The combination of Gentamycin and colistin has additional antibacterial action. Gentamycin
belongs to the group of aminoglycosides and acts bactericidal against mainly Gram-negative
bacteria like E. coli Klebsiella, Pasteurella and Salmonella spp. The bactericidal action is
based on inhibition of bacterial protein synthesis. Colistin, a cyclic poly-peptide antibiotic has
bacterial action against selected Gramnegativebacteria. The primary bacterial eect of
colistin is a blockade of the cell division of bacteria followed by secondary progressive lysis.