Baylor brush cutoffs will be place in 1 ml of cysteine transport medium with 20% glycerol and stored at -70 C until processed at the Laboratory of co-I Dr. Graham where will be cultured in medium consisting of of a horse blood agar (HBA) plate (nonselective medium) or an HBA plate containing 10 μg/ml nalidixic acid, 5 μg/ml trimethoprim, 3 μg/ml, vancomycin and 2 μg/ml amphotericin B (selective medium). MIC testing for clarithromycin, tinidazole and amoxicillin will be conducted using agar dilution methods.