American Foulbrood Researchers – The Few, The Committed

If you’ve been reading this blog for a bit, you know that I’ve had run-ins with American Foulbrood (AFB) for two years in a row.  I run naturally treated, antibiotic-free hives, in which I eliminate with the elimination of all comb over 5 years old, and old brood comb over 3 years old.

Honeybees at Brookfield Farm Bees and Honey, Maple FAlls, WA

Brookfield Farm Bees at Top Entrance

But even with those efforts AFB still appears – once it’s in an apiary, it is hard to get it out, short of removing all drawn comb.   The spores can live 40 years.  I got fed up last year and removed all unoccupied brood comb, regardless of age (it is painful to destroy comb that has only been drawn out for a few months, believe me).

Time For A Natural Change?

When AFB hit the only solution was to do what has been done for over a century: kill the bees in those hives, burn all frames, and scorch the rest of the gear.  In both years AFB turned up in the fall, so shaking the bees onto undrawn foundation was not an option: there’s nothing with which the bees can drawn comb from October to April.

All that killing and burning – techniques that inspired me to go on a world-wide search for research being done on ways to fight and hopefully kill the AFB spores without destroying the hive.

Technology Schematic 1916

Technology 1916 (wikipedia commons)

A century has passed since American Foulbrood was identified as a unique honeybee disease.  In that time we went from the first AM radio transmissions to ships at sea to smartphones; and from speculation about the existance of vitamins in food to mapping DNA.

I figured there must be someone in the world working on finding a natural way to fight these tough bacteria with 21st century methods.

The Dedicated Few

Happily I found two groups.  Yes, two. That’s all, but they are there.  This makes me:

  • Pleased : that these folks are working on fighting American Foulbrood with natural substances.
  • Shocked : that there’s only two groups that I could locate

Las Vegas : Home of US American Foulbrood Microbiology Research

University of Las Vegas, Nevada Sign

University of Las Vegas, Nevada

OK, AFB is not what I think of right away when I think of Vegas – my mental image strays more towards Hunter S. Thompsons’ “Fear and Loathing“.  But environmental microbiology student Diane Yost and microbiologist Professor Penny Amy are undertaking AFB research at the University of Nevada, Las Vegas.

Working under a grant from the US Department of Agriculture, Yost and Amy are looking at the potential of fighting the AFB bacteria (Paenibacillus larvae) with bacteriophages.  A bacteriophage is a parasitic virus that infects bacteria then reproduces inside of it, killing the bacteria.  (I love these little phages) This “virus kills bacteria” concept is being tested on other bacteria which have become resistant to antibiotics.

Microbiology image from Gulf Breeze Laboratory

Microbiology In Action

Yost and Amy began by testing over 100 differnet types of samples from dirt and flowers to beeswax to lip balm, looking for beeswax with AFB and bacteriophages.

  • They found 31 phages.
  • They tested those on 8 strains of American Foulbrood bacteria
  • 3 naturally occuring bacteriophages showed promise against all 8 AFB strains.
  • If further research shows them to be able to infect and kill AFB bacteria, that would be the first step in the search for a natural treatment for American Foul Brood.

Yes, all the above just gets to the first step.  The work is quite complicated and challenging

  1. Yost and Amy are attempting to locate molecules that would cause AFB spores to germinate at the wrong times, which would then lay the spores opens to attack by enzymes that would tear apart the bacterias’ cell walls.  Those enzymes would be produced by the bacteriopages.
  2. Step two would be to isolate and use natural compounds and amino acids found in adult bees  to protect the honeybee larva.

The goal, writes Yost, is to create “treatments that can protect bees as well as remove the infectious spores from the hive without the risk of resistance posed by current antibiotic treatments or contamination of the hive and its products.”

You can read more about theire work in a paper they preesnted last year at the General Meeting of the American Society for Microbiology.

York, U.K. :

Food And Environmental REsearch Agency, York UK logo

At the Fera National Bee Unit and the University of York, researchers are looking at ways of controling AFB by looking at how the disease spreads.  “the underlying philosophy is to understand how outbreaks spread. The idea is that better advice to apiarists should result in fewer outbreaks, and colony destruction becomes the last resort treatment,” explains Professor Thorunn Helgason.

Part of their research focuses on the genetic diversity of AFB bacteria found in Europe and how that diversity affects the spread of the disease.  One graduate student at the University has designed a genetic marker system that will allow researchers to more easily differentiate and follow strains of AFB.

German AFB Research in 2008

I did find references to American Foulbrood research being done five years ago by Professor Elke Genersch, a microbiologist working in Berlin.  Professor Genersch and collegues discovered that the AFB bacteria replicate in the midgut of the bee larvae, where they live off the food eaten by the bee larvae. The bacteria increase in number until they completely fill the gut.  Then they explode out of the gut, expand though the cavity that contain all the larvas organs.  This kills the larva.  The resulting goo is ridden with bacteria spores.

This work is part of the basis on which todays work is being done.  I tried to contact Professor Genersch, to discover what work has subsequently been done, but I failed to connect.


Scientific research takes a long time.  Results have to be examined and replicated.  So although a natural treatement for American Foulbrood is probably not just around the corner, it is good to know that some people are working on alternatives to killing bees and burning equipment or to the continuous development of new antibiotics to which the bacteria soon become resistant.


We are now on what I think is the fourth antibiotic used against AFB in the United States.  Many countries have banned the use of antibiotics in beehives.

  • Antibiotics stay in the hive, with the bees, their pollen, and their honey.
  • Antibiotics do NOT kill the AFB spores.
    If continuous antibiotic use stops on a hive, AFB will florish and kill the hive
  • Antibiotics only serve to allow infected bee larva to survive.
  • Antibiotic treated hives are potentially filled with viable AFB spores.
    These spores can be passed on to other hives through drone visits and robber bees.
    These spores, on reaching another hive, will replicate and kill that hive.

Hope For the Future

Honeybee with lots of pollen : Brookfield Farm Bees And Honey, Maple Falls, WA

Happy Honeybee

There is hope that one day there will be a natural treatement to combat American Foul Brood.  It won’t be tomorrow or the next day, and it will take a lot of dedicated scientific study to find that treatment.  I, for one, am very greatful to the researchers who undertake this work.  Their work could one day bring an end to a disease that has threatened honeybees for over a century.

That’s the news from Brookfield Farm Bees And Honey, Maple Falls, Washington.  We’ve had a few nice days where the bees flew, and lots of rainy, overcast days where they stayed in.  I’m hoping for a good spring – with the Big Leaf Maples coming into bloom in about one month.  In the meantime, it’s just good to see the girls fly in our brief moments of sun.

About Bean

I am the beekeeper at Brookfield Farm Bees And Honey, near Maple Falls, Washington. My bees fly from naturally treated, antibiotic-free hives in the foothills of Mt. Baker (the second most glaciated volcano in Washington). I sell the raw honey my bees make, as well as honey produced by Washington beekeepers who are friends - the emphasis is on raw honey from naturally treated, antibiotic-free hives. I also make and sell Beeswax Salves. You can find me at the Ballard Farmers' Market in Seattle on Sundays from 10-3. When not with the bees, you'll most likely meet me up some mountain trail, pinhole camera and digital camera slung over my shoulders, and my pack goats trailing behind me.
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