Free access
Volume 28, Number 6, 1997
Page(s) 357 - 365
Apidologie 28 (1997) 357-365
DOI: 10.1051/apido:19970603

Microflora in the honeybee digestive tract: counts, characteristics and sensitivity to veterinary drugs

V. Radaa, M. Máchováb, J. Hukc, M. Marounekd and D. Duskovád

a  Czech University of Agriculture in Prague, Prague 6, Suchdol 165 21, Czech Republic
b  Bee Retearch Institute, Dol 252 66, Libcice nad Vltavou, Czech Republic
c  Research Institute of Antibiotics and Biotransformations, Roztoky u Prahy 252 63, Czech Republic
d  Institute of Animal Physiology and Genetics, Czech Academy of Sciences, Uhríneves 104 00, Czech Republic

Abstract - Experiments were carried out to enumerate and characterize the microorganisms in the midgut and rectum of the honeybee. Counts of aerobic microorganisms were distinctly lower than counts of anaerobes (104-10 5 viable cells per gram of intestinal contents versus 108-10 9 per gram). Total numbers of anaerobic microorganisms were almost identical with counts of anaerobic Grampositive acidoresistant rods. These bacteria represent the principal groups of microorganisms in the bee digestive tract. Anaerobic and aerobic microorganisms, lactobacilli, coliforms, staphylococci, Bacillus sp, and yeasts were found in all bees. Only one out of 31 isolates (Bifidobacterium asteroides) was identified at the species level. Fluvalinate, fumagillin and nystatin significantly increased mortality of bees. Treated bees kept in cages contained more yeasts than control bees in the beehive. The veterinary drugs tested significantly increased counts of yeasts in comparison with the control.

Key words: Apis mellifera / associated microflora / Bifidobacterium / veterinary drugs