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Title: Genetic Detection and Quantification of Nosema Apis and N. Ceranae in the Honey Bee

Author
item Bilodeau, Lanie
item Rinderer, Thomas
item Beaman, Glenda - Lorraine
item Danka, Robert

Submitted to: Journal of Invertebrate Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/12/2009
Publication Date: 1/2/2010
Citation: Bourgeois, A.L., Rinderer, T.E., Beaman, G.D., Danka, R.G. 2010. Genetic Detection and Quantification of Nosema Apis and N. Ceranae in the Honey Bee. Journal of Invertebrate Pathology. 103:53-58.

Interpretive Summary: The incidence of nosemosis has increased in prevalence in recent years due to an emerging infestation of Nosema ceranae in managed honey bee populations in much of the world. A real-time PCR assay was developed to facilitate detection and quantification of both N. apis and N. ceranae in both single bee and pooled samples. The genetic assay is highly sensitive and is capable of detection of single spore-equivalents. Real-time PCR results were calibrated to spore counts generated by standard microscopy procedures. The assay was used to examine bees from commercial apiaries sampled in November 2008 and March 2009. Bees from each colony were pooled. A large amount of variation between colonies was evident, signifying the need to examine large numbers of colonies. Changes in N. ceranae levels were evident among apiaries, with some showing an increase in infestation levels and others showing a decrease. This demonstrates the need for thorough sampling of apiaries and the need for a rapid test for both detection and quantification of both Nosema spp. This assay provides the opportunity for detailed study of disease resistance, infection kinetics, and improvement of disease management practices for honey bees.

Technical Abstract: The incidence of nosemosis has increased in prevalence in recent years due to an emerging infestation of Nosema ceranae in managed honey bee populations in much of the world. A real-time PCR assay was developed to facilitate detection and quantification of both N. apis and N. ceranae in both single bee and pooled samples. The genetic assay is highly sensitive and is capable of detection of single spore-equivalents. Real-time PCR results were calibrated to spore counts generated by standard microscopy procedures. The assay was used to examine bees from commercial apiaries sampled in November 2008 and March 2009. Bees from each colony were pooled. A large amount of variation between colonies was evident, signifying the need to examine large numbers of colonies. Due to sampling constrainsts, a subset of colonies (from 5 apiaries) were sampled in both seasons. In November, N. apis levels were 1212 ± 148 spores/bee and N. ceranae levels were 51073 ± 31155 spores/bee. In March, no N. apis was detected, N. ceranae levels were 11824 ± 6304 spores/bee. Changes in N. ceranae levels were evident among apiaries, with some showing an increase in infestation levels and others showing a decrease. This demonstrates the need for thorough sampling of apiaries and the need for a rapid test for both detection and quantification of both Nosema spp. This assay provides the opportunity for detailed study of disease resistance, infection kinetics, and improvement of disease management practices for honey bees.