MACROLIDES INDUCED SUPPRESSION OF VIRULENCE FACTORS PRODUCED BY STAPHYLOCOCCUS-AUREUS

The effect of sub-MICs of azithromycin, clarithromycin and roxithromyc in, as compared to erythromycin, on the production of coagulase, beta- hemolysin, lecithinase and deoxyribonuclease by Staphylococcus aureus was studied. All new macrolides completely inhibited coagulase and bet a-hemolysin production and partially inhibited lecithinase and deoxyri bonuclease. Such inhibition is not related either to growth inhibition or to inhibition of enzyme activity. Erythromycin, on the other hand, had no effect on coagulase or beta-hemolysin production but slightly suppressed the production of lecithinase and deoxyribonuclease. This i nhibitory effect might have clinical significance if it was found to o ccur in vivo.