There’s more and more evidence that antibiotic-resistant American foulbrood (AFB) is for real in Florida (January 2000). Mr. Laurence Cutts of the Division of Plant Industry’s Apiary Bureau, is burning more colonies that have become symptomatic than in past years. Many of these have been treated with antibiotic apparently to little avail.
Tests at both the Florida and Federal Beekeeping Laboratory in Beltsville, Maryland have confirmed what appears to be a growing tolerance by the causative organism (Paenibacillus larvae larvae) for the only currently labeled antibiotic, Terramycin®. This should be no surprise. It parallels what is happening in other livestock industries, as well as humans, signaling that the era of antibiotics as a wonder drug may be drawing to a close.
The good news is that Dr. H. Shimanuki of the Beltsville Bee Laboratory sees a new era dawning such that we can expect to see advances made in the materials and methods available for detection, prevention and control of AFB. The bad news is that this may take some time, and those beekeepers having the problem now could be ill-equipped to deal with it. One of the reasons for this is that many are not familiar with the disease’s etiology and detection. These have taken low priority in the face of 40 years of effective masking by Terramycin®.
At the same time, a major deterrence to spreading American foulbrood, bee inspection, is being eliminated in many regions. An example of this trend comes from Jim Bach, Washington State’s chief apiarist, who has announced his program will be terminated on January 5, 2000. Indeed, in 1991, Richard Taylor, long respected for his contributions to the bee literature, has called for an end to mandatory bee inspection. He said experience had shown that with the use of antibiotics, beekeepers could control the disease themselves without governmental regulation. The reason bee inspection existed, however, was not because of bureaucratic imposition, but at the behest of beekeepers themselves, who were affected by epidemics they could not control. Granted bee inspection laws were enacted before antibiotics, however, to summarily abandon them seemed like the proverbial “throwing the baby out with the bath water.”
Given the present situation, it is prudent for beekeepers to return to those practices that are known to keep American foulbrood at bay. These include routine inspection for the disease and the judicious use of fire for colonies showing symptoms, especially if these persist after feeding antibiotic. Simply throwing Terramycin® at an AFB problem is a practice that should be carefully re-evaluated. Other routine hygienic procedures include ensuring that colonies are disease free before exchanging combs, abandoning the practice of open feeding, and scrupulously washing barrels that contained honey before loading them with feeding syrup.
What of Hygienic Honey Bees?
In the meantime, I received a terse note from Mr. Steve Taber: “Back in the ‘30s Dr. Park at Iowa state showed you could breed AFB resistant bees in 3 to 4 generations…About 20 years later, Dr. Rothenbuhler determined the genetic method of resistance. And about 20 years ago, I showed how easy it was for any beekeeper to find hygienic bees in his own bees.”
It may well be that resistance to Terramycin® will be a prime incentive for beekeepers to finally begin implement this hygienic technology to its fullest potential. Steve closed his note by saying that hygienic honey bees also show resistance to chalkbrood and perhaps Varroa as well. This was prescient, as now a Varroa-sensitive hygienic honey bee (VSH) now exists.
