|Pristinamycin IIA is a macrolide antibiotic. It is a member of the streptogramin A group of antibiotics and one component of pristinamycin (the other being pristinamycin IA). It is produced by Streptomyces graminofaciens and other bacteria.
For the treatment of bacterial infections.
mechanism of action
Virginiamycin M1 is a macrocyclic lactone antibiotic that acts syngeristically with the structurally unrelated cyclic depsipeptides more commonly known as the virginiamycins B (ostreogrycin B or streptogramin B) and S to inhibit peptide elongation. This is achieved by blocking formation of a peptide bond between the growing peptide chain (peptidyl-tRNA) linked to the 50S ribosome and aminoacyl-tRNA. Virginiamycin M1 has proven to be highly active against Gram positive bacteria, particularly methicillin-resistant S. aureus.