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.
Nosema ceranae is the most widespread microsporidian species which infects the honey bees of Apis mellifera by causing the weakening of their colonies and a decline in their productive and ...reproductive capacities. The only registered product for its control is the antibiotic fumagillin; however, in the European Union, there is no formulation registered for use in beekeeping. Thymol (3-hydroxy-p-cymene) is a natural essential-oil ingredient derived from Thymus vulgaris, which has been used in Varroa control for decades. The aim of this study was to investigate the effect of thymol supplementation on the expression of immune-related genes and the parameters of oxidative stress and bee survival, as well as spore loads in bees infected with the microsporidian parasite N. ceranae. The results reveal mostly positive effects of thymol on health (increasing levels of immune-related genes and values of oxidative stress parameters, and decreasing Nosema spore loads) when applied to Nosema-infected bees. Moreover, supplementation with thymol did not induce negative effects in Nosema-infected bees. However, our results indicate that in Nosema-free bees, thymol itself could cause certain disorders (affecting bee survival, decreasing oxidative capacity, and downregulation of some immune-related gene expressions), showing that one should be careful with preventive, uncontrolled, and excessive use of thymol. Thus, further research is needed to reveal the effect of this phytogenic supplement on the immunity of uninfected bees.
Among numerous factors that contribute to honey bee colony losses and problems in beekeeping, pesticides and
have been often reported. In contrast to insecticides, whose effects on bees have been ...widely studied, fungicides did not attract considerable attention. Prochloraz, an imidazole fungicide widely used in agriculture, was detected in honey and pollen stored inside hives and has been already proven to alter immune gene expression of honey bees at different developmental stages. The aim of this study was to simulate the realistic conditions of migratory beekeeping, where colonies, both uninfected and infected with
, are frequently transported to the vicinity of crop fields treated with prochloraz. We investigated the combined effect of prochloraz and
on honey bees that faced fungicide during the larval stage through food consumption and microsporidium infection afterwards. The most pronounced changes in gene expression were observed in newly emerged
-free bees originating from colonies previously contaminated with prochloraz. As exclusively upregulation was registered, prochloraz alone most likely acts as a challenge that induces activation of immune pathways in newly emerged bees. The combination of both stressors (prochloraz and
infection) exerted the greatest effect on six-day-old honey bees. Among ten genes with significantly altered expression, half were upregulated and half downregulated.
as a sole stressor had the weakest effects on immune gene expression modulation with only three genes significantly dysregulated. In conclusion, food contaminated with prochloraz consumed in larval stage could present a threat to the development of immunity and detoxification mechanisms in honey bees.
Depending on the infection level and colony strength,
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
control. In this study, in a cage experiment,
infected bees were treated with fumagillin or the extract of
mushroom, a possible alternative for
control. Bee survival,
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-
effect and protection from
-induced immunosuppression and oxidative stress were proven in
-infected bees. However, a protective effect of the natural
extract was detected, without any side effects but with immunostimulatory activity in the preventive application. The results of this research suggest the potential of
extract for
control, which needs to be further investigated.
With an almost global distribution,
Varroa destuctor
is the leading cause of weakening and loss of honey bee colonies. New substances are constantly being tested in order to find those that will ...exhibit high anti-
Varroa
efficacy at low doses/concentrations, without unwanted effects on bees. Lithium (Li) salts stood out as candidates based on previous research. The aims of this study were to evaluate Li citrate hydrate (Li-cit) for its contact efficacy against
Varroa
, but also the effect of Li-cit on honey bees by estimating loads of honey bee viruses, expression levels of immune-related genes and genes for antioxidative enzymes and oxidative stress parameters on two sampling occasions, before the treatment and after the treatment. Our experiment was performed on four groups, each consisting of seven colonies. Two groups were treated with the test compound, one receiving 5 mM and the other 10 mM of Li-cit; the third received oxalic acid treatment (OA group) and served as positive control, and the fourth was negative control (C group), treated with 50% w/v pure sucrose-water syrup. Single trickling treatment was applied in all groups. Both tested concentrations of Li-cit, 5 and 10 mM, expressed high varroacidal efficacy, 96.85% and 96.80%, respectively. Load of Chronic Bee Paralysis Virus significantly decreased (
p
< 0.01) after the treatment in group treated with 5 mM of Li-cit. In OA group, loads of Acute Bee Paralysis Virus and Deformed Wing Virus significantly (
p
< 0.05) increased, and in C group, loads of all viruses significantly (
p
< 0.01 or
p
< 0.001) increased. Transcript levels of genes for abaecin, apidaecin, defensin and vitellogenin were significantly higher (
p
< 0.05—
p
< 0.001), while all oxidative stress parameters were significantly lower (
p
< 0.05—
p
< 0.001) after the treatment in both groups treated with Li-cit. All presented results along with easy application indicate benefits of topical Li-cit treatment and complete the mosaic of evidence on the advantages of this salt in the control of
Varroa
.
Agaricus bisporus water crude extract was tested on honey bees for the first time. The first part of the cage experiment was set for selecting one concentration of the A. bisporus extract. ...Concentration of 200 µg/g was further tested in the second part of the experiment where bee survival and food consumption were monitored together with Nosema infection level and expression of five genes (abaecin, hymenoptaecin, defensin, apidaecin, and vitellogenin) that were evaluated in bees sampled on days 7 and 15. Survival rate of Nosema-infected bees was significantly greater in groups fed with A. bisporus-enriched syrup compared to those fed with a pure sucrose syrup. Besides, the anti-Nosema effect of A. bisporus extract was greatest when applied from the third day which coincides with the time of infection with N. ceranae. Daily food consumption did not differ between the groups indicating good acceptability and palatability of the extract. A. bisporus extract showed a stimulative effect on four out of five monitored genes. Both anti-Nosema and nutrigenomic effects of A. bisporus extract were observed when supplementation started at the moment of N. ceranae infection or preventively (before or simultaneously with the infection).
To improve the genomic evaluation of milk-related traits in Holstein-Friesian (HF) cattle it is essential to identify the associated candidate genes. Novel SNP-based analyses, such as the genetic ...mapping of inherited diseases, GWAS, and genomic selection, have led to a new era of research. The aim of this study was to analyze the association of each individual SNP in Serbian HF cattle with milk production traits and inbreeding levels. The SNP 60 K chip Axiom Bovine BovMDv3 was deployed for the genotyping of 334 HF cows. The obtained genomic results, together with the collected phenotypic data, were used for a GWAS. Moreover, the identification of ROH segments was performed and served for inbreeding coefficient evaluation and ROH island detection. Using a GWAS, a polymorphism, rs110619097 (located in the intron of the
gene), was detected to be significantly (
< 0.01) associated with the milk protein concentration in the first lactation (adjusted to 305 days). The average genomic inbreeding value (F
) was 0.079. ROH islands were discovered in proximity to genes associated with milk production traits and genomic regions under selection pressure for other economically important traits of dairy cattle. The findings of this pilot study provide useful information for a better understanding of the genetic architecture of milk production traits in Serbian HF dairy cows and can be used to improve lactation performances in Serbian HF cattle breeding programs.
Protection of honey bees is of great economic importance because of their role in pollination. Crucial steps towards this goal are epidemiological surveys of pathogens connected with honey bee ...losses. In this study deformed wing virus (DWV), chronic bee paralysis virus (CBPV), acute bee paralysis virus (ABPV) and sacbrood virus (SBV) were investigated in colonies of different strength located in five regions of Serbia. The relationship between colony strength and virus occurrence/infection intensity were assessed as well as the genetic relationship between virus sequences from Serbia and worldwide. Real-time RT-PCR analyses detected at least one virus in 87.33% of colonies. Single infection was found in 28.67% colonies (21.33%, 4.00%, 2.67% and 0.67% in cases of DWV, ABPV, SBV and CBPV, respectively). In the majority of colonies (58.66%) more than one virus was found. The most prevalent was DWV (74%), followed by ABPV, SBV and CBPV (49.30%, 24.00% and 6.70%, respectively). Except for DWV, the prevalence of the remaining three viruses significantly varied between the regions. No significant differences were found between colony strength and either (i) the prevalence of DWV, ABPV, SBV, CBPV and their combinations, or (ii) DWV infection levels. The sequences of honey bee viruses obtained from bees in Serbia were 93-99% identical with those deposited in GenBank.
, a microsporidian parasite, as one of the stressors that contribute to honey bee decline, has a significant negative impact on the longevity, productivity, and reproductive capacity of honey bee ...colonies. There are several different strategies for
infection control, including natural-based and antibiotic-based products. In this study, we tested wormwood and oak bark-based supplement "Medenko forte" on survival,
infection, oxidative stress, and expression of immune-related genes in artificially
-infected bees. The results revealed a positive influence on the survival of
-infected bees, irrespectively of the moment of supplement application (day 1, day 3, or day 6 after bee emergence), as well as reduction of
loads and, consequently,
-induced oxidative stress. Supplementation had no negative effects on bee immunity, but better anti-
than immune-stimulating effects were affirmed based on expression levels of abaecin, defensin, hymenoptaecin, apidaecin, and vitellogenin genes. In conclusion, the tested supplement "Medenko forte" has great potential in the health protection of
-infected bees. However, further investigations need to be performed to elucidate its mechanisms of action.
One of the most important approaches in the prevention and treatment of nosemosis is the use of herbal preparations as food supplements for bees. Therefore, the aim of this study was to investigate ...the effects of a plant-based supplement branded as “B+” on honeybees in a laboratory experiment. Four experimental groups were established: treated group (T), N. ceranae-infected and treated group (IT), N. ceranae-infected group (I) and non-infected group (NI). Survival, N. ceranae spore load and oxidative stress parameters together with expression levels of antioxidant enzyme genes and vitellogenin gene were monitored. The mortality in the T, IT and NI groups was significantly (p < 0.001) lower than in than in the I group. Within Nosema-infected groups, the IT group had a significantly lower (p < 0.001) number of N. ceranae spores than the I group. In addition, expression levels of genes for antioxidant enzymes were lower (p < 0.001) in the IT group compared to the I group. The concentration of malondialdehyde and the activities of antioxidant enzymes (superoxide dismutase, catalase and glutathione S-transferase) were significantly lower (p < 0.001) in the IT group compared to the I group. No negative effects of the tested supplement were observed. All these findings indicate that the tested supplement exerted beneficial effects manifested in better bee survival, reduced N. ceranae spore number and reduced oxidative stress of bees (lower expression of genes for antioxidant enzymes and oxidative stress parameters).
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