The Effect of Polysorbate 80 on Antibiotics’ Sensitivity

Abstract

This study aims to assess the direct antibacterial effect of the surfactant polysorbate 80 on Pseudomonas aeruginosa isolate when it was tested alone, as well as to assess the combining effects of this surfactant with the commonly used antibiotics.Agar well diffusion method was carried out to assess the antibacterial activity of different concentrations of polysorbate 80 alone on the bacterial isolate. Antibiotic sensitivity test was performed by testing number of antibiotics applied against pseudomonal isolate, firstly; by applying the surfactant alone at different concentrations, secondly, without polysorbate 80 and thirdly; with the presence of various concentrations of the surfactant (0.025, 0.05, 0.1, 0.2, 0.4, 0.6, 1, 2, 3, 4, 5 and 6) % (v/v media) applied to the media.The results of the study revealed that polysorbate 80 alone had no antibacterial activity at the tested concentrations but it showed a highly potentiative effects when it was combined with some antibiotics. These effects appeared either in changing the bacterial sensitivity profile to antibiotics which was reflected by changing the resistance state to sensitivity state of Pseudomonas aeruginosa isolate toward cloxacillin, cephalothin, cefotaxime and gentamicin at (5) % (v/v) and (6) % (v/v). Or by significantly enhancing the pre- existing anti- pseudomonal activity which was reflected by increasing the diameter of inhibition zones produced by meropeneme (p<0.01) and amikacin (p<0.05) when tested against Pseudomonas aeruginosa.As a conclusion, polysorbate 80 had no antibacterial activity but it had produced a potentiative effect with some antibiotics while it had no effects with the others.