Dietary amino acid and vitamin complex protects honey bee from immunosuppression caused by Nosema ceranae.

Uros Glavinic,Nada Lakic,Zoran Stanimirovic,Jevrosima Stevanovic,Tamas Petrovic,Vladimir Draskovic,Biljana Stankovic,Sanjay B Jadhao

doi:10.1371/journal.pone.0187726

Uros Glavinic, Nada Lakic + Show 6 more

Open Access

https://doi.org/10.1371/journal.pone.0187726

Copy DOI

Abstract

Microsporidium Nosema ceranae is well known for exerting a negative impact on honey bee health, including down-regulation of immunoregulatory genes. Protein nutrition has been proven to have beneficial effects on bee immunity and other aspects of bee health. Bearing this in mind, the aim of our study was to evaluate the potential of a dietary amino acid and vitamin complex “BEEWELL AminoPlus” to protect honey bees from immunosuppression induced by N. ceranae. In a laboratory experiment bees were infected with N. ceranae and treated with supplement on first, third, sixth and ninth day after emergence. The expression of genes for immune-related peptides (abaecin, apidaecin, hymenoptaecin, defensin and vitellogenin) was compared between groups. The results revealed significantly lower (p<0.01 or p<0.001) numbers of Nosema spores in supplemented groups than in the control especially on day 12 post infection. With the exception of abacein, the expression levels of immune-related peptides were significantly suppressed (p<0.01 or p<0.001) in control group on the 12th day post infection, compared to bees that received the supplement. It was supposed that N. ceranae had a negative impact on bee immunity and that the tested amino acid and vitamin complex modified the expression of immune-related genes in honey bees compromised by infection, suggesting immune-stimulation that reflects in the increase in resistance to diseases and reduced bee mortality. The supplement exerted best efficacy when applied simultaneously with Nosema infection, which can help us to assume the most suitable period for its application in the hive.

Highlights

Nosema spp. microsporidia frequently parasitize adult honey bees [1]
Expressions of genes that code for these immune-related proteins were investigated in several studies: Antunez et al [24] demonstrated that expressions of some genes in N. ceranae infected bees were significantly down-regulated, and Chaimanee et al [27] reaffirmed host immunosuppression by N. ceranae infection
Mann-Whitney U test results showed that the number of N. ceranae spores was significantly lower in bees collected on day 6 than in those collected on day 12 p.i. (3.781 z 3.785; p

Summary

Introduction

Nosema spp. microsporidia frequently parasitize adult honey bees [1]. Two species have been described: Nosema apis and N. ceranae. Protection of immunosuppression caused by Nosema ceranae over N. apis, as much greater occurrence and much wider geographical distribution of the former have been evidenced in most parts of the world [1,2,3,4,5,6,7,8,9]. Insects have a robust immune system to defend themselves against the attack of different pathogens. This system includes physical barriers as the first line of defense, and innate cellular and humoral immunity -a second line of defence [19]. Some results revealed the positive impact of nutrition on certain aspects of bee immunity [32,33], including those of pollen nutrients on genes affecting longevity and the production of some antimicrobial peptides [34,35]

Objectives

Methods

Results

Conclusion