Enrofloxacin is a synthetic chemotherapeutic agent belonging to fluoroquinolones; it
inhibits DNA synthesis in the nucleus of microorganisms’ cells. Enrofloxacin has a bactericidal
action against Gram-positive and Gram-negative bacteria like Staphylococcus aureus,
Enterobacteriaceae, Pasteurella spp., Brucella spp., Haemophilus spp., Actinobacillus spp.,
Mycoplasma spp., Chlamydia spp., Bordetella bronchis ptica, Pseudomonas aeruginosa,
Salmonella spp., etc. Trimethoprim inhibits the bacterial reductase of dihydrofolic acid
(DHF). Trimethoprim is active against a broad range of microorganisms including Grampositive
and Gram-negative aerobic bacteria, Chlamydia, Pectoris (Actinomycetes),
certain Mycobacteria and Protozoa, as well as many anaerobic bacteria. Mycobacterium
tuberculosis, Treponema pallidum, Pseudomonas aeruginosa and Mycoplasma species –
are not sensiti e, or resistant to Trimethoprim. Haemophilus parainfluenzae, Haemophilus
ducreyi, Citrobacter freundii etc., Klebsiella oxytoca etc., Enterobacter cloacae, Serratia
marcescens and other Gram-negative species are generally susceptible to Trimethoprim.
Colistin is an Antibiotic from the group of polymyxins which are synthesized by aerobic
spore-forming coli Bacillus polymyxa. Colistin has a bactericidal action against Gramnegative
bacteria like E. coli, Salmonella spp., Pasteurella spp., Haemophilus spp., and
Bordetella spp. Colistin binds to phospholipids of the cytoplasmic membrane, and
increases its permeability for both intra- and external cellular components which leads to
the destruction of the bacterial cell.
ROUTE OF ADMINISTRATION
