DOI: 10.36347/sjams.2019.v07i04.028

Pages: 1512-1516

Background: Sepsis, skin & soft tissue infections, intra-abdominal infections, urinary tract infections and respiratory tract infections caused by Gram negative bacteria are most common in clinical laboratories. The acquired resistance of most bacteria to antimicrobials is unpredictable and requires routine antimicrobial susceptibility testing. Aims& Methods: This study was conducted during one-year period to determine antimicrobial resistance among Gram-negative bacilli in common clinical infections and to find antimicrobial sensitivity pattern of resistant isolates. Samples were cultured on Mac Conkey agar and Blood agar and identified by standard microbiological techniques. Antimicrobial susceptibility testing was done by Kirby-Bauer disk diffusion method and resistance patterns were recorded. Antimicrobials tested were Cephalosporins (Ceftazidime), β-lactam/ β-lactamase inhibitor (Cefoperazone, Piperacillin, Cefoperazone/Sulbactam & Piperacillin/Tazobactam), carbapenems (Imipenem & Meropenem), monobactam (Aztreonam), fluoroquinolones (Ciprofloxacin & Ofloxacin), Cotrimoxazole and aminoglycosides (Amikacin). Screening of ESBL producers and Carbapenemase producers was done by using Ceftazidime and Imipenem disks as markers respectively. Quality control was performed using ATCC strains every week. Results: Among the total 2399 Gram-negative bacterial pathogens isolated, Klebsiella spp were 1156 (48.2%), E. coli were 844 (35.2%), Pseudomonas spp were 276 (11.5%) & others were 123 (5.1%). Most GNB were sensitive to carbapenems followed by Cefoperazone/Sulbactam & Piperacillin/Tazobactam. ESBL positive rates ranged from 77% – 80% in E. coli, 75% - 78% in Klebsiella spp&70%– 74% in Pseudomonas spp. Carbapenem resistance rates were 3-7% &was high among Pseudomonas spp. Conclusion: There is an increasing trend of ESBL production among common Gram-negative bacterial pathogens. Carbapenems & Cefoperazone/Sulbactam are better agents though resistance to carbapenems is slowl