中国重症监护病房革兰阴性菌耐药性连续7年监测研究

Continuous surveillance of antimicrobial resistance among nosocomial gram-negative bacilli from intensive care units in China

目的 探讨我国医院内重症监护病房革兰阴性菌 ,特别是肠杆菌科细菌的耐药变迁 ,以指导临床合理使用抗生素。方法 从 1994～ 2 0 0 1年从我国 32家医院分离到 10 2 79株革兰阴性菌 ,其中肠杆菌科细菌 5 82 9株 ,采用E试验法测定亚胺培南等数 10种抗生素对这些菌株的最低抑菌浓度(MIC)。结果 最常见的细菌为铜绿假单胞菌、大肠埃希菌、克雷伯菌属、不动杆菌属、肠杆菌属、嗜麦芽窄食单胞菌。呼吸道标本中最常见的是铜绿假单胞菌 ( 2 5 % )、肺炎克雷伯菌 ( 18% ) ,鲍曼不动杆菌 ( 11% ) ;再次为血和尿标本中最常见的是大肠埃希菌、肺炎克雷伯菌、铜绿假单胞菌。 7年中 ,对所有革兰阴性菌活性最高、且历年其活性不减的是亚胺培南 ( 87% ) ,其次是头孢哌酮 /舒巴坦 (但它的敏感率从 86 %降至 75 % )和阿米卡星 ( 75 % ) ,再次为头孢他啶 ( 73% )、头孢吡肟 ( 72 % )、哌拉西林 /三唑巴坦 ( 71% )。 7年中大肠埃希菌、肺炎克雷伯菌对亚胺培南的敏感性为 98% ,MIC90 为 0 5 μg/ml。阿米卡星、头孢他啶、头孢哌酮 /舒巴坦、哌拉西林 /三唑巴坦、头孢吡肟的体外敏感性分别为 84%、83%、83 %、80 %、80 % ,但头孢哌酮 /舒巴坦的敏感率从 1996年的 90 %降至 2 0 0 1年的 74% 。

Objective To investigate the change of antimicrobial resistance among nosocomial gram-negative bacilli, especially those of Enterobacteriaceae isolated from intensive care units from 1994 to 2001 in China. Methods E test was made to determine the minimal inhibitory concentrations (MIC) of 10 279 isolates of gram-negative bacilli (including 5 829 strains of bacilli of Enterobacteriaceae) from 32 hospitals in China from 1994 to 2001. Results The most common pathogens were Pseudomonas aeruginosa; Escherichia coli, Klebsiella spp, Acinetobacter spp. Enterobacter spp, and Stenotrophomonas maltophilia. The most common pathogens in respiratory tract specimens were Pseudomonas aeruginosa (25%), Klebsiella pneumoniae (18%), and Acinetobacter baumanni (11%). The most common pathogens in blood and urine specimens were Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. The antibiotic remaining the most active against all of the gram-negative bacilli for 7 years was imipenem (with a susceptibility rate of 87%), followed by cefoperazone/sulbactam (however, with a susceptibility rate decreasing from 86% to 75%), amikacin (75%), ceftazidime (73%), cefepime (72%), and piperacillin/tazobactam (71%). The susceptibility rate of Escherichia coli Klebsiella pneumoniae to imipenem remained 98% with a MIC 90 of 0.5 μg/ml during the 7 years, much higher than those to amikacin (84%), ceftazidime (83%), cefoperazone/sulbactam (83%), piperacillin/tazobactam (80%), and cefepime (80% ). The susceptibility rate of these two species to cefoperazone/sulbactam decreased from 90% in 1996 to 74% in 2001. While the susceptibility to cefotaxime and ceftriaxone decreased from 82% to 57%. The susceptibility rate of Escherichia coli to ciprofloxacin decreased from 54% to 25% and that of Klebsiella pneumoniae to ciprofloxacin decreased from 90% to 75%. The prevalence of extended spectrum β-lactamases in these two species increased from 11% in 1994 to 34% in 2001. The most active antibiotics against Enterobacter cloacae were imipenem, cefepime, amikacin with the susceptible rates of 95%, 76%, and 70%, respectively; the susceptibility rates of Citrobacter freundii to imipenem, cefepime, amikacin, and cefoperazone/sulbactam were 94%, 80%, 80%, and 78% respectively. Only 40%～60% isolates of Enterobacter cloacae and Citrobacter freundii were susceptible to third-generation cephalosporins. Conclusion Imipenem remains highly active against Enterobacteriaceae, but the activities of other antibiotics have decreased in recent years.