In VitroSusceptibility of Pythium insidiosum to Macrolides and Tetracycline Antibiotics

Abstract

ABSTRACTWe describe thein vitroactivity of macrolides and tetracycline antibiotics againstPythium insidiosum. The MICs were determined according to CLSI procedures (visual MIC) and by a colorimetric method [3-(4,5-dimethyl-2-thiazyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT)]. The lowest geometric mean (GM) MIC (MICs in μg/ml) (0.39 and 0.7 by visual reading and colorimetric method, respectively) and MIC ranges (0.125 to 2.0) were obtained for minocycline, while the highest MICs were shown for erythromycin (GM of 7.58 and 12.25 by visual reading and colorimetric method, respectively, and MIC ranged from 2 to 32). This significantin vitroactivity makes these classes of antibiotics good candidates for experimental treatment of pythiosis.