Sader H S, Tosin I, Sejas L, Miranda E
Special Clinical Microbiology Laboratory, Department of Infectious and Parasitic Diseases, Universidade Federal de São Paulo, Brazil.
Braz J Infect Dis. 2000 Feb;4(1):22-8.
Recently, two new combinations of Beta-lactam antibiotics with Beta-lactamase inhibitors became commercially available in Brazil: piperacillin/tazobactam and ampicillin/sulbactam. This study was designed to assess and compare the in-vitro activity of these new compounds, as well as that of ticarcillin/clavulanic acid, against bacteria isolated in our environment. A total of 749 bacteria isolated at São Paulo Hospital were tested using the disk diffusion method, in compliance with NCCLS standardization, using strict quality control. Only one sample per patient was included in the study. Oxacillin-resistant staphylococcus samples were not included in this study. Of the total samples tested, 84.5% were susceptible to piperacillin/tazobactam, 81.2% to ticarcillin/clavulanic acid, and 77.6% to ampicillin/sulbactam. Piperacillin/tazobactam was also found to be the most active combination of the three against Enterobacteriaceae ( n = 312), inhibiting 91.7% of the bacteria tested. Ticarcillin/clavulanic acid was active against 85.8% of the Enterobacteriaceae, while ampicillin/sulbactam inhibited 83.2% of the samples. This order of the spectrum of action (piperacillin/tazobactam > ticarcillin/clavulanic acid >ampicillin/sulbactam )was maintained for the majority of Enterobacteriaceae species analyzed. Pseudomonas aeruginosa ( n = 117) showed extremely high resistance to the three combinations. Piperacillin/tazobactam was active against 61.5% of the samples, while ticarcillin/clavulanic acid was active against 56.4% of the samples of this species. The activity of ampicillin/sulbactam against P. aeruginosa was extremely low; however, this was the most active combination against Acinetobacter baumannii ( 87.0% susceptibility). Piperacillin/tazobactam was the most active combination against Stenotrophomonas (Xanthomonas )maltophilia (100% susceptibility) and Burkholderia cepacia (90.9% susceptibility). The three combinations showed excellent activity against the Gram-positive cocci tested (97.3% to 98.2% susceptibility). In sum, piperacillin/tazobactam was more active against all Gram-negative species than the other two combinations, with the exception of A. baumannii, and showed similar activity against Gram-positive cocci.
最近，两种新型β-内酰胺类抗生素与β-内酰胺酶抑制剂的组合在巴西上市：哌拉西林/他唑巴坦和氨苄西林/舒巴坦。本研究旨在评估和比较这些新化合物以及替卡西林/克拉维酸对我们环境中分离出的细菌的体外活性。使用纸片扩散法，按照美国国家临床实验室标准化委员会（NCCLS）的标准并采用严格的质量控制，对圣保罗医院分离出的749株细菌进行了检测。本研究仅纳入每位患者的一个样本。耐苯唑西林葡萄球菌样本未纳入本研究。在所有检测样本中，84.5%对哌拉西林/他唑巴坦敏感，81.2%对替卡西林/克拉维酸敏感，77.6%对氨苄西林/舒巴坦敏感。哌拉西林/他唑巴坦还被发现是这三种药物中对肠杆菌科细菌（n = 312）活性最强的组合，能抑制91.7%的受试细菌。替卡西林/克拉维酸对85.8%的肠杆菌科细菌有活性，而氨苄西林/舒巴坦能抑制83.2%的样本。对于大多数分析的肠杆菌科菌种，这种作用谱顺序（哌拉西林/他唑巴坦＞替卡西林/克拉维酸＞氨苄西林/舒巴坦）得以维持。铜绿假单胞菌（n = 117）对这三种组合均表现出极高的耐药性。哌拉西林/他唑巴坦对61.5%的该菌种样本有活性，而替卡西林/克拉维酸对56.4%的该菌种样本有活性。氨苄西林/舒巴坦对铜绿假单胞菌的活性极低；然而，它是对鲍曼不动杆菌活性最强的组合（敏感性为87.0%）。哌拉西林/他唑巴坦是对嗜麦芽窄食单胞菌（嗜麦芽黄单胞菌）（敏感性100%）和洋葱伯克霍尔德菌（敏感性90.9%）活性最强的组合。这三种组合对所检测的革兰氏阳性球菌均表现出优异的活性（敏感性为97.3%至98.2%）。总之，除鲍曼不动杆菌外，哌拉西林/他唑巴坦对所有革兰氏阴性菌的活性均高于其他两种组合，且对革兰氏阳性球菌表现出相似的活性。
