Department of Pharmaceutical Biotechnology, School of Pharmacy, Isfahan University of Medical Sciences, Isfahan, Iran.
Students Research Committee, School of Pharmacy, Isfahan University of Medical Sciences, Isfahan, Iran.
Indian J Med Microbiol. 2021 Jul;39(3):358-362. doi: 10.1016/j.ijmmb.2021.04.006. Epub 2021 Apr 24.
Nowadays, Acinetobacter baumannii is resistant to almost all available antibiotics. The evaluation of synergistic effects between the antibiotics against this pathogen is among the efforts to counteract its antimicrobial resistance. This study aimed to evaluate possible synergistic effect of colistin and ampicillin/sulbactam (separately) with several antibiotics against clinical isolates of multi-drug resistant (MDR) A. baumannii.
Acinetobacter baumannii strains were isolated from biological samples of hospitalized patients with any type of nosocomial infection related to this pathogen. Only MDR strains (resistance to at least three classes of antibiotics including cephalosporins, fluoroquinolones, and aminoglycosides) were included in the study. After determining the minimum inhibitory concentration (MIC) of antibiotics against the isolates by broth microdilution test, the checkerboard method was used for evaluation of any possible synergistic effect of both colistin and ampicillin/sulbactam with several other antibiotics.
Twenty isolates underwent synergy test for colistin and 20 isolates for ampicillin/sulbacatam. Doxycycline (55%), azithromycin (35%), and co-trimoxazole (35%) had the most frequency of synergistic effect with colistin. On the other hand, amikacin and gentamicin (55%), doxycycline (50%), co-trimoxazole (45%), azithromycin (40%), and cefepime (40%) had the most frequency of synergistic effect with ampicillin/sulbactam. No antagonistic effect was observed for both antibiotics.
Colistin and ampicillin/sulbactam have substantial synergistic effect with several antibiotics especially doxycycline, co-trimoxazole, azithromycin, and amikacin (with ampicillin/sulbactam) against MDR strains of Acinetobacter baumannii.
目前，鲍曼不动杆菌几乎对所有可用的抗生素都具有耐药性。评估抗生素对这种病原体的协同作用是对抗其抗微生物耐药性的努力之一。本研究旨在评估多药耐药（MDR）鲍曼不动杆菌临床分离株中黏菌素和氨苄西林/舒巴坦（分别）与几种抗生素联合使用的可能协同作用。
从住院患者与该病原体相关的任何类型医院获得性感染的生物样本中分离出鲍曼不动杆菌菌株。仅纳入对至少三类抗生素（包括头孢菌素、氟喹诺酮类和氨基糖苷类）耐药的 MDR 菌株。通过肉汤微量稀释试验确定抗生素对分离株的最低抑菌浓度（MIC）后，使用棋盘法评估黏菌素和氨苄西林/舒巴坦与其他几种抗生素联合使用的任何可能协同作用。
对 20 株黏菌素和 20 株氨苄西林/舒巴坦进行了协同试验。多西环素（55%）、阿奇霉素（35%）和复方磺胺甲噁唑（35%）与黏菌素协同作用最频繁。另一方面，阿米卡星和庆大霉素（55%）、多西环素（50%）、复方磺胺甲噁唑（45%）、阿奇霉素（40%）和头孢吡肟（40%）与氨苄西林/舒巴坦协同作用最频繁。两种抗生素均未观察到拮抗作用。
黏菌素和氨苄西林/舒巴坦与几种抗生素（尤其是多西环素、复方磺胺甲噁唑、阿奇霉素和阿米卡星（与氨苄西林/舒巴坦））对 MDR 鲍曼不动杆菌菌株具有显著协同作用。
