Causative agent of European Foulbrood?

• A. Melissococcus pluton
• B. Paenibacillus larvae
• C. Nosema apis
• D. Ascosphaera apis

Answer: (A)

European foulbrood is caused by Melissococcus pluton, a bacterium that infects honey bee larvae. It tends to attack very young brood, and infected larvae die and liquefy, producing a patchy brood pattern with crumbly, brown larval remains in the cells rather than the firm, dark scales seen with some other foulbrood diseases. A practical clue is that European foulbrood does not produce the ropy, stringy material when you pull on the remains, which helps distinguish it from American foulbrood. The organism spreads through contaminated brood food and hive equipment, so management focuses on removing infected brood, maintaining colony health, and, where allowed, using antibiotics to suppress the infection. For comparison, other listed agents cause different diseases: Paenibacillus larvae causes American foulbrood, Nosema apis causes Nosema disease in adults, and Ascosphaera apis causes chalkbrood.