خلاصه مقاله:Background and Aim
Acinetobacter spp. is known as an important nosocomial pathogen and shows continuous raise in antimicrobial resistance.Efflux genes have been reported to be existed in both gram-negative and gram-positive bacteria. Our aim was to evaluate role efflux pumps and antimicrobial susceptibility in MDR Acinetobacter baumannii.
The antimicrobial susceptibility pattern was determined by using the standard disk diffusion method according to CLSI guidelines.The Distribution of tetA, tetB tetM and adeABC genes were determined by polymerase chain reaction method. Minimum inhibitory concentration (MIC) of tetracycline in the presence and absence of cccp measured by microdilution method according to CSLI guidelines. Agar Ethidium bromide method was used to evaluate the overexpression of adeABC efflux pump.The methodology used is ML Agar plates containing EtBr concentrations 1mg/L.
Almost all isolates were resistant to a wide range of antibiotics; tetracycline (80%), imipenem (76%), Ciprofloxacin (90%) and the lowest resistance rate was found to colistin (0 %). The tetA, tetB, tetM, adeABC genes were identified in 5(10%), 31(62) , 0 and 38 (95%) isolates respectively.MIC of tetracycline was observed in isolates in presence and absence of efflux pump inhibitor (EPI). MDR bacteria were analyzed by agar ethidium bromide (Cartwheel) method and increased activity of adeABC efflux pumps in 4 isolates were confirmed.
Agar ethidium bromide Cartwheel method is a fast and convenient method for assessing the ethidium bromide secretion in various bacterial genera that can be used in quickly diagnose and treatment of multidrug-resistant bacteria.
Keywords: Agar ethidium bromide Cartwheel,AdeABC, Acinetobacter baumannii