Which antibiotics can be used to treat American Foulbrood?

• A. Penicillin
• B. Erythromycin
• C. No antibiotics are effective
• D. Oxytetracycline and tylosin

Answer: (D)

American Foulbrood is caused by Paenibacillus larvae, a spore-forming bacterium that infects developing bee larvae. Antibiotics can suppress the disease by inhibiting bacterial growth, especially when used during the brood-rearing period, but they do not destroy the durable spores that can persist in the hive. The antibiotics used for treatment are oxytetracycline and tylosin, which both target bacterial protein synthesis and help reduce infection levels in the brood. Penicillin isn’t effective against this organism, and erythromycin isn’t the standard choice for AFB treatment. Remember that antibiotic use is only part of control—hive sanitation, replacement of heavily infected combs, and sometimes requeening are essential to prevent reinfection since spores can linger in the environment.