The antibiotic virginiamycin is produced byStreptomyces virginiaeand is a member of the virginiamycin family. Each member is produced as a mixture of two structurally different compounds that exhibit synergistic antibacterial activity. There are two groups: virginiamycin M1 (VM1) and virginiamycin S (VS). VM1 is a polyunsaturated macrocyclic petolide. VM1 and VS are both used to inhibit protein synthesis since they are bacteriostatic. When used in combination they are more effective. Virginiamycin is used as a performance promoter in animal husbandry. They are chemically modified to make therapeutic drugs such as quinupristin and dalfopristin.
