Abstract
Screening of the prevalence of Paenibacillus larvae spores in honey bee colonies in apiaries from 162 districts, belonging to nine provinces was carried out during 2009-2011. The honey samples were examined by the use of a culture method. Based on the number of CFUs grown on Columbia sheep blood agar medium, the level of infection and probability of American foulbrood outbreak was estimated. Altogether, 6,510 pooled honey samples from 32,550 bee colonies located in 2,294 apiaries were collected. P. larvae was identified in 45% of the surveyed apiaries. The widest distribution of P. larvae was found in the Małopolskie province. Culture-positive honey samples were obtained for 71% of the apiaries and in a half of them, the level of spores was high. In the Warmińsko-Mazurskie province, the presence of the bacterium was detected in 58% of the apiaries. In the remaining provinces, from 26% to 47% of the apiaries were contaminated with P. larvae spores