Detection of two Microsporidia pathogens of the European honey bee Apis Mellifera (Insecta: Apidae) in Western Siberia.

Two species of microsporidia, Nosema apis and Nosema ceranae, occur regularly and cause significant losses in apiculture throughout the world. N. ceranae is thought to be an emerging pathogen of the European honey bee which is replacing N. apis. Microscopic analysis of honey bees collected in Tyumen region, South-Western Siberia, suggested presence of two microsporidial pathogens slightly differing in spore size and shape. PCR detection using species-specific primer sets 312APIS and 218MITOC followed by PCR product sequencing confirmed the diagnosis of N. apis and N. ceranae, respectively. Microsporidia were present in private apiaries through 2008-2010, and among 21 colonies from 7 localities, two colonies were infected with both pathogens, while infections with N. apis only were detected in 8, and with N. ceranae only in 13 colonies. These data suggest that N. ceranae is widely spread in South-Western Siberia alongside with N. apis and is able to persist in the regions with average January temperatures below -18°C.