Ardebili Abdollah, Talebi Malihe, Azimi Leila, Rastegar Lari Abdolaziz
Department of Microbiology, Faculty of Medicine, Iran University of Medical Sciences, Tehran, IR Iran ; Antimicrobial Resistance Research Center, Iran University of Medical Sciences, Tehran, IR Iran.
Antimicrobial Resistance Research Center, Iran University of Medical Sciences, Tehran, IR Iran.
Jundishapur J Microbiol. 2014 Jan;7(1):e8691. doi: 10.5812/jjm.8691. Epub 2014 Jan 1.
Acinetobacter baumannii is an important human pathogen with increasing notoriety in the recent years, as a causative organism of drug resistant nosocomial infections, particularly in immunocompromised patients hospitalized in burn centers.
The aim of this study was to determinate the role of efflux pump(s) in ciprofloxacin resistance of A. baumannii strains isolated from burn patients.
Sixty-five A. baumannii strains were isolated from the burn patients hospitalized in Motahari Burns and Reconstruction Center in Tehran, Iran. Susceptibility test to ciprofloxacin was carried out by disk agar diffusion and agar dilution methods, according to the CLSI guidelines. Activity of the efflux system was evaluated using efflux pump inhibitor carbonyl cyanide 3-chlorophenylhydrazone (CCCP).
All Acinetobacter isolates were resistant to ciprofloxacin. The Minimum inhibitory concentration (MIC) range of ciprofloxacin in isolates was 4 to 128 µg/mL or greater. Moreover, susceptibility of strains to ciprofloxacin was highly increased in the presence of efflux pump inhibitor; So that, for 86.1% (56/65) of isolates, CCCP reduced the MIC by 2 to 64 folds.
Our findings are suggestive that efflux-based system may play a role in fluoroquinolone resistance in A. baumannii isolates, affecting hospitalized patients. The ability of Acinetobacter to acquire resistance to these potent antimicrobials by the efflux pump mechanism is a concern. Therefore, new strategies are required in order to eliminate the efflux transport activity from the resistant bacteria causing nosocomial infections and provide more appropriate approaches for treatment and management of troubling infections.
鲍曼不动杆菌是一种重要的人类病原体，近年来声名狼藉，是耐药性医院感染的致病菌，尤其是在烧伤中心住院的免疫功能低下患者中。
本研究旨在确定外排泵在从烧伤患者中分离出的鲍曼不动杆菌菌株对环丙沙星耐药性中的作用。
从伊朗德黑兰莫塔哈里烧伤与重建中心住院的烧伤患者中分离出65株鲍曼不动杆菌菌株。根据CLSI指南，采用纸片琼脂扩散法和琼脂稀释法对环丙沙星进行药敏试验。使用外排泵抑制剂羰基氰3-氯苯腙（CCCP）评估外排系统的活性。
所有不动杆菌分离株均对环丙沙星耐药。分离株中环丙沙星的最低抑菌浓度（MIC）范围为4至128μg/mL或更高。此外，在外排泵抑制剂存在的情况下，菌株对环丙沙星的敏感性显著增加；因此，对于86.1%（56/65）的分离株，CCCP将MIC降低了2至64倍。
我们的研究结果表明，基于外排的系统可能在鲍曼不动杆菌分离株对氟喹诺酮类药物的耐药性中起作用，影响住院患者。不动杆菌通过外排泵机制获得对这些强效抗菌药物耐药性的能力令人担忧。因此，需要新的策略来消除引起医院感染的耐药菌的外排转运活性，并为治疗和管理棘手的感染提供更合适的方法。
