Lol, yes.Originally Posted by Calum
This linky:http://pub.epsilon.slu.se/1053/1/Avhandling.pdf is a paper I keep going back to to explode some myths about AFB, our own NBU seems scared to tread on this ground in case beekeepers twig their colonies need not necessarily be destroyed if they have AFB and they can rid themselves (sometimes !) of the infection given a fresh start on clean comb.
Great find that paper, MBC. First time I have seen it.
It certainly backs up what Calum suggested about not feeding a newly housed swarm.
Page 18
It also shows that there are AFB spores in a colony without symptoms necessarily being present.None of the swarms showed any clinical disease symptoms at any time. This indicates that the amount of spores
needed to produce clinical disease are not transmitted by swarms, or at least that they are not readily available to the larvae. If clinical symptoms appear, it is on a non-detectable level. It seems reasonable that a “no brood, no food” argument is
valid here, as well as in the artificial swarm case. Because the bees do not have
any stored food they will consume whatever contaminated honey they have in their
honey sac. Also, there are no larvae available to the swarm to which they can
transmit spores before most contaminated food carried from the mother colony is
consumed.
Page 14
Twenty-two percent of the individual colonies
were clinically diseased. All samples from clinically diseased colonies were
positive. Of the remaining colonies, 77% were positive although they had no
visible symptoms of AFB. We found a significant relationship between the number
of clinically diseased cells in the colony and the number of colony-forming units
(cfu) in the laboratory cultures. Colony-forming units are the number of bacterial
colonies that grow on the agar plates.
Fifty-four percent of the apiaries contained clinically diseased colonies. In the
lab cultures, however, 70 % of the clinically healthy apiaries were positive for
AFB.
Last edited by Jon; 11-05-2012 at 09:53 AM.
Glad to have the qualification (and that was always missed out by those I heard talking about this), but from what I know of the disease I'm unconvinced that stress triggers a build-up. Seems to be true for chalkbrood (at least, damp weather and low income seems to help that one). Levels of EFB locally seem to wax and wane and I'm far from convinced that dearth has a big role. Is there any real evidence for this? Yes, the disease often seems to appear at the end of the spring flow, but this doesn't mean that stress is involved. Maybe the bees that are being hygienic are distracted while there is a major flow on and the levels build up then. I should say this is more speculation, not fact.
Feed the bees, we've been told, and the disease will decline or not appear. Happy to be correct (as always) but I don't see it.
Need to be careful. We are talking about both AFB and EFB now and the same logic may not necessarily apply to both.
Regarding EFB my understanding is that a good flow can mask the problem in the short term but makes it worse later. The reason is that with EFB the larva usually starves to death before being sealed due the the fact that the bacteria rob the food from its gut. With a good flow on the bees can overfeed to compensate and the larva dies after reaching the pupa stage. At this pint the doomed larva has already voided its gut and filled the cell with millions of bacteria waiting to be spread by the house bees when they clean it out.
I suspect the thinking that foulbroods are in every colony at sub-clinical level applies more to countries that do not employ our strict policy of eradication.
Rosie
Not sure Steve. MBC's link referred to Sweden.I suspect the thinking that foulbroods are in every colony at sub-clinical level applies more to countries that do not employ our strict policy of eradication.
Treatment and control
In Sweden, no treatment is allowed for clinically diseased colonies. Instead a
stamping out policy is employed, which means that the bees have to be destroyed
and the contaminated equipment destroyed or thoroughly cleaned (Anon., 2002).
Several treatment strategies are allowed in other countries, such as treatment with
antibiotics and apicultural techniques like artificial swarming. Treatment with
antibiotics is not allowed in the EU, but is common in, for example, USA and
Canada where preventive treatments with antibiotics is considered a routine
procedure to avoid outbreaks of AFB. Not surprisingly, antibiotic resistant strains
of P. larvae have evolved (Miyagi et al., 2000). Another problem with this
practice is residues of antibiotics in honey and other hive products (Bogdanov,
2006).
I'm sure in some countries ( cant remember which !) the accepted practice is to requeen if efb rears its head, which seems to make the problem go away for them ! Not that I'm condoning this practice as its sure to allow the bacteria to spread, but it does shed light on how trivial some beekeepers view EFB.
Jon, with regard to that paper, my favourite revelation is the bit where swarms from colonies infected with AFB often had AFB at detectable levels but no clinical symptoms, but if they didnt develop full blown AFB within the first brood cycle, six months later no AFB at all was detectable. Interesting stuff indeed !
None of this indicates our policies on controlling bee diseases in the UK are incorrect, to the contrary the Upsala paper concludes that eradication is the best way forward for AFB colonies
At the risk of going too far off topic there's an interesting afb related paper at
http://aem.asm.org/cgi/reprint/75/10/3344.pdf
There's also a great thread on beesource regarding the same -needs sifting through but the posts from Robert Russell and a few others are very informative:
http://www.beesource.com/forums/show...ight=foulbrood
Last edited by prakel; 11-05-2012 at 11:25 AM.
That is indeed interesting, as it would suggest that a shook swarm carried out carefully could save a colony. But in practice, hobby beekeepers would stop reporting AFB symptoms to the authorities and would bollock about trying to deal with the situation in house with varying degrees of success for both themselves and their beekeeping neighbours. If someone beside me had colonies with AFB I think I would prefer to see them on the pyre.
What sort of "beside" is that Jon? Do you mean someone other than you or someone next to you?
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