Intestinal enterobacteria of the hibernating Apis mellifera mellifera L. bees

Dynamics of enterobacteria of normal intestinal microflora was studied in Apis mellifera mellifera L. bees hibernating under snow in the Western Urals. The cell numbers (N) of the predominant species Klebsiella oxytoca increased from 10-106 CFU/bee in November 2004 to 104-107 CFU/bee in March 2005; its frequency of occurrence (P) increased from 92 to 100%. Increase of Providencia rettgeri (11.2004: N up to 106, P 25%; 03.2005: N 102-106, P 80%) was accompanied by the substitution of Morganella morganii (11.2004: N up to 106, P 25%) with Proteus vulgaris (03.2005: N up to 105, P 8%). By spring, Hafnia alvei and Citrobacter sp., which are pathogenic to bees, disappeared (11.2004: N up to 105, P 13 and 10%, respectively). Endophytic species Pantoea agglomerans, Leclecria sp., and other representatives of the “Enterobacter agglomerans” group were present in November and after the first emergence in spring (N up to 105; November: P 15%; April: P 23%). In April, the number of enterobacteria decreased to 105, and P. rettgeri became the predominant species (P 54%) instead of K. oxytoca (P 43%).