2005年中国十五家教学医院院内获得革兰阴性病原菌耐药性分析

目的监测2005年我国不同地区15家教学医院分离的医院获得革兰阴性病原菌的耐药性。方法按设计方案收集非重复的1927株院内获得革兰阴性病原菌。菌株经中心实验室复核后，采用琼脂稀释法测定6类18种抗菌药物的最低抑菌浓度（MIC），数据输入WHONET5．4软件进行耐药性分析。结果不产超广谱β内酰胺酶（ESBLs）的大肠埃希菌、肺炎克雷伯菌和奇异变形杆菌对被测β内酰胺类药物的敏感性均较高，而对于产ESBLs的大肠杆菌和肺炎克雷伯菌，敏感率大于80％的药物只有美罗培南、亚胺培南和哌拉西林-三唑巴坦。不产ESBLs大肠埃希菌对氟喹诺酮类药物的敏感性很低（34．8％-36．1％），产ESBLs大肠埃希菌的敏感性则更低（13．4％～17．1％）。对于易产头孢菌素酶（AmpC）的菌株（包括阴沟肠杆菌、产气肠杆菌、枸橼酸杆菌属、沙雷菌属、普通变形杆菌），敏感率均大于80％的抗生素有美罗培南、亚胺培南、哌拉西林-三唑巴坦，另外，敏感性较高的抗菌药物还包括头孢吡肟（67．3％-100％）、阿米卡星（67．3％～95．2％）、头孢他啶（52．9％-100％）和头孢哌酮-舒巴坦（51．9％～100％），氟喹诺酮类药物的敏感率为52．5％～86．2％。铜绿假单胞菌对多黏菌素B的敏感性最高（95．6％），敏感率在70％～80％之间的药物有美罗培南、亚胺培南、阿米卡星和哌拉西林-三唑巴坦。鲍曼不动杆菌对多黏菌素B的敏感率达98．3％，继之为亚胺培南（80．8％）、美罗培南（76．2％）和米诺环素（67．4％），其他药物的敏感率低于60％。对嗜麦芽窄食单胞菌，敏感性较高的抗菌药物有米诺环素（85．0％）、左氧氟沙星（82．5％）和甲氧苄啶-磺胺甲曙唑（77．5％）。对洋葱伯克霍尔德菌，敏感性相对较高的抗菌药物有米诺环素（77．2％）和美罗培南（61．4％）。结论碳青酶烯类、哌拉西林-三唑巴坦、阿米卡星和头孢吡肟对医院分离的肠杆菌科菌保持了较高的抗菌活性，而非发酵革兰阴性杆菌对临床常用药物的敏感性较以往监测有所降低。

Surveillance of antimicrobial resistance among nosocomial gram-negative pathogens from 15 teaching hospitals in China in 2005

OBJECTIVE: To investigate the antimicrobial resistance among the nosocomial gram-negative pathogens from 15 teaching hospitals located in different areas in China in 2005. METHODS: A total of 1927 non-repetitive nosocomial gram-negative pathogens were collected from 15 teaching hospitals in different areas in China and sent to the central lab for reidentification and susceptibility testing. The levels of minimal inhibitory concentration (MIC) of 18 antimicrobial agents were determined by agar dilution method. WHONET 5.4 software was used to analyze the data. RESULTS: The strains of Escherichia coli, Klebsiella pneumoniae, and Proteous mirabilis isolates that did not produce extended spectrum beta lactamases (ESBLs) showed high sensitivity to beta-lactams. The antibiotics with a susceptibility rates over 80% against the strains of Entorobacter cloacae, Enterobacter aerogene, Citrobacter spp, Serratia spp, and Proteous vulgaris producing AmpC enzyme included meropenem, imipenem, and piperacillin-tazobactam, and these 3 drugs showed a susceptibility rate of more than 80% against the ESBL-producing strains of Escherichia coli and Klebsiella pneumoniae. Other antimicrobial agents showing a relatively high activity against Enterobacter spp, Citrobacter spp, Serratia spp and Proteous vulgaris included cefepime (67.3% - 100%), amikacin (67.3% - 95.2%), ceftazidime (52.9% - 100%) and cefoperazone-sulbactam (51.9% - 100%). The susceptibility rate of fluoroquinolones was 34.8% - 36.1% against non-ESBL-producing Escherichia coli and was 13.4% - 17.1% against ESBL-producing isolates. The most active agent against Pseudomonas aeruginosa was polymyxin B (95.6%). The agents with the activity rates of 70% - 80% included meropenem, imipenem, amikacin, and piperacillin-tazobactam. The antibiotic with a high susceptible rate against Acinetobacter baumannii was polymyxin B (98.3%), followed by imipenem (80.8%), meropenem (76.2%), and minocycline (67.4%). The susceptible rates of other agents were all below 60%. The agents with relatively high activity against Stenotrophomonas maltophilia included minocycline (85%), levofloxacin (82.5%), and trimethoprim-sulfamethoxazole (77.5%). The agents with a relatively high activity against Burkholderia cepacia included minocycline (77.2%) and meropenem (61.4%). CONCLUSION: Carbapenem, piperacillin-tazobactam, amikacin and cefepime remained relatively high activity against nosocomial Enterobacteriaceae, Non-fermenting pathogens have lower susceptibility to the antimicrobial agents than before.