A radiometric method for objectively screening large numbers of compounds against Pneumocystis carinii in vitro.
A relatively simple method is reported for accurately quantitating the incorporation of [3H]para aminobenzoic acid (pABA) into the folates of Pneumocystis carinii cultured in vitro, and the subsequent development of a highly sensitive and reproducible 96-well microtitre plate drug screening system. Incorporation of [3H]pABA under optimized conditions has been utilized as a selective indicator of the in vitro viability of P. carinii against which the inhibitory effects of potential drugs were quantified. The anti-Pneumocystis agents pentamidine, sulfamethoxazole, 566C80 and piritrexim gave median inhibitory concentration values of 7.3, 0.1, 1.4 and approximately 100 microM, respectively in this assay. The results suggest that this 96-well plate P. carinii [3H]pABA-incorporation system is suitable as a rapid high throughput primary in vitro screen for detecting compounds with anti-Pneumocystis activity.
Comley
J C
JC
Department of Molecular Sciences, Wellcome Research Laboratories, Beckenham, Kent, UK.
Mullin
R J
RJ
Wolfe
L A
LA
Hanlon
M H
MH
Ferone
R
R
D010129:4-Aminobenzoic Acid; D000818:Animals; D004353:Drug Evaluation, Preclinical / Q000379:methods*; D005492:Folic Acid; D008297:Male; D011010:Pneumocystis / Q000187:drug effects*; D011874:Radiometry; D051381:Rats; D011919:Rats, Inbred Strains; D014316:Tritium
D014316:Tritium; D005492:Folic Acid; D010129:4-Aminobenzoic Acid