Publications by authors named "Raquel Martin-Hernandez"

Two microsporidian species infect honeybees worldwide, Nosema apis and Nosema ceranae. Two different clinical patterns are considered: nosemosis type A (N. apis) and nosemosis type C (N.

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  • Deformed wing virus (DWV) in honey bees has gained attention due to its spread linked to the varroa mite, a parasite that affects honey bee populations.
  • The study focuses on the impact of varroa on DWV evolution by examining honey bee colonies across the Azores archipelago, where varroa is present on only some islands.
  • Results indicate that some varroa-free islands maintained distinct variants of DWV, suggesting that certain strains can thrive without the varroa mite, highlighting the complex relationship between the virus and its vector.
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The worldwide dispersal of the ectoparasitic mite Varroa destructor from its Asian origins has fundamentally transformed the relationship of the honey bee (Apis mellifera) with several of its viruses, via changes in transmission and/or host immunosuppression. The extent to which honey bee-virus relationships change after Varroa invasion is poorly understood for most viruses, in part because there are few places in the world with several geographically close but completely isolated honey bee populations that either have, or have not, been exposed long-term to Varroa, allowing for separate ecological, epidemiological, and adaptive relationships to develop between honey bees and their viruses, in relation to the mite's presence or absence. The Azores is one such place, as it contains islands with and without the mite.

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The genus Vairimorpha was proposed for several species of Nosema in 1976 (Pilley, 1976), almost 70 years after Nosema apis Zander (Zander, 1909). Tokarev and colleagues proposed the redefinition of 17 microsporidian species in four genera, Nosema, Vairimorpha, Rugispora, and Oligosporidium, based on phylogenetic trees of two genetic markers (SSU rRNA and RPB1) (Tokarev et al., 2020).

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  • The gut microbiota in honey bees plays a crucial role in their health but can be disrupted by infections, particularly from an intracellular parasite affecting midgut cells.
  • Younger worker bees are more susceptible to this parasite, which leads to changes in their gut bacterial communities, though the exact effects are not fully understood.
  • Experimental infection at different ages revealed that infected bees had higher levels of certain bacterial species, while older non-infected bees maintained higher loads of different bacteria, indicating that both infection and the bees' age significantly influence gut microbiota composition.
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  • * The study focuses on the trypanosomatid parasite Lotmaria passim, which can form multicellular biofilms—a lifestyle that enhances its survival in harsh conditions.
  • * Findings indicate that these parasites' biofilm formation increases their resistance to environmental stressors, which helps explain their prevalence and its potential impacts on honeybee populations.
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Evidence suggests that acaricide residues, such as tau-fluvalinate and coumaphos, are very prevalent in honey bee colonies worldwide. However, the endpoints and effects of chronic oral exposure to these compounds remain poorly understood. In this study, we calculated LC and LDD endpoints for coumaphos and tau-fluvalinate, and then evaluated in vivo and in vitro effects on honey bees using different biomarkers.

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Bee trypanosomatids have not been widely studied due to the original belief that these organisms were not pathogenic to honey bees. However, trypanosomatids have been linked to increased winter mortality in honey bee colonies in recent years and it has been shown that these pathogens can shorten a honey bee worker's lifespan in laboratory conditions. These studies found that this mortality corresponded to dose-dependent infection.

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  • Trypanosomatids are prevalent protozoan parasites in honey bees, with Lotmaria passim being the most common species globally, especially studied in Portugal's Madeira and Azores due to their isolation and absence of major honey bee threats.
  • The analysis of 661 honey bee colonies revealed a high prevalence of L. passim, often as the sole species present, and although colonies with Varroa destructor had more L. passim, those with Nosema ceranae showed no significant correlation.
  • High-throughput sequencing identified two main haplotypes of L. passim, suggesting that both L. passim and Crithidia bombi have been associated with honey bees prior to the introduction of V. destructor and N.
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Unlabelled: Pollination services to increase crop production are becoming more and more important, as we are facing both climate change and a growing world population. Both are predicted to impact food security worldwide. High-density, commercial beekeeping has become a key link in the food supply chain, and diseases have become a central issue in hive losses around the world.

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Avian trichomonosis is a parasitic disease caused mainly by Trichomonas gallinae and other Trichomonas species. It can be asymptomatic, or it can produce a necrotic lesion in the upper digestive tract and spread to other organs, causing the death of the infected birds. In this study, we aimed to evaluate an adapted real-time PCR method for the diagnosis of different genotypes and species of avian oropharyngeal trichomonads.

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  • A study monitored the intracellular parasite of honey bees across six apiaries in four Mediterranean countries to assess infection rates and their impact on colony health and honey production.
  • All apiaries, except one in Portugal, showed positive infection rates, with the highest intra-colony infections in Israel, and a notable negative correlation between infection levels and colony strength in Spain and mainland Portugal.
  • The findings indicate that infection effects vary based on geographical location and beekeeping practices, highlighting the need for further research on host-parasite dynamics and their implications for bee management strategies.
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In the last years, an increase has been observed in the adulteration of bee pollen. Consequently, different tools are required to authenticate the origin of this product, such as a study of the profile and composition of a specific family of compounds. The present study investigates the potential of betaines and related compounds as markers of the apiary of origin and harvest period of 71 bee pollen samples.

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  • Nosema ceranae is a widespread pathogen affecting honey bees (Apis mellifera) and was found to be the dominant species in the Azores, with a notable increase in prevalence from 2014 to 2020.
  • Sampling across multiple islands indicated a significant rise in N. ceranae infections, particularly in Terceira and São Jorge.
  • Interestingly, the islands of Flores and Santa Maria remain free from N. ceranae and Varroa destructor, making them unique havens for honey bees in Europe.
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There is mounting evidence that acaricides are among the most prevalent medicinal compounds in honey bee hive matrices worldwide. According to OCDE guideline No. 245 chronic lethal concentration of tau-fluvalinate (at concentrations ranging from 77.

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is a trypanosomatid species that was initially described in the digestive tract of Hemiptera. However, this parasite was recently detected in honey bee colonies in Spain, raising the question as to whether bees can act as true hosts for this species. To address this issue, worker bees were experimentally infected with choanomastigotes from the early stationary growth phase and after 12 days, their hindgut was extracted for analysis by light microscopy and TEM.

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Nosema ceranae is an intracellular parasite that infects honeybees' gut altering the digestive functions; therefore, it has the potential of affecting the composition of the gut microbiome. In this work, individual bees of known age were sampled both in spring and autumn, and their digestive tracts were assessed for N. ceranae infection.

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  • Bee pollen is a popular food supplement known for its bioactive substances and energy-boosting properties, containing proteins, amino acids, lipids, and glucosinolates.
  • A study analyzed 72 bee pollen samples and 11 commercial samples from different Spanish regions using advanced liquid chromatography to determine their glucosinolate content.
  • The results showed that glucosinolate levels could successfully identify the geographical origin and harvesting periods of the bee pollen samples.
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To study the influence of thiamethoxam exposure on colony strength and pathogen prevalence, an apiary (5 colonies) was placed in front of a plot sown with winter oilseed rape (wOSR), just before the flowering phase. Before sowing, the seeds were treated with an equivalent application of 18 g thiamethoxam/ha. For comparison, a second apiary (5 colonies) was located in front of a separate 750 m plot sown with untreated wOSR.

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The microsporidia is an intracellular parasite of honeybees' midgut, highly prevalent in colonies for which important epidemiological information is still unknown. Our research aimed at understanding how age and season influence the onset of infection in honeybees and its development in the colony environment. Adult worker honeybees of less than 24h were marked and introduced into 6 different colonies in assays carried out in spring and autumn.

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(1) Background: Q fever is a worldwide zoonosis caused by that have cases reported in humans and animals almost everywhere. The aim of this study was to describe the seasonality of in the wild rabbit () and the tick in a meso-Mediterranean ecosystem. (2) Methods: two populations of wild rabbits that differ in whether or not they share habitat with ungulates, mainly red deer () were sampled for a year to collect ticks, blood and vaginal or anal swabs.

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Trypanosomatids are among the most prevalent parasites in bees but, despite the fact that their impact on the colonies can be quite important and that their infectivity may potentially depend on their genotypes, little is known about the population diversity of these pathogens. Here we cloned and sequenced three non-repetitive single copy loci (DNA topoisomerase II, glyceraldehyde-3-phosphate dehydrogenase and RNA polymerase II large subunit, RPB1) to produce new genetic data from Crithidia bombi, C. mellificae and Lotmaria passim isolated from honeybees and bumblebees.

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  • Insect pollination is essential for ecosystems, but global pollinator decline is threatening this service, largely due to the spread of pathogens through managed bees.
  • Research on pathogen transmission has mostly focused on specific species, with limited studies on community-level impacts, highlighting a need for more comprehensive data to protect pollinators.
  • This study detected the microsporidia pathogens Nosema ceranae and N. apis in diverse wild bee species in semiarid Mediterranean regions, indicating N. ceranae's ability to spread and raise concerns about its potential role as a vector in these ecosystems.
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In this case report, we analyze the possible causes of the poor health status of a professional apiary located in Gajanejos (Guadalajara, Spain). Several factors that potentially favor colony collapse were identified, including infection, alone or in combination with other factors (e.g.

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