The issues of antibiotic uses in food animals and the emergence of
resistant strains of bacteria have been discussed for many years.  Those of
us who have spent careers using diagnostics to identify pathogens
responsible for animal mortality and/or production losses, and subsequently
testing those bacteria responsible for disease are often disillusioned when
receiving a resistance/susceptible pattern that sometimes leaves no good
option for treatment due to the pathogen's high level of resistance to many
classes of antibiotics (see methicillin resistance Staphylococcus aureus).
An example of this is the increasing resistance patterns of bacteria to
third generation cephalosporins; a class of antibiotics extremely important
in human medicine and likewise, an important tool for therapeutic
treatments in animals.

There is plenty of literature now recognizing the resistance of
Paenibacillus larvae, the causative agent of American Foulbrood, to
tetracycline.  A few citations are listed below.  What is not yet clear is
the whether a resistant strain to *Melissococcus plutonices,* the causative
agent of European Foulbrood, is on the horizon.

Evans, J.D., (2003) Diverse origins of tetracycline resistance in the honey
bee bacterial pathogen Paenibacillus larvae.  J Invert Path, 83, p46-50.

Alippi,  Adriana, et al, (2007) Evidence for plasmid-mediated tetracycline
resistance in Paenibacillus larvae, the causal agent of American Foulbrood
(AFB) disease in honeybees.  Vet Microbiology, 12, p290-303.

Kochansky, J., et al, (2001)  Screening alternative antibiotics against
oxytetracycline-susceptible and -resistant Paenibacillus larvae.  Apidologie,
32, p215-222.

Murray, K.D., et al,  (2007) Analysis of pMA67, a predicted rolling-circle
replicating, mobilizable, tetracycline-resistance plasmid from the honey
bee pathogen, Paenibacillus larvae. Plasmid, 58, p89-100

Since the passage of the Veterinary Feed Directive (VFD, 2017, USA), uses
of antibiotics in a therapeutic fashion per label directions for the
targeted species, is still permitted in food animals (and this includes
bees) under the supervision and guidance of a licensed veterinarian.  It
would still be appropriate to use oral tetracycline in a therapeutic
fashion in the case of documented European Foulbrood (laboratory
confirmation).  Use of oral antibiotics for production reasons only (such
as increasing weight gains in poultry and beef cattle) is now forbidden.
 Use of antibiotics as a preventative is currently open to interpretation.
Your local apiary inspector or veterinarian can usually make the
determination that based on the history in your area, if your hives have an
extremely high chance of being infected by disease, one could make the case
of using antibiotics in a preventative fashion during a specific period of
time.  A good example is the use of oral chlortetracycline in Midwestern
beef cattle during the exposure period to Anaplasmosis.  Under this
circumstance, rules of VFD still apply and must be under the order and
guidance of a licensed veterinarian and can only be used under specific
directives written on the prescription.

The bottom line is that the use of antibiotics in your apiary should never
be used as a bandage for poor management.  I've seen it throughout my
career, the best management teams that utilize many sets of skills to
mitigate disease always seem to outperform those that rely on drugs to
solve health issues in their operations.

What works today, may not work tomorrow.  Then what?
-- 
Richard Steel, V.M.D.
Tillamook,  OR

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