scholarly journals Biological invasions in rodent communities: from ecological interactions to zoonotic bacterial infection issues

2017 ◽  
Author(s):  
Christophe Diagne ◽  
M. Galan ◽  
Lucie Tamisier ◽  
Jonathan d’Ambrosio ◽  
Ambroise Dalecky ◽  
...  
Keyword(s):  
Disease Risk ◽  
Rattus Rattus ◽  
Experimental Studies ◽  
Amplicon Sequencing ◽  
Invasion Success ◽  
Enemy Release ◽  
Ecological Interactions ◽  
Invasion Process ◽  
Mus Musculus Domesticus ◽  
Zoonotic Bacteria

AbstractSeveral hypotheses (such as ‘enemy release’, ‘novel weapon’, ‘spillback’ and ‘dilution/density effect’) suggest changes in host-parasite ecological interactions during biological invasion events. Such changes can impact both invasion process outcome and the dynamics of exotic and/or endemic zoonotic diseases. To evaluate these predictions, we investigated the ongoing invasions of the house mouse Mus musculus domesticus, and the black rat, Rattus rattus, in Senegal (West Africa). We focused on zoonotic bacterial communities depicted using 16S rRNA amplicon sequencing approach in both invasive and native rodents sampled along two well-defined invasion routes. Overall, this study provided new ecological evidence connecting parasitism and rodent invasion process, with diverse potential roles of zoonotic bacteria in the invasion success. Our results also highlighted the main factors that lie behind bacterial community structure in commensal rodents. Further experimental studies as well as comparative spatio-temporal surveys are necessary to decipher the actual role of zoonotic bacteria in these invasions. Our data also gave new support for the difficulty to predict the direction in which the relationship between biodiversity changes and disease risk could go. These results should be used as a basis for public health prevention services to design reservoir monitoring strategies based on multiple pathogen surveillance.

scholarly journals Parasites and invasions: changes in gastrointestinal helminth assemblages in invasive and native rodents in senegal

2016 ◽  
Author(s):  
Christophe Diagne ◽  
Alexis Ribas ◽  
Nathalie Charbonnel ◽  
Ambroise Dalecky ◽  
Caroline Tatard ◽  
...  
Keyword(s):  
Rattus Rattus ◽  
Enemy Release Hypothesis ◽  
Hymenolepis Diminuta ◽  
Invasion Success ◽  
Transmission Risk ◽  
Enemy Release ◽  
Individual Species ◽  
Mus Musculus Domesticus ◽  
Gastrointestinal Helminth ◽  
Invasion Fronts

AbstractUnderstanding why some exotic species become widespread and abundant in their colonized range is a fundamental issue that still needs to be addressed. Among many hypotheses, newly established host populations may benefit from a parasite loss (“enemy release” hypothesis) through impoverishment of their original parasite communities or reduced infection levels. Moreover, the fitness of competing native hosts may be affected by the acquisition of exotic taxa from invaders (“parasite spillover”) and/or by an increased transmission risk of native parasites due to their amplification by invaders (“parasite spillback”). We focused on gastrointestinal helminth communities to determine whether these predictions could explain the ongoing invasion success of the commensal house mouse (Mus musculus domesticus) and black rat (Rattus rattus), as well as the associated drop of native Mastomys species, in Senegal. For both invasive species, our results were consistent with the predictions of the enemy release hypothesis. A decrease of helminth overall prevalence and individual species richness was observed along the invasion gradients as well as lower specific prevalence/abundance (Aspiculuris tetraptera in M. m. domesticus, Hymenolepis diminuta in R. rattus) on the invasion fronts. Conversely, we did not find strong evidence of helminth spill-over or spill-back in invasion fronts, where native and invasive rodents co-occurred. Further experimental research is needed to determine whether and how the loss of helminths and reduced infection levels along invasion routes may result in any advantageous effects on invader fitness and competitive advantage.

scholarly journals Differential immune gene expression associated with contemporary range expansion in two invasive rodents in Senegal

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Nathalie Charbonnel ◽  
Maxime Galan ◽  
Caroline Tatard ◽  
Anne Loiseau ◽  
Christophe Diagne ◽  
...  
Keyword(s):  
Gene Expression ◽  
Differential Expression ◽  
House Mouse ◽  
Expression Profiles ◽  
Rattus Rattus ◽  
Gene Expression Profiles ◽  
Invasion Success ◽  
Immune Gene ◽  
Mus Musculus Domesticus ◽  
Black Rat

Abstract Biological invasions are major anthropogenic changes associated with threats to biodiversity and health. However, what determines the successful establishment and spread of introduced populations remains unclear. Here, we explore several hypotheses linking invasion success and immune phenotype traits, including those based on the evolution of increased competitive ability concept. We compared gene expression profiles between anciently and recently established populations of two major invading species, the house mouse Mus musculus domesticus and the black rat Rattus rattus, in Senegal (West Africa). Transcriptome analyses identified differential expression between anciently and recently established populations for 364 mouse genes and 83 rat genes. All immune-related genes displaying differential expression along the mouse invasion route were overexpressed at three of the four recently invaded sites studied. Complement activation pathway genes were overrepresented among these genes. By contrast, no particular immunological process was found to be overrepresented among the differentially expressed genes of black rat. Changes in transcriptome profiles were thus observed along invasion routes, but with different specific patterns between the two invasive species. These changes may be driven by increases in infection risks at sites recently invaded by the house mouse, and by stochastic events associated with colonization history for the black rat. These results constitute a first step toward the identification of immune eco-evolutionary processes potentially involved in the invasion success of these two rodent species.

scholarly journals Differential immune gene expression associated with contemporary range expansion of two invasive rodents in Senegal

2018 ◽  
Author(s):  
Nathalie Charbonnel ◽  
Maxime Galan ◽  
Caroline Tatard ◽  
Anne Loiseau ◽  
Christophe Amidi Diagne ◽  
...  
Keyword(s):  
Gene Expression ◽  
House Mouse ◽  
Expression Profiles ◽  
Rattus Rattus ◽  
Invasion Success ◽  
Phenotypic Traits ◽  
Immune Gene ◽  
Mus Musculus Domesticus ◽  
Black Rat ◽  
Invasion Routes

BackgroundBiological invasions are major anthropogenic changes associated with threats to biodiversity and health. What determines the successful establishment of introduced populations still remains unsolved. Here we explore the appealing assertion that invasion success relies on immune phenotypic traits that would be advantageous in recently invaded sites.ResultsWe compared gene expression profiles between anciently and recently established populations of two major invading species, the house mouse Mus musculus domesticus and the black rat Rattus rattus, in Senegal. Transcriptome analyses revealed respectively 364 and 83 differentially expressed genes along the mouse and rat invasion routes. Among them, 20.0% and 10.6% were annotated with functions related to immunity. All immune-related genes detected along the mouse invasion route were over-expressed in recently invaded sites. Genes of the complement activation pathway were over-represented. Results were less straightforward when considering the black rat as no particular immunological process was over-represented.ConclusionsWe revealed changes in transcriptome profiles along invasion routes. Patterns differed between both invasive species. These changes potentially be driven by increased infection risks in recently invaded sites for the house mouse and stochastic events associated with colonization history for the black rat. These results provide a first step in identifying the immune ecoevolutionary processes potentially involved in invasion success.

scholarly journals Same Invasion, Different Routes: Helminth Assemblages May Favor the Invasion Success of the House Mouse in Senegal

2021 ◽  
Vol 8 ◽  
Author(s):  
Christophe Diagne ◽  
Laurent Granjon ◽  
Caroline Tatard ◽  
Alexis Ribas ◽  
Arame Ndiaye ◽  
...  
Keyword(s):  
House Mouse ◽  
Native Species ◽  
Invasion Success ◽  
Enemy Release ◽  
Mus Musculus Domesticus ◽  
Invasion Pathways ◽  
Invasion Fronts ◽  
Invasion Routes ◽  
Rodent Communities

Previous field-based studies have evidenced patterns in gastrointestinal helminth (GIH) assemblages of rodent communities that are consistent with “enemy release” and “spill-back” hypotheses, suggesting a role of parasites in the ongoing invasion success of the exotic house mouse (Mus musculus domesticus) in Senegal (West Africa). However, these findings came from a single invasion route, thus preventing to ascertain that they did not result from stochastic and/or selective processes that could differ across invasion pathways. In the present study, we investigated the distribution of rodent communities and their GIH assemblages in three distinct zones of Northern Senegal, which corresponded to independent house mouse invasion fronts. Our findings first showed an unexpectedly rapid spread of the house mouse, which reached even remote areas where native species would have been expected to dominate the rodent communities. They also strengthened previous insights suggesting a role of helminths in the invasion success of the house mouse, such as: (i) low infestation rates of invading mice by the exotic nematode Aspiculuris tetraptera at invasion fronts—except in a single zone where the establishment of the house mouse could be older than initially thought, which was consistent with the “enemy release” hypothesis; and (ii) higher infection rates by the local cestode Mathevotaenia symmetrica in native rodents with long co-existence history with invasive mice, bringing support to the “spill-back” hypothesis. Therefore, “enemy release” and “spill-back” mechanisms should be seriously considered when explaining the invasion success of the house mouse—provided further experimental works demonstrate that involved GIHs affect rodent fitness or exert selective pressures. Next steps should also include evolutionary, immunological, and behavioral perspectives to fully capture the complexity, causes and consequences of GIH variations along these invasion routes.

scholarly journals First Detection of Bartonella spp. in Small Mammals from Rice Storage and Processing Facilities in Myanmar and Sri Lanka

2021 ◽  
Vol 9 (3) ◽  
pp. 658
Author(s):  
Inga Böge ◽  
Martin Pfeffer ◽  
Nyo M. Htwe ◽  
Pyai P. Maw ◽  
Siriwardana Rampalage Sarathchandra ◽  
...  
Keyword(s):  
Sri Lanka ◽  
Small Mammals ◽  
Target Genes ◽  
Bartonella Henselae ◽  
Rattus Rattus ◽  
Suncus Murinus ◽  
Mammal Species ◽  
Urban Settlements ◽  
D 12 ◽  
Zoonotic Bacteria

(1) Background: Bartonella spp. are zoonotic bacteria with small mammals as main reservoirs. Bartonella spp. prevalence in small mammals from Myanmar and Sri Lanka are yet unknown. (2) Methods: Small mammals were snap trapped in Sri Lanka and Myanmar in urban surroundings. Spleens-derived DNA was screened for Bartonella spp. using conventional PCR based on three target genes. Positive samples were sequenced. (3) Results: 994 small mammals were collected comprising 6 species: Bandicota bengalensis, Bandicota indica, Rattus exulans, Rattus rattus, Mus booduga, and Suncus murinus. In Myanmar, the Bartonella prevalence in Bandicoot rats (68.47%) was higher than in Rattus rattus (41.67%), Rattus exulans (21.33%), and Suncus murinus (3.64%). Furthermore the prevalence in Myanmar (34%, n = 495) was twice as high as in Sri Lanka (16%, n = 499). In Sri Lanka, Bartonella spp. occurred almost exclusively in R. rattus. In Myanmar, Bartonella kosoyi was mainly detected (56%), followed by Bartonella sp. KM2529 (15%), Bartonella sp. SE-Bart D (12%) and Bartonella henselae (1%). In Sri Lanka, B. phoceensis (60%) and Bartonella sp. KM2581 (33%) were predominant. (4) Conclusions: Bartonella spp. were detected in all investigated small mammal species from Myanmar and Sri Lanka for the first time. Bartonella kosoyi and B. henselae are zoonotic. As these small mammals originated from urban settlements, human bartonellosis seems likely to occur.

scholarly journals Vitamin D as A Protector of Arterial Health: Potential Role in Peripheral Arterial Disease Formation

2019 ◽  
Vol 20 (19) ◽  
pp. 4907 ◽  
Author(s):  
Smriti Murali Krishna
Keyword(s):  
Cardiovascular Disease ◽  
Vitamin D ◽  
Peripheral Arterial Disease ◽  
Vitamin D Deficiency ◽  
Disease Risk ◽  
Cardiovascular Disease Risk ◽  
Experimental Studies ◽  
Arterial Disease ◽  
Current Evidence ◽  
Peripheral Arterial

Atherosclerotic occlusive diseases and aneurysms that affect large and medium-sized arteries outside the cardiac and cerebral circulation are collectively known as peripheral arterial disease (PAD). With a rise in the rate of aging population worldwide, the number of people diagnosed with PAD is rapidly increasing. The micronutrient vitamin D is an important steroid hormone that acts on many crucial cellular mechanisms. Experimental studies suggest that optimal levels of vitamin D have beneficial effects on the heart and blood vessels; however, high vitamin D concentrations have been implicated in promoting vascular calcification and arterial stiffness. Observations from various clinical studies shows that deficiency of vitamin D has been associated with a greater risk of PAD. Epidemiological studies have often reported an inverse relation between circulating vitamin D status measured in terms of 25-hydroxivitamin D [25(OH)D] levels and increased cardiovascular disease risk; however, randomized controlled trials did not show a consistent positive effect of vitamin D supplementation on cardiovascular disease risk or events. Even though PAD shares all the major risk factors with cardiovascular diseases, the effect of vitamin D deficiency in PAD is not clear. Current evidence suggests a strong role of vitamin D in promoting genomic and epigenomic changes. This review summarises the current literature that supports the notion that vitamin D deficiency may promote PAD formation. A better understanding of underlying pathological mechanisms will open up new therapeutic possibilities which is the main unmet need in PAD management. Furthermore, epigenetic evidence shows that a more holistic approach towards PAD prevention that incorporates a healthy lifestyle, adequate exercise and optimal nutrition may be more effective in protecting the genome and maintaining a healthy vasculature.

Factors determining the distribution of introduced mammals in nature reserves of the southern province, New Caledonia

2003 ◽  
Vol 30 (2) ◽  
pp. 187 ◽  
Author(s):  
Sophie Rouys ◽  
Jörn Theuerkauf
Keyword(s):  
Rattus Norvegicus ◽  
New Caledonia ◽  
Canis Familiaris ◽  
Rattus Rattus ◽  
Nature Reserves ◽  
House Mice ◽  
Mus Musculus Domesticus ◽  
Southern Province ◽  
Feral Populations ◽  
Norway Rats

We studied the distribution of introduced mammals in six nature reserves of New Caledonia's southern province. Polynesian rats (Rattus exulans) were common in both rainforest and shrubland but their abundance decreased with increasing altitude. Ship rats (Rattus rattus) were abundant in rainforest but less numerous in shrubland and their abundance did not increase with altitude. We found no Norway rats (Rattus norvegicus) or house mice (Mus musculus domesticus) in reserves. Feral pigs (Sus scrofa) used mainly rainforest but also shrubland and preferred foraging in valleys with alluvial soils. Rusa deer (Cervus timorensis) selected shrubland over rainforest. Feral cats (Felis catus) were widely distributed in the reserves, whereas dogs (Canis familiaris) strayed into reserves but did not form feral populations.

scholarly journals Reducing Bias Amplification in the Presence of Unmeasured Confounding through Out-of-Sample Estimation Strategies for the Disease Risk Score

2014 ◽  
Vol 2 (2) ◽  
pp. 131-146 ◽  
Author(s):  
Richard Wyss ◽  
Mark Lunt ◽  
M. Alan Brookhart ◽  
Robert J. Glynn ◽  
Til Stürmer
Keyword(s):  
Instrumental Variables ◽  
Risk Score ◽  
Disease Risk ◽  
Prognostic Score ◽  
Experimental Studies ◽  
Summary Score ◽  
Study Cohort ◽  
Unmeasured Confounding ◽  
Treatment Prevalence ◽  
Disease Risk Score

AbstractThe prognostic score, or disease risk score (DRS), is a summary score that is used to control for confounding in non-experimental studies. While the DRS has been shown to effectively control for measured confounders, unmeasured confounding continues to be a fundamental obstacle in non-experimental research. Both theory and simulations have shown that in the presence of unmeasured confounding, controlling for variables that affect treatment (both instrumental variables and measured confounders) amplifies the bias caused by unmeasured confounders. In this paper, we use causal diagrams and path analysis to review and illustrate the process of bias amplification. We show that traditional estimation strategies for the DRS do not avoid bias amplification when controlling for predictors of treatment. We then discuss estimation strategies for the DRS that can potentially reduce bias amplification that is caused by controlling both instrumental variables and measured confounders. We show that under certain assumptions, estimating the DRS in populations outside the defined study cohort where treatment has not been introduced, or in outside populations with reduced treatment prevalence, can control for the confounding effects of measured confounders while at the same time reduce bias amplification.

scholarly journals Plant-Soil Interactions of an Invasive Plant Species in its Native Range Help to Explain its Invasion Success Elsewhere

2021 ◽  
Author(s):  
Anna Aldorfová ◽  
Věra Hanzelková ◽  
Lucie Drtinová ◽  
Hana Pánková ◽  
Tomáš Cajthaml ◽  
...  
Keyword(s):  
Invasive Species ◽  
Invasive Plant ◽  
Seedling Emergence ◽  
Invasion Success ◽  
Enemy Release ◽  
Native Range ◽  
Non Invasive ◽  
Secondary Range ◽  
Plant Soil ◽  
Root Shoot Ratio

Abstract Purpose: To compare plant-soil feedback (PSF) of invasive Cirsium vulgare and non-invasive C. oleraceum in their native range to test a hypothesis that the invasive species is more limited by specialized pathogens in the native range and/or able to benefit more from generalist mutualists, and thus may benefit more from loss of specialized soil biota in a secondary range.Methods: We assessed changes in soil nutrients and biota following soil conditioning by each species and compared performance of plants grown in self-conditioned and control soil, from which all, some or no biota was excluded. Results: The invasive species depleted more nutrients than the non-invasive species and coped better with altered nutrient levels. The invasive species had higher seedling emergence which benefited from presence of non-specific microbes. The invasive species biomass responded less positively to specialized (self-conditioned) microbiota and more negatively to specialized larger-sized biota compared to the non-specialized control biota, suggesting the species may benefit more from enemy release and suffer less from loss of specialized mutualists when introduced to a secondary range. The invasive species showed greater ability to decrease its root-shoot ratio in presence of harmful biota and thus reduce their negative effects on its performance.Conclusions: Our study highlights the utility of detailed PSF research in the native range of species for understanding the factors that regulate performance of invasive and non-invasive species in their native range, and for pinpointing the types of biota involved in their regulation and how this changes across the plants life cycle.

scholarly journals Enemy release mitigates inbreeding depression in native and invasive Silene latifolia populations: experimental insight into the role of inbreeding × environment interactions in invasion success

2018 ◽  
Author(s):  
Karin Schrieber ◽  
Sabrina Wolf ◽  
Catherina Wypior ◽  
Diana Höhlig ◽  
Stephen R. Keller ◽  
...  
Keyword(s):  
Genetic Differentiation ◽  
Inbreeding Depression ◽  
Invasive Plants ◽  
Natural Enemies ◽  
Invasion Success ◽  
Interactive Effects ◽  
Plant Performance ◽  
Silene Latifolia ◽  
Enemy Release ◽  
Fruit Number

AbstractInbreeding and enemy infestation are common in plants and can synergistically reduce their performance. This inbreeding × environment (I×E) interaction may be of particular importance for the success of plant invasions if introduced populations experience a release from attack by natural enemies relative to their native conspecifics. Using native and invasive plant populations, we investigate whether inbreeding affects infestation damage, whether inbreeding depression in performance is mitigated by enemy release and whether genetic differentiation among native and invasive plants modifies these I×E interactions. We used the plant invader Silene latifolia and its natural enemies as a study system. We performed two generations of experimental out- and inbreeding within eight native (European) and eight invasive (North American) S. latifolia populations under controlled conditions using field-collected seeds. Subsequently, we exposed the offspring to an enemy exclusion and inclusion treatment in a common garden in the species’ native range to assess the interactive effects of population origin (range), breeding treatment and enemy treatment on infestation damage as well as plant performance. Inbreeding increased flower and leaf infestation damage in plants from both ranges, but had opposing effects on fruit damage in native versus invasive plants. Both inbreeding and enemy infestation had negative effects on plant performance, whereby inbreeding depression in fruit number was higher in enemy inclusions than exclusions in plants from both ranges. Moreover, the magnitude of inbreeding depression in fruit number was lower in invasive than native populations. Our results support that inbreeding increases enemy susceptibility of S. latifolia, which magnifies inbreeding depression in the presence of enemies. Enemy release in the invaded habitat may thus increase the persistence of inbred founder populations and thereby contribute to successful invasion. Moreover, our findings emphasize that genetic differentiation among native and invasive plants can shape the magnitude and even the direction of inbreeding effects.

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