American foulbrood Flashcards
what is the disease
histolysis infectiosa perniciosa larvae apium or pestis americana larvae apium
what organisation should AFB be reported to
it has to be reported to world organization for animal health OIE
most dangerous bee disease
highly contagious
pathogen of AFB
paenibacillus - bacillus larvae
characteristics of AFB
gram positive
spore forming
what is infective in AFB
only spores - 2.5 billion produced in each infected larvae
what are the spores resistant to
to heat, cold, disinfectants, desiccation and humidity
what stage is most susceptible to AFB
larvae most susceptible during early larval stages
how many spores are enough to initiate a fatal infection
10 spores or fewer after about 12-36 hours after hatching
when do larvae die
soon after they have been sealed due to septicaemia
how do larvae older than 2 days old become infected
with only millions of spores
which larvae are most susceptible
more susceptible are queen larvae than larvae of workers
latent period length
takes 5 days
diseased cell description
capping becomes moist and darken in colour
shape of the capping
as larvae shrinks the capping is drawn down and becomes concave when normally it is convex
colour of dead larvae
pearly white to a creamy brown
smell of larvae
fish glue like smell
infected brood colour
will turn chocolate brown and melt into a mass on the floor of the cell - pupal tongue syndrome
what happens in bad cases
very dark brown scales found on lower parts which is very difficult to remove and can remain infective for up to 30 years
diagnosing AFB
inspect the combs
study in UV light
mil probe = milk will curdle within a minute
PCR
cultivating bacterium
what can you stain the spore with
staining of spores with methylene blue
treatment of AFB
some countries allow oxytetracycline hydrochloride or sulfathiazole
what are antibiotics not effective against
infectious spores - only suppress clinical symptoms and mask the disease
breeding honey bee genetic stock
shows an increased immune response against the disease
other controls of AFB
biocontrol through antagonistic bacteria and treat with natural antibacterial substances like essential oils or propoil
