Departamento de Clínica Médica, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, São Paulo, SP, Brazil.
Rev Soc Bras Med Trop. 2013 May-Jun;46(3):299-303. doi: 10.1590/0037-8682-0012-2013.
Pseudomonas aeruginosa isolates related to nosocomial infections are often resistant to multiple antibacterial agents. In this study, antimicrobial combinations were evaluated to detect in vitro synergy against clinical isolates of P. aeruginosa.
Four clinical P. aeruginosa isolates were selected at random among other isolates from inpatients treated at the public University hospital in Ribeirão Preto, SP, Brazil. Two isolates were susceptible to imipenem (IPM-S) and several other antimicrobials, while the other two isolates were imipenem and multidrug resistant (IPM-R). The checkerboard method was used to assess the interactions between antimicrobials.
Combinations of imipenem or other anti-Pseudomonas drugs with complementary antibiotics, such as aminoglycosides, fosfomycin and rifampin, reached synergy rates of 20.8%, 50%, 62.5% and 50% for the two IPM-S and two IPM-R Pseudomonas isolates, respectively. Imipenem, piperacillin-tazobactam and ceftazidime yielded a greater synergy rate than cefepime or ciprofloxacin. Synergist combinations were more commonly observed when the complementary drug was tobramycin (65%) or fosfomycin (57%).
Some antibacterial combinations led to significant reductions of the minimum inhibitory concentrations of both drugs, suggesting that they could be clinically applied to control infections caused by multidrug-resistant P. aeruginosa.
与医院感染相关的铜绿假单胞菌分离株通常对多种抗菌药物具有耐药性。在这项研究中，评估了抗菌药物组合以检测体外对铜绿假单胞菌临床分离株的协同作用。
从巴西里贝朗普雷图公立大学医院接受治疗的住院患者的其他分离株中随机选择了四个临床铜绿假单胞菌分离株。两个分离株对亚胺培南（IPM-S）和其他几种抗菌药物敏感，而另外两个分离株对亚胺培南和多种药物耐药（IPM-R）。使用棋盘法评估了抗菌药物之间的相互作用。
亚胺培南或其他抗假单胞菌药物与互补抗生素（如氨基糖苷类、磷霉素和利福平）的组合对两个 IPM-S 和两个 IPM-R 铜绿假单胞菌分离株的协同率分别为 20.8%、50%、62.5%和 50%。亚胺培南、哌拉西林-他唑巴坦和头孢他啶的协同率高于头孢吡肟或环丙沙星。当互补药物为妥布霉素（65%）或磷霉素（57%）时，协同组合更为常见。
一些抗菌药物组合导致两种药物的最低抑菌浓度显著降低，表明它们可能在临床上用于控制多重耐药铜绿假单胞菌引起的感染。
