Sulfa drug screening in yeast: fifteen sulfa drugs compete with p-aminobenzoate in Saccharomyces cerevisiae

Sulfa drugs have been used as antimicrobials for decades but resistance is now a problem. For major eukaryotic pathogens, including Plasmodium and Pne umocystis. sulfa drug testing is difficult or impossible. We have shown tha t the eukaryote yeast can be used as a model fur the study of sulfa drugs w ithin certain parameters. Fifteen sulfa drugs inhibited yeast growth in a m anner indicating competition with p-aminobenzoate (pABA). Such competition resulted from direct addition of pABA or through increased expression of th e pABA synthase gene (ABZI). The model system predicts that overexpression of the pABA synthase gene can lead to drug resistance. (C) 2001 Federation of European Microbiological Societies. Published by Elsevier Science B.V. A ll rights reserved.