Beneficial microorganisms for honey bees health

Honeybees (Apis mellifera and other species) are considered as the most economically important insect species for humans and the ecosystems, not only as honey producers but also and especially as pollinators of agricultural, horticultural crops and wild plants, contributing at the pollination of 35% of the global food production. Unfortunately, honeybee decline started about 30 years ago, with the arrival from Asia of the bee mite Varroa destructor. Since then, honeybees have been damaged by different kinds of biotic and abiotic stressor factors, cumulating any kind of damages, and posing a serious threat to the agricultural field. Many scientists agree that bee decline is a multifactorial process in which a mechanism seems to be more important in a given period of the year than in another, and different mechanisms may predominate in another period or in other environments. Of those multifactorial processes, leading factors are the new emergent pathogens, such as Nosema ceranae a gut pathogen causing serious threat to bees and the consequent death of the colony; Pesticides and other environmental stress factors are furthering enhancing the high pathogenicity on bees, weakening more and more the delicate beehive superorganism balance. The major science concern about the bees usually regards the study of the bee pathogens and their interaction with an increasingly anthropized environment (e.g.: pollution and sub lethal poisonings). Only few research projects (of high scientific importance) have been carried out using an approach aimed to fix the problems linked with it. Even less are the researches investigating probiotic microorganisms as growth promoter, in order to obtain a better wealth and wellbeing of the bees. In the light of these possibilities the aim of my research is the development of -environmental friendly- microbial technologies aimed to increase the health of the bees

Bifidobacterium xylocopae sp. nov. and Bifidobacterium aemilianum sp. nov., from the carpenter bee (Xylocopa violacea) digestive tract

Social bees harbor a community of gut mutualistic bacteria, among which bifidobacteria occupy an important niche. Recently, four novel species have been isolated from guts of different bumblebees, thus allowing to suppose that a core bifidobacterial population may be present in wild solitary bees. To date there is sparse information about bifidobacteria in solitary bees such as Xylocopa and Osmia spp., this study is therefore focused on the isolation and characterization of bifidobacterial strains from solitary bees, in particular carpenter bee (Xylocopa violacea), builder bee (Osmia cornuta), and red mason bee (Osmia rufa). Among the isolates from Osmia spp. no new species have been detected whereas among Xylocopa isolates four strains (XV2, XV4, XV10, XV16) belonging to putative new species were found. Isolated strains are Gram-positive, lactate- and acetate-producing and possess the fructose-6-phosphate phosphoketolase enzyme. Full genome sequencing and genome annotation were performed for XV2 and XV10. Phylogenetic relationships were determined using partial and complete 16S rRNA sequences and hsp60 restriction analysis that confirmed the belonging of the new strains to Bifidobacterium genus and the relatedness of the strains XV2 and XV10 with XV16 and XV4, respectively. Phenotypic tests were performed for the proposed type strains, reference strains and their closest neighbor in the phylogenetic tree. The results support the proposal of two novel species Bifidobacterium xylocopae sp. nov. whose type strain is XV2 (=DSM 104955T = LMG 30142T), reference strain XV16 and Bifidobacterium aemilianum sp. nov. whose type strain is XV10 (=DSM 104956T = LMG 30143T), reference strain XV4

Combined effect of a neonicotinoid insecticide and a fungicide on honeybee gut epithelium and microbiota, adult survival, colony strength and foraging preferences

Fungicides, insecticides and herbicides are widely used in agriculture to counteract pathogens and pests. Several of these molecules are toxic to non-target organisms such as pollinators and their lethal dose can be lowered if applied as a mixture. They can cause large and unpredictable problems, spanning from behavioural changes to alterations in the gut. The present work aimed at understanding the synergistic effects on honeybees of a combined in-hive exposure to sub-lethal doses of the insecticide thiacloprid and the fungicide penconazole. A multidisciplinary approach was used: honeybee mortality upon exposure was initially tested in cage, and the colonies development monitored. Morphological and ultrastructural analyses via light and transmission electron microscopy were carried out on the gut of larvae and forager honeybees. Moreover, the main pollen foraging sources and the fungal gut microbiota were studied using Next Generation Sequencing; the gut core bacterial taxa were quantified via qPCR. The mortality test showed a negative effect on honeybee survival when exposed to agrochemicals and their mixture in cage but not confirmed at colony level. Microscopy analyses on the gut epithelium indicated no appreciable morphological changes in larvae, newly emerged and forager honeybees exposed in field to the agrochemicals. Nevertheless, the gut microbial profile showed a reduction of Bombilactobacillus and an increase of Lactobacillus and total fungi upon mixture application. Finally, we highlighted for the first time a significant honeybee diet change after pesticide exposure: penconazole, alone or in mixture, significantly altered the pollen foraging preference, with honeybees preferring Hedera pollen. Overall, our in-hive results showed no severe effects upon administration of sublethal doses of thiacloprid and penconazole but indicate a change in honeybees foraging preference. A possible explanation can be that the different nutritional profile of the pollen may offer better recovery chances to honeybees

Environment or genetic isolation? An atypical intestinal microbiota in the Maltese honeybee Apis mellifera spp. ruttneri

Apis mellifera evolved mainly in African, Asian and European continents over thousands of years, leading to the selection of a considerable number of honey bees subspecies that have adapted to various environments such as hot semi-desert zones and cold temperate zones. With the evolution of honey bee subspecies, it is possible that environmental conditions, food sources and microbial communities typical of the colonised areas have shaped the honey bee gut microbiota. In this study the microbiota of two distinct lineages (mitochondrial haplotypes) of bees Apis mellifera ruttneri (lineage A) and Apis mellifera ligustica and carnica (both lineage C) were compared. Honey bee guts were collected in a dry period in the respective breeding areas (the island of Malta and the regions of Emilia-Romagna and South Tyrol in Italy). Microbial DNA from the honey bee gut was extracted and amplified for the V3-V4 regions of the 16S rRNA gene for bacteria and for ITS2 for fungi. The analyses carried out show that the Maltese lineage A honey bees have a distinctive microbiota when compared to Italian lineage C honey bees, with the most abundant genera being Bartonellaceae and Lactobacillaceae, respectively. Lactobacillaceae in Maltese Lineage A honey bees consist mainly of Apilactobacillus instead of Lactobacillus and Bombilactobacillus in the lineage C. Lineage A honey bee gut microbiota also harbours higher proportions of Arsenophonus, Bombella, Commensalibacter and Pseudomonas when compared to lineage C. The environment seems to be the main driver in the acquisition of these marked differences in the gut microbiota . However, the influence of other factors such as host genetics, seasonality or geography may still play a significant role in the microbiome shaping, in synergy with the environmental aspects

First record of Leptus spp. (Acari: Erythraeidae) parasitizing stingless bees (Apidae: Meliponini)

The first occurrence of Leptus mites parasitizing different species of stingless bees is reported. The samples were collected in the Argentinian province of Misiones on flowers and managed stingless bee colonies. Although the frequency registered was very low, the current report is relevant as it will drive research efforts on the understanding of parasite-host dynamics, consequences at the community level, and disease management in wild and productive contexts.Fil: Martínez, Pablo Antonio. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Biología; ArgentinaFil: Alvarez, Leopoldo Jesús. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Entomología; ArgentinaFil: Garrido, Paula Melisa. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones en Sanidad Producción y Ambiente. - Comisión de Investigaciones Científicas de la Provincia de Buenos Aires. Instituto de Investigaciones en Sanidad Producción y Ambiente; ArgentinaFil: Porrini, Darío Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Provincia de Buenos Aires. Municipalidad de General Pueyrredon. Secretaría de Cultura. Museo Municipal de Ciencias Naturales Lorenzo Scaglia; ArgentinaFil: Muller, Pablo Fernando. Instituto Superior de Formacion Docente Profesorado En Ciencias Agrarias y Proteccion Ambiental.; ArgentinaFil: Alberoni, Daniele. Universidad de Bologna; ItaliaFil: Porrini, Martín Pablo. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones en Sanidad Producción y Ambiente. - Comisión de Investigaciones Científicas de la Provincia de Buenos Aires. Instituto de Investigaciones en Sanidad Producción y Ambiente; Argentin

Investigations on the gut microbiota of the Maltese honeybee (Apis mellifera ruttneri)

In this study, the gut microbiota of Apis mellifera ruttneri was studied through microbial dependent and independent techniques, hypothesising particular distinctive differences from the rest of the European honeybees.peer-reviewe

Investigations on the gut microbiota of the Maltese honeybee (Apis mellifera ruttneri)

In this study, the gut microbiota of Apis mellifera ruttneri was studied through microbial dependent and independent techniques, hypothesising particular distinctive differences from the rest of the European honeybees.peer-reviewe

Honeybee (Apis mellifera) gut microbiota shaping post medicaments oral administration

In the last decades, honeybees have been afflicted by several gut diseases such as the American Foulbrood (caused by Paenibacillus larvae), the European Foulbrood (Melissococcus plutonius) and Nosemosis (Nosema ceranae). The virulence of these diseases is enhanced by synergy with abiotic stressors such as climate change, causing noteworthy losses in honeybee colonies and consequitively honey production.peer-reviewe

Beneficial Bacteria and Plant Extracts Promote Honey Bee Health and Reduce Nosema ceranae Infection

The research aims to give new insights on the effect of administering selected bacterial strains, isolated from honey bee gut, and/or a commercial plant extract blend ( HiveAlive®) on Nosema ceranae. Analyses were first performed under laboratory conditions such as different infective doses of N. ceranae, the effect of single strains and their mixture and the influence of pollen administration. Daily survival and feed consumption rate were recorded and pathogen development was analysed using qPCR and microscope counts. Biomarkers of immunity and physiological status were also evaluated for the different treatments tested using one bacterial strain, a mixture of all the bacteria and/or a plant extract blend as treatments. The results showed an increase of abaecin transcript levels in the midgut of the honey bees treated with the bacterial mixture and an increased expression of the protein vitellogenin in the haemolymph of honey bees treated with two separate bacterial strains (Bifidobacterium coryneforme and Apilactobacillus kunkeei). A significant effectiveness in reducing N. ceranae was shown by the bacterial mixture and the plant extract blend regardless of the composition of the diet. This bioactivity was seasonally linked. Quantitative PCR and microscope counts showed the reduction of N. ceranae under different experimental conditions. The antiparasitic efficacy of the treatments at field conditions was studied using a semi-field approach which was adapted from research on insecticides for the first time, to analyse antiparasitic activity against N. ceranae. The approach proved to be reliable and effective in validating data obtained in the laboratory. Both the mixture of beneficial bacteria and its association with Hive Alive ® are effective in controlling the natural infection of N. ceranae in honey bee colonies.peer-reviewe

Spatio-Temporal Features of Visual Exploration in Unilaterally Brain-Damaged Subjects with or without Neglect: Results from a Touchscreen Test

Cognitive assessment in a clinical setting is generally made by pencil-and-paper tests, while computer-based tests enable the measurement and the extraction of additional performance indexes. Previous studies have demonstrated that in a research context exploration deficits occur also in patients without evidence of unilateral neglect at pencil-and-paper tests. The objective of this study is to apply a touchscreen-based cancellation test, feasible also in a clinical context, to large groups of control subjects and unilaterally brain-damaged patients, with and without unilateral spatial neglect (USN), in order to assess disturbances of the exploratory skills. A computerized cancellation test on a touchscreen interface was used for assessing the performance of 119 neurologically unimpaired control subjects and 193 patients with unilateral right or left hemispheric brain damage, either with or without USN. A set of performance indexes were defined including Latency, Proximity, Crossings and their spatial lateral gradients, and Preferred Search Direction. Classic outcome scores were computed as well. Results show statistically significant differences among groups (assumed p<0.05). Right-brain-damaged patients with USN were significantly slower (median latency per detected item was 1.18 s) and less efficient (about 13 search-path crossings) in the search than controls (median latency 0.64 s; about 3 crossings). Their preferred search direction (53.6% downward, 36.7% leftward) was different from the one in control patients (88.2% downward, 2.1% leftward). Right-brain-damaged patients without USN showed a significantly abnormal behavior (median latency 0.84 s, about 5 crossings, 83.3% downward and 9.1% leftward direction) situated half way between controls and right-brain-damaged patients with USN. Left-brain-damaged patients without USN were significantly slower and less efficient than controls (latency 1.19 s, about 7 crossings), preserving a normal preferred search direction (93.7% downward). Therefore, the proposed touchscreen-based assessment had evidenced disorders in spatial exploration also in patients without clinically diagnosed USN