Antimicrobial resistance patterns of Acinetobacter baumannii


ackground:Acinetobacter baumannii is a significant opportunistic pathogen and it is generally associated with benign colonization of hospitalized patients. Objective:To investigate skin colonizationwithAcinetobacter baumanniiin hospitalized patients and healthy volunteers.Antimicrobial resistance patterns of Acinetobacter baumanniiwasassessed by determining the minimum inhibitory concentrations (MICs) of thirteen different antimicrobial agents.Patients and Methods: The study performed on hospitalizedpatients at Rizgary and Hawler teaching hospitals and healthy volunteers who attended to supermarkets in Erbil, Iraq. A single sample was obtained once from each of the forehead, one ear pinna, one armpit, finger webs of one hand and toe webs of one footto isolatedAcinetobacter baumannii,then identified using phenotypic and genotypic properties. All isolates examined for their antimicrobial susceptibility bytheagar dilution method.Results: Among 600 hospitalized patients, 79 (13.17%) colonized with Acinetobacter baumannii, yielding 155 isolates that are resistant to 57.42% ceftriaxone, 56.77% cefotaxime, 45.81% ceftazidime and 40.65% ciprofloxacin.Whilethe most effective antimicrobial agentswith MIC50/90values (minimum inhibitory concentrations required to inhibit 50% and 90% of the isolates, respectively) were as follows:imipenem, 80.65%, 0.25/16 mg/L;doxycycline, 80.65%, 1/16mg/L;amikacin, 79.35%, 2/64 mg/L. However, 53 Acinetobacter baumanniiisolated from healthy volunteers that showedresistance to50.94% ceftriaxone (MIC50/90,64/128 mg/L), 45.28% ceftazidime, 43.40% cefotaxime, and 35.85% ciprofloxacin. Fortunately, all 208 Acinetobacter baumanniiwere sensitive to polymyxin B (MIC50=0.25mg/L).Conclusion: The rates of Acinetobacterbaumannii colonizedpatients higher thanhealthy volunteers, whereas an antimicrobial minimum inhibitory concentrationsvalue of cefepime, cefotaxime, imipenem, amikacin, ciprofloxacin, and levofloxacin were significantly higher in patients than healthy volunteers. Polymyxin B had activity against allAcinetobacter baumanniistrains.