A Culture Technique for the Detection of Bacillus Larvae in Honeybees

Abstract
A culture procedure involving heat treatment and employing sheep blood agar was used for the isolation of Bacillus larvae from bees. B. larvae was cultured from all 18 samples collected from hives affected with American foulbrood (AFB) disease and from 2 (3·8%) samples taken from 56 apparently normal hives with no previous history of AFB. B. larvae was also isolated from 12 (26·1%) of 46 apparently normal hives from apiaries with AFB-diseased hives or from apiaries with recent histories of AFB. Bacillus alvei was found to be a common inhabitant of bees being isolated from 55 (45·8%) of the 120 samples examined. The incorporation of agar at a concentration of 7% in the culture plates prevented the characteristic swarming of this organism and enabled the isolation of B. larvae from bee extracts containing B. alvei.