Variation in honey bee gut microbial diversity affected by ontogenetic stage, age and geographic location

Social honey bees, Apis mellifera, host a set of distinct microbiota, which is similar across the continents and various honey bee species. Some of these bacteria, such as lactobacilli, have been linked to immunity and defence against pathogens. Pathogen defence is crucial, particularly in larval stages, as many pathogens affect the brood. However, information on larval microbiota is conflicting. Seven developmental stages and drones were sampled from 3 colonies at each of the 4 geographic locations of A. mellifera carnica, and the samples were maintained separately for analysis. We analysed the variation and abundance of important bacterial groups and taxa in the collected bees. Major bacterial groups were evaluated over the entire life of honey bee individuals, where digestive tracts of same aged bees were sampled in the course of time. The results showed that the microbial tract of 6-day-old 5th instar larvae were nearly equally rich in total microbial counts per total digestive tract weight as foraging bees, showing a high percentage of various lactobacilli (Firmicutes) and Gilliamella apicola (Gammaproteobacteria 1). However, during pupation, microbial counts were significantly reduced but recovered quickly by 6 days post-emergence. Between emergence and day 6, imago reached the highest counts of Firmicutes and Gammaproteobacteria, which then gradually declined with bee age. Redundancy analysis conducted using denaturing gradient gel electrophoresis identified bacterial species that were characteristic of each developmental stage. The results suggest that 3-day 4th instar larvae contain low microbial counts that increase 2-fold by day 6 and then decrease during pupation. Microbial succession of the imago begins soon after emergence. We found that bacterial counts do not show only yearly cycles within a colony, but vary on the individual level. Sampling and pooling adult bees or 6th day larvae may lead to high errors and variability, as both of these stages may be undergoing dynamic succession

Detailed proteome mapping of newly emerged honeybee worker hemolymph and comparison with the red-eye pupal stage

International audienceAbstractThe honeybee, Apis mellifera, undergoes complete metamorphosis before transitioning to the adult stage. The newly emerged individual and the red-eye pupa stage are well defined and easily recognizable in the time life cycle honeybee and, therefore, very useful for studying physiological and developmental factors. We analyzed in detail the hemolymph proteome of newly emerged honeybee worker using 2D-E-MS/MS (pI 3-10 and 4-7). The comparison of identical hemolymph volumes (20 μL per 2D-E) for newly emerged bee and red-eye pupa revealed a dramatic decrease in the number of spots (qualitative changes) and overall protein quantity during the non-feeding stage. The results increase our knowledge about honeybee metamorphosis during the non-feeding period and clarify previous findings regarding particular proteins. The results will be useful for future comparative physiological, developmental, and host-pathogen studies on individual or population level

In vitro growth-inhibitory effect of plant-derived extracts and compounds against Paenibacillus larvae and their acute oral toxicity to adult honey bees

In total, 26 natural compounds of various chemical classes (flavonoids, alkaloids, terpenoids) and 19 crude extracts from selected plants were tested in vitro for antibacterial activity against three strains of P. larvae, the causal agent of American Foulbrood Disease of honey bees (AFB) by the broth microdilution method. Among the individual substances, sanguinarine (MIC 4 μg/ml), followed by thymoquinone, capsaicin, trans-2-hexenal and nordihydroguaiaretic acid (MIC 4–32 μg/ml) possessed the strongest antibacterial effect. In case of extracts, common hop (Humulus lupulus L.) and myrtle (Myrtus communis L.) methanolic-dichloromethane extracts exhibited the highest growth-inhibitory effect with MICs ranging from 2 to 8 μg/ml. Acute oral toxicity of the most active natural products was determined on adult honey bees, showing them as non-toxic at concentrations as high as 100 μg peer bee. Our study leads to identification of highly potent natural products effective against AFB in vitro with very low MICs compared to those reported in literature, low toxicity to adult honey bees and commercial availability suggesting them as perspective, low cost and consumer-acceptable agents for control of AFB

Bacterial community associated with worker honeybees (Apis mellifera) affected by European foulbrood

Background Melissococcus plutonius is an entomopathogenic bacterium that causes European foulbrood (EFB), a honeybee (Apis mellifera L.) disease that necessitates quarantine in some countries. In Czechia, positive evidence of EFB was absent for almost 40 years, until an outbreak in the Krkonose Mountains National Park in 2015. This occurrence of EFB gave us the opportunity to study the epizootiology of EFB by focusing on the microbiome of honeybee workers, which act as vectors of honeybee diseases within and between colonies. Methods The study included worker bees collected from brood combs of colonies (i) with no signs of EFB (EFB0), (ii) without clinical symptoms but located at an apiary showing clinical signs of EFB (EFB1), and (iii) with clinical symptoms of EFB (EFB2). In total, 49 samples from 27 honeybee colonies were included in the dataset evaluated in this study. Each biological sample consisted of 10 surface-sterilized worker bees processed for DNA extraction. All subjects were analyzed using conventional PCR and by metabarcoding analysis based on the 16S rRNA gene V1–V3 region, as performed through Illumina MiSeq amplicon sequencing. Results The bees from EFB2 colonies with clinical symptoms exhibited a 75-fold-higher incidence of M. plutonius than those from EFB1 asymptomatic colonies. Melissococcus plutonius was identified in all EFB1 colonies as well as in some of the control colonies. The proportions of Fructobacillus fructosus, Lactobacillus kunkeei, Gilliamella apicola, Frischella perrara, and Bifidobacterium coryneforme were higher in EFB2 than in EFB1, whereas Lactobacillus mellis was significantly higher in EFB2 than in EFB0. Snodgrassella alvi and L. melliventris, L. helsingborgensis and, L. kullabergensis exhibited higher proportion in EFB1 than in EFB2 and EFB0. The occurrence of Bartonella apis and Commensalibacter intestini were higher in EFB0 than in EFB2 and EFB1. Enterococcus faecalis incidence was highest in EFB2. Conclusions High-throughput Illumina sequencing permitted a semi-quantitative analysis of the presence of M. plutonius within the honeybee worker microbiome. The results of this study indicate that worker bees from EFB-diseased colonies are capable of transmitting M. plutonius due to the greatly increased incidence of the pathogen. The presence of M. plutonius sequences in control colonies supports the hypothesis that this pathogen exists in an enzootic state. The bacterial groups synergic to both the colonies with clinical signs of EFB and the EFB-asymptomatic colonies could be candidates for probiotics. This study confirms that E. faecalis is a secondary invader to M. plutonius; however, other putative secondary invaders were not identified in this study

1H NMR Profiling of Honey Bee Bodies Revealed Metabolic Differences between Summer and Winter Bees

In temperate climates, honey bee workers of the species Apis mellifera have different lifespans depending on the seasonal phenotype: summer bees (short lifespan) and winter bees (long lifespan). Many studies have revealed the biochemical parameters involved in the lifespan differentiation of summer and winter bees. However, comprehensive information regarding the metabolic changes occurring in their bodies between the two is limited. This study used proton nuclear magnetic resonance (1H NMR) spectroscopy to analyze the metabolic differences between summer and winter bees of the same age. The multivariate analysis showed that summer and winter bees could be distinguished based on their metabolic profiles. Among the 36 metabolites found, 28 metabolites have displayed significant changes from summer to winter bees. Compared to summer bees, trehalose in winter bees showed 1.9 times higher concentration, and all amino acids except for proline and alanine showed decreased patterns. We have also detected an unknown compound, with a CH3 singlet at 2.83 ppm, which is a potential biomarker that is about 13 times higher in summer bees. Our results show that the metabolites in summer and winter bees have distinctive characteristics; this information could provide new insights and support further studies on honey bee longevity and overwintering

Ecofriendly synergists for insecticide formulations (EcoSyn)

EcoSyn consists of a consortium of experts to optimise the use of synergists in agriculture and public health by elucidating the relationship between synergist chemical structure and activity on a variety of target insect metabolic enzymes: this will enhance the efficacy of insecticides against resistant and susceptible pest insects in both laboratory and field environments. Repeated use of synthetic insecticides has resulted in the development of insecticide resistance; inhibition of insect defence enzymes by synergists would allow increased kill of resistant pests and control of susceptible pests with reduced insecticidal rates. EcoSyn has characterised interactions of novel synergists based on PBO (piperonyl butoxide) against known resistance-conferring P450/esterase proteins by both in vitro and in vivo assays. Candidate synergists have also been tested against pollinators and in long-term selection experiments to investigate changes in insect pest transcriptom

Evaluación sensorial de mieles Checas.

ÍNDICE Prólogo.Piana, Maria Lucia La denominación de origen geográfico "Miel Checa" utilizada por los apicultores checos. Bednár, Michal Evaluación sensorial de mieles checas.Bednár, Michal y Vit Olivier, Patricia Etiquetas de mieles checas.Bednár, Michal; Titera, Dalibor; Kamler, Frantiek y Vit Olivier, Patricia El sistema de certificación de mieles en el Instituto de Investigaciones Apícolas en Dol, para pequeños apicultores en la República Checa.Bednár, Michal; Vorechovská, Marcela y Titera, Dalibor Concurso de mieles checas 2006, para promover la calidad de la miel de abejas.Titera, Dalibor y Bednár, Michal Implicaciones de la cría de reinas y patología apícola en la calidad de la miel checa.Titera, Dalibor y Bednár, Michal Propuesta de certificaciones de calidad para servicio comunitario obligatorio de estudiantes de educación superior en Venezuela.González, Isbelia; Quintero, Fanny y Vit Olivier, Patricia Beneficios de una acreditación del laboratorio Ciencia de los Alimentos para el servicio de ingresos propios, motivada por la organización en BRI Dol.Santiago, Bertha; Quintero, Fanny; González, Isbelia y Vit Olivier, Patricia Actividad antioxidante total (AAT) de mieles checas.Gutiérrez, María Gabriela; Bednár, Michal; Titera, Dalibor; Rodríguez M., Antonio Jesús y Vit Olivier, Patricia Í[email protected]@[email protected]@cantv.net, [email protected] monográfico13-12-200

Heatmap summarising the relative density of dominant denaturing electrophoresis bands of the 16S rRNA amplicon profiles of the total gastrointestinal tract contents of several honey bee ontogenetic stages.

<p>1-, 3- and 6-day old larvae (L1, L3 and L6, respectively), white and black pupae (PW, PB), young bees, drones and flying bees (BY, DR and BF, respectively) collected in 4 different locations (Dol, Postrizin, Ustrasice, Hostice). Samples are sorted by ontogenetic stage (A) and location (B). The colours refer to relative band strength according to the colour key.</p

Boxplot of quantitative real-time PCR (qRT-PCR) data of the abundance of selected bacterial groups in pooled samples of total gastrointestinal tract of each honey bee ontogenetic stage.

<p>The Y axis shows log-transformed copies of the 16S rRNA gene per gram of honey bee gastrointestinal tract. Boxes show pooled data from 4 locations and 3 hives at each location. 1-, 3- and 6-day old larvae (L1, L3 and L6, respectively), white and black pupae (PW, PB), young bees, drones and flying bees (BY, DR and BF, respectively). The codes of the outliers refer to the location (Pos: Postrizin, Hos: Hostice, Ust: Ustrasice) and colony number (1, 2, 3).</p