European Foul Brood

Causal agent		Melissococcus plutonius – a bacteria Similar appearance to streptococci and can occur in chains, but can be pleomorphic. Gram + Requires anaerobic culture and colonies may take 4 days to appear.
Other names		EFB
Age group		Very young larvae
Egg	Larvae		Pupae	Adult - worker	Drone		Queen
No	Yes
Clinical signs
Season		Generally seen in the springtime				The larvae are not glistening white. They change colour to a tan (shown) and eventually black. As the larvae die early before they are capped the house bees remove the larvae
Outside		None
Odour		Odour – sour smell
Brood		Spotty pattern on the broom frame. May appear as a crossword puzzle.
Cappings		Open cells – unsealed brood. A few torn cappings
Larvae appearance		Larvae are white to yellow to black. May be granular in appearance. Intestines may be visible through skin
Scales (larvae)		Larvae die very young and appear as a rubbery pile at bottom on cell. Loose within the cell. Lies usually twisted in cell.
Other		May be no clinical signs
Infectivity
		Larvae infected through honey
		The spores are resistant for 3 years
Transmission
		Through honey
		Transmission between hives by drifting and robbing
Post-mortem Lesions
		Very young larvae died at bottom of cell, before capping
Diagnosis
		Appearance of brood
		Culture
		Field diagnosis using lateral flow devices looking for antibodies in the bees
Treatment
		Tetracycline and Tylosin. Provide in spring and autumn in sugar
		Clinical signs predominate when colony is under stress
Control		Maintain a strong colony – lots of food and re-Queen annually. Ensure that the crude protein content of bees is above 40%. When bees drop to less than 30% they become more susceptible to EFB.
		Control using the shook swam technique
		Severe cases destroy hive by burning
Common differentials
		American Foul Brood
Zoonosis		None