1,720,967 research outputs found
Treatment based on formic acid for Varroa destructor control with two different evaporators: efficacy and tolerability comparison
Full text linkFormic acid based treatments are active also against Varroas enclosed inside sealed brood. For its organic nature and the low risk of long-lasting residues in bee products, are very popular in Northern Europe, but could be problematic in Southern regions where summer temperatures are higher. In this study efficacy and tolerability of a 60% aqueous solution of formic acid administered via two different evaporators: (Aspro-Novar-Form® and Nassenheider professional®) were compared. Total efficacy was on average high (> 80%), but with high variability among the different colonies, without significant differences between the two evaporators. No significant differences in tolerability between the two approaches were observed, however, the number of bees after treatment in the AN group is on average higher than in the NH group. Further field comparisons should be conducted to explore the differences in tolerability that arose in this study
Intestinal Yeast flora of honey bee in presence/absence of Nosema spp.: preliminary results
No full textIn the last years, several research are aimed at the study of the intestinal microbiota of honey bee
and their role in bee health. The literature reports that the flora of healthy bees is dominated by
bacteria while only 1% is represented by yeasts and other fungi. Some authors describe that various
diseases or stress increase the number of yeasts. Borsuk et al (2013 Med. Weter. 2013, 69, 726-729)
studying the yeast microflora in bees experimentally infected by Nosema spp. noted an increase of
yeasts in presence of a weak degree of Nosema infection, while heavy infections reduced the
number of yeasts. In the present work, we describe preliminary result about the research of yeasts
in bee guts in presence/absence of natural infection by Nosema spp. A total of 200 bees were
collected from June to October 2015 in apiaries of Bologna province. The bees were euthanasized
by placing their 4-5 minutes in freezer, then each single bee was dipped in ethyl alcohol, the gut
was aseptically removed and put in 500 microliter of sterile saline in eppendorf and ground with
pestle. One hundred microliter of the suspension were used for counting the number of Nosema spp
spores per gut in a Burker chamber; other 100 microliters were spread onto the surface of Petri
plates containing Sabouraud Dextrose Agar with Chloramphenicol and incubated at 30°C for 7 days
to count the number of CFU (Colony Forming Unit)/gut. Nosema spp was found in 25/200 (12.5%)
bee, with number of spore/gut ranging from 5000 to 34 million. Yeasts were found in 55/200
(27.5%) bee, with an approximate number of CFUs/gut ranging from 5 to 14000. The yeast CFU
was significatively correlated to the number of Nosema spores (Spearman's rho p = 0.016). The
species composition of yeast will be further elucidated
Could honey bees signal the spread of antimicrobial resistance in the environment?
No full textThe honey bee has long been known to be a bioindicator of environmental pollution and the use of antimicrobials in the beekeeping industry is strictly regulated. For these reasons, this paper was aimed to evaluate for the first time the role of Apis mellifera as a possible indicator of environmental antimicrobial resistance (AMR). The study isolated and analysed the resistance patterns of Enterobacteriaceae from a pool of honey bee guts located in five different environmental sites (ES), where different antimicrobial selective pressures were hypothesized. In all, 48 isolates were considered for identification and underwent analyses of AMR to ampicillin, amoxicillin/clavulanic acid, cefazolin, ceftazidime, tetracycline, imipenem, enrofloxacin, amikacin and trimethoprim/sulfamethoxazole. In all, 12 isolates out of 48 (25%) showed resistance to at least one antimicrobial drug. There were no significant differences between the resistance rates observed in the ESs, even if the highest percentage of resistance was found in ES4. Resistances to amoxicillin/clavulanic acid resulted significantly higher than those detected towards the other antimicrobials. Amoxicillin/clavulanic acid is not commonly used in beekeeping but it is extensively used in animals and in humans, suggesting an environmental origin of this resistance and supporting the hypothesis that honey bees could be used as indicators of AMR spread in the environment. Significance and Impact of the Study: In this study, a possible role of honey bees as indicator of environmental antimicrobial resistance is hypothesized. Enterobacteriaceae were isolated from bees living in different environmental sites (ES) where different antimicrobial selective pressures were hypothesized. Even if no differences between the resistances in the five ES were observed, the resistance rates for amoxicillin/clavulanic acid, compared to other antimicrobials, were significantly higher. Since amoxicillin/clavulanic acid is not used in beekeeping but it is extensively used in animals and in humans, an environmental origin of this resistance is suggested that supports our hypothesis
Shotgun sequencing of honey DNA can describe honey bee derived environmental signatures and the honey bee hologenome complexity
Full text linkHoney bees are large-scale monitoring tools due to their extensive environmental exploration. In their activities and from the hive ecosystem complex, they get in close contact with many organisms whose traces can be transferred into the honey, which can represent an interesting reservoir of environmental DNA (eDNA) signatures and information useful to analyse the honey bee hologenome complexity. In this study, we tested a deep shotgun sequencing approach of honey DNA coupled with a specifically adapted bioinformatic pipeline. This methodology was applied to a few honey samples pointing out DNA sequences from 191 organisms spanning different kingdoms or phyla (viruses, bacteria, plants, fungi, protozoans, arthropods, mammals). Bacteria included the largest number of species. These multi-kingdom signatures listed common hive and honey bee gut microorganisms, honey bee pathogens, parasites and pests, which resembled a complex interplay that might provide a general picture of the honey bee pathosphere. Based on the Apis mellifera filamentous virus genome diversity (the most abundant detected DNA source) we obtained information that could define the origin of the honey at the apiary level. Mining Apis mellifera sequences made it possible to identify the honey bee subspecies both at the mitochondrial and nuclear genome levels
Evaluation of Varroa control techniques in Apis Mellifera by a proteomich approach
No full textOne of the main biotic threat to honey bees all over the world is the ectoparasitic mite Varroa
destructor (Acari: Mesostigmata). Without proper treatment, colonies are doomed and collapse
within two years. Many treatments are used by beekeepers, with well-established acaricidal
efficacy; however very little is known on the impact of the above-mentioned treatments on the wellbeing
of the colony. Biochemical markers represent an interesting tool to assess the animal and
human welfare. Particularly promising for our purposes seems to be the evaluation of vitellogenin
in the hemolymph of a pool of bees. The potential of this protein can be foreseen considering his
pivotal role in the homeostasis of social insect colonies. In fact, the function of vitellogenin in these
species is not limited to egg yolk constitution: trophic, antioxidant and hormonal function are also
described. The aim of this research was to test the impact of two different Varroa control techniques
by analyzing the vitellogenin content in the hemolymph.
Brood interruption by queen caging (five colonies) and brood removal (five colonies) followed by
trickling of Api-Bioxal (Oxalic acid based acaricide) were performed. The hemolymph of 30 bees
per colony was sampled and pooled. Four samplings were considered: pre manipulation, after
manipulation, autumn (wintering phase) and winter. All the samples underwent SDS-PAGE and
quantification of vitellogenin, qualitative analysis of other relevant proteins was also performed.
Vitellogenin was successfully isolated and identified by mass spectrometry. Our data are
confirmatory of the abundance of this protein in the hemolymph of worker bees and interesting
differences were found depending on the season. Major differences were also found between the
experimental groups, suggesting the expected different impact of the techniques and stressing the
need of an objective tool to better evaluate and understand the techniques for Varroa control
Essential (Mg, fe, zn and cu) and non-essential (cd and pb) elements in predatory insects (vespa crabro and vespa velutina): A molecular perspective
Full text linkThe recent introduction of the Asian yellow-legged hornet, Vespa velutina, into Europe has raised concern regarding the threat to honeybees and the competition with the European hornet, Vespa crabro. The aim of this study was to investigated essential (Mg, Fe, Zn, Cu) and non-essential (Cd and Pb) elements in these two species. Element concentrations were determined in the whole body and separately in the head, thorax and abdomen using atomic absorption spectrometry (AAS). The changes in essential element concentration and speciation during metamorphosis were also studied using size exclusion chromatography followed by AAS and proteomic analysis. In both species, the essential elements were more concentrated in the abdomen due to the presence of fat bodies. Magnesium, Fe and Zn concentrations were significantly higher in V. crabro than in V. velutina and could have been related to the higher aerobic energy demand of the former species required to sustain foraging flight. Low concentrations of Cd and Pb were indicative of low environmental exposure. The concentration and speciation of essential elements, particularly Fe, varied among the developmental stages, indicating a modification of ligand preferences during metamorphosis. Overall, the results in the present study provide a better understanding of the hornet metal metabolism and a foundation for additional studies
Field application of an innovative approach to assess honeybee health and nutritional status
Full text linkEnvironment, forage quality, management practices, pathogens, and pesticides influence honeybee responses to stressors. This study proposes an innovative approach to assess colony health and performance using molecular diagnostic tools by correlating hemolymph proteins with common measures of colony strength, prevalent honeybee pathogens (Varroa destructor and Nosema spp.), and essential trace elements (iron, zinc and copper). Colonies were selected from four apiaries located in different environmental and foraging conditions in the province of Bologna (Italy). Hemolymph samples were taken from June to October 2019. The Varroa infestation of the colonies was estimated by assessing the natural mortality of the mites, while the bees were tested for Nosema spp. spores using a microscopic method. Hemolymph proteins were quantified and separated using SDS-PAGE, and colony performance was assessed by determining adult bees, total brood, honey, and pollen reserves. The biomarkers measured proved to be useful for monitoring changes in performance and trophic conditions during summer and early autumn. Significant correlations were found between hemolymph proteins and colony performance measures. A positive correlation between pollen reserves, vitellogenin, and hexamerin 70a highlights the importance of these proteins for successful overwintering. In October, Varroa infestation was negatively correlated with total proteins, vitellogenin, apolipophorin II, transferrin, and hexamerin 70a, with negative implications for overwintering; furthermore, Varroa infestation was also negatively correlated with iron content, potentially affecting iron homeostasis
Influence of two different Varroa treatments on the most abundant proteins of honey bee hemolymph
No full textEvaluation of the effect of different techniques on vitellogenin and other abundant hemolymph proteins to obtain successful wintering of the colonie
SDS-PAGE-Based Quantitative Assay of Hemolymph Proteins in Honeybees: Progress and Prospects for Field Application
Full text linkIn human and veterinary medicine, serum proteins are considered to be useful biomarkers for assessing the health and nutritional status of the organism. Honeybee hemolymph has a unique proteome that could represent a source of valuable biomarkers. Therefore, the aims of this study were to separate and identify the most abundant proteins in the hemolymph of worker honeybees to suggest a panel of these proteins that could represent useful biomarkers for assessing the nutritional and health status of the colonies and, finally, to analyze them in different periods of the year. Four apiaries were selected in the province of Bologna, and the bees were analyzed in April, May, July, and November. Thirty specimens from three hives of each apiary were sampled and their hemolymph was collected. The most represented bands obtained after 1D sodium-dodecyl-sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) were cut from the gel, and the proteins were identified using an LC-ESI-Q-MS/MS System. A total of twelve proteins were unmistakably identified; the two most abundant proteins were apolipophorin and vitellogenin, which are known biomarkers of bee trophic and health status. The two other proteins identified were transferrin and hexamerin 70a, the first being involved in iron homeostasis and the second being a storage protein. Most of these proteins showed an increase from April to November, mirroring the physiological changes of honeybees during the productive season. The current study suggests a panel of biomarkers from honeybee hemolymph worth testing under different physiological and pathological field conditions
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