scholarly journals Species Identity, Life History, and Geographic Distance Influence Gut Bacterial Communities in Lab-Reared and European Field-Collected Culicoides Biting midges

2021 ◽  
Author(s):  
Tim W. R. Möhlmann ◽  
Cajo J. F. ter Braak ◽  
Dennis E. te Beest ◽  
Marc Hendriks ◽  
Els H. Nijhuis ◽  
...  
Keyword(s):  
Bacterial Communities ◽  
Vector Competence ◽  
Bacterial Species ◽  
Geographic Distance ◽  
Limited Information ◽  
Wildlife Diseases ◽  
Species Identity ◽  
Biting Midges ◽  
Biting Midge ◽  
Insect Gut

AbstractBacteria are part of the insect gut system and influence many physiological traits of their host. Gut bacteria may even reduce or block the transmission of arboviruses in several species of arthropod vectors. Culicoides biting midges are important arboviral vectors of several livestock and wildlife diseases, yet limited information is available on their gut bacterial communities. Addressing this gap will help inform how these communities can be manipulated and ultimately used as novel tools to control pathogens. To assess how bacterial communities change during the life stages of lab-reared C. nubeculosus and C. sonorensis, endosymbiotic bacteria were identified using Illumina sequencing of 16S rRNA and taxonomically characterised. Analyses were conducted to determine how gut bacterial communities in adults are influenced by species identity and geographic distance among biting midge populations. Communities of the two lab-reared Culicoides species significantly changed after pupation and with maturation into 6-day-old adults. Pseudomonas, Burkholderiaceae and Leucobacter bacteria were part of a core community that was trans-stadially transmitted and found throughout their life cycle. Among field-collected biting midges, the bacterial communities were unique for almost each species. Cardinium, Rickettsia and Wolbachia were some of the most abundant bacteria in midges collected from wetlands. Only Pseudomonas was present in high relative abundance in all field-collected species. In this study, species identity, as well as geographic distance, influenced the gut bacterial communities and may partly explain known inter- and intra-species variability in vector competence. Additionally, stably associated bacterial species could be candidates for paratransgenic strategies to control vector-borne pathogens.

Complete sporogony of the blood parasite Haemoproteus nucleocondensus in common biting midges: why is its transmission interrupted in Europe?

Parasitology ◽  
2020 ◽  
Vol 147 (5) ◽  
pp. 593-600
Author(s):  
Rita Žiegytė ◽  
Elena Platonova ◽  
Rasa Bernotienė ◽  
Gediminas Valkiūnas ◽  
Vaidas Palinauskas
Keyword(s):  
Ecological Factors ◽  
Great Majority ◽  
Point Of View ◽  
Blood Parasites ◽  
Acrocephalus Arundinaceus ◽  
Species Identity ◽  
Biting Midges ◽  
Breeding Sites ◽  
Biting Midge ◽  
Average Temperature

AbstractHaemoproteus species (Haemoproteidae) are widespread blood parasites and are transmitted by Culicoides biting midges and Hippoboscidae louse flies. Although these pathogens may cause morbidity or mortality, the vectors and patterns of transmission remain unknown for the great majority of avian haemoproteids. Haemoproteus nucleocondensus has been frequently reported in Europe in great reed warblers Acrocephalus arundinaceus after their arrival from African wintering grounds, but this infection has not been found in juveniles at the breeding sites. The factors that prevent its transmission remain unclear. This study was designed to test whether the sporogony of H. nucleocondensus (lineage hGRW8) can be completed in Culicoides impunctatus, one of the most abundant European biting midge species. Wild-caught females were infected with H. nucleocondensus from great reed warblers. Microscopic examination and PCR-based methods were used to detect sporogonic stages and to confirm species identity. This study showed that H. nucleocondensus completes sporogony in C. impunctatus, suggesting that there are no obstacles to its transmission from the point of view of vector availability and average temperature in Northern Europe. We discuss other ecological factors which should be considered to explain why the transmission of H. nucleocondensus and some other Southern origin haemosporidians are interrupted in North Europe.

Integration of culture-dependent and independent methods provides a more coherent picture of the pig gut microbiome

2020 ◽  
Vol 96 (3) ◽  
Author(s):  
Gavin J Fenske ◽  
Sudeep Ghimire ◽  
Linto Antony ◽  
Jane Christopher-Hennings ◽  
Joy Scaria
Keyword(s):  
Bacterial Communities ◽  
Bacterial Species ◽  
Shotgun Metagenomics ◽  
Culture Techniques ◽  
Microbiome Composition ◽  
Culture Independent ◽  
Health And Disease ◽  
The Media ◽  
And Function ◽  
Culture Dependent

ABSTRACT Bacterial communities resident in the hindgut of pigs, have profound impacts on health and disease. Investigations into the pig microbiome have utilized either culture-dependent, or far more commonly, culture-independent techniques using next generation sequencing. We contend that a combination of both approaches generates a more coherent view of microbiome composition. In this study, we surveyed the microbiome of Tamworth breed and feral pigs through the integration high throughput culturing and shotgun metagenomics. A single culture medium was used for culturing. Selective screens were added to the media to increase culture diversity. In total, 46 distinct bacterial species were isolated from the Tamworth and feral samples. Selective screens successfully shifted the diversity of bacteria on agar plates. Tamworth pigs are highly dominated by Bacteroidetes primarily composed of the genus Prevotella whereas feral samples were more diverse with almost equal proportions of Firmicutes and Bacteroidetes. The combination of metagenomics and culture techniques facilitated a greater retrieval of annotated genes than either method alone. The single medium based pig microbiota library we report is a resource to better understand pig gut microbial ecology and function. It allows for assemblage of defined bacterial communities for studies in bioreactors or germfree animal models.

scholarly journals Rhizobacterial communities of five co-occurring desert halophytes

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5508 ◽  
Author(s):  
Yan Li ◽  
Yan Kong ◽  
Dexiong Teng ◽  
Xueni Zhang ◽  
Xuemin He ◽  
...  
Keyword(s):  
Bacterial Community ◽  
Community Composition ◽  
Plant Species ◽  
Bacterial Communities ◽  
Bacterial Community Composition ◽  
Community Diversity ◽  
Species Identity ◽  
Halostachys Caspica ◽  
Lycium Ruthenicum ◽  
Limonium Gmelinii

BackgroundRecently, researches have begun to investigate the microbial communities associated with halophytes. Both rhizobacterial community composition and the environmental drivers of community assembly have been addressed. However, few studies have explored the structure of rhizobacterial communities associated with halophytic plants that are co-occurring in arid, salinized areas.MethodsFive halophytes were selected for study: these co-occurred in saline soils in the Ebinur Lake Nature Reserve, located at the western margin of the Gurbantunggut Desert of Northwestern China. Halophyte-associated bacterial communities were sampled, and the bacterial 16S rDNA V3–V4 region amplified and sequenced using the Illumina Miseq platform. The bacterial community diversity and structure were compared between the rhizosphere and bulk soils, as well as among the rhizosphere samples. The effects of plant species identity and soil properties on the bacterial communities were also analyzed.ResultsSignificant differences were observed between the rhizosphere and bulk soil bacterial communities. Diversity was higher in the rhizosphere than in the bulk soils. Abundant taxonomic groups (from phylum to genus) in the rhizosphere were much more diverse than in bulk soils. Proteobacteria, Firmicutes, Actinobacteria, Bacteroidetes and Planctomycetes were the most abundant phyla in the rhizosphere, while Proteobacteria and Firmicutes were common in bulk soils. Overall, the bacterial community composition were not significantly differentiated between the bulk soils of the five plants, but community diversity and structure differed significantly in the rhizosphere. The diversity ofHalostachys caspica,Halocnemum strobilaceumandKalidium foliatumassociated bacterial communities was lower than that ofLimonium gmeliniiandLycium ruthenicumcommunities. Furthermore, the composition of the bacterial communities ofHalostachys caspicaandHalocnemum strobilaceumwas very different from those ofLimonium gmeliniiandLycium ruthenicum. The diversity and community structure were influenced by soil EC, pH and nutrient content (TOC, SOM, TON and AP); of these, the effects of EC on bacterial community composition were less important than those of soil nutrients.DiscussionHalophytic plant species played an important role in shaping associated rhizosphere bacterial communities. When salinity levels were constant, soil nutrients emerged as key factors structuring bacterial communities, while EC played only a minor role. Pairwise differences among the rhizobacterial communities associated with different plant species were not significant, despite some evidence of differentiation. Further studies involving more halophyte species, and individuals per species, are necessary to elucidate plant species identity effects on the rhizosphere for co-occurring halophytes.

scholarly journals Bifidobacterium adolescentis shows potential to strengthen host defence against gastrointestinal infection via inhibition of the opportunistic pathogen Candida albicans and stimulation of human-isolated macrophages killing capacity in vitro

2020 ◽  
Vol 2 (7A) ◽  
Author(s):  
Liviana Ricci ◽  
Joanna Mackie ◽  
Megan D. Lenardon ◽  
Caitlin Jukes ◽  
Ahmed N. Hegazy ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Bacterial Species ◽  
Opportunistic Pathogen ◽  
Limited Information ◽  
Human Gut ◽  
Bifidobacterium Adolescentis ◽  
Host Immune Responses ◽  
Opportunistic Fungal Pathogen ◽  
Antimicrobial Metabolites

The human gut microbiota enhances the host’s resistance to enteric pathogens via colonisation resistance, a phenomenon that is driven by multiple mechanisms, such as production of antimicrobial metabolites and activation of host immune responses. However, there is limited information on how individual gut bacterial species, particularly many of the dominant anaerobes, might impact the host’s defence. This study investigated the potential of specific human gut isolates to bolster the host’s resistance to infection. First, by antagonising the opportunistic fungal pathogen Candida albicans, and secondly, by modulating the killing capacity of human-isolated macrophages in vitro. Co-culturing C. albicans with faecal microbiota from different healthy individuals revealed varying levels of fungal inhibition. In vitro assays with a panel of representative human gut anaerobes confirmed that culture supernatants from certain bacterial isolates, in particular of Bifidobacterium adolescentis, significantly inhibited C. albicans growth. Mechanistic studies revealed that microbial fermentation acids including acetate and lactate, in combination with the associated decrease in pH, were strong drivers of this inhibitory activity. In the second in vitro assay, human-isolated macrophages were exposed to bacterial supernatants, and subsequently tested for their capacity to eliminate adherent-invasive Escherichia coli. Among the gut anaerobes tested, B. adolescentis was revealed to exert the strongest immunostimulatory and killing effect when compared to the unstimulated macrophages control. B. adolescentis is known to be stimulated by dietary consumption of resistant starch andmay therefore represent an attractive target for the development of probiotic and prebiotic interventions tailored to enhancethe host’s natural defences against infection.

scholarly journals Linearmycins Activate a Two-Component Signaling System Involved in Bacterial Competition and Biofilm Morphology

2017 ◽  
Vol 199 (18) ◽  
Author(s):  
Reed M. Stubbendieck ◽  
Paul D. Straight
Keyword(s):  
Antibiotic Resistance ◽  
Abc Transporter ◽  
Bacterial Communities ◽  
Biofilm Formation ◽  
Bacterial Species ◽  
Bioactive Metabolites ◽  
Signaling System ◽  
Content Type ◽  
Two Component ◽  
Analytical Approaches

ABSTRACT Bacteria use two-component signaling systems to adapt and respond to their competitors and changing environments. For instance, competitor bacteria may produce antibiotics and other bioactive metabolites and sequester nutrients. To survive, some species of bacteria escape competition through antibiotic production, biofilm formation, or motility. Specialized metabolite production and biofilm formation are relatively well understood for bacterial species in isolation. How bacteria control these functions when competitors are present is not well studied. To address fundamental questions relating to the competitive mechanisms of different species, we have developed a model system using two species of soil bacteria, Bacillus subtilis and Streptomyces sp. strain Mg1. Using this model, we previously found that linearmycins produced by Streptomyces sp. strain Mg1 cause lysis of B. subtilis cells and degradation of colony matrix. We identified strains of B. subtilis with mutations in the two-component signaling system yfiJK operon that confer dual phenotypes of specific linearmycin resistance and biofilm morphology. We determined that expression of the ATP-binding cassette (ABC) transporter yfiLMN operon, particularly yfiM and yfiN, is necessary for biofilm morphology. Using transposon mutagenesis, we identified genes that are required for YfiLMN-mediated biofilm morphology, including several chaperones. Using transcriptional fusions, we found that YfiJ signaling is activated by linearmycins and other polyene metabolites. Finally, using a truncated YfiJ, we show that YfiJ requires its transmembrane domain to activate downstream signaling. Taken together, these results suggest coordinated dual antibiotic resistance and biofilm morphology by a single multifunctional ABC transporter promotes competitive fitness of B. subtilis. IMPORTANCE DNA sequencing approaches have revealed hitherto unexplored diversity of bacterial species in a wide variety of environments that includes the gastrointestinal tract of animals and the rhizosphere of plants. Interactions between different species in bacterial communities have impacts on our health and industry. However, many approaches currently used to study whole bacterial communities do not resolve mechanistic details of interspecies interactions, including how bacteria sense and respond to their competitors. Using a competition model, we have uncovered dual functions for a previously uncharacterized two-component signaling system involved in specific antibiotic resistance and biofilm morphology. Insights gleaned from signaling within interspecies interaction models build a more complete understanding of gene functions important for bacterial communities and will enhance community-level analytical approaches.

Symbiotic bacteria of helminths: what role may they play in ecosystems under anthropogenic stress?

2016 ◽  
Vol 90 (6) ◽  
pp. 647-657 ◽  
Author(s):  
N.J. Morley
Keyword(s):  
Climate Change ◽  
Environmental Stress ◽  
Bacterial Communities ◽  
Bacterial Species ◽  
Symbiotic Bacteria ◽  
Anthropogenic Pressure ◽  
Anthropogenic Stress ◽  
Similar Function ◽  
Free Living ◽  
Terrestrial Habitats

AbstractSymbiotic bacteria are a common feature of many animals, particularly invertebrates, from both aquatic and terrestrial habitats. These bacteria have increasingly been recognized as performing an important role in maintaining invertebrate health. Both ecto- and endoparasitic helminths have also been found to harbour a range of bacterial species which provide a similar function. The part symbiotic bacteria play in sustaining homeostasis of free-living invertebrates exposed to anthropogenic pressure (climate change, pollution), and the consequences to invertebrate populations when their symbionts succumb to poor environmental conditions, are increasingly important areas of research. Helminths are also susceptible to environmental stress and their symbiotic bacteria may be a key aspect of their responses to deteriorating conditions. This article summarizes the ecophysiological relationship helminths have with symbiotic bacteria and the role they play in maintaining a healthy parasite and the relevance of specific changes that occur in free-living invertebrate–bacteria interactions under anthropogenic pressure to helminths and their bacterial communities. It also discusses the importance of understanding the mechanistic sensitivity of helminth–bacteria relationships to environmental stress for comprehending the responses of parasites to challenging conditions.

scholarly journals Labour sharing promotes coexistence in atrazine degrading bacterial communities

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Loren Billet ◽  
Marion Devers ◽  
Nadine Rouard ◽  
Fabrice Martin-Laurent ◽  
Aymé Spor
Keyword(s):  
Bacterial Communities ◽  
Gene Loss ◽  
Bacterial Species ◽  
Single Species ◽  
Microbial Consortia ◽  
The Public ◽  
Herbicide Atrazine ◽  
Set Up ◽  
Multiple Species ◽  
Isolated Species

AbstractMicrobial communities are pivotal in the biodegradation of xenobiotics including pesticides. In the case of atrazine, multiple studies have shown that its degradation involved a consortia rather than a single species, but little is known about how interdependency between the species composing the consortium is set up. The Black Queen Hypothesis (BQH) formalized theoretically the conditions leading to the evolution of dependency between species: members of the community called ‘helpers’ provide publicly common goods obtained from the costly degradation of a compound, while others called ‘beneficiaries’ take advantage of the public goods, but lose access to the primary resource through adaptive degrading gene loss. Here, we test whether liquid media supplemented with the herbicide atrazine could support coexistence of bacterial species through BQH mechanisms. We observed the establishment of dependencies between species through atrazine degrading gene loss. Labour sharing between members of the consortium led to coexistence of multiple species on a single resource and improved atrazine degradation potential. Until now, pesticide degradation has not been approached from an evolutionary perspective under the BQH framework. We provide here an evolutionary explanation that might invite researchers to consider microbial consortia, rather than single isolated species, as an optimal strategy for isolation of xenobiotics degraders.

scholarly journals Cuticular and Internal Chemical Composition of Biting Midges Culicoides spp. (Diptera: Ceratopogonidae), Potential Vectors of Viral Diseases

2014 ◽  
Vol 9 (8) ◽  
pp. 1934578X1400900
Author(s):  
Mikel González ◽  
Sergio López ◽  
Gloria Rosell ◽  
Arturo Goldarazena ◽  
Angel Guerrero
Keyword(s):  
Chemical Composition ◽  
Gas Chromatography Mass Spectrometry ◽  
Viral Diseases ◽  
Chemical Profile ◽  
Biting Midges ◽  
Biting Midge ◽  
Branched Hydrocarbons ◽  
Hexane Extracts ◽  
Major Chemical ◽  
First Time

The chemical profile of the cuticle and internal tissues of four species of Culicoides have been studied for the first time by gas chromatography-mass spectrometry. The chemical composition of females of C. obsoletus s.l. and C. lupicaris, vectors of diverse viral diseases, have been compared with that of other biting midges, such as C. kibunensis and C. fascipennis, and the non-biting midge Forcipomyia bipunctata. A total of 61 compounds belonging to 8 major chemical classes were identified in cuticular and internal tissues in n-hexane extracts. The compounds include carboxylic acids (CAs) (C6-C20), with C16:0, C16:1 and C18:1 being dominant, branched hydrocarbons (C29 to C38 mono/di/trimethylalkanes), linear hydrocarbons (C15 to C33, mainly odd chain carbons), terpenes (geranylacetone, geranylgeraniol acetate, squalene, terpenic alcohol), steroids (cholesterol), aldehydes (C9-C10 and even chain C20 to C30), and esters. The chemical profile depends on the species and whether the extracts are external (cuticle) or internal. The contents of linear and branched hydrocarbons and aldehydes was high in cuticular extracts but practically absent in internal tissues, which were, in contrast, rich in CAs, terpenes and steroids. The results are discussed and compared with other Culicoides midges and mosquito-related species.

scholarly journals Culicoides biting midges at the National Zoological Gardens of South Africa : research communication

2007 ◽  
Vol 74 (4) ◽  
Author(s):  
K. Labuschagne ◽  
L.J. Gerber ◽  
I. Espie ◽  
S. Carpenter
Keyword(s):  
South Africa ◽  
Vector Competence ◽  
Far East ◽  
Wild Animals ◽  
Light Traps ◽  
Biting Midges ◽  
Research Communication ◽  
Culicoides Imicola ◽  
Large Numbers ◽  
Culicoides Biting Midges

Culicoides biting midges (Diptera: Ceratopogonidae) are responsible for the transmission of a large number of pathogens to livestock and wild animals. In this study the presence of the genus, using light traps based at four different sites within the National Zoological Gardens of South Africa, was investigated during 2002-2004. In total, 37 species were recorded, including large numbers of Culicoides imicola Kieffer, 1913, which is responsible for the transmission of economically important arboviruses in South Africa, Europe, Middle and Far East. These results are discussed with reference to the wider Culicoides fauna in the Onderstepoort area of South Africa, their vector competence as well as biosecurity at the National Zoological Gardens.

scholarly journals A Pilot Study of Chronological Microbiota Changes in a Rat Apical Periodontitis Model

2020 ◽  
Vol 8 (8) ◽  
pp. 1174
Author(s):  
Ok-Jin Park ◽  
Moon-Hee Jeong ◽  
Eun-Hye Lee ◽  
Mi-Ran Cho ◽  
Jaehong Hwang ◽  
...  
Keyword(s):  
Bacterial Communities ◽  
Bradyrhizobium Japonicum ◽  
Alveolar Bone ◽  
Bacterial Species ◽  
Root Apex ◽  
Apical Periodontitis ◽  
Microbial Infection ◽  
Pulp Chamber ◽  
Experimental Rat Model ◽  
Histopathologic Changes

Apical periodontitis caused by microbial infection in the dental pulp is characterized by inflammation, destruction of the pulpal and periradicular tissues, and alveolar bone resorption. We analyzed the chronological changes in microbiota using a pyrosequencing-based approach combined with radiologic and histopathologic changes in a rat apical periodontitis model. During the three-week observation, the pulp and periapical area showed a typical progress of apical periodontitis. A total of 27 phyla, 645 genera, and 1276 species were identified. The root apex had a lower bacterial species diversity than the pulp chamber. Proteobacteria, Firmicutes, Bacteroidetes, and Actinobacteria were dominant phyla in both the pulp chamber and root apex. Remarkably, bacterial communities showed a tendency to change in the root apex based on the disease progression. At the genus level, Escherichia, Streptococcus, Lactobacillus, Rodentibacter, and Bacteroidetes were dominant genera in the pulp chamber. The most abundant genera in the root apex were Bradyrhizobium, Halomonas, and Escherichia. The species Azospirillum oryzae increased in the pulp chamber, whereas the species Bradyrhizobium japonicum and Halomonas stevensii were highly observed in the root apex as the disease progressed. The experimental rat model of apical periodontitis demonstrated a relationship between the microbiota and the apical periodontitis progression.

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