中国重症监护病房革兰阴性菌耐药性连续7年监测研究

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1994-2001年从我国32家医院分离到10279株革兰阴性菌,其中肠杆菌科细菌5829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（25%）,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最大肠埃希菌,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0.5μg/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2001年的74%,而头孢噻肟及头孢曲松的敏感性从82%降至57%,环丙沙星对大肠埃希菌的敏感率从54%降到25%,对肺炎克雷伯菌的敏感性从90%降至75%。大肠埃希菌和肺炎克雷伯菌超广谱β内酰胺酶的比例从1994年的11%升高到2001年的34%。对于阴沟肠杆菌,体外活性最高的是亚胺培南,头孢吡肟,阿米卡星,敏感率分别为95%,76%,70%,对于弗劳地枸橼酸菌,亚胺培南,头孢吡肟,阿米卡星,头孢哌酮/三唑巴坦敏感率最高。分别为94%,80%,80%,78%。而这两种菌对三代头孢菌素的敏感率仅为40%-60%。结论 亚胺培南对肠杆菌科细菌保持很高的敏感性,但其他抗生素的活性在降低。

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

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 micro g/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 beta-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% approximately 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.