Honey bee diseases, the crisis and risk for beekeepers
Honeybees have been domesticated in artificial hives for the production of honey that has been used as an important carbohydrate source and food sweetener. Bees produce honey from the sugary secretions of other insects, by regurgitation, enzymatic activity, and water evaporation. Honey gets its sweetness from the monosaccharides fructose and glucose and has about the same relative sweetness as sucrose. Most microorganisms do not grow in honey, so sealed honey does not spoil, even after thousands of years.
However, like all living organisms, honeybees can suffer from pests and diseases. Those bee diseases such as American foulbrood, European foulbrood and nosemosis can be treated by antibiotics or chemotherapeutics.
American foulbrood (AFB)
This disease is caused by the spore-forming bacterium, Paenibacillus larvae which attacks older larvae and young pupae of the honey bee. The bacterial spores are very infective and can remain viable for years, hence in many countries infected colonies are eradicated by fire, while some countries, like USA, Canada and Argentina, allow the use of antibiotics to keep the disease in control. Antibiotics can only mitigate, but will not eliminate the disease and therefore infected hives must be treated constantly to prevent a foulbrood outbreak. Left untreated, foulbrood destroys the hive’s bee population and can annihilate an apiary.
European foulbrood (EFB)
EFB is closely related to AFB in symptomatology. This disease is caused by the bacterium Melissococcus plutonius, which does not form spores and generally only attacks younger bee larvae, hence, this disease is considered less problematic than AFB. In the past EFB has been successfully controlled by sanitizing measures or requeening, some antimicrobials, like oxytetracycline, have been demonstrated to be an effective treatment of EFB.
Nosemosis
This disease is caused by spores of the microsporidian fungi Nosema apis or Nosema ceranae. Adult bees are infected and the digestion of pollen is impaired, resulting in a shortening of the life span of the bees, and sometimes depopulation and bee colony losses. High incidences of Nosema are directly related to stress, such as periods of long confinement or nutritional imbalance. N.ceranae was originally a parasite of the Asian honey bee but now is widespread in some European regions.
In the EU, honeybees are classified as food producing animals. The antibiotics and chemotherapeutics of interest in apiculture includes tetracyclines, aminoglycosides, sulfonamides, macrolides, lincosamides, amphenicols, nitrofurans, nitroimidazoles, fluoroquinolones and fumagillin. If you are interested in the veterinary drug residue in honey, welcome to read our companion piece Crisis – Risk hide in honey (antibiotics residues)
Further reading
Antibiotics residue in honey, the hidden crisis and risk November 24, 2020
