Molecular epidemiology of multidrug-resistant clinical isolates of Acinetobacter baumannii A 10-year analysis in a large tertiary care university hospital in central Europe with international admissions

Background Over the last 10 years, multidrug resistant Acinetobacter baumannii has been spreading worldwide as emerging microorganisms that negatively impact on the outcome of in-hospital patients. Methods Between 2007 and 2016, all isolates of patients of the Vienna General Hospital (VGH), tested positive for multidrug resistant Acinetobacter baumannii (MDR A. baumannii) strains, were investigated with respect to their genetic relationship. Patient medical histories were reviewed in order to collect discriminating factors related to MDR A. baumannii colonization or infection. Results A total of 79 isolates of 76 patients were obtained. For 44 of them (55.7%) the first diagnosis ward was an intensive care unit (ICU). A total of 10 genotype clusters were identified and 35 cases (44.3%) of in-hospital acquisition in our institution could be detected. Multidrug resistant Acinetobacter baumannii isolates were acquired before admission to our hospital in 44 cases (55.7%) and in 31 (70.5%) they belonged to patients who had previous exposure to the healthcare setting of high prevalence countries for MDR A. baumannii. Conclusion Patients admitted to our hospital with a previous healthcare contact in a high prevalence country for multidrug resistant Acinetobacter baumannii should be screened before admission to high-risk wards. Isolation of these patients until microbiological results could reduce negative outcome in these wards.