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

摘要

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。%Objective To investigate the antimicrobial susceptibilities of nosocomial multi-drug resistant Acinetobacter 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 com-monly 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 .Re-sults A total of 664 MDR-AB and 268 MDR-PA isolates were collected .Pan-drug resistant ( PDR) was detec-ted 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%and 72.6% 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 mero-penem 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 resist -ant profiles .Conclusions Colistin and tigecycline are the most active drugs against MDR-AB, while colistin and amikacin have comparably good performance to MDR-PA.