Determination of polymyxin B, minocycline, colistin and phosphomycin susceptibilities in Acinetobacter baumannii strains showing carbapenem resistant multidrug resistance phenotype

Objective: In this study, the sensitivity of minocycline, polymyxin B, cholestin and phosphomycin to carbapenem resistant multiresistant Acinetobacter baumannii (A. baumannii) strains (resistant to three or more antibiotic groups) isolated from patients in Ankara Training and Research Hospital It was aimed. Material and Method: Eighty nosocomial A. baumanii strains with a carbapenem resistant multidrug resistance phenotype were included in the study. Sensitivities of minocycline, polymyxin B and phosphomycin were determined by disc diffusion test and colistin susceptibility test by disk diffusion and E-test methods. Results: Eighty (100%) polymyxin B, 75 (93,75%) minocycline sensitive and 4 (5%) medium susceptible to 80 carbapenem resistant A.baumannii strains were evaluated by disc diffusion method. 75 (93.5%) were sensitive to colistin, 5 (6.25%) were moderately sensitive to colistin and 2 (2.5%) were sensitive to phosphomycin. By e-test, all 80 strains (100%) were detected as susceptible to colistin. The MIC range for colistin was 0.125-1.5 μg / ml, the MIC 50 value was 025 μg / ml (the MIC range was found to be 0.5 μg / ml). Conclusion: Polymyxin B and minocycline could be used in therapy because phosphomycin B and susceptibility rates were high in empirical treatment of carbamazepine resistant multispecific A.baumannii strains in our hospital. Phosphomycin could not be used in treatment because of high resistance rate