A Discussion on Foulbrood

[Calum]

This Conversation originated in the Beekeeping Myths (http://www.sbai.org.uk/sbai_forum/showthread.php?792-Beekeeping-myths) Thread but a few of us felt that it was far too useful and interesting to be buried within what is a fairly lighthearted topic so I've broken the relevant posts out into this thread.

Nellie.

Good tip from our FB. Make casts from colonies that want to swarm. But break out all their queen cells after 5 days and add a frame form your best colony, otherwise you will breed colonies that want to swarm more over time.

Also don't give stores frames/feed a swarm for 2-3 days after capture so they use their own recourses. Otherwise if they carried AF in their stomach full of honey they will store it with all the problems that entails. Starve them a bit and they'll eat it up resolving the problem.

[Jon]

Are you posting the foul brood thing as a tip or a myth!
I wonder how many colonies with foul brood would be capable of growing enough to produce a swarm which carried spores.

[Calum]

a tip. If the hive you put them in has food, they'll empty their bellies and the spores are in the new hive. which they will then raise their first young with.

[Jon]

I was more thinking along the lines of, can colonies with foulbrood ever grow strongly enough to be capable of swarming. Foulbrood is a severe drain on resources and must restrict colony growth. They say most foulbrood cases are caused by beekeepers moving equipment about, especially old comb, or else bees robbing out a colony which has succumbed to foulbrood. Ruary might know something about the possibility of swarms carrying foulbrood spores.

[Neils]

Must admit that I wouldn't like to commit something in writing around it one way or another. I certainly get the reasoning behind it but if you've got a swarm full of honey, diseased or not, would they take the feed to make comb to store the diseased honey? If you fed a heavy syrup would that change things?

[gavin]

Ruary might know something about the possibility of swarms carrying foulbrood spores.

Pretty sure that it happens.

Anyway, back to the myths: EFB is a stress disease. (As in, promoted strongly by stress rather than causing it).

[Jon]

I think a lot of bee disease is stress related and for that reason alone it is good to minimize disturbance**, disruption, heavy handling, opening on cold days etc.

I have read, may be another myth, that foulbrood spores are usually present in a colony, same as nosema spores, but it takes stress to raise the spore count to a critical level and induce the symptoms of the disease.

**Not yet advocating let alone beekeeping

[gavin]

Yeah, I have read that too and had it quoted at me from people who should know better. Simply don't believe it. EFB is missing from large areas and is still actively colonising parts of the UK. Once it it there it may bubble up again from latent infection (eg contaminated comb) but I don't believe that it is near-ubiquitious and awaiting stress to trigger it. Tooth fairy stuff.

[mbc]

EFB is missing from large areas and is still actively colonising parts of the UK. Once it it there it may bubble up again from latent infection (eg contaminated comb) but I don't believe that it is near-ubiquitious and awaiting stress to trigger it. Tooth fairy stuff.

Hardly tooth fairy stuff, it just needs a little qualification to make it entirely accurate.
If the causative agent, melissococcus plutonius, is present at a sub clinical level then a stress event (typically a dearth of food when there is brood to nurture) can trigger a clinical outbreak of what we know as EFB, of course if the causative agent isnt present it wont magically appear out of thin air.
Colonies with AFB frequently get up to swarming strength and swarm if they go undetected, the 'dont feed a swarm for a couple of days' tip is a percentages thing, we may as well make it less likely that anything is passed from one generation to the next ( vertical transmission).
Finally, the forest fire/smoke thing will never be known unless bee psychiatry jumps to fantastic levels where we can really plumb the depths of a bee's mind, my money's on it being partly true and the confusion caused by the foreign smell of danger helps distract the bees from defensive behaviour.

[Calum]

Colonies with AFB frequently get up to swarming strength and swarm if they go undetected, the 'dont feed a swarm for a couple of days' tip is a percentages thing, we may as well make it less likely that anything is passed from one generation to the next ( vertical transmission).


If you gather a swarm that is of unknown origin you have two choices to try and protect yourself from them bringing (possibly large levels of) FB spores with them.
1. Burn a sulphur strip in the swarm box after collection (with the bees still in it)
2. Starve them a bit

choice one is 100% sure to protect you
choice two is a percentages thing

[mbc]

If you gather a swarm that is of unknown origin you have two choices to try and protect yourself from them bringing (possibly large levels of) FB spores with them.
1. Burn a sulphur strip in the swarm box after collection (with the bees still in it)
2. Starve them a bit

choice one is 100% sure to protect you
choice two is a percentages thing
Lol, yes.

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.

[Jon]

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

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.

It also shows that there are AFB spores in a colony without symptoms necessarily being present.
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.

[gavin]

If the causative agent, melissococcus plutonius, is present at a sub clinical level then a stress event (typically a dearth of food when there is brood to nurture) can trigger a clinical outbreak of what we know as EFB, of course if the causative agent isnt present it wont magically appear out of thin air.

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.

[Jon]

Need to be careful. We are talking about both AFB and EFB now and the same logic may not necessarily apply to both.

[Rosie]

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

[Jon]

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.

Not sure Steve. MBC's link referred to Sweden.

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).

[mbc]

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

[prakel]

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/showthread.php?261291-American-Foulbrood-(afb)&highlight=foulbrood

[Jon]

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 !

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.

[Rosie]

What sort of "beside" is that Jon? Do you mean someone other than you or someone next to you?:D

[Jon]

Beside as in nearby rather than as well as. Steve that's you outed as a grammar pedant! Mind you there are a few of us here.
Cross your fingers as Megan Seymour will be inspecting some of my colonies on 26th May as part of a whistlestop tour of NI.

[Bumble]

Fera's advice is to shook swarm a colony with EFB. I've heard it said that starving a swarm for two or three days, then shook swarming it onto new ,will make sure the new combs are disease free. I don't know anybody who's done it though, my main concern would be that they would abscond

[Rosie]

"Fera's advice is to shook swarm a colony with EFB."

While bumble makes a good point I would like to clarify the fact that it's illegal to do anything once foulbrood is found except inform the NBU and impose your own standing order on your apiary. I'm sure Bumble realises this but I fear his post could be misunderstood by a beginner.

The bee inspector might decide to carry out a shook swarm but the choice is in his/her hands, unless the rules are different in Scotland.

Rosie

[gavin]

Perhaps I could inteject here that in Scotland we are under an obligation to get in touch with our own bee health regulatory people, aka Steve.

BeesMailbox@scotland.gsi.gov.uk

or your local RPID office

http://www.scotland.gov.uk/Topics/farmingrural/Agriculture/AOcontacts/contacts

Yes, the law is the same. Suspect foulbrood and you have to get in touch.

Is that twice now you've misidentified the gender of a valued poster?! You are worse than Eric :p.

[Rosie]

Oops - sorry! I'll have to try to avoid words like his/her/him/hers they just get me into trouble.

Rosie (a him)

What sex is Eric, by the way :)

[gavin]

I wouldn't wish to pigeon-hole him ...

[Bumble]

I would like to clarify the fact that it's illegal to do anything once foulbrood is found except inform the NBU and impose your own standing order on your apiary. I'm sure Bumble realises this but I fear his post could be misunderstood by a beginner.

The bee inspector might decide to carry out a shook swarm but the choice is in his/her hands, unless the rules are different in Scotland.
Good point.

The UK Foulbrood disease legislation is covered on the Fera (Beebase) FAQ page https://secure.fera.defra.gov.uk/beebase/public/faq.cfm

It might be worth mentioning that it's a good idea to register with Fera/Beebase to be sure of receiving seasonal updates from inspectors (advisors) as well as warnings of local disease outbreaks. Our local Regional Bee Inspector is very approachable, and extremely helpful.

As for gender issues - without hints or pictures, how would anybody know? This is the internet, after all.

[gavin]

England and Wales I suspect. The Scottish pages (inc links to the Scottish legislation) are here:

http://www.scotland.gov.uk/Topics/farmingrural/Agriculture/animal-welfare/bee

Have I been doing too much gender-outing?!

PS Bumble is actually a burly Stonehaven professional shot-putter who lives with his artist lover in a garret somewhere in southern England .... ;) .... mibbae.

[Ruary]

Fera's advice is to shook swarm a colony with EFB. I've heard it said that starving a swarm for two or three days, then shook swarming it onto new ,will make sure the new combs are disease free. I don't know anybody who's done it though, my main concern would be that they would abscond

I've been away and so am coming in late to this thread!
There was a paper presented at the Dublin Apimondia which tested mhaking the swarm into clean (i.e new) brood boxes with drawn foundation, and then after a period ( I think it was a week) semoving the bees into a second clean (i.e New) brood box with new frames and foundation. In the majority of cases the colonies did not show clinical signs of AFB after this treatment. However tow of the colonies showed AFB the next year.
When I had my last outbreak some years ago, I performed this procedure on all the colonies which did not show any signs of AFB, I also burned all the colonies with clinical signs and all the super frames from that apiary. I had a recurrence of AFB the next year and had to destroy a firther two colonies.
It has been stated often enough that treating in this manner is selecting the most virulent strains of AFB!

[Neils]

Killing the colonies/burning or by changing the colony out repeatedly onto new foundation?

[gavin]

In theory ...

- killing the colonies selects against virulent strains of bug and/or susceptible bees

- shook swarming doesn't select for or against resistant bees but might select for virulent bugs

In reality ...

The bugs are under constant selection for virulence anyway. Selecting against susceptible bees may be the strongest effect (in addition to removing inoculum of course).

[The Drone Ranger]

See "Infectious Diseases of The Honeybee " L.Bailey 1963 pages 130 -140 for explanation of why a drop in available incoming food increases EFB infection.
Also resistance and effects of culling diseased hives

You are worse than Eric
Is that the Eric who was banned ??
I think its time to lift the lifetime ban
A couple of weeks in the sin bin should have been enough.
As I remember that was all about inbreeding and got a bit heated
Recently somebody else got a yellow card over chemical abuse
I kind of like the idea that some people are over enthusiastic
If the Forum just had 3 or 4 contributors saying how great AMM are that would be a bit flat.
PS Will.i.am of the Voice has joined BiBBa and is now known as Will,i.amm

[Jon]

Eric was unbanned a while back but hasn't started to post again. Eric we love you. Lets have some more of your blether and nonsense.


I kind of like the idea that some people are over enthusiastic

Me too, as long as it does not descend into shouting or insults. Back to the foulbrood. This thread has already been relocated.

[Bumble]

PS Bumble is actually a burly Stonehaven professional shot-putter who lives with his artist lover in a garret somewhere in southern England .... ;) .... mibbae.
mibbae!

Or mibbae a New Year's Eve Swinger, or mibbae a granny with hair tucked neatly into a bun, or .... ;)


It has been stated often enough that treating in this manner is selecting the most virulent strains of AFB!
Or the most susceptible of bees?

I thought it was standard that AFB colonies, and equipment, were destroyed. Is it different in Ireland?

Fera says, on page 10 of this booklet https://secure.fera.defra.gov.uk/beebase/downloadDocument.cfm?id=7
Control of the disease [AFB] is through compulsory destruction of infected colonies, which is a very effective measure.

I'm a bit neurotic about the foulbroods you see, and have almost worn out our copies of those bookelts. There was EFB in our area last year you see. We were lucky, I hope we continue to be. RBI is due to inspect our bees soon, to check.

Our bees seem healthy and active, and we haven't seen any signs, so if the diagnosis is positive we hope the inspector would trust antibiotics or shook swarm, but we do know that heavily diseased colonies or infected colonies that are weak are destroyed.

[Ruary]

Sorry wrote it too fast and did not re-read!
Non destructive methods select for the most virulent strains as they are the ones which give rise to clinical symptoms. Some bees can deal with the more benign strains and in that case obviously the pupae do not die, so there are no sunken cappings nor decaying pupae which are the classic signs of AFB.
Destructive methods kill off the bacteria by burning/ burying.

[The Drone Ranger]

Les Bailey tells us that the bees most resistant were those that removed infected larvae before 10 days but removal after that its worse than useless

Now I think that means killing larvae after capping and judging which bees remove the most dead larva might not tell us much

And more importantly after a threshold number of infected larva is reached memory says they used 100 cells both the resistant and susceptible bees all succumbed

Also if the ratio of nurse bees to larva is high, bees reject far fewer infected larva.
That condition can occur when there is a sudden drop in income I think that could be caused by spell of bad weather or the rape ending for instance

It's best to read the book though because taking a few lines here to cover his research seems wrong in a way, so the bits after italics are my views not his necessarily

[Neils]

What's the book title DR?

In relation to removal of infected larvae, my understanding (and it's late so I may be getting mixed up) is that can contribute to the spread as the same bees that are removing larvae are then going on to feed other, so far, healthy larvae and the disease spreads through that cross contamination of removing infected brood then getting, now infected from mouth parts exposed to infected brood, food which is then fed. In some respects might a less hygienic behaviour actually be beneficial?

Hygienic behaviour good for varroa but bad for foul brood? (simplistic I know, sorry).

[Ruary]

What's the book title DR?

In relation to removal of infected larvae, my understanding (and it's late so I may be getting mixed up) is that can contribute to the spread as the same bees that are removing larvae are then going on to feed other, so far, healthy larvae and the disease spreads through that cross contamination of removing infected brood then getting, now infected from mouth parts exposed to infected brood, food which is then fed. In some respects might a less hygienic behaviour actually be beneficial?

Hygienic behaviour good for varroa but bad for foul brood? (simplistic I know, sorry).

I wonder?

It depends on when the larvae are removed if the skin is intact then removal should not cause spread of bacteria from it as all the bacteria (infecting that larva) is contained within it.
Ruary

[Rosie]

I thought the spread depended on whether the larvae had defecated in the cell or not bfore dying. The ones that are not well fed die early and keep the bacteria in their gut. The better fed ones last long enough to defecate and the bacteria is spread whenever the cell is cleaned whether the bees are hygienic or not.

Rosie

[The Drone Ranger]

See "Infectious Diseases of The Honeybee " L.Bailey 1963 pages 130 -140 for explanation of why a drop in available incoming food increases EFB infection.
Also resistance and effects of culling diseased hives


from earlier post :)

The early removal of larva is in relation to AFB where removing the larva before infective spores have fully developed is key
The resistance trials were conducted using 100 scales introduced to health hives
Some hives could cope others collapsed
Once the number of introduced scales was increased all hives succumbed

[mbc]

Once the number of introduced scales was increased all hives succumbed

Steve Taber said he managed to breed a strain of bee which he could introduce a badly infected (with AFB)brood frame to, and they would clean it up fine.

[The Drone Ranger]

Steve Taber said he managed to breed a strain of bee which he could introduce a badly infected (with AFB)brood frame to, and they would clean it up fine.

The bees they brought to this study were all survivor colonies from areas with very high infection rates
The plan was to breed from these resistant colonies
The limits of their resistance was tested
There was a breeding program using isolated mating stations
They managed a slight increase in resistance in the first generation and no further improvement in subsequent breeding.
The project failed to produce bees with sufficient increase in resistance to be meaningful.
The characteristics could not be sufficiently well fixed even in a closed population to be worthwhile