COMPARATIVE STUDY OF MODE OF ACTION OF PARA-AMINOSALICYLIC ACID ON MYCOBACTERIUM KANSASII AND MYCOBACTERIUM TUBERCULOSIS

Publisher Website
Google Scholar
Abstract
All strains of Mycobacterium kansaii demonstrated increased resistance to p-amino solicylic acid (PAS) and the inhibition index (PAS/PABAXp-amino-zenzene acid) for each of the strains was greater than that for Mycobacterium tuberculosis. Partial reversal of the PAS inhibition occurred in the presence of methionine only for M kansasii, whereas both meth-ionine and oleic acid were required by M tuberculosis for reversal of drug activity. Essentially complete reversal of the inhibition of M kansasii by PAS occurred when p-amino benzyl alcohol was included in oleate-Kirchner medium. Para-aminobenzyl alcohol also functions as a PAS antagonist in drug-resistant strains of M tuberculosis but not in drug-susceptible tubercle bacilli. Mycobacterium kansaii utilized methionine, and oleate, present in human serum for non-competitive reversal of PAS inhibition. Mycobacterium tuberculosis utilized the oleic acid but could not utilize the free methionine necessary for noncompetitive antagonism of the drug.