scholarly journals Microbiome Structure Influences Infection by the Parasite Crithidia bombi in Bumble Bees

2018 ◽  
Vol 84 (7) ◽  
Author(s):  
Blair K. Mockler ◽  
Waldan K. Kwong ◽  
Nancy A. Moran ◽  
Hauke Koch
Keyword(s):  
Gut Microbiota ◽  
Bombus Terrestris ◽  
Bacterial Load ◽  
Bumble Bees ◽  
Bumble Bee ◽  
Bacterial Populations ◽  
Important Species ◽  
Content Type ◽  
Crithidia Bombi ◽  
Microbiome Diversity

ABSTRACT Recent declines in bumble bee populations are of great concern and have prompted critical evaluations of the role of pathogen introductions and host resistance in bee health. One factor that may influence host resilience when facing infection is the gut microbiota. Previous experiments with Bombus terrestris , a European bumble bee, showed that the gut microbiota can protect against Crithidia bombi , a widespread trypanosomatid parasite of bumble bees. However, the particular characteristics of the microbiome responsible for this protective effect have thus far eluded identification. Using wild and commercially sourced Bombus impatiens , an important North American pollinator, we conducted cross-wise microbiota transplants to naive hosts of both backgrounds and challenged them with a Crithidia parasite. As with B. terrestris , we find that microbiota-dependent protection against Crithidia operates in B. impatiens . Lower Crithidia infection loads were experimentally associated with high microbiome diversity, large gut bacterial populations, and the presence of Apibacter , Lactobacillus Firm-5, and Gilliamella spp. in the gut community. These results indicate that even subtle differences between gut community structures can have a significant impact on a microbiome's ability to defend against parasite infections. IMPORTANCE Many wild bumble bee populations are under threat due to human activity, including through the introduction of pathogens via commercially raised bees. Recently, it was found that the bumble bee gut microbiota can help defend against a common parasite, Crithidia bombi , but the particular factors contributing to this protection are unknown. Using both wild and commercially raised bees, we conducted microbiota transplants to show that microbiome diversity, total gut bacterial load, and the presence of certain core members of the microbiota may all impact bee susceptibility to Crithidia infection. Bee origin (genetic background) was also a factor. Finally, by examining this phenomenon in a previously uninvestigated bee species, our study demonstrates that microbiome-mediated resistance to Crithidia is conserved across multiple bumble bee species. These findings highlight how intricate interactions between hosts, microbiomes, and parasites can have wide-ranging consequences for the health of ecologically important species.

scholarly journals Activation of host constitutive immune defence by an intestinal trypanosome parasite of bumble bees

Parasitology ◽  
2003 ◽  
Vol 126 (3) ◽  
pp. 253-260 ◽  
Author(s):  
M. J. F. BROWN ◽  
Y. MORET ◽  
P. SCHMID-HEMPEL
Keyword(s):  
Immune System ◽  
Bombus Terrestris ◽  
Parasitic Infection ◽  
Bumble Bees ◽  
Host Immune System ◽  
Immune Defence ◽  
Important Species ◽  
Crithidia Bombi ◽  
Resource Stress ◽  
Host Parasite

Many parasites, including important species that affect humans and livestock, must survive the harsh environment of insect guts to complete their life-cycle. Hence, understanding how insects protect themselves against such parasites has immediate practical implications. Previously, such protection has been thought to consist mainly of mechanical structures and the action of lectins. However, recently it has become apparent that gut infections may interact with the host immune system in more complex ways. Here, using bumble bees, Bombus terrestris and their non-invasive gut trypanosome, Crithidia bombi, as a model system we investigated the effects of parasitic infection, host resources and the duration of infections on the host immune system. We found that infection doubled standing levels of immune defence in the haemolymph (the constitutive pro-phenoloxidase system), which is used as a first, general defence against parasites. However, physical separation of the parasite from the haemolymph suggests the presence of a messenger system between the gut and the genes that control the pro-phenoloxidase system. Surprisingly, we found no direct effect of host resource-stress or duration of the infection on the immune system. Our results suggest a novel and tactical response of insects to gut infections, demonstrating the complexity of such host–parasite systems.

scholarly journals No evidence of effects or interaction between the widely used herbicide, glyphosate, and a common parasite in bumble bees

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12486
Author(s):  
Edward A. Straw ◽  
Mark J.F. Brown
Keyword(s):  
Chronic Exposure ◽  
Multiple Stressors ◽  
Bombus Terrestris ◽  
Bumble Bees ◽  
Acute Exposure ◽  
Bumble Bee ◽  
Term Survival ◽  
Crithidia Bombi ◽  
Bee Health ◽  
Acute And Chronic Exposure

Background Glyphosate is the world’s most used pesticide and it is used without the mitigation measures that could reduce the exposure of pollinators to it. However, studies are starting to suggest negative impacts of this pesticide on bees, an essential group of pollinators. Accordingly, whether glyphosate, alone or alongside other stressors, is detrimental to bee health is a vital question. Bees are suffering declines across the globe, and pesticides, including glyphosate, have been suggested as being factors in these declines. Methods Here we test, across a range of experimental paradigms, whether glyphosate impacts a wild bumble bee species, Bombus terrestris. In addition, we build upon existing work with honey bees testing glyphosate-parasite interactions by conducting fully crossed experiments with glyphosate and a common bumble bee trypanosome gut parasite, Crithidia bombi. We utilised regulatory acute toxicity testing protocols, modified to allow for exposure to multiple stressors. These protocols are expanded upon to test for effects on long term survival (20 days). Microcolony testing, using unmated workers, was employed to measure the impacts of either stressor on a proxy of reproductive success. This microcolony testing was conducted with both acute and chronic exposure to cover a range of exposure scenarios. Results We found no effects of acute or chronic exposure to glyphosate, over a range of timespans post-exposure, on mortality or a range of sublethal metrics. We also found no interaction between glyphosate and Crithidia bombi in any metric, although there was conflicting evidence of increased parasite intensity after an acute exposure to glyphosate. In contrast to published literature, we found no direct impacts of this parasite on bee health. Our testing focussed on mortality and worker reproduction, so impacts of either or both of these stressors on other sublethal metrics could still exist. Conclusions Our results expand the current knowledge on glyphosate by testing a previously untested species, Bombus terrestris, using acute exposure, and by incorporating a parasite never before tested alongside glyphosate. In conclusion our results find that glyphosate, as an active ingredient, is unlikely to be harmful to bumble bees either alone, or alongside Crithidia bombi.

scholarly journals Olfactory coding in the antennal lobe of the bumble bee Bombus terrestris

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Marcel Mertes ◽  
Julie Carcaud ◽  
Jean-Christophe Sandoz
Keyword(s):  
Honey Bees ◽  
Antennal Lobe ◽  
Bombus Terrestris ◽  
Bumble Bees ◽  
Foraging Strategies ◽  
Bumble Bee ◽  
Carbon Chain Length ◽  
Olfactory Coding ◽  
Major Transitions

AbstractSociality is classified as one of the major transitions in evolution, with the largest number of eusocial species found in the insect order Hymenoptera, including the Apini (honey bees) and the Bombini (bumble bees). Bumble bees and honey bees not only differ in their social organization and foraging strategies, but comparative analyses of their genomes demonstrated that bumble bees have a slightly less diverse family of olfactory receptors than honey bees, suggesting that their olfactory abilities have adapted to different social and/or ecological conditions. However, unfortunately, no precise comparison of olfactory coding has been performed so far between honey bees and bumble bees, and little is known about the rules underlying olfactory coding in the bumble bee brain. In this study, we used in vivo calcium imaging to study olfactory coding of a panel of floral odorants in the antennal lobe of the bumble bee Bombus terrestris. Our results show that odorants induce reproducible neuronal activity in the bumble bee antennal lobe. Each odorant evokes a different glomerular activity pattern revealing this molecule’s chemical structure, i.e. its carbon chain length and functional group. In addition, pairwise similarity among odor representations are conserved in bumble bees and honey bees. This study thus suggests that bumble bees, like honey bees, are equipped to respond to odorants according to their chemical features.

scholarly journals Cross-infectivity of honey and bumble bee-associated parasites across three bee families

Parasitology ◽  
2020 ◽  
Vol 147 (12) ◽  
pp. 1290-1304 ◽  
Author(s):  
Lyna Ngor ◽  
Evan C. Palmer-Young ◽  
Rodrigo Burciaga Nevarez ◽  
Kaleigh A. Russell ◽  
Laura Leger ◽  
...  
Keyword(s):  
Experimental Tests ◽  
Bumble Bees ◽  
Floral Resources ◽  
Bumble Bee ◽  
Broad Host Range ◽  
Osmia Lignaria ◽  
Social Bees ◽  
Crithidia Bombi ◽  
Halictus Ligatus ◽  
Parasite Replication

AbstractRecent declines of wild pollinators and infections in honey, bumble and other bee species have raised concerns about pathogen spillover from managed honey and bumble bees to other pollinators. Parasites of honey and bumble bees include trypanosomatids and microsporidia that often exhibit low host specificity, suggesting potential for spillover to co-occurring bees via shared floral resources. However, experimental tests of trypanosomatid and microsporidial cross-infectivity outside of managed honey and bumble bees are scarce. To characterize potential cross-infectivity of honey and bumble bee-associated parasites, we inoculated three trypanosomatids and one microsporidian into five potential hosts – including four managed species – from the apid, halictid and megachilid bee families. We found evidence of cross-infection by the trypanosomatids Crithidia bombi and C. mellificae, with evidence for replication in 3/5 and 3/4 host species, respectively. These include the first reports of experimental C. bombi infection in Megachile rotundata and Osmia lignaria, and C. mellificae infection in O. lignaria and Halictus ligatus. Although inability to control amounts inoculated in O. lignaria and H. ligatus hindered estimates of parasite replication, our findings suggest a broad host range in these trypanosomatids, and underscore the need to quantify disease-mediated threats of managed social bees to sympatric pollinators.

scholarly journals Deep Sequencing Uncovers Caste-Associated Diversity of Symbionts in the Social Ant Camponotus japonicus

mBio ◽  
2020 ◽  
Vol 11 (2) ◽  
Author(s):  
Akiko Koto ◽  
Masaru Konishi Nobu ◽  
Ryo Miyazaki
Keyword(s):  
Gut Microbiota ◽  
Deep Sequencing ◽  
Social Insects ◽  
Rrna Gene ◽  
Bacterial Populations ◽  
Content Type ◽  
Carpenter Ant ◽  
And Behavior ◽  
Lineage Divergence ◽  
Camponotus Japonicus

ABSTRACT Symbiotic microorganisms can have a profound impact on the host physiology and behavior, and novel relationships between symbionts and their hosts are continually discovered. A colony of social ants consists of various castes that exhibit distinct lifestyles and is, thus, a unique model for investigating how symbionts may be involved in host eusociality. Yet our knowledge of social ant-symbiont dynamics has remained rudimentary. Through 16S rRNA gene deep sequencing of the carpenter ant Camponotus japonicus symbiont community across various castes, we here report caste-dependent diversity of commensal gut microbiota and lineage divergence of “Candidatus Blochmannia,” an obligate endosymbiont. While most prevalent gut-associated bacterial populations are found across all castes (Alphaproteobacteria, Gammaproteobacteria, Bacteroidetes, and Cyanobacteria), we also discovered uncultured populations that are found only in males (belonging to Corynebacteriales, Alkanindiges, and Burkholderia). Most of those populations are not detected in laboratory-maintained queens and workers, suggesting that they are facultative gut symbionts introduced via environmental acquisition. Further inspection of “Ca. Blochmannia” endosymbionts reveals that two populations are dominant in all individuals across all castes but that males preferentially contain two different sublineages that are diversified from others. Clearly, each caste has distinct symbiont communities, suggesting an overlooked biological aspect of host-symbiont interaction in social insects. IMPORTANCE Social animals, such as primates and some insects, have been shown to exchange symbiotic microbes among individuals through sharing diet or habitats, resulting in increased consistency of microbiota among social partners. The ant is a representative of social insects exhibiting various castes within a colony; queens, males, and nonreproductive females (so-called workers) show distinct morphologies, physiologies, and behaviors but tightly interact with each other in the nest. However, how this social context affects their gut microbiota has remained unclear. In this study, we deeply sequenced the gut symbiont community across various castes of the carpenter ant Camponotus japonicus. We report caste-dependent diversity of commensal gut microbial community and lineage divergence of the mutualistic endosymbiont “Candidatus Blochmannia.” This report sheds light on the hidden diversity in microbial populations and community structure associated with guts of males in social ants.

scholarly journals Bumble bees (Hymenoptera: Apidae: Bombus terrestris) collecting honeydew from the giant willow aphid (Hemiptera: Aphididae)

2019 ◽  
Vol 68 ◽  
pp. 75-83 ◽  
Author(s):  
Sydney A. Cameron ◽  
Sarah A. Corbet ◽  
James B. Whitfield
Keyword(s):  
Leaf Litter ◽  
Bombus Terrestris ◽  
Bumble Bees ◽  
Bumble Bee ◽  
Ambient Conditions ◽  
Floral Nectar ◽  
Phloem Sap ◽  
Evaporative Concentration ◽  
Large Numbers ◽  
Leaf Surfaces

Only rarely have bumble bees (Bombus) been observed collecting honeydew from aphids (Aphididae) feeding on phloem sap. This behavior may be rare because the percentage of sugar in honeydew egested from aphids is generally well below the sugar concentration in floral nectars preferred by bumble bees. Nonetheless, in August 2018, near St. Buryan, Penzance, Cornwall, UK (56.0602N; -5.6034W) we observed large numbers of wild Bombusterrestris (Linnaeus) collecting honeydew from a colony of the giant willow aphid Tuberolachnussalignus Gmelin feeding on the stems of the willow Salixalba. Unlike aphid-tending ants, who glean fresh honeydew directly from the aphid anal opening, the bumble bees were collecting honeydew from leaf litter below the aphid colony. We hypothesized that honeydew collected from exposed ground surfaces was more concentrated due to evaporation under ambient conditions than that released directly from the anus (fresh honeydew). We thus monitored sugar concentrations of fresh honeydew and compared them with the concentrations of the crop contents of worker bumble bees foraging from the leaf litter. Our data show that the concentration of sugar in fresh honeydew was as much as 10% w/w lower than that collected from leaf surfaces, as measured from the crop contents of foragers. The unusually hot, dry weather in Cornwall may have enhanced evaporative concentration of honeydew while restricting floral nectar sources, thus favoring honeydew collection by B.terrestris, a generalist bumble bee forager.

scholarly journals Dynamic Change of Gut Microbiota in the Male Bee of Bombus terrestris (Hymenoptera: Apidae)

2021 ◽  
Vol 13 (9) ◽  
pp. 163
Author(s):  
Kai Li ◽  
Liuhao Wang ◽  
Zhengyi Zhang ◽  
Yulong Guo ◽  
Jun Guo ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Bombus Terrestris ◽  
Dynamic Change ◽  
Reproductive Activity ◽  
Gut Bacteria ◽  
Bumble Bees ◽  
Reproductive Capacity ◽  
Developmental Age ◽  
The Relationship ◽  
Total Bacteria

The gut microbiota plays a key role in the development and health of bumble bees. Male bees are important for the reproductive activity of a colony, yet there are few studies on their gut microbiota. By using qPCR, we found that significant changes in total bacteria and six important bacteria genera from different developmental age points in males. And we compare the gut bacteria of male bees with workers. The results indicate that Gilliamella, Snodgrassella, and Lactobacillus are the dominant gut bacteria in male bees, which is consistent with the previous studies in worker bees, however, there are more total bacteria in male bees. Another gut bacteria genus, Bacillus may be a probiotic bacteria for reproduction in male bees, although the possible function of these bacteria require further study. This research can provide insight into the relationship between the bacterial community and the physiological health and reproductive capacity of male bumble bees.

scholarly journals Antibiotic-Induced Alterations of the Murine Gut Microbiota and Subsequent Effects on Colonization Resistance against Clostridium difficile

mBio ◽  
2015 ◽  
Vol 6 (4) ◽  
Author(s):  
Alyxandria M. Schubert ◽  
Hamide Sinani ◽  
Patrick D. Schloss
Keyword(s):  
Clostridium Difficile ◽  
Gut Microbiota ◽  
Normal Structure ◽  
The United States ◽  
Context Dependency ◽  
Dependent Manner ◽  
Colonization Resistance ◽  
Bacterial Populations ◽  
Content Type ◽  
Antibiotic Perturbations

ABSTRACTPerturbations to the gut microbiota can result in a loss of colonization resistance against gastrointestinal pathogens such asClostridium difficile. AlthoughC. difficileinfection is commonly associated with antibiotic use, the precise alterations to the microbiota associated with this loss in function are unknown. We used a variety of antibiotic perturbations to generate a diverse array of gut microbiota structures, which were then challenged withC. difficilespores. Across these treatments we observed thatC. difficileresistance was never attributable to a single organism, but rather it was the result of multiple microbiota members interacting in a context-dependent manner. Using relative abundance data, we built a machine learning regression model to predict the levels ofC. difficilethat were found 24 h after challenging the perturbed communities. This model was able to explain 77.2% of the variation in the observed number ofC. difficileper gram of feces. This model revealed important bacterial populations within the microbiota, which correlation analysis alone did not detect. Specifically, we observed that populations associated with thePorphyromonadaceae,Lachnospiraceae,Lactobacillus, andAlistipeswere protective and populations associated withEscherichiaandStreptococcuswere associated with high levels of colonization. In addition, a population affiliated with theAkkermansiaindicated a strong context dependency on other members of the microbiota. Together, these results indicate that individual bacterial populations do not drive colonization resistance toC. difficile. Rather, multiple diverse assemblages act in concert to mediate colonization resistance.IMPORTANCEThe gastrointestinal tract harbors a complex community of bacteria, known as the microbiota, which plays an integral role preventing its colonization by gut pathogens. This resistance has been shown to be crucial for protection againstClostridium difficileinfections (CDI), which are the leading source of hospital-acquired infections in the United States. Antibiotics are a major risk factor for acquiring CDI due to their effect on the normal structure of the indigenous gut microbiota. We found that diverse antibiotic perturbations gave rise to altered communities that varied in their susceptibility toC. difficilecolonization. We found that multiple coexisting populations, not one specific population of bacteria, conferred resistance. By understanding the relationships betweenC. difficileand members of the microbiota, it will be possible to better manage this important infection.

scholarly journals Whole-Cell Screen of Fragment Library Identifies Gut Microbiota Metabolite Indole Propionic Acid as Antitubercular

2017 ◽  
Vol 62 (3) ◽  
Author(s):  
Dereje A. Negatu ◽  
Joe J. J. Liu ◽  
Matthew Zimmerman ◽  
Firat Kaya ◽  
Véronique Dartois ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Molecular Mass ◽  
Propionic Acid ◽  
Bacterial Load ◽  
Cell Activity ◽  
Antitubercular Activity ◽  
Whole Cell ◽  
Content Type ◽  
Dependent Growth

ABSTRACT Several key antituberculosis drugs, including pyrazinamide, with a molecular mass of 123.1 g/mol, are smaller than the usual drug-like molecules. Current drug discovery efforts focus on the screening of larger compounds with molecular masses centered around 400 to 500 g/mol. Fragment (molecular mass < 300 g/mol) libraries have not been systematically explored for antitubercular activity. Here we screened a collection of 1,000 fragments, present in the Maybridge Ro3 library, for whole-cell activity against Mycobacterium tuberculosis . Twenty-nine primary hits showed dose-dependent growth inhibition equal to or better than that of pyrazinamide. The most potent hit, indole propionic acid [IPA; 3-(1 H -indol-3-yl)propanoic acid], a metabolite produced by the gut microbiota, was profiled in vivo . The molecule was well tolerated in mice and showed adequate pharmacokinetic properties. In a mouse model of acute M. tuberculosis infection, IPA reduced the bacterial load in the spleen 7-fold. Our results suggest that IPA should be evaluated as an add-on to current regimens and that fragment libraries should be further explored to identify antimycobacterial lead candidates.

Sign in / Sign up

Export Citation Format

Share Document