Zoonotic Virus Seroprevalence among Bank Voles, Poland, 2002-2010

Bank voles in Poland are reservoirs of zoonotic viruses. To determine seroprevalence of hantavirus, arenavirus, and cowpox virus and factors affecting seroprevalence, we screened for antibodies against these viruses over 9 years. Cowpox virus was most prevalent and affected by extrinsic and intrinsic factors. Long-term and multisite surveillance is crucial.Non peer reviewe

The body surface proteolytic systemof Apis mellifera in preserving the health of bee colonies.

Ostatnio coraz częściej mówi się i pisze o efekcie CCD (colony collapse disorder), którego przejawem jest masowe ginięcie rodzin pszczelich Apis mellifera. Pociąga to za sobą ogromne straty ekonomiczne w produkcji roślin oleistych, owoców i warzyw. Pomimo wysiłku naukowców z całego świata, problem masowego ginięcia pszczół nie został jeszcze rozwiązany, a przyjmuje on już wymiar globalny. Trzeba podkreślić, że w wielu przypadkach, potencjalne czynniki chorobotwórcze (każdy osobno) nie powodują złych następstw. Dlatego coraz liczniejsze grono badaczy uważa, że za CCD odpowiadają nie tyle te czynniki per se, ale raczej ogólny spadek odporności pszczół spowodowany postępem cywilizacyjnym oraz intensyfikacją rolnictwa i metod hodowli. W tym kontekście poznawanie mechanizmów i uwarunkowań odporności/oporności pszczół, może przyczynić się do lepszego zapobiegania CCD i wielu innym chorobom.Ważnym składnikiem zewnętrznej bariery obronnej Apis mellifera jest warstwa biologicznie aktywnych białek na powierzchni ciała. Chronią one organizm przed inwazją patogenów. Ostatnio wykazano, że wiele z tych białek ma aktywność proteaz i inhibitorów proteaz. A na ich aktywność na powierzchni ciała pszczół wpływ ma stadium rozwojowe owada, kasta oraz zanieczyszczenie środowiska.The CCD effect (colony collapse disorder), manifested in the massive disappearing of bee (Apis mellifera) colonies, has recently become the reason for much debate and inspired numerous publications. The phenomenon entails enormous economic losses in the production of oil plants, fruit and vegetables. Despite scientists' efforts worldwide, the problem of massive dying out of bees has not been solved yet. Meanwhile, it has assumed global dimensions. It must be stressed that, in many cases, potential pathogenic factors (separately) do not have untoward consequences. Therefore, increasingly more researchers think that CCD is not caused by those factors per se, but rather by a general immunity impairment that stems from the progress of civilization, as well as intensified agriculture and breeding. In this context, understanding the mechanisms and conditions of apian immunity/resistance can help better prevent CCD and numerous other diseases. An important element of the external protective barrier of Apis mellifera is the biologically active protein layer on the body surface. The proteins protect the organism from pathogen invasions. Recently, it has been shown that many of those proteins are characterised by protease and protease-inhibitor activity. More specifically, this body-surface activity in bees depends on the developmental phase and caste of the insect, as well as environmental pollution

Reproductive potential accelerates preimaginal development of rebel workers in Apis mellifera

SIMPLE SUMMARY: All female honeybee larvae may develop into workers or queens, depending on the food they receive. During this period, queen mandibular pheromones (QMP) perform a regulatory function in inhibiting ovarian development in adult workers. These pheromones are transmitted (via trophallaxis) by workers to pass information to larvae on the presence or absence of the queen. Queen-less conditions are conducive to the emergence of rebel workers that are set to reproduce, and do not participate in the rearing of successive bee generations in contrast to the sterile, normal workers. We posited that rebels are not only similar to queens in some anatomical features, but also develop in a shorter time in comparison to normal workers. Therefore, the aim of this study was to compare the duration of preimaginal development in rebel and normal workers. Our results confirmed that the workers who develop in a queen-less colony undergo a shorter preimaginal development than those in a queen-right colony. ABSTRACT: Rebel workers develop from eggs laid by the previous queen, before it went swarming and left the colony orphaned, until the emergence of a new queen. In contrast to normal workers developing in the queen’s presence, rebels are set to reproduce and avoid rearing of successive bee generations. They have more ovarioles in their ovaries, as well as more developed mandibular glands and underdeveloped hypopharyngeal glands, just like the queen. We posited that rebels are not only similar to queens in some anatomical features, but also develop in a shorter time in comparison to normal workers. Therefore, the aim of this study was to compare preimaginal development duration in rebel and normal workers. The results show that rebels, i.e., workers with a higher reproductive potential, had a significantly shorter preimaginal development period (mean ± SD, 19.24 ± 0.07 days) than normal workers (22.29 ± 0.32 days). Our result confirmed that workers who develop in a queen-less colony undergo a shorter preimaginal development than those in a queen-right colony

Nosema ceranae Infection Promotes Proliferation of Yeasts in Honey Bee Intestines.

BACKGROUND:Nosema ceranae infection not only damages honey bee (Apis melifera) intestines, but we believe it may also affect intestinal yeast development and its seasonal pattern. In order to check our hypothesis, infection intensity versus intestinal yeast colony forming units (CFU) both in field and cage experiments were studied. METHODS/FINDINGS:Field tests were carried out from March to October in 2014 and 2015. N. ceranae infection intensity decreased more than 100 times from 7.6 x 108 in March to 5.8 x 106 in October 2014. A similar tendency was observed in 2015. Therefore, in the European eastern limit of its range, N. ceranae infection intensity showed seasonality (spring peak and subsequent decline in the summer and fall), however, with an additional mid-summer peak that had not been recorded in other studies. Due to seasonal changes in the N. ceranae infection intensity observed in honey bee colonies, we recommend performing studies on new therapeutics during two consecutive years, including colony overwintering. A natural decrease in N. ceranae spore numbers observed from March to October might be misinterpreted as an effect of Nosema spp. treatment with new compounds. A similar seasonal pattern was observed for intestinal yeast population size in field experiments. Furthermore, cage experiments confirmed the size of intestinal yeast population to increase markedly together with the increase in the N. ceranae infection intensity. Yeast CFUs amounted to respectively 2,025 (CV = 13.04) and 11,150 (CV = 14.06) in uninfected and N. ceranae-infected workers at the end of cage experiments. Therefore, honey bee infection with N. ceranae supported additional opportunistic yeast infections, which may have resulted in faster colony depopulations

Curcumin Stimulates Biochemical Mechanisms of Apis Mellifera Resistance and Extends the Apian Life-Span

We examined the influence of curcumin-supplemented feeding on worker lifespan, Nosema resistance, key enzyme activities, metabolic compound concentrations and percentage of the global DNA methylation. Two worker groups (Apis mellifera) were set up: 1) control group; workers were fed ad libitum with sucrose syrup; 2) workers were fed with the syrup with the addition of curcumin. Dead workers were removed every two days and the Nosema spp. infection levels were assessed. Hemolymph was taken from living workers for biochemical analyses. The global DNA methylation level was analysed using DNA from worker heads and thoraces. The bees that consumed curcumin lived longer and were less infested with Nosema spp. The curcumin-treated workers had higher concentrations of proteins, non-enzymatic biomarkers (triglycerides, glucose, cholesterol, Mg2+ and Ca2+), uric acid and creatinine, as well as elevated activities of antioxidant enzymes (SOD , GPx, CAT , GST ), neutral proteases, protease inhibitors, enzymatic biomarkers (AST , ALT , ALP ). The concentrations of albumin and urea, and the activities of acidic and alkaline proteases were higher in the control group. Curcumin decreased global DNA methylation levels especially in older bees in which the natural, age-related level increase was observed. Most of the parameters increased over the apian youth and adulthood, and decreased in older bees. The decrease was markedly delayed in the bees fed with curcumin. Curcumin appeared to be an unexpectedly effective natural bio-stimulator, improving apian health and vitality. This multifactorial effect is caused by the activation of many biochemical processes involved in the formation of apian resistance

Influence of Amitraz and Oxalic Acid on the Cuticle Proteolytic System of <em>Apis mellifera</em> L. Workers

This work verifies that amitraz and oxalic acid treatment affect honeybee cuticle <em><strong>proteolytic enzymes (CPE).</strong></em> Three bee groups were monitored: oxalic acid treatment, amitraz treatment, control. Electrophoresis of hydrophilic and hydrophobic CPE was performed. Protease and protease inhibitor activities (<em>in vitro</em>) and antifungal/antibacterial efficiencies (<em>in vivo</em>), were analyzed. Amitraz and oxalic acid treatment reduced hydrophobic, but did not affect hydrophilic, protein concentrations and reduced both hydrophilic and hydrophobic body surface asparagine and serine protease activities in relation to most substrates and independently of pH. The activities of natural cuticle inhibitors of acidic, neutral, and alkaline proteases were suppressed as a result of the treatments, corresponding with reduced antifungal and antibacterial activity. Electrophoretic patterns of low-, medium-, and high-molecular-weight proteases and protease inhibitors were also affected by the treatments

Imidacloprid Pesticide Causes Unexpectedly Severe Bioelement Deficiencies and Imbalance in Honey Bees Even at Sublethal Doses

Pesticides impair honeybee health in many ways. Imidacloprid (IMD) is a pesticide used worldwide. No information exists on how IMD impact the bees’ body bioelement balance, which is essential for bee health. We hypothesized that IMD disturbs this balance and fed the bees (in field conditions) with diets containing 0 ppb (control), 5 ppb (sublethal considered field-relevant), and 200 ppb (adverse) doses of IMD. IMD severely reduced the levels of K, Na, Ca, and Mg (electrolytic) and of Fe, Mo, Mn, Co, Cu, Ni, Se, and Zn, while those of Sn, V, and Cr (enzymatic) were increased. Levels of P, S, Ti, Al, Li, and Sr were also decreased, while only the B content (physiologically essential) was increased. The increase in Tl, Pb, and As levels (toxic) was alarming. Generally, IMD, even in sublethal doses, unexpectedly led to severe bioelement malnutrition in 69% of bioelements and to a stoichiometric mismatch in the remaining ones. This points to the IMD-dependent bioelement disturbance as another, yet unaccounted for, essential metabolic element which can interfere with apian health. Consequently, there is a need for developing methods of bioelement supplementation of the honey bee diet for better preventing bee colony decline and protecting apian health status when faced with pesticides

Reproductive potential impacts body maintenance parameters and global DNA methylation in honeybee workers (Apis mellifera L.)

The widely accepted hypothesis in life history evolution about the trade-off between fecundity and longevity is not confirmed by long-living and highly fecund queens in eusocial insects. The fact that the queens and facultatively sterile workers usually arise from genetically identical eggs but differ in DNA methylation makes them a good model for studies on senescence, eusocial evolution, and epigenetics. Therefore, honeybees seem to be especially useful here because of long living rebel-workers (RW) with high reproductive potential recently described. Longevity, ovariole number, nosema tolerance, and global DNA methylation have been assayed in normal workers (NW) versus RW in hives and cages. RW always lived longer than NW and unexpectedly extended longevity of NW when they were together, similarly as the presence of a queen did. RW lived longer despite the fact that they had higher Nosema spore load; surprisingly they became infected more easily but tolerated the infection better. Global DNA methylation increased with age, being lower in RW than in NW. Therefore, RW are queen-like considering global DNA methylation and the link between fecundity, longevity, and body maintenance. Presented features of RW expands possibilities of the use of honeybees as a model for studies on senescence, nosemosis, eusocial evolution, and epigenetics

Segmentation of the subcuticular fat body in Apis mellifera females with different reproductive potentials

Abstract Evolution has created different castes of females in eusocial haplodiploids. The difference between them lies in their functions and vulnerability but above all in their reproductive potentials. Honeybee queens are highly fertile. On the other hand, the workers are facultatively sterile. However, rebel workers, i.e. workers that develop in a queenless colony, reproduce more often than normal workers. As a result, the fat body of these bees, which apart from acting as the energy reserve, is also the site of numerous metabolic processes, had to specialize in different functions perfected over millions of years of eusocial evolution. Assuming that the variety of functions manifests itself in the pleomorphic structure of the fat body cells, we predicted that also different parts of the fat body, e.g. from different segments of the abdomen, contain different sets of cells. Such differences could be expected between queens, rebels and normal workers, i.e. females with dramatically different reproductive potentials. We confirmed all these expectations. Although all bees had the same types of cells, their proportion and segmental character corresponded with the caste reproductive potential and physiological characteristics shaped in the evolutionary process. The females with an increased reproductive potential were characterized by the presence of oenocytes in the third tergite and high concentrations of compounds responsible for energy reserves, like glucose, glycogen and triglycerides. Queens had very large trophocytes, especially in the third tergite. Only in workers did we observe intercellular spaces in all the segments of the fat body, as well as high protein concentrations—especially in the sternite. As expected, the rebels combined many features of the queens and normal workers, what with other findings can help understand the ways that led to the origin of different castes in females of eusocial Hymenoptera