Search

Simple Summary: Honeybees are vital pollinators, essential for maintaining ecosystems and biodiversity, but there is rising concern about the health of managed honey bee colonies, especially in heavily human-influenced ecosystems. Multiple factors contribute to this decline, including environmental conditions, forage quality, and pesticide use. These elements have a complex effect on the health and nutritional status of honeybee colonies and influence their response to disease and various stressors. In this study, the authors propose a new approach to assess colony health by correlating common measures of colony strength such as honey and pollen reserves, the number of bees, and brood with hemolymph proteins, common bee pathogens (Varroa destructor and Nosema spp.), and essential trace elements (iron, zinc, and copper). Significant correlations were found between hemolymph proteins and colony performance measures, and between V. destructor and hemolymph proteins and iron content. In conclusion, this study confirms the need for a more holistic approach to honeybee health considering all the relevant aspects and critical points that may affect colony survival. Environment, 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. [ABSTRACT FROM AUTHOR]

Hepatitis E virus belonging to the Rocahepevirus ratti species, genotype HEV-C1, has been extensively reported in rats in Europe, Asia and North America. Recently, human cases of hepatitis associated with HEV-C1 infection have been reported, but the zoonotic nature of rat-HEV remains controversial. The transmission route of rat-HEV is unidentified and requires further investigation. The HEV strains of the Paslahepevirus balayani species, belonging to the same Hepeviridae family, and including the zoonotic genotype HEV-3 usually found in pigs, have also sporadically been identified in rats. We sampled 115 rats (liver, lung, feces) between 2020 and 2023 in Northeast Italy and the HEV detection was carried out by using Reverse Transcription PCR. HEV RNA was detected in 3/115 (2.6%) rats who tested positive for HEV-C1 strains in paired lung, intestinal contents and liver samples. Overall, none tested positive for the Paslahepevirus balayani strains. In conclusion, our results confirm the presence of HEV-rat in Italy with a prevalence similar to previous studies but show that there is a wide heterogeneity of strains in circulation. The detection of HEV-C1 genotype of Rocahepevirus ratti species in some human cases of acute hepatitis suggests that HEV-C1 may be an underestimated source of human infections. This finding, with the geographically widespread detection of HEV-C1 in rats, raises questions about the role of rats as hosts for both HEV-C1 and HEV-3 and the possibility of zoonotic transmission. [ABSTRACT FROM AUTHOR]

This article in the Journal of Fish Diseases examines the effects of the fungicide dimethomorph on various species of oomycetes, which are harmful to plants and animals, including humans. The study specifically focuses on three oomycete species that cause significant economic losses in agriculture and aquaculture. Through in vitro tests and scanning electron microscopy, the researchers found that dimethomorph inhibited the growth of the oomycetes and caused morphological changes in one species. The study suggests that more research is needed to fully understand these pathogens and develop effective treatments. [Extracted from the article]

Formic 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. [ABSTRACT FROM AUTHOR]

The aim of this research project was to evaluate the effects of ionizing radiations on Aspergillus spp. and on aflatoxin B1 levels contaminating maize grains. Eight samples of maize were irradiated by ionizing radiations respectively at doses of 3, 5, 7 and 10 kGy. The control samples showed a mean total viable mycetes count of 106 CFU/g and the mean levels of aflatoxin B1, detected by HPLC/FL, were 1212.8 median 1319 ppb. The effects of γ radiations on Aspergillus spp. produced a dose-dependent decrease in total moulds count and the appearance of some mutants. The AFB1 contamination was evaluated in samples irradiated at the 10 kGy dose, the maximum overall average absorbed radiation dose allowed by the European Community Directive. The results showed an increased AFB1 with mean level of 1975.8 ppb and median 1924.5 ppb.