Expression levels of genes for defensin, vitellogenin, apidaecin and hymenoptaecin in group I-BW3 on different sampling days.

<p>IBW-3 group was infected with <i>N</i>. <i>ceranae</i> spores on 3^rd and treated with “BEEWELL AminoPlus” from 3^rd day after emerging. Bees were sampled for analyses on 3^rd, 6^th and 12^th day <i>N</i>. <i>ceranae</i> post-infection. Different letters denote significant differences between collection times.</p

Dietary amino acid and vitamin complex protects honey bee from immunosuppression caused by <i>Nosema ceranae</i>

<div><p>Microsporidium <i>Nosema ceranae</i> 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 <i>N</i>. <i>ceranae</i>. In a laboratory experiment bees were infected with <i>N</i>. <i>ceranae</i> 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 <i>Nosema</i> 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 12^th day post infection, compared to bees that received the supplement. It was supposed that <i>N</i>. <i>ceranae</i> 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 <i>Nosema</i> infection, which can help us to assume the most suitable period for its application in the hive.</p></div

Expression levels of genes for abaecin, hymenoptaecin, defensin, apidaecin and vitellogenin on day 12 after the infection with <i>N</i>. <i>ceranae</i> in groups treated with “BEEWELL AminoPlus”.

<p>Groups were infected with <i>N</i>. <i>ceranae</i> spores on 3^rd day after emerging and treated with “BEEWELL AminoPlus” from 1^st (I-BW1), 3^rd (I-BW3), 6^th (I-BW6) and 9^th (I-BW9) day, while the control group (I) was infected with <i>N</i>. <i>ceranae</i> but not treated. Different letters denote significant differences between groups.</p

Expression levels of abaecin gene on day 3 after the infection with <i>N</i>. <i>ceranae</i> in groups treated with amino acid—Vitamin complex “BEEWELL AminoPlus”.

<p>Groups were infected with <i>N</i>. <i>ceranae</i> spores on day 3 after emerging and treated with “BEEWELL AminoPlus” from day 1 (I-BW1) and day 3 (I-BW3), while the control group (I) was infected, but not treated. Different letters denote significant differences between groups.</p

The modification of a laboratory cage: A plastic jar with small holes made for aeration and a plastic mesh sink strainer inserted into the lid allowing bees to take the food from a small petri dish placed below.

<p>The modification of a laboratory cage: A plastic jar with small holes made for aeration and a plastic mesh sink strainer inserted into the lid allowing bees to take the food from a small petri dish placed below.</p

Expression levels of genes for abaecin, apidaecin and vitellogenin in control (I) and IBW-1 group on different sampling days.

<p>IBW-1 group was infected with <i>N</i>. <i>ceranae</i> spores on 3^rd and treated with “BEEWELL AminoPlus” from 1^st day after emerging, while the control (I) was infected with <i>N</i>. <i>ceranae</i> but not treated. Bees were sampled for analyses on 3^rd, 6^th and 12^th day after the infection with <i>N</i>. <i>ceranae</i>. Different letters denote significant differences between groups.</p

<i>Nosema</i> spore loads in control and groups treated with amino acid and vitamin complex “BEEWELL AminoPlus” on days 6 and 12 after the infection with <i>N</i>. <i>ceranae</i>.

<p>Groups were infected with <i>N</i>. <i>ceranae</i> spores on 3^rd day after emerging and treated with “BEEWELL AminoPlus” from 1^st (I-BW1), 3^rd (I-BW3), 6^th (I-BW6) and 9^th (I-BW9) day after emerging, while the control (I) was infected but not treated. Different letters denote significant differences between groups.</p