Prevalence and Drug Resistance of Acinetobacter Baumannii in ICU of a Teaching Hospital

Background: Acinetobacter strains as opportunistic hospital pathogens are resistant to a large number of antibiotics and are the cause of various infections such as bacteremia, pneumonia, meningitis, urinary tract infections and surgical site infections. This study is aimed at assessing the prevalence of acinetobacter baumannii and its drug resistance in Intensive Care Unit (ICU) of a teaching hospital. Methodo: This cross-sectional study was conducted on the patients admitted to the ICU for one year. Urine, wound and sputum samples of the admitted patients to the hospital were collected 48 hours later and cultured. Antibiotic resistance was measured using two methods, namely Disk Diffusion and E-test ,and the data were analyzed using SPSS, Ver. 20 and the level of statistical significance was considered to be p < 0.05. Results: From the total positive cultures, 51% were caused by gram-negative bacteria, 42% by gram-positive bacteria and 7% by fungi, while the abundance of Acinetobacter baumannii was 17%. Among the samples affected by Acinetobacter baumannii, 45.71% were female and 54.29% were male with a mean age of 71.69%; the admissions were due to surgical problems in 34.29% of the cases and due to internal conditions in 65.71% of the cases. Totally, 90% of the patients suffered from comorbidities, the most common of which were HTN and DM; 42.9% of the patients had a history of antibiotic use before admission and the most commonly used antibiotics were Cephalosporins. Acinetobacter baumannii was most commonly isolated from sputum and then from BAL. Disk Diffusion method indicated high resistance to some antibiotics, namely Imipenem, Meropenem, Piperacillin-Tazobactam, Ciprofloxacin, Cefotaxime, Cefepime, Ceftriaxone and Ceftazidime. In this method, 100% of the samples were susceptible to Colistin. In E-test method, two cases of resistant to Colistin were reported. In this method, almost 1/3 of the samples were reported to be susceptible to Rifampicin, or showed intermediate resistance to it. Conclusion: The results of this study showed that clinical isolates of Acinetobacter, especially Acinetobacter baumannii show high resistance to antibiotics, particularly to the third generation Cephalosporins and broadspectrum Penicillins.