-S23/S21鲍曼不动杆菌和铜绿假单胞菌的碳青霉烯类新旧折点进行对比分析。结果本研究共收集到MDR-AB 664株,未发现全耐药鲍曼不动杆菌;收集到MDR-PA 268株,其中有4株全耐药铜绿假单胞菌。外科病房及ICU病房是多重耐药菌株的主要来源。MDR-AB对黏菌素的敏感率最高,为96.8%;替加环素的敏感率为72.6%,其余药物的敏感率均低于55%。MDR-PA对黏菌素的敏感率仅为72.4%,但对阿米卡星的敏感率(64.2%)明显高于MDR-AB(16.7%)。在CLSI折点改变后,MDR-AB对亚胺培南及美罗培南的敏感率仅分别下降了1.3%和0.6%,但MDR-PA对亚胺培南及美罗培南的敏感率分别下降了5.5%和8.6%。ICU病房来源的MDR-AB及MDR-PA对碳青霉烯酶类药物敏感率都明显低于外科及其他病房。不同地域来源多重耐药菌株的耐药谱有所差异。结论黏菌素和替加环素对MDR-AB有良好的抗菌活性,黏菌素及阿米卡星对MDR-PA抗菌活性较好。

Antimicrobial Susceptibility of Multi-drug Resistant Acinetobacter Baumannii and Pseudomonas Aeruginosa Isolates from 27 Hospitals in China

Objective To investigate the antimicrobial susceptibilities of nosocomial multi-drug resistantAcinetobacter baumannii（ MDR-AB） and multi-drug resistant Pseudomonas aeruginosa（ MDR-PA） isolates.Methods MDR-AB and MDR-PA isolates were collected between August 2011 and July 2012 from 27 hospitals in China. All isolates were collected from high quality samples with definite infection diagnoses,whilst isolates from sputum and screen samples were strictly excluded. Minimum inhibitory concentrations（ MICs） of 12 commonly used antimicrobial agents were tested by broth microdilution method in a microbiology laboratory. CLSI clinical breakpoints（ CBPs） of pre-and post-revision were applied and compared in determination of MDR. Results A total of 664 MDR-AB and 268 MDR-PA isolates were collected. Pan-drug resistant（ PDR） was detected in four Pseudomonas aeruginosa but not in Acinetobacter baumannii. The majority of isolates were collected from ICUs and surgical wards. Colistin and tigecycline were the most active agents against MDR-AB（ 96. 8% and72. 6% susceptible,respectively）,while no other drug exhibited activity of 55% susceptible. Only 72. 4% of MDR-PA isolates remained susceptible to colistin,but amikacin was more active to MDR-PA（ 64. 2%） than MDR-AB（ 16. 7%）. By applying revised CBPs,the susceptibility of MDR-AB isolates to imipenem and meropenem decreased by 1. 3% and 0. 6%,respectively,whereas the susceptibility of MDR-PA to these two drugs decreased by〉 5. 5% and 8. 6%,respectively. The carbapenems susceptible rate of isolates collected from ICUs was lower than surgical and other wards. Isolates collected from different geographic regions showed varied resistant profiles. Conclusions Colistin and tigecycline are the most active drugs against MDR-AB,while colistin and amikacin have comparably good performance to MDR-PA.