AN AGAR DIFFUSION METHOD FOR EVALUATION OF ANTIMYCOPLASMA SUBSTANCES

Abstract

An agar diffusion method for testing antibiotics and other chemicals inhibiting Mycoplasma species has been developed. Paper discs dipped in solutions of the candidate compounds are placed on agar plates heavily seeded with Mycoplasma cells. After over-night incubation, the agar surface is flooded for 5 minutes with a 2, 6-dichlorophenolindophenol solution. The viable cells reduce the dye while the killed cells do not. Dose response curves with slopes between 3 and 4 were obtained when discs containing chloramphenicol, chlortetracycline, or tylosin were placed on agar seeded with Mycoplasma laidlaxvii type B. The technique can also be used for preparing bioautographs of paper or thin layer chromatograms.