Objective: Acinetobacter spp are opportunistic pathogens that are commonly isolated in intensive care units (ICU). They are an important pathogen in nosocomial sepsis and ventilator associated pneumonia especially in the ICU’s. The most important reason for this is the development of multiple resistance mechanisms. Acinetobacter spp are known to possess resistance mechanisms to diverse antibiotic groups, and recently resistance to colistin has also been observed in our department. Aim of this study was to document frequency and resistance patterns of Acinetobacter spp infections and to study the effect of colistin sensitivity on ICU mortality and length of stay.

Material and Methods: Patients who were treated between July 2013 and November 2014 in medical ICU of Ankara Univercity Faculty of Medicine were analyzed retrospectively and patients with Acinetobacter spp. Infections were enrolled. Their age, sex, Acute Physiology and Chronic Health Evaluation (APACHE) II score, admission diagnoses and underlying disease, infection foci, previously used antibiotics, antibiotic resistance patterns of Acinetobacter strains, ICU survival and length of stay were recorded on the database created for the study.

Results: During the study period, 134 patients were admitted to ICU. Of them 33 (24.6%) who developed Acinetobacter spp. infection were included. Nineteen of these patients (57.6%) were male. The mean age was 69.39±17.41. All strains were carbapenem resistant, 9 (27.2%) had also colistin resistance. When patients were grouped according to colistin sensitivity of the pathogenic straines, groups were similar in terms of age, APACHE II score, immunosuppression, underlying diseases. And there was no significant difference in survival and length of stay in ICU between the two groups.

Conclusion: Acinetobacter spp. infections were observed in patients who were on broad spectrum antibiotics and colistin resistance was observed in patients who had received colistin before. However in the study, no negative effect on survival and ICU length of stay with the colistin-resistant strains was observed.