Retardation of the Emergence of Isoniazid-Resistant Mycobacteria by Phenothiazines and Quinacrine

Publisher Website
Google Scholar
Abstract
Summary Growth of Mycobacterium intracellulare strain P-55 (“Battey” organism) was most strikingly retarded by a combination of isoniazid (INH) and paraaminosalicylic acid (PAS), though the organism was resistant to PAS and only marginally sensitive to INH. Among the phenothiazines, chlorpromazine, promethazine, and hydroxyzine also delayed outgrowth in the presence of INH by the “Battey” organism. Quinacrine hydrochloride also prolonged growth inhibition of strain P-55 in the presence of INH. The dibenzazepine, amitriptyline, was less effective than the phenothiazines in delaying INH resistance in strain P-55. The P-55 strain was quite sensitive to streptomycin but none of the resistance-retardants delayed outgrowth of drugrefractory organisms. Though strain P-55 was resistant to PAS at 50 μg/ml, only 5 μg PAS/ml with either INH or streptomycin was able to vastly reduce the viable count. Neither ethionamide nor ethambutol prolonged the lag in growth of the “Battey” organism caused by INH.

This publication has 0 references indexed in Scilit: