Nosema apis and N. ceranae in western honeybee (Apis mellifera) - geographical distribution and current methods of diagnosis.

Abstract

During the last two decades, along the wellknown microsporidian Nosema apis, a new species – N. ceranae – is continuously spreading across the world where the western honeybee (Apis mellifera) is kept and bred by both professionals and hobbyists. Recent studies revealed that this species which jumped host from the asian honeybee (Apis cerana) to the more common western honeybee is present at least in the two American continents, Europe, Asia and Australia. Although the traditional standard diagnosis method is by visually detecting the Nosema spp. microspores by light microscopy, this approach can’t make the difference between the two species. Thus, a much reliable, accurate and sensitive diagnosis method is by molecular techniques, like multiplex PCR, RFLP, Real Time qPCR or Microarray methods. These main molecular techniques are briefly presented as well, along with the differences between the two species at the amplified DNA fragments level