Development Of A Loop-Mediated Isothermal Amplification (Lamp) And A Direct Lamp For The Specific Detection Ofnosema Ceranae, A Parasite Of Honey Bees

Nosema ceranaeis a ubiquitous microsporidian pathogen infecting the midgut of honey bees. The infection causes bee nosemosis, a disease associated with malnutrition, dysentery, and lethargic behavior, and results in considerable economic losses in apiculture. The use of a rapid, sensitive, and inexpensive DNA-based molecular detection method assists in the surveillance and eventual control of this pathogen. To this end, a loop-mediated isothermal amplification (LAMP) assay targeting the single-copy gene encoding the polar tube protein 3 (PTP3) has been developed. Genomic DNA ofN. ceranae-infected forager bees sampled from distant geographic regions could be reliably amplified using the established LAMP assay. TheN. ceranae-LAMP showed higher sensitivity than a classical reference PCR (98.6 vs 95.7%), when both approaches were applied to the detection ofN. ceranae. LAMP detected a ten-fold lower infection rate than the reference PCR (1 pg vs 10 pg genomic DNA, respectively). In addition, we show highly specific and sensitive detection ofN. ceranaefrom spore preparations in a direct LAMP format. No cross-reactions with genomic DNA and/or spores fromN. apis, often co-infectingA. mellifera, or fromN. bombi, infecting bumble bees, were observed. This low-cost and time-saving molecular detection method can be easily applied in simple laboratory settings, facilitating a rapid detection ofN. ceranaein honey bees in epidemiological studies, surveillance and control, as well as evaluation of therapeutic measures against nosemosis.