Percorrer por autor "Tosi, Simone"
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- High accuracy monitoring of honey bee colony development by a quantitative methodPublication . Capela, Nuno; Dupont, Yoko L.; Rortais, Agnès; Sarmento, Artur; Papanikolaou, Alexandra; Topping, Christopher J.; Arnold, Gérard; Pinto, M. Alice; Rodrigues, Pedro J.; More, Simon J.; Tosi, Simone; Alves, Thiago da Silva; Sousa, José PauloHoney bees are key insect pollinators, providing important economic and ecological value for human beings and ecosystems. This has triggered the development of several monitoring methods for assessing the temporal development of colony size, food storage, brood and pathogens. Nonetheless, most of these methods are based on visual assessments that are observer-dependent and prone to bias. Furthermore, the impact on colony development (invasiveness), as well as accuracy, were rarely considered when implementing new methods. In this study, we present and test a novel accurate and observer-independent method for honey bee colony assessment, capable of being fully standardized. Honey bee colony size is quantified by assessing the weight of adult bees, while brood and provision are assessed by taking photos and conducting image analysis of the combs with the image analysis software DeepbeeVR . The invasiveness and accuracy of the method were investigated using field data from two experimental apiaries in Portugal, comparing results from test and control colonies. At the end of each field experiment, most of the tested colonies had the same colony size, brood levels and honey production as the control colonies. Nonetheless, continuous weight data indicated some disturbance in tested colonies in the first year of monitoring. The overall accuracy of the image analysis software was improved by training, indicating that it is possible to adapt the software to local conditions. We conclude that the use of this fully quantitative method offers a more accurate alternative to classic visual colony assessments, with negligible impact on colony development.
- Honeybee gut microbiota as an emerging endpoint for pesticide risk assessmentsPublication . Rosa-Fontana, Annelise; Aguado-López, Daniel; Jabal-Uriel, Clara; Martín-Hernández, Raquel; Higes, Mariano; Pinto, M. Alice; Henriques, Dora; Tosi, Simone; Rodríguez Gomez, Juan MiguelA recent roadmap for the integration of environmental microbiotas in risk assessments under the European Food Safety Authority (EFSA) remit has been published. Healthy honeybee gut microbiota has emerged as a promising avenue to protect bees against stressors. Honeybees exhibit a consistent core microbiota, and dysbiosis, as part of a multiple stressor system, may be an indicator of adverse scenarios. We therefore investigated the honeybee gut microbiota of Apis mellifera carnica workers exposed to a single concentration of the insecticide flupyradifurone (FPF, 36ppm). The laboratory trials were carried out in accordance with official protocols (OECD Nº 245). The abdomen of each bee was separated from the thorax, and DNA extraction was performed individually. Full-length 16s rRNA amplicon metagenomic was sequenced through PacBio sequel II (HiFi/CCS mode). The absolute abundance of four bacterial genera constituting the core honeybee microbiota unveiled a Lactobacillus-dominated gut in both treated and non-treated bees. Treated bees exhibited a twofold increase in the bacterial load of Snodgrassella, contrasting with a 50% reduction in the Bifidobacterium load and the complete absence of Gilliamella as compared to the untreated bees. Our findings revealed that FPF disrupted the honeybee gut microbiota. We have developed a new approach, overlooked in risk assessments studies so far, to assess the impact of pesticides bee health until now. Thus, we propose its use as a novel endpoint in pesticide risk assessments. Current risk assessments are performed in a tiered approach, i. e., moving from laboratory assays (first screening) to semi field and field studies, and require no sublethal effect assessments. We therefore advocate for the inclusion of honeybee gut microbiota dysbiosis as a sublethal effect in the first screening step of risk assessments, and as a key parameter to assess pollinator’s health.
- Honeybee gut microbiota is an imperative endpoint for pesticide risk assessmentPublication . Rosa-Fontana, Annelise; Aguado-López, Daniel; Uriel Clara, Jabal; Martín-Hernández, Raquel; Higes, Mariano; Pinto, M. Alice; Henriques, Dora; Tosi, Simone; Rodríguez Gomez, Juan MiguelIn nature, honeybee workers acquire their stable gut microbial community by the 7th day post-emergence, with older bees transmitting microorganisms to younger bees in the comb, thereby establishing natural microbial diversity. In contrast, younger caged bees sampled for laboratory trials (OECD Guideline No. 245) are in contact with older bees for only a few hours. Newly emerged bees harbor minimal to no bacteria, potentially resulting in lower diversity, richness, and bacterial loads in their gut. However, this method best simulates the natural state within a controlled environment.Existing studies have modified standardized protocols to simulate the microbiota present in the honeybee digestive tract within the hive environment. A common approach involves diluting the gut contents of forager bees and incorporating this into the diet of caged bees. In our trials, we strictly adhered to OECD Guideline No. 245 (Chronic Oral Toxicity Test; 10-Day Feeding), exposing newly emerged Apis mellifera carnica workers to a single concentration of the insecticide flupyradifurone (FPF, 36 ppm). The standard reference dimethoate (1 ppm) and control groups (pure food and food + acetone) were also included. DNA was extracted individually from the bee abdomens, and full-length 16S rRNA amplicon metagenomics were sequenced using PacBio Sequel II (HiFi/CCS mode). The absolute abundance of four bacterial genera comprising the core honeybee microbiota revealed a Lactobacillus-dominated gut in both treated and untreated bees. Treated bees exhibited a twofold increase in the bacterial load of Snodgrassella, contrasting with a 50% reduction in Bifidobacterium and the complete absence of Gilliamella compared to untreated bees. Our findings demonstrate that FPF significantly disrupts the honeybee gut microbiota. This study presents, for the first time, the composition of the gut microbiota in honeybees strictly subjected to the OECD guideline without modifications or adaptations. Results from OECD-based tests already meet reliability requirements for risk assessments. Therefore, following OECD standards strictly illuminate three distinct advantages: (1) streamlining the process leading to a ring test, (2) reducing variations introduced by external factors potentially brought into hives by foraging bees, and (3) reducing bacterial diversity in lab-tested bees, thereby facilitating the establishment of acceptable fluctuations in microbiota composition. We have developed a new approach, overlooked in risk assessments studies so far, to assess the impact of pesticides on bee health. We propose adopting this approach as a new endpoint in pesticide risk assessments. Specifically, we advocate for the inclusion of honeybee gut microbiota dysbiosis as a sublethal effect in the first screening step of risk assessments, and as a key parameter to assess pollinator's health. We will present a summary of the most relevant bacteria for bee health, alongside fluctuations in the microbiota and diversity indices. Additionally, we will provide recommendations on the most suitable indicators for assessing gut microbiota dysbiosis.