RESUMO
Introduction: Currently colistin is increasingly being used against multidrug resistant gram negative bacteria which include Pseudomonas aeruginosa,,Acinetobacterbaumanii,Escherichia coli, Klebsiellapneumoniae& Salmonella enterica. [1] Colistin resistant organisms are reported in various parts of world. Methods: Total 200 MDR GNB isolates were included in the study & tested for their susceptibility to colistin by Kirby Bauer Disc Diffusion Test. Results:Isolates consisted of 64 Escherichia coli,45 Pseudomonas aeruginosa,44 Klebsiella pneumoniae,32 Citrobacter koseri,13 Acinetobacterbaumanii& 2 Proteus mirabilis. Of these, 69 (34.5%) were resistant to Colistin. Colistin resistance in highest number was detected in Escherichia coliisolates obtained from various samples. Conclusion: As colistin resistance is emerging rapidly,measures are necessary to restrict indiscriminate use of antimicrobials& to adhere strictly to the hospital antibiotic policy. it is also the need of an hour that newer antimicrobials get discovered soon to tackle such MDR microorganisms.