Search Results (35)

Recent high annual losses of honey bee (Apis mellifera) colonies, averaging 40% in the United States from 2008 to 2025, are concerning for beekeepers, growers, policy makers, and scientists. Viruses, the most abundant group of honey bee pathogens, impact honey bee fitness and contribute to colony losses. Several studies have utilized next-generation sequencing (NGS) technologies to discover new honey beeinfecting viruses and expand our understanding of the honey bee virome. Herein, we examined the viromes of honey bees obtained from longitudinally monitored, commercially managed colonies that experienced population decline (average ~44%) during the 2022–2023 beekeeping season. We hypothesized new viruses or virus genome variants may be associated with these declines. To test this hypothesis, we sequenced RNA obtained from virus-augmented honey bee samples from representative colonies managed by four beekeeping operations in California. We discovered three undescribed partitivirus-like sequences that were prevalent and abundant in all beekeeping operations, a new Lake Sinai virus, and a sequence variant of acute bee paralysis virus. In addition, we re-sequenced the genomes of 16 previously characterized bee and/or Varroa destructor mite infecting viruses and two previously described, but not well-characterized, partitivirus-like sequences (i.e., Apis mellifera associated partiti-like virus 1 and Hubeipartiti-like virus 34). Virus abundance was greater in libraries representing colonies that died during the monitoring period. Full article

This study aimed to determine the presence of relevant infectious and parasitic agents (IPAs) in managed honeybees from Central Italy and the Republic of Kosovo and Albania to assess the overall health status of local apiaries by determining the contamination levels and co-occurrence. Therefore, pathogens and parasites such as Paenibacillus larvae, Melissococcus plutonius, Vairimorpha apis, V. ceranae, the acute bee paralysis virus (ABPV), black queen cell virus (BQCV), chronic bee paralysis virus (CBPV), deformed wing virus variants DWV-A and DWV-B, and the parasitoid flies Megaselia scalaris and Senotainia tricuspis were detected by quantitative polymerase chain reaction (qPCR) and reverse transcriptase qPCR (RT-qPCR) in clinically healthy adult honeybees collected from 187 apiaries in the Abruzzo and Molise regions of Central Italy, 206 apiaries in the Republic of Kosovo in 2022 and 2023 and 18 apiaries in Albania in 2022. The percentages of positive samples and contamination for V. ceranae, P. larvae and DWV-B were significantly higher in the Republic of Kosovo and Albania, while the percentages of samples positive for M. plutonius, CBPV, DWV-A, and the parasitoid flies were higher in Central Italy. Additionally, P. larvae and some viruses showed significantly different occurrence rates between the two years in Italy and the Republic of Kosovo. The co-occurrence of IPAs also differed between the two geographic areas. Their varying distribution could depend on epidemiological dynamics, climatic factors, and management practices specific to each country, whose relative impact should be defined to guide targeted interventions to reduce honeybee mortality. Full article

This study aimed to investigate the presence of known bee viruses in the European hornet (Vespa crabro, Linnaeus, 1758), a species recognized as a bee predator in Hungary. Several viruses affecting honeybees (Apis mellifera, Linnaeus, 1758), such as deformed wing virus (DWV), sacbrood virus (SBV), chronic bee paralysis virus (CBPV), and acute bee paralysis virus (ABPV), have been documented in various wasp species. For instance, DWV has been frequently isolated in Vespa orientalis (Linnaeus, 1761), and ABPV has been detected in V. orientalis. Additionally, viruses like Kashmir bee virus (KBV) and Black queen cell virus (BQCV) have been confirmed in other wasp species such as Vespula germanica and Vespa velutina. Despite this, data on virus presence in V. crabro remain limited. Between August and October 2023, we tested 40 adult V. crabro workers, collected from Kiskunlacháza and Vácduka, for viral infections using polymerase chain reaction (PCR). Our results confirmed the presence of genetic material from DWV and ABPV infection in adult workers of the European hornet, which showed no morphological alterations. This study provides the first detection of DWV (in Hungary) and ABPV in V. crabro, contributing to our understanding of virus transmission pathways in wasp species and their potential impact on bee populations. Full article

In Argentina, various studies have reported the detection of multiple viruses in honey-producing and queen-rearing apiaries, with Aparavirus apisacutum, the causal agent of acute bee paralysis (ABP), demonstrating a particularly high prevalence. The potential of RNA interference (RNAi) as a strategy to control honey bee viruses has been explored, with initial findings indicating that RNAi could aid in mitigating the economic losses associated with viral infections. This study aimed to evaluate the effect of RNAi technology mediated by double-stranded RNA (dsRNA) on the dynamics of ABPV infection in adult honey bees. Fragments of the ABPV replicase and VP1 genes were used as templates for dsRNA synthesis via in vitro transcription. A gene silencing experiment was conducted through oral administration using five treatments: control, specific dsRNA + Virus, Virus alone, specific dsRNA alone, and non-specific dsRNA + virus. Bee survival was recorded over 10 days for all treatments, and samples were subsequently processed for viral quantification using quantitative real-time PCR. The oral administration of specific dsRNA reduced the viral replication curve, decreased the average viral loads and increased bee survival. This is the first report demonstrating the reduction in ABPV infection in adult honey bees through post-transcriptional gene silencing achieved via oral administration of dsRNA. Full article

In urbanized environments, the expansion of urban areas has led to the creation of fragmented green spaces such as gardens and parks. While these areas provide essential habitats for pollinators, they may also inadvertently concentrate specimens of different species, increasing opportunities for pathogen transmission. This study highlights the importance of investigating pathogen dynamics in urban ecosystems, focusing on managed pollinators, such as Apis mellifera Linnaeus, 1758, and their wild counterparts. Over a two-year monitoring period in Milan, Italy, we examined the interactions between pollinator populations in urban green spaces and the spillover of honeybee pathogens. Our findings confirm widespread RNA virus transmission between honeybees and wild pollinators, supporting the previous studies. Notably, the Acute Bee Paralysis Virus (ABPV) exhibited the highest prevalence across both sampling years, underscoring its significant role in pathogen dynamics. These results emphasize the need for regular research to mitigate pathogen spillover risks in urban pollinator communities and inform conservation strategies. Full article

Background: Accumulating evidence from clinical trials, large registries, and meta-analyses of population studies shows that increased Blood Pressure Variability (BPV) is predictive of Cardiovascular (CV) outcomes, independently of the average Blood Pressure (BP) values. One of the mechanisms explaining the relationship between BPV and target organ damage is the inflammatory response. The Systemic Immune Inflammation Index (SII), which relies on peripheral blood cell counts, including platelets, neutrophils, and lymphocytes, has emerged as a predictor of prognosis and outcomes in various diseases. The aim of this study was to investigate the association of the SII with Ambulatory Blood Pressure Variability (ABPV) in newly diagnosed hypertensive patients. Methods: This study was designed as a cross-sectional observational study. A total of 1606 consecutive newly diagnosed Hypertension (HT) patients were included in the study. The population was evaluated across 3 different categories according to HT grades (5 groups), eligibility for antihypertensive therapy (2 groups) and ABPV levels (2 groups). Results: Significant differences were observed between ABPV groups in terms of Neutrophil to Lymphocyte ratio, Platelet to Lymphocyte ratio, glucose, SII, high-sensitive CRP, HT grade, Inter-Ventricular Septum, Posterior Wall thickness, and Left Ventricular Mass (p < 0.005). There was a significant relationship between SII and ABPV (r: 0.619, p < 0.05). At the cutoff value of 580.49, SII had 77% sensitivity and 71% specificity for ABPV > 14 (AUC: 0.788). Conclusions: SII may assist in developing an early treatment approach to minimize complications in patients with high ABPV who are at a higher risk of CV events. Full article

In this study, honeybee viruses were identified in naturally infected honeybee colonies (Apis mellifera carnica). From nine selected samples of clinically affected and ten samples of healthy honeybee colonies, different strains of honeybee viruses were first detected using quantitative real-time RT-PCR methods. Twenty-two nucleotide sequences of the complete genomes of honeybee viruses were identified using the Illumina Next-Generation Sequencing (NGS) method: acute bee paralysis virus (ABPV) (n = 4), black queen cell virus (BQCV) (n = 3), chronic bee paralysis virus (CBPV) (n = 2), deformed wing virus (DWV) (n = 5), Lake Sinai virus (LSV) (n = 4), sacbrood bee virus (SBV) (n = 1), Apis rhabdovirus-1 (ARV-1) (n = 1), bee macula-like virus (BeeMLV) (n = 1) and Hubei partiti-like virus 34 (HPLV34) (n = 1). The nucleotide sequences of ABPV, BQCV, DWV and SBV are the first complete genomes of these viruses identified in Slovenia and they represent an important contribution to our understanding of the genetic diversity of honeybee viruses. ARV-1, BeeMLV and HPLV34 were detected and sequenced for the first time in Slovenia. Full article

In the last few years, the isolation and amplification of DNA or RNA from the environment (eDNA/eRNA) has proven to be an alternative and non-invasive approach for molecular identification of pathogens and pests in beekeeping. We have recently demonstrated that bee pollen and bee bread represent suitable biological material for the molecular identification of viral RNA. In the present study, we extracted total RNA from different bee products (pollen, n = 25; bee bread, n = 17; and royal jelly, n = 15). All the samples were tested for the presence of six of the most common honey bee-associated viruses—Deformed wing virus (DWV), Acute bee paralysis virus (ABPV), Chronic bee paralysis virus (CBPV), Sacbrood virus (SBV), Kashmir bee virus (KBV), and Black queen cell virus (BQCV)—using a reverse transcription polymerase chain reaction (RT-PCR). We successfully detected six records of DWV (10.5%, 6/57), four of ABPV (7.0%, 4/57), three of Israeli acute paralysis virus (IAPV) (5.3%, 3/57), and two of BQCV (3.5%, 2/57). Using ABPV primers, we also successfully detected the presence of IAPV. The obtained viral sequences were analyzed for phylogenetic relationships with the highly similar sequences (megablast) available in the GenBank database. The Bulgarian DWV isolates revealed a high homology level with strains from Syria and Turkey. Moreover, we successfully detected a DWV strain B for the first time in Bulgaria. In contrast to DWV, the ABPV isolates formed a separate clade in the phylogenetic tree. BQCV was closely grouped with Russian isolates, while Bulgarian IAPV formed its own clade and included a strain from China. In conclusion, the present study demonstrated that eRNA can be successfully used for molecular detection of honey bee-associated viruses in bee products. The method can assist the monitoring of the health status of honey bee colonies at the local, regional, and even national levels. Full article

Verifying the inclusivity of molecular detection methods gives indications about the reliability of viral infection diagnosis because of the tendency of viral pathogens to undergo sequence variation. This study was aimed at selecting inclusive probes based on reverse transcription–quantitative PCR (RT-qPCR) assays for the diagnosis of the most widespread and detrimental viruses infecting honeybees, namely the acute bee paralysis virus (ABPV), the black queen cell virus (BQCV), the chronic paralysis bee virus (CBPV), the deformed wing virus variants A (DWVA) and B (DWVB), and the sacbrood virus (SBV). Therefore, previously described detection methods were re-evaluated in silico for their specificity and inclusivity. Based on this evaluation, selected methods were modified, or new ones were designed and tested in duplex RT-qPCR reactions. The limits of detection (LODs), effect of multiplexing on sensitivity and the viral RNA quantification potential in bees and hive debris were assessed. This study made available diagnostic assays able to detect an increased number of virus variants compared with previously described tests and two viral pathogens in a single PCR reaction. Full article

Honeybee diseases are one of the most significant and most common causes of honeybee colonies’ weakness and death. An early diagnosis of subclinical infections is necessary to implement precautionary and control measures. Sampling debris from hive bottom boards is simple, non-invasive, and cheap. In this study, we collected winter debris samples in apiaries located in the continental part of Croatia. We used molecular methods, PCR and qPCR, for the first time to analyze those samples. Laboratory results were compared with the health condition and strength of honeybee colonies at an apiary in spring. Our study successfully identified the presence and quantity of various pathogens, including the presence of Vairimorpha spp. (Nosema spp.), quintefied Paenibacillus larvae, Acute Bee Paralysis Virus (ABPV), Black Queen Cell Virus (BQCV), Deformed Wing Virus (DWV), and Sacbrood Virus (SBV). However, our analysis did not detect Melissococcus plutonius, Crithidia mellificae, Lotmaria passim, and Aethina tumida. Samples of winter debris were also examined for the presence and quantification of the V. destructor mites, and their natural mite fall was observed in spring. Honeybee colonies were simultaneously infected by an average of four to six pathogens. Some observed honeybee colonies developed characteristic symptoms, while others did not survive the winter. Full article

Honey bee viruses in combination with varroa mite are very damaging for honey bee colonies worldwide. There are no effective methods to control the viral load in honey bee colonies except regular and effective control of mites. Integrated Pest Management strategies are required to effectively control mites with veterinary medicines based on organic compounds. We evaluated the effect of two brood interruption techniques, queen caging (QC) and trapping comb (TC), followed by an oxalic acid treatment, on the mite fall, colony strength, and viral load of Deformed Wing Virus (DWV) and Acute Bee Paralysis Virus (ABPV). In this paper, we report the data obtained in two experimental sites, in Slovenia and Italy, in terms of the varroacide efficacy, colony strength, and viral load. The number of adult bees after the adoption of the two techniques showed similar decreasing trends in both locations. The viral load of Acute Bee Paralysis Virus did not show any significant reduction after 25 days, reported as the number of Real-Time PCR cycles needed to detect the virus. The viral load of DWV also did not show a significant reduction after 25 days. The acaricidal efficacy of the applied protocols was high in both experimental groups and in both apiaries. Both the queen caging and trapping comb techniques, followed by an oxalic acid treatment, can be considered effective varroa treatment strategies, but further studies should be carried out to evaluate the long-term effects on viral loads to plan the Integrated Pest Management strategy with the right timing before wintering. Full article

In recent years, honey bee colony losses in the Republic of Kosovo remained largely unknown. From 2019 to 2021, 81 apiaries with different disease suspicions were investigated in the framework of honey bee disease passive surveillance. Fifty-nine of the eighty-one apiaries were tested for Vairimorpha ceranae, Vairimorpha apis, trypanosomatids Lotmaria passim, and Crithidia mellificae. All samples were positive for V. ceranae (100%) whereas L. passim was found with a lower frequency (11.9%). V. apis and C. mellificae were not found. Thirteen of the eighty-one apiaries were tested for seven viruses (ABPV, CBPV, DWV, BQCV, SBV, IAPV, KBV) and five of them were found (ABPV, CBPV, DWV, BQCV, SBV). The most frequently detected viruses in honey bees and Varroa mites were DWV (100%) followed by BQCV, ABPV, SBV, and CBPV (92.3%, 69.2%, 30.8%, and 7.7%, respectively). Varroa mite samples had different degrees of co-infection by viruses. Nine of the eighty-one apiaries consisted of brood combs with larvae, eight of them were AFB positive, ERIC I genotype, and one EFB positive. This paper represents the first molecular investigation (PCR) and detection of the honey bee viruses ABPV, CBPV, DWV, BQCV, and SBV as well as V. ceranae, L. passim, and M. plutonius in the Republic of Kosovo. Full article

Honey bees are essential for crop and wild plant pollination. However, many countries have reported high annual colony losses caused by multiple possible stressors. Diseases, particularly those caused by viruses, are a major cause of colony losses. However, little is known about the prevalence of honey bee pathogens, particularly virus prevalence, in Egyptian honey bees. To address this shortfall, we determined the prevalence of widespread bee viruses in honey bee colonies in Egypt—whether it is affected by geography, the season, or infestation with Varroa destructor (varroa) mites. Honey bee worker samples were collected from 18 geographical regions across Egypt during two seasons: winter and summer of 2021. Three apiaries were chosen in each region, and a pooled sample of 150 worker bees was collected from five colonies in each apiary then screened by qPCR for 10 viral targets: acute bee paralysis virus (ABPV), black queen cell virus (BQCV), chronic bee paralysis virus (CBPV), deformed wing virus (DWV) genotypes A (DWV-A), B (DWV-B) and D (Egyptian bee virus), Israeli acute paralysis virus (IAPV), Kashmir bee virus (KBV), sacbrood virus (SBV), and slow bee paralysis virus (SBPV). Our results revealed that DWV-A was the most prevalent virus, followed by BQCV and ABPV; the DWV genotype now spreading across the world, DWV-B, was not detected. There was no difference in varroa infestation rates as well as virus prevalence between winter and summer. However, colonies infected with BQCV had a significantly higher varroa count (adjusted p < 0.05) in the winter season, indicating that there is a seasonal association between the intensity of infestation by varroa and the presence of this virus. We provide data on the current virus prevalence in Egypt, which could assist in the protection of Egypt’s beekeeping industry. Moreover, our study aids in the systematic assessment of the global honey bee virome by filling a knowledge gap about the prevalence of honey bee viruses in Egypt. Full article

Widespread parasites, along with emerging threats, globalization, and climate change, have greatly affected honey bees’ health, leading to colony losses worldwide. In this study, we investigated the detection of biotic stressors (i.e., viruses, microsporidian, bacteria, and fungi) in Apis cerana by surveying the colonies across different regions of Thailand (Chiang Mai in the north, Nong Khai and Khon Kaen in the northeast, and Chumphon and Surat Thani in the south, in addition to the Samui and Pha-ngan islands). In this study, we detected ABPV, BQCV, LSV, and Nosema ceranae in A. cerana samples through RT-PCR. ABPV was only detected from the samples of Chiang Mai, whereas we found BQCV only in those from Chumphon. LSV was detected only in the samples from the Samui and Pha-ngan islands, where historically no managed bees are known. Nosema ceranae was found in all of the regions except for Nong Khai and Khon Kaen in northeastern Thailand. Paenibacillus larvae and Ascosphaera apis were not detected in any of the A. cerana samples in this survey. The phylogenetic tree analysis of the pathogens provided insights into the pathogens’ movements and their distribution ranges across different landscapes, indicating the flow of pathogens among the honey bees. Here, we describe the presence of emerging pathogens in the Asian honey bee as a valuable step in our understanding of these pathogens in terms of the decline in eastern honey bee populations. Full article

The European honeybee contributes to the agriculture by its pollination; however, the overwintering loss rate over the last decades is worrisome. Varroa destructor is considered one of the most important causes of bee colony declines. This project aims to correlate the infestation by varroa to the hemolymph sugar concentrations and bacterial and viral coinfections. Six highly infested and six control hives were compared over time. Pooled hemolymph samples from honeybees were collected for sugar concentration measurements using a previously validated portable glucometer. The hemolymph samples were submitted for bacteriology. Multiplex RT-PCR analysis was performed on honeybees for six viruses: DWV-A, DWV-B, BQCV, ABPV, KBV, and IAPV. There was also no predominance of pathogenic bacteria. In September, sugar concentrations in hemolymph were significantly lower in highly infested hives than in control hives. Infested hives showed markedly higher viral loads except for ABPV. DWV-A and BQCV viral loads from highly infested hives were significantly higher in September compared to July. A continued and severe exposure to varroa leads to increased viral charges and decreased sugar concentrations, suggesting alterations in immunity, metabolism, and reserve mobilization. These parameters contribute to the weakening and mortality of the colonies. Full article