Potential of Fumagillin and Agaricus blazei Mushroom Extract to Reduce Nosema ceranae in Honey Bees.

Abstract

Simple SummaryNosemosis is a disease in bees that causes severe problems for their vitality, reproduction and productivity. Traditionally, the treatment involves the application of fumagillin, an antibiotic with proven effect. Recently, fumagillin production and registration has faced problems worldwide, leading to the absence of adequate treatment. Motivated by the reported health issues and the occurrence of residues after fumagillin application, scientists around the world have sought a medication or a supplement that could help beekeepers to control Nosema. Current trends include the search for alternative non-antibiotic treatments. In a laboratory (cage) experiment, we studied the effect of fumagillin and natural extract of mushroom Agaricus blazei on the survival of Nosema infected bees, Nosema spore loads and levels of immune-related gene expression and oxidative stress markers. The results undoubtedly confirmed the anti-Nosema effect of fumagillin, as seen in better bee survival and monitored parameters; its application without Nosema infection (preventive) caused disturbance in some of the parameters. The application of A. blazei extract, however, showed positive effects in both preventive and curative applications. These beneficial properties of A. blazei extract indicate a potential that needs to be further investigated.Depending on the infection level and colony strength, Nosema ceranae, a microsporidian endoparasite of the honey bee may have significant consequences on the health, reproduction and productivity of bee colonies. Despite exerting some side effects, fumagillin is most often used for Nosema control. In this study, in a cage experiment, N. ceranae infected bees were treated with fumagillin or the extract of Agaricus blazei mushroom, a possible alternative for Nosema control. Bee survival, Nosema spore loads, the expression levels of immune-related genes and parameters of oxidative stress were observed. Fumagillin treatment showed a negative effect on monitored parameters when applied preventively to non-infected bees, while a noticeable anti-Nosema effect and protection from Nosema-induced immunosuppression and oxidative stress were proven in Nosema-infected bees. However, a protective effect of the natural A. blazei extract was detected, without any side effects but with immunostimulatory activity in the preventive application. The results of this research suggest the potential of A. blazei extract for Nosema control, which needs to be further investigated.