Bacteriostatic action of progesterone on staphylococci and other microorganisms.

Yotis, William (Loyola University, Hines, Ill.), and Ronald Stanke. Bacteriostatic action of progesterone on staphylococci and other microorganisms. J. Bacteriol. 92:1285-1289. 1966.-Progesterone has been examined in vitro for antibacterial activity against 10 microorganisms. Turbidimetric and manometric techniques were used to assay the antibacterial activity of progesterone. The organisms tested consisted of Staphylococcus aureus, S. epidermidis, Gaffkya tetragena, Bacillus subtilis, Listeria monocytogenes, Candida albicans, Escherichia coli, Aerobacter aerogenes, Salmonella paratyphi, and Proteus vulgaris. Antibacterial action was shown by progesterone only against the gram-positive microorganisms when they were grown in tryptic soy broth containing 10 to 20 mug of progesterone per ml. Pregnenolone, 4-pregnen-20beta-ol-3-one, and 5alpha-pregnane also possessed antistaphylococcal properties, whereas pregnanolone, pregnandione, 11alpha-hydroxyprogesterone, and 17alpha-hydroxyprogesterone did not. The bacteriostatic action of progesterone on staphylococci was exerted primarily during the first 8 hr of incubation, and it was reduced in the presence of oxygen. In the presence of 20 mug of progesterone per ml, there was significant reduction in the oxidation by resting staphylococcal suspensions or utilization by staphylococci of pyruvate as an energy source during growth.