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?  

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