Effect of propolis on Nosema ceranae infection under laboratory conditions.

MARTÍN P. PORRINI; DAMIANI,N; MENDOZA YAMANDU; GARRIDO P, M.; NEGRI PEDRO; INVERNIZZI CIRO; EGUARAS, M.

Kiev

Congreso; 43º International Apicultural congress Apimondia; 2013

Apimondia

EFFECT OF PROPOLIS ON Nosema ceranae INFECTION UNDER LABORATORY CONDITIONS Porrini Martín P.1,2, Damiani Natalia1,2, Mendoza Yamandú3, Garrido P. Melisa1,2, Negri Pedro1,2, Invernizzi Ciro 4, Eguaras Martín J. 1,2. 1 School of Exact and Natural Sciences, National University of Mar del Plata, Arthropods Laboratory, Funes 3350 (7600) Mar del Plata, Argentina - 2 National Scientific and Technical Research Council (CONICET). 3 INIA - National Agricultural Research Institute. La Estanzuela Colonia-Uruguay. Ruta 50 km 11-4 Laboratory of Etology, Faculty of Science, UdelaR, Igua y Mataojo, Montevideo, Uruguay. E-mail: mporrini@mdp.edu.ar Propolis have shown an interesting pharmacological activity against several bee diseases but its activity against Nosema ceranae have not been previously evaluated. The effects of propolis administration pre and post infection with N. ceranae spores were studied in two bioassays (A and B, respectively). Combs obtained from healthy colonies were incubated until imagoes emergence. In assay ?A?, three propolis soft extracts from different geographical locations of Pampean region from Argentina were administered ad libitum in candy (5% w/v) during 10 days. Three replicates of 20 bees were employed for each extract and control treatments. Eleven days post emergence, mass inoculation was performed with 3ml of sugar solution containing 6,3x106 spores/ml or control solution. Ten bees per replicate were removed 10 days post infection (p.i.), and its midguts dissected to measure intensity of spores. In assay ?B?, one of the propolis extract selected from trial ?A?, was administered in candy (5% w/v) after individual inoculation with 7.0x104 spores. Individuals were removed at 7 and 14 days p.i. Feed intake and mortality of bees were daily measured during both assays. Spores intensity values showed no differences between propolis and control treatments (Assay A: Kruskal-Wallis test, P< 0.05; Assay B: T- test, P=0.6 on day 7 p.i. and P=0.099 on day 14 p.i.). The propolis treatments were consumed avidly, with daily average of 0.05g/bee. Survival curves showed no differences between treatments in both assays (Gehan-Breslow test, Assay A: P= 0.63; Assay B: P= 0.54). Results have demonstrated the absence of antiparasitic activity of propolis against N. ceranae (including protective or post infection administration). Also, the level of activity did not depend on location origin of the propolis. However, the avidity of consume and the absence of lethal effects makes feasible the use of propolis in long term systemic administration assays.