Abstract

The effect of the mutagen (acridine orange) on the multi-resistant antibiotics beta lactamase producing Staphylococcus aureus strain of bovine and human origin was investigated and tested individually using iodiometric (cell supervision) method for the level of beta-lactamase produced by each strain and antibiotic – sensitivity screening using single disc agar diffusion method. Analyses revealed that 80% of the isolates from bovine origin produced beta-lactamase while only 20% showed absence of the enzyme, while 68% of the human isolates produced beta-lactamase while only 32% showed absence of the enzyme sensitivity to cefotaxime, cefuroxime and ceftriaxine were observed in both strains of bovine and human origin. At high concentrations of the mutagen (250  µg/ml), zones of inhibitions were low for penicillin, amoxicillin and augmentine at reference MIC’s of 0.25 µg/ml, while the cephalosporins recorded high zones of inhibition at 0.5 and 1.0 µg/ml reference MIC’s in all the strains at 250 and 200 µg/ml of the concentration of the mutagen (acridine orange). The resistance bovine strains producing beta-lactamase resisted curing with acridine orange than the human strains of S. aureus.

Key words: Acridine orange, Staphylococcus aureus, beta-lactamase, iodometric.