Antibiotic susceptibility pattern of gram-negative bacterial isolates with special mention on colistin resistance from Intensive Care Unit of a tertiary care hospital: a prospective study assessing the impact of microbial resistance on clinical outcomes

Background: The frequent use of broad-spectrum antibiotics in ICU leads to increased rates antimicrobial resistance and occurrence multidrug-resistant (MDR) micro-organisms. aim this study was evaluate the pattern colistin susceptibility among bacterial isolates from patients. Method: It is a prospective with 70 nonrepetitive samples. clinical data obtained department records. gram-negative were identified by conventional biochemical tests. determined Kirby-Bauer disc diffusion method. ESBL producers detected double test using ceftazidime, cefotaxime alone combination clavulanic acid. MBL detection done imipenem+ EDTA combined test. Colistin sensitivity broth microdilution according CLSI guidelines. Results: Out culture positive specimens. most common bacteria isolated samples Acinetobacter spp. (41%), followed Klebsiella (20%). Among these 45% producers, 38.5% 14% both producers. present 5.7% ICU. Conclusions: Non-fermenters agent causing infections. An alarmingly high rate especially ICU-acquired infections, necessitates new therapeutic strategies prevent emergence control resistance.