eskalin eskalinv micamicina mikamycin mikamycine mikamycinum ostreogricina ostreogrycin ostreogrycine ostreogrycinum pristinamicina pristinamycine pristinamycinum pyostacine stafac stafytracine staphylomycin stapyocine starfac streptogramin vernamycin virgimycin virgimycine virginiamicina virginiamycin virginiamycina virginiamycinum