Analysis of Clinically Significant Acinetobacter Spp Isolated from a Base Hospital (BH) of Sri Lanka during a One-Year Period

Abstract

Introduction: Acinetobacter spp are potential opportunistic pathogens. Being a water-trophic organism, it stays in humidifier water, sink basins, suction apparatus, disinfectant fluids etc. Number of cases due to Acinetobacter spp are increasing globally & locally. Treatment of Acinetobacter infections is a great challenge due to its resistance to most antibiotics. However, awareness about antibiotic sensitivity (ABST) pattern of the organism would streamline empiric antibiotic therapy. Objective: To identify the burden & ABST pattern of Acinetobacter spp isolated duringa one-year period. Method: A descriptive, cross-sectional study was carried out involving patients with clinically significant Acinetobacter infection at BH, Wathupitiwala from 01/08/2017 to 31/07/2018. The number of Acinetobacter spp identified from the total number of positive cultures obtained during the same period was analyzed. Demographic& clinical data of patients infected with Acinetobacter spp were also analyzed. ABST (John-Stokes method) of Acinetobacter spp were analyzed for gentamicin, amikacin, cefotaxime, ceftazidime, ceftriaxone, cefepime, cefoperazone-sulbactam, piperacillin-tazobactam, ampicillin-sulbactam, ticarcillin-clavulanic acid, ciprofloxacin, levofloxacin, co-trimoxazole, meropenem& polymyxin B. Results: Of 920 total bacterial cultures performed over the study period, 44% (404/920 - urine samples, 26% (238/920) - sputum, 23% (215/920) - pus & wound swabs & 7% (63/920) - blood. Of positive blood cultures, 7% (5/63) were by Acinetobacter. Of the total, satisfactorily taken sputum samples, 21% (65/238) were positive for Acinetobacter. Acinetobacter positivitywas 7% (17/215) from pus & wound swabs. None (0/404) of the urine samples grew Acinetobacter. Of 87 patients, who had Acinetobacter infections, all were inpatients while 56.3% were males & 43.7% were females. Age distribution; 0% children (<12 years), 68.9 % adults (12- 65 years) & 31.1% elderly (>65 years) patients. As per ABST, sensitivity was 4.5% for cefotaxime, 6.9% for ceftriaxone, 9.2% for ticarcillin-clavulanic acid & ceftazidime each, 12.6% for cefepime, 16% for gentamicin & ciprofloxacin each, 14.9% for piperacillin-tazobactam & meropenem each, 16.1% for levofloxacin & co-trimoxazole each, 17.2% for ampicillin-sulbactam, 25.3% for amikacin, 60.9% for cefoperazone-sulbactam, & 94.2% for polymyxin B. Conclusion: Most Acinetobacter spp were recovered from respiratory samples indicating its preponderance to cause respiratory tract infections. Most Acinetobacter infections were from inward, adult, males. A great majority of Acinetobacter spp were sensitive to polymyxin B. Only about 2/3rd of isolates were sensitive to cefoperazone-sulbactam & sensitivity was <25% for commonly used cephalosporins, carbapenems, quinolones, aminoglycosides, co-trimoxazole, & beta-lactam – beta-lactam inhibitor combinations