Synergistic effect of Ceftriaxone and diclofenac against Escherichia Coli

Background: The emergence of resistant strains of bacteria has rendered many useful antibiotics ineffective. The researchers areforced to try combination of two or more antibiotics, or addition of a non- antibacterial to them. Ceftriaxone, a third-generationcephalosporin agent is used to treat many infectious diseases, especially those caused by members of Enterobacteriaceae family.We tested the efficacy of ceftriaxone, alone and in combination with various concentrations of diclofenac sodium, againstEscherichia coli.Objective: To study the synergistic effect of ceftriaxone and its combination with non-antibiotic drug diclofenac sodium againstEscherichia coli ATCC 25922 isolate.Material and Methods: Agar well diffusion technique was applied. 30 µl of solutions of ceftriaxone, and its combination withdifferent concentrations of diclofenac sodium and DMSO were transferred aseptically into the wells. Agar plates were placed in incubator at 37°C for 24 hours. Mean zone of inhibition of each drug was calculated.Results: Ceftriaxone 30µg formed a zone of inhibition of 35 mm. Its combination with 25µg and 50µg of diclofenac sodium formedzone of inhibition of 37.5mm while its combination with 100µg diclofenac sodium formed a zone of inhibition of 38.6mm and formed39.8mm zone of inhibition when combined with 200µg diclofenac sodium.Conclusion: Ceftriaxone activity increased when combined with different concentrations of diclofenac sodium drug showing asynergistic effect of their combination.Key words: ceftriaxone, Diclofenac sodium, E. coli, Synergism