Virginiamycin

Streptogramin Antibiotic (non‑ribosomal Peptide)Rx: ResearchCompound: Approved

Also known as: Bactocill, Eskalin, Stafac, Streptogramin A/B mixture, Virginiamycin M1, Virginiamycin M1 + S1, Virginiamycin S1, VM

Educational Only — Not medical advice. Consult a qualified clinician before using any peptide.

Source Virginiamycin at Peptiology

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Summary

Virginiamycin is a mixture of two streptogramin peptides (virginiamycin M1 and S1) used primarily as a veterinary feed additive for growth promotion and disease prevention in livestock.

Mechanism of Action

Inhibits bacterial protein synthesis by binding to the 50S ribosomal subunit; component A blocks the peptide‑exit tunnel, component B interferes with peptidyl transferase activity, producing synergistic bacteriostatic effect.

Routes of Administration

Oral

Goals & Uses

  • Gram-positive bacterial infection treatmentAntimicrobialLow
  • Prevention of necrotic enteritis in poultryVeterinary / Infectious DiseaseModerate
  • Prevention of bacterial enteric infections in animalsVeterinaryModerate
  • Growth promotion in livestockVeterinary / AgriculturalModerate

Contraindications

  • Pregnant or lactating animalsReproductiveModerate
  • Known hypersensitivity to streptograminsAllergyHigh
  • Human therapeutic useRegulatory/safetyHigh

Adverse Effects

  • Residue accumulation in food productsFood SafetyUnknown
  • Selection for streptogramin-resistant enterococci (VRE)Antimicrobial ResistanceUnknown
  • DiarrheaGastrointestinalCommonLoose or frequent stools
  • Gastrointestinal upset (in treated animals)GastrointestinalUncommon
  • Selection of resistant bacteriaMicrobialCommon

Drug Interactions

  • Other protein synthesis inhibitorsModerate
  • Quinupristin/dalfopristin (Synercid)High

Population Constraints

  • Humans (general)Regulatory / SafetyAbsolute
  • EU livestockGeographic / RegulatoryAbsolute
  • Human patientsClinicalAbsolute
  • Organic-certified livestock operationsAgricultural RegulatoryAbsolute

Regulatory Status

  • European UnionWithdrawnBanned for use in animal feed due to resistance concerns.
  • United StatesWithdrawnNo longer approved for use as a growth promoter; not approved for human medicine.
  • United KingdomWithdrawnSame as EU.

Withdrawn or not approved for human use in the US and EU; historically approved for veterinary use but many jurisdictions have restricted or banned its use as a growth promoter due to antimicrobial resistance concerns.

Evidence & Sources

No sources recorded yet.

Frequently Asked Questions

What is Virginiamycin?

Virginiamycin is a mixture of two streptogramin peptides (virginiamycin M1 and S1) used primarily as a veterinary feed additive for growth promotion and disease prevention in livestock.

What is Virginiamycin used for?

Virginiamycin is educationally associated with: Gram-positive bacterial infection treatment, Prevention of necrotic enteritis in poultry, Prevention of bacterial enteric infections in animals, Growth promotion in livestock. Educational only — not medical advice.

How is Virginiamycin administered?

Recorded routes of administration: Oral.

What are the potential side effects of Virginiamycin?

Reported adverse effects include: Residue accumulation in food products, Selection for streptogramin-resistant enterococci (VRE), Diarrhea, Gastrointestinal upset (in treated animals), Selection of resistant bacteria. This list is not exhaustive — consult a qualified clinician.

Who should avoid Virginiamycin?

Recorded contraindications: Pregnant or lactating animals, Known hypersensitivity to streptogramins, Human therapeutic use. Consult a qualified clinician before use.