any of various antibacterial substances derived from the bacterium Streptomyces virginiae, used in antibiotics and in animal feed as a growth stimulant.
vir·gin·ia·my·cin (vər-jĭn'yə-mī'sĭn) n. Any of several antibacterial substances derived from an actinomycete related to Streptomyces virginiae, used chiefly as an additive in animal feed.
[New Latin virginiae, specific epithet (from genitive sing. of Virginia, Virginia) + -mycin.]