Med. Weter. 69 (12), 726-729, 2013

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Borsuk G., Ptaszyńska A. A., Olszewski K., Paleolog J.
Impact of nosemosis on the intestinal yeast flora of honey bees
Intestinal microflora is a very important part of the digestive system in every animal, and plays a role in the synthesis of vitamins and the metabolism of many toxic chemical compounds. The indigenous intestinal flora of bees changes even as a result of changing their diet from natural to artificial or placing them in cages. Such factors have an impact on the health of bees and on the strength of whole colonies. In our study, intestinal fungi isolated from healthy bees and from bees infected with Nosema spp. belonged to two genera: Candida and Saccharomyces. The approximate numbers of yeast CFUs (colony forming units) obtained from healthy Apis mellifera carnica and Buckfast bees were, respectively, 2 880 - 5 180 and 1 056 - 4 120. Apis mellifera carnica and Buckfast bees were similarly sensitive to slight Nosema spp. infections, but heavy infestations had a greater impact on the intestinal microflora of A. m. carnica. The degree of Nosema spp. infestation had an impact on the quantitative composition of the intestinal microflora of bees. Slightly infected bees of Apis mellifera carnica had up to 44 915 yeast CFUs per bee, and Buckfast bees up to 28 705 yeast CFUs per bee. Surprisingly, a heavy infestation reduced the number of yeast CFUs to no more than 120 in A. m. carnica bees and to no more than 164 in Buckfast bees. Therefore, in studies in which the number of yeast CFUs is used as the main indicator of stress in bees, the potential presence and the degree of Nosema spp. infestation needs to be taken into account. .
Key words: Apis mellifera, Buckfast, Nosema spp., yeasts, intestinal microflora