Pfaller Michael A, Sader Helio S, Fritsche Thomas R, Jones Ronald N
Department of Pathology and Epidemiology, University of Iowa College of Medicine and College of Public Health, Iowa City, IA 52242, USA.
Diagn Microbiol Infect Dis. 2006 Sep;56(1):63-8. doi: 10.1016/j.diagmicrobio.2006.02.009. Epub 2006 May 2.
To assess the effect of ceftazidime resistance on the activity of other antimicrobial agents, 3030 ceftazidime-resistant Gram-negative bacilli (GNB) isolates (of a total of 42061 GNB) were tested against a panel of more than 30 agents. Ceftazidime resistance was observed in 40.3% of Acinetobacter spp., 16.9% of Pseudomonas aeruginosa, and 5.7% of Enterobacteriaceae isolates. The highest rates of ceftazidime resistance among the enteric GNB were observed with Enterobacter spp. (20.9%) >Citrobacter spp. (15.3%) > indole-positive Proteae (10.1%). Overall, 90% of ceftazidime-resistant Enterobacteriaceae and 30% of ceftazidime-resistant P. aeruginosa remained susceptible to the "4th-generation" cephalosporin, cefepime. The activities (% susceptible) of other antimicrobials tested against ceftazidime-resistant Enterobacteriaceae and P. aeruginosa, respectively, were as follows: amikacin, 90% and 88%; ciprofloxacin, 63% and 46%; gentamicin, 59% and 67%, imipenem, 99% and 65%; levofloxacin, 69% and 44%; and piperacillin/tazobactam only 40% and 12%. Ceftazidime-resistant GNB exhibited high rates of resistance to other antimicrobials. Cefepime was very active against ceftazidime-resistant enteric GNB (AmpC enzyme producers), especially Enterobacter spp. (94.3% susceptible), Citrobacter spp. (96.7% susceptible), and indole-positive Proteae (89.6% susceptible), and showed activity similar to that of ceftazidime against all P. aeruginosa and Acinetobacter spp. isolated in North American medical centers. Continued resistances surveillance monitoring will be necessary to assess the effectiveness of widely used broad-spectrum antimicrobials as novel resistance mechanisms emerge.
为评估头孢他啶耐药性对其他抗菌药物活性的影响，对3030株耐头孢他啶革兰阴性杆菌（GNB）分离株（总共42061株GNB）进行了一组30多种药物的测试。在40.3%的不动杆菌属、16.9%的铜绿假单胞菌和5.7%的肠杆菌科分离株中观察到头孢他啶耐药性。在肠道GNB中，头孢他啶耐药率最高的是肠杆菌属（20.9%）>柠檬酸杆菌属（15.3%）>吲哚阳性变形菌（10.1%）。总体而言，90%的耐头孢他啶肠杆菌科细菌和30%的耐头孢他啶铜绿假单胞菌对“第四代”头孢菌素头孢吡肟仍敏感。针对耐头孢他啶肠杆菌科细菌和铜绿假单胞菌测试的其他抗菌药物的活性（%敏感）分别如下：阿米卡星，90%和88%；环丙沙星，63%和46%；庆大霉素，59%和67%；亚胺培南，99%和65%；左氧氟沙星，69%和44%；哌拉西林/他唑巴坦仅为40%和12%。耐头孢他啶GNB对其他抗菌药物表现出高耐药率。头孢吡肟对耐头孢他啶肠道GNB（AmpC酶产生菌）非常有效，尤其是肠杆菌属（94.3%敏感）、柠檬酸杆菌属（96.7%敏感）和吲哚阳性变形菌（89.6%敏感），并且对北美医疗中心分离的所有铜绿假单胞菌和不动杆菌属的活性与头孢他啶相似。随着新的耐药机制出现，持续的耐药性监测对于评估广泛使用的广谱抗菌药物的有效性将是必要的。
