Arastoo Vojdani - Department of Microbiology & Virology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
Amir Hossein Esfandiari - Department of Microbiology & Virology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
Maryam Moradpour - Department of Microbiology & Virology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
Masoud Youssefi - Antimicrobial Resistance Research Center, Mashhad University of Medical Sciences, Mashhad, Iran

BACKGROUND AND OBJECTIVEIn recent decades, Acinetobacter baumannii is considered a significant nosocomial pathogen on a global scale. Due to the excessive use of antibiotics, multi-drug resistant (MDR) Acinetobacter baumannii strains emerged, indicating high resistance to a broad spectrum of antibiotics. Fluoroquinolones such as ciprofloxacin and levofloxacin are viable choices in bacterial infection because of bacteriostatic activity and high oral bioavailability, but the extensive implementation of these antibiotics leads to increase fluoroquinolones-resistant bacteria. Thus, the determination of Acinetobacter baumannii sensitivity to Fluoroquinolones namely ciprofloxacin and levofloxacin seems necessaryMATERIALS AND METHODSOne hundred isolates of A. baumannii were obtained between June and September of ۲۰۱۶ based on biochemical tests (growth on agar media, lack of fermentation of lactose, negative oxidase test, immobilization on the SIM environment, ALK / ALK pattern on TSI and non-production of pigment), and the molecular method (detection of blaOXA-۵۱ gene). Antibiotic susceptibility tests for ciprofloxacin and levofloxacin were performed by E-test and broth dilution.RESULTS AND DISCUSSIONIn this observational study, the blaOXA-۵۱-like genes, which are considered unique to A. baumannii species, were present in all isolates (۱۰۰/۱۰۰). The distribution proportion of sample type was reported in Table ۱. The E-test and broth dilution showed that ۹۸% of isolates were resistant to ciprofloxacin and levofloxacin (۹۸/۱۰۰).CONCLUSIONIn conclusion, the results indicated a substantial percentage of resistance to Ciprofloxacin and levofloxacin among samples of Acinetobacter baumannii. The connection between antibiotic usage and the development of antibiotic resistance is currently under investigation, however, it is a complicated matter with several factors to take into account. These factors include over usage of antibiotics, cross-transmission of resistance, transfer of resistance between different wards of a hospital, and community contributions to resistance. Genotyping investigations could provide wide insight into Ciprofloxacin and levofloxacin-resistance Acinetobacter baumanni.

Acinetobacter baumanni, Fluoroquinolones-resistant, E-test, Broth dilution