Sahm D F, Critchley I A, Kelly L J, Karlowsky J A, Mayfield D C, Thornsberry C, Mauriz Y R, Kahn J
MRL, Herndon, Virginia 20171, USA.
Antimicrob Agents Chemother. 2001 Jan;45(1):267-74. doi: 10.1128/AAC.45.1.267-274.2001.
Given the propensity for Enterobacteriaceae and clinically significant nonfermentative gram-negative bacilli to acquire antimicrobial resistance, consistent surveillance of the activities of agents commonly prescribed to treat infections arising from these organisms is imperative. This study determined the activities of two fluoroquinolones, levofloxacin and ciprofloxacin, and seven comparative agents against recent clinical isolates of Enterobacteriaceae, Pseudomonas aeruginosa, Acinetobacter baumannii, and Stenotrophomonas maltophilia using two surveillance strategies: 1) centralized in vitro susceptibility testing of isolates collected from 27 hospital laboratories across the United States and 2) analysis of data from The Surveillance Network Database-USA, an electronic surveillance network comprising more than 200 laboratories nationwide. Regardless of the surveillance method, Enterobacteriaceae, P. aeruginosa, and A. baumannii demonstrated similar rates of susceptibility to levofloxacin and ciprofloxacin. Susceptibilities to the fluoroquinolones approached or exceeded 90% for all Enterobacteriaceae except Providencia spp. (</=65%). Approximately 70% of P. aeruginosa and 50% of A. baumanii isolates were susceptible to both fluoroquinolones. Among S. maltophilia isolates, 50% more isolates were susceptible to levofloxacin than to ciprofloxacin. Overall, the rate of ceftazidime nonsusceptibility among Enterobacteriaceae was 8.7%, with fluoroquinolone resistance rates notably higher among ceftazidime-nonsusceptible isolates than ceftazidime-susceptible ones. Multidrug-resistant isolates were present among all species tested but were most prevalent for Klebsiella pneumoniae and Enterobacter cloacae. No gram-negative isolates resistant only to a fluoroquinolone were encountered, regardless of species. Thus, while levofloxacin and ciprofloxacin have maintained potent activity against Enterobacteriaceae, the potential for fluoroquinolone resistance, the apparent association between fluoroquinolone and cephalosporin resistance, and the presence of multidrug resistance in every species examined emphasize the need to maintain active surveillance of resistance patterns among gram-negative bacilli.
鉴于肠杆菌科细菌和具有临床意义的非发酵革兰氏阴性杆菌易于获得抗菌药物耐药性，因此必须对常用于治疗由这些微生物引起的感染的药物活性进行持续监测。本研究采用两种监测策略，确定了两种氟喹诺酮类药物（左氧氟沙星和环丙沙星）以及七种对照药物对近期分离的肠杆菌科细菌、铜绿假单胞菌、鲍曼不动杆菌和嗜麦芽窄食单胞菌的活性：1）对从美国27家医院实验室收集的分离株进行集中体外药敏试验；2）分析来自美国监测网络数据库的数据，该数据库是一个由全国200多家实验室组成的电子监测网络。无论采用何种监测方法，肠杆菌科细菌、铜绿假单胞菌和鲍曼不动杆菌对左氧氟沙星和环丙沙星的药敏率相似。除普罗威登斯菌属（≤65%）外，所有肠杆菌科细菌对氟喹诺酮类药物的药敏率接近或超过90%。约70%的铜绿假单胞菌分离株和50%的鲍曼不动杆菌分离株对两种氟喹诺酮类药物敏感。在嗜麦芽窄食单胞菌分离株中，对左氧氟沙星敏感的分离株比环丙沙星多50%。总体而言，肠杆菌科细菌中头孢他啶不敏感率为8.7%，头孢他啶不敏感分离株中的氟喹诺酮耐药率明显高于头孢他啶敏感分离株。在所有测试菌种中均存在多重耐药分离株，但在肺炎克雷伯菌和阴沟肠杆菌中最为普遍。无论菌种如何，均未发现仅对氟喹诺酮耐药的革兰氏阴性分离株。因此，虽然左氧氟沙星和环丙沙星对肠杆菌科细菌仍保持较强活性，但氟喹诺酮耐药的可能性、氟喹诺酮与头孢菌素耐药之间的明显关联以及每个检测菌种中多重耐药的存在，都强调了对革兰氏阴性杆菌耐药模式进行积极监测的必要性。
