scholarly journals Borrelia afzelii alters reproductive success in a rodent host

2018 ◽  
Vol 285 (1884) ◽  
pp. 20181056 ◽  
Author(s):  
Claire Cayol ◽  
Anna Giermek ◽  
Andrea Gomez-Chamorro ◽  
Jukka Hytönen ◽  
Eva Riikka Kallio ◽  
...  
Keyword(s):  
Reproductive Success ◽  
Host Population ◽  
Natural Host ◽  
Myodes Glareolus ◽  
Offspring Size ◽  
Rodent Host ◽  
Mating Partner ◽  
Borrelia Afzelii ◽  
Bank Voles ◽  
The Impact

The impact of a pathogen on the fitness and behaviour of its natural host depends upon the host–parasite relationship in a given set of environmental conditions. Here, we experimentally investigated the effects of Borrelia afzelii, one of the aetiological agents of Lyme disease in humans, on the fitness of its natural rodent host, the bank vole ( Myodes glareolus ), in semi-natural conditions with two contrasting host population densities. Our results show that B. afzelii can modify the reproductive success and spacing behaviour of its rodent host, whereas host survival was not affected. Infection impaired the breeding probability of large bank voles. Reproduction was hastened in infected females without alteration of the offspring size at birth. At low density, infected males produced fewer offspring, fertilized fewer females and had lower mobility than uninfected individuals. Meanwhile, the infection did not affect the proportion of offspring produced or the proportion of mating partner in female bank voles. Our study is the first to show that B. afzelii infection alters the reproductive success of the natural host. The effects observed could reflect the sickness behaviour due to the infection or they could be a consequence of a manipulation of the host behaviour by the bacteria.

scholarly journals Experimental Morogoro Virus Infection in Its Natural Host, Mastomys natalensis

Viruses ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 851
Author(s):  
Chris Hoffmann ◽  
Stephanie Wurr ◽  
Elisa Pallasch ◽  
Sabrina Bockholt ◽  
Toni Rieger ◽  
...  
Keyword(s):  
Persistent Infection ◽  
Virus Transmission ◽  
Host Population ◽  
Natural Host ◽  
Lassa Virus ◽  
Mastomys Natalensis ◽  
Natural Hosts ◽  
History Of ◽  
Morogoro Virus ◽  
The Impact

Natural hosts of most arenaviruses are rodents. The human-pathogenic Lassa virus and several non-pathogenic arenaviruses such as Morogoro virus (MORV) share the same host species, namely Mastomys natalensis (M. natalensis). In this study, we investigated the history of infection and virus transmission within the natural host population. To this end, we infected M. natalensis at different ages with MORV and measured the health status of the animals, virus load in blood and organs, the development of virus-specific antibodies, and the ability of the infected individuals to transmit the virus. To explore the impact of the lack of evolutionary virus–host adaptation, experiments were also conducted with Mobala virus (MOBV), which does not share M. natalensis as a natural host. Animals infected with MORV up to two weeks after birth developed persistent infection, seroconverted and were able to transmit the virus horizontally. Animals older than two weeks at the time of infection rapidly cleared the virus. In contrast, MOBV-infected neonates neither developed persistent infection nor were able to transmit the virus. In conclusion, we demonstrate that MORV is able to develop persistent infection in its natural host, but only after inoculation shortly after birth. A related arenavirus that is not evolutionarily adapted to M. natalensis is not able to establish persistent infection. Persistently infected animals appear to be important to maintain virus transmission within the host population.

scholarly journals First isolation and genetic characterization of Puumala orthohantavirus strains from France

2020 ◽  
Author(s):  
Johann Vulin ◽  
Séverine Murri ◽  
Sarah Madrières ◽  
Maxime Galan ◽  
Caroline Tatard ◽  
...  
Keyword(s):  
Bank Vole ◽  
Endemic Area ◽  
High Throughput Sequencing ◽  
Hemorrhagic Fever ◽  
Amino Acid Sequences ◽  
Myodes Glareolus ◽  
Wild Rodents ◽  
Bank Voles ◽  
A Cell ◽  
The Impact

AbstractPuumala orthohantavirus (PUUV) causes a mild form of hemorrhagic fever with renal syndrome (HFRS) named nephropathia epidemica (NE), regularly diagnosed in Europe. France represents the Western frontier of NE expansion in Europe with two distinct areas: the endemic area (Northeast) where PUUV circulates in rodent populations and where many cases of NE are detected in humans and non-endemic area (Southwest) where the virus is not detected and only a few human cases have been reported. The country is a pertinent target to study factors that influence the evolution of PUUV distribution. In this study, we describe for the first time the isolation of two PUUV strains from two distinct French geographical areas: Ardennes (endemic area) and Loiret (non-endemic area). To isolate PUUV efficiently, we selected wild rodents (Myodes glareolus, the specific reservoir of PUUV) from these areas that were seronegative for anti-PUUV IgG (ELISA) but associated with viral RNA load in lung (qRT-PCR). With this design, we are able to cultivate and maintain these two strains in VeroE6 cells but also to propagate efficiently and rapidly both strains in a bank vole colony. Complete coding sequences of S and M segments were determined by Sanger sequencing of RNA extracted from positive bank voles (naturally and experimentally infected) and from supernatant of Vero E6. For the M segment, nucleotidic sequences were 100% identical for both strains. For the S segment, the amino acid sequences from each strain revealed one mismatch between sequences obtained from tissue and from supernatant, revealing a “bank vole” and a “cell” signature. High throughput sequencing confirmed Sanger results, and provided a better assessment of the impact of isolation methods on intra-host viral diversity.

scholarly journals Borrelia afzelii does not suppress the development of anti-tick immunity in bank voles

2020 ◽  
Author(s):  
Andrea Gomez-Chamorro ◽  
Yating Li ◽  
Adrian Herrera ◽  
Olivier Rais ◽  
Hans Dautel ◽  
...  
Keyword(s):  
Bank Vole ◽  
Myodes Glareolus ◽  
Acquired Immunity ◽  
Salivary Gland Extract ◽  
Borrelia Afzelii ◽  
Tick Vector ◽  
Bank Voles ◽  
Gland Extract ◽  
Tick Transmission ◽  
Vertebrate Hosts

AbstractVector-borne pathogens manipulate their vertebrate hosts to enhance their transmission to arthropod vectors. The ability of vertebrate hosts to develop acquired immunity against arthropod vectors represents an existential threat for both the vector and the pathogen. The purpose of the study was to test whether the tick-borne spirochete bacterium Borrelia afzelii could suppress the development of acquired immunity to its tick vector Ixodes ricinus in the bank vole Myodes glareolus, which is an important host for both the tick and the pathogen. We created a group of B. afzelii-infected bank voles and an uninfected control group by exposing lab-reared animals to infected or uninfected ticks. At 1, 2, and 3 months post-infection, all bank voles were infested with larval I. ricinus ticks. The bank voles developed a strong antibody response against tick salivary gland extract proteins. This anti-tick immunity had negative effects on tick fitness traits including engorged larval weight, unfed nymphal weight, larva-to-nymph molting time and larva-to-nymph molting success. Infection with B. afzelii did not suppress the development of acquired immunity against I. ricinus ticks. The development of anti-tick immunity was strongly correlated with a dramatic temporal decline in both the bacterial abundance in the host ear tissues and the host-tick transmission success of B. afzelii. Our study suggests that the development of anti-tick immunity in bank voles has important consequences for the density of infected ticks and the risk of Lyme borreliosis.ImportanceMany pathogens enhance their persistence and transmission by suppressing the immune system of their host. We used an experimental infection approach to test whether the Lyme disease pathogen, Borrelia afzelii, could suppress the development of acquired immunity against its tick vector (Ixodes ricinus) in the bank vole (Myodes glareolus), but found no evidence for this phenomenon. Uninfected and B. afzelii-infected bank voles both developed a strong IgG antibody response against tick salivary gland extract following repeated infestations with I. ricinus ticks. The development of anti-tick immunity was negatively correlated with the abundance of B. afzelii in ear tissue biopsies and with host-to-tick transmission to I. ricinus ticks. Our study suggests that anti-tick immunity in the bank vole reduces the prevalence of this important tick-borne pathogen.

Research data of an article: " Borrelia afzelii alters reproductive success in a rodent host"

JYX ◽  
2018 ◽  
Author(s):  
Claire Cayol ◽  
Anna Giermek ◽  
Andrea Gomez-Chamorro ◽  
Jukka Hytönen ◽  
Eva Riikka Kallio ◽  
...  
Keyword(s):  
Reproductive Success ◽  
Research Data ◽  
Rodent Host ◽  
Borrelia Afzelii

scholarly journals Climate change accelerates winter transmission of a zoonotic pathogen

AMBIO ◽  
2021 ◽  
Author(s):  
Saana Sipari ◽  
Hussein Khalil ◽  
Magnus Magnusson ◽  
Magnus Evander ◽  
Birger Hörnfeldt ◽  
...  
Keyword(s):  
Climate Change ◽  
Host Population ◽  
Reservoir Host ◽  
Pathogen Transmission ◽  
Myodes Glareolus ◽  
Zoonotic Pathogen ◽  
The North ◽  
Bank Voles ◽  
Zoonotic Risk ◽  
Climate Change Effect

AbstractMany zoonotic diseases are weather sensitive, raising concern how their distribution and outbreaks will be affected by climate change. At northern high latitudes, the effect of global warming on especially winter conditions is strong. By using long term monitoring data (1980–1986 and 2003–2013) from Northern Europe on temperature, precipitation, an endemic zoonotic pathogen (Puumala orthohantavirus, PUUV) and its reservoir host (the bank vole, Myodes glareolus), we show that early winters have become increasingly wet, with a knock-on effect on pathogen transmission in its reservoir host population. Further, our study is the first to show a climate change effect on an endemic northern zoonosis, that is not induced by increased host abundance or distribution, demonstrating that climate change can also alter transmission intensity within host populations. Our results suggest that rainy early winters accelerate PUUV transmission in bank voles in winter, likely increasing the human zoonotic risk in the North.

scholarly journals Epidemiology and fitness effects of wood mouse herpesvirus in a natural host population

2012 ◽  
Vol 93 (11) ◽  
pp. 2447-2456 ◽  
Author(s):  
Sarah C. L. Knowles ◽  
Andy Fenton ◽  
Amy B. Pedersen
Keyword(s):  
Host Species ◽  
Human Herpesvirus ◽  
Wood Mouse ◽  
Natural Host ◽  
Myodes Glareolus ◽  
Wood Mice ◽  
Murine Gammaherpesvirus ◽  
Bank Voles ◽  
Natural Host Species ◽  
Route Of Transmission

Rodent gammaherpesviruses have become important models for understanding human herpesvirus diseases. In particular, interactions between murid herpesvirus 4 and Mus musculus (a non-natural host species) have been extensively studied under controlled laboratory conditions. However, several fundamental aspects of murine gammaherpesvirus biology are not well understood, including how these viruses are transmitted from host to host, and their impacts on host fitness under natural conditions. Here, we investigate the epidemiology of a gammaherpesvirus in free-living wood mice (Apodemus sylvaticus) and bank voles (Myodes glareolus) in a 2-year longitudinal study. Wood mouse herpesvirus (WMHV) was the only herpesvirus detected and occurred frequently in wood mice and also less commonly in bank voles. Strikingly, WMHV infection probability was highest in reproductively active, heavy male mice. Infection risk also showed a repeatable seasonal pattern, peaking in spring and declining through the summer. We show that this seasonal decline can be at least partly attributed to reduced recapture of WMHV-infected adults. These results suggest that male reproductive behaviours could provide an important natural route of transmission for these viruses. They also suggest that gammaherpesvirus infection may have significant detrimental effects in wild hosts, questioning the view that these viruses have limited impacts in natural, co-evolved host species.

scholarly journals Infection Dynamics of the Tick-Borne Pathogen “Candidatus Neoehrlichia mikurensis” and Coinfections with Borrelia afzelii in Bank Voles in Southern Sweden

2013 ◽  
Vol 80 (5) ◽  
pp. 1645-1649 ◽  
Author(s):  
Martin Andersson ◽  
Kristin Scherman ◽  
Lars Råberg
Keyword(s):  
Myodes Glareolus ◽  
Content Type ◽  
Borrelia Afzelii ◽  
Bank Voles ◽  
Infection Dynamics ◽  
Vertebrate Hosts ◽  
High Level ◽  
Longitudinal Sampling ◽  
Neoehrlichia Mikurensis ◽  
Sampling Season

ABSTRACTThe tick-borne bacterium “CandidatusNeoehrlichia mikurensis” has recently been recognized as a human pathogen. Together withBorrelia afzelii, it is one of the most common pathogens found in the tickIxodes ricinus. Here, we compared the epidemiologies of “Ca. Neoehrlichia mikurensis” andB. afzeliiby longitudinal sampling from May to September in one of their most abundant vertebrate hosts, the bank vole (Myodes glareolus), using real-time PCR for detection and quantification. The prevalences of “Ca. Neoehrlichia mikurensis” andB. afzeliiwere determined to be 19% (50/261) and 22% (56/261), respectively. The prevalence of “Ca. Neoehrlichia mikurensis” increased significantly during the sampling season. The clearance rate of “Ca. Neoehrlichia mikurensis” was significantly higher than that ofB. afzelii. We found a high frequency of double infections; 46% of all samples infected with “Ca. Neoehrlichia mikurensis” also had a coinfection withB. afzelii. The frequency of coinfections was significantly higher than expected from the prevalence of each pathogen. The high level of coinfections can be caused by interactions between the pathogens or might reflect variation in general susceptibility among voles.

scholarly journals Isolation and Genetic Characterization of Puumala Orthohantavirus Strains from France

Pathogens ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 349
Author(s):  
Johann Vulin ◽  
Séverine Murri ◽  
Sarah Madrières ◽  
Maxime Galan ◽  
Caroline Tatard ◽  
...  
Keyword(s):  
Endemic Area ◽  
Genetic Characterization ◽  
Myodes Glareolus ◽  
Bank Voles ◽  
North Eastern ◽  
Isolation Methods ◽  
Area North ◽  
The Impact ◽  
Rodent Populations

Puumala orthohantavirus (PUUV) causes a mild form of haemorrhagic fever with renal syndrome (HFRS) called nephropathia epidemica (NE), regularly diagnosed in Europe. France represents the western frontier of the expansion of NE in Europe with two distinct areas: an endemic area (north-eastern France) where PUUV circulates in rodent populations, with the detection of many human NE cases, and a non-endemic area (south-western France) where the virus is not detected, with only a few human cases being reported. In this study, we describe the different stages of the isolation of two PUUV strains from two distinct French geographical areas: Ardennes (endemic area) and Loiret (non-endemic area). To isolate PUUV efficiently, we selected wild bank voles (Myodes glareolus, the specific reservoir of PUUV) captured in these areas and that were seronegative for anti-PUUV IgG (ELISA) but showed a non-negligible viral RNA load in their lung tissue (qRT-PCR). With this study design, we were able to cultivate and maintain these two strains in Vero E6 cells and also propagate both strains in immunologically neutral bank voles efficiently and rapidly. High-throughput and Sanger sequencing results provided a better assessment of the impact of isolation methods on viral diversity.

scholarly journals Polymorphism of TLR2 in bank vole populations in North Eastern Poland is not associated with Borrelia afzelii infection prevalence

2020 ◽  
Vol 65 (4) ◽  
pp. 779-791
Author(s):  
Ewa Tarnowska ◽  
Magdalena Niedziałkowska ◽  
Joanna Stojak ◽  
Bogumiła Jędrzejewska
Keyword(s):  
Bank Vole ◽  
Innate Immune ◽  
Myodes Glareolus ◽  
Infection Prevalence ◽  
Borrelia Afzelii ◽  
Immune Genes ◽  
Ne Poland ◽  
Bank Voles ◽  
North Eastern ◽  
Innate Immune Genes

Abstract Polymorphism in innate immune genes in host populations can structure spatial variation in the prevalence of infectious diseases. In Europe, Borrelia afzelii is an important tick-borne pathogen of small mammals including the bank voles (Myodes glareolus). The Toll-like receptor 2 (TLR2) is an innate immune receptor that is important for detecting Borrelia burgdorferi sensu lato pathogens. The TLR2 gene is polymorphic in bank vole populations and is classified into four distinct clusters: C1, C2, C3, and C4. The C2 and C4 clusters versus the C1 and C3 clusters are associated with lower versus higher infection prevalence, respectively. We detected three TLR2 clusters in 487 bank voles from 30 populations in NE Poland: 84.2% of the obtained sequences belonged to the C1 variant, 7.2% to C2, and 8.6% to C3. However, no clear spatial structure of TLR2 clusters among the populations was detected. B. afzelii infection prevalence across all studied individuals was 12.1% and varied from 0 to 37.5% among populations. There were no significant differences in B. afzelii prevalence among voles carrying alleles of different TLR2 clusters, or between individuals belonging to two mtDNA lineages. Most infected individuals were adults, and males were infected more often than females. There was no significant relationship between the prevalence of TLR2 clusters in the vole populations and climatic and environmental factors within the study area. We therefore could not confirm an adaptive role of the TLR2 C2 alleles in reducing B. afzelii infection prevalence in bank voles.

Kalahari Cheetahs

2017 ◽  
Author(s):  
Gus Mills ◽  
Margaret Mills
Keyword(s):  
Reproductive Success ◽  
Spatial Ecology ◽  
Prey Selection ◽  
Arid Ecosystems ◽  
Foraging Success ◽  
Ecological Processes ◽  
Demographic Groups ◽  
Important Prey ◽  
Hunting Behaviour ◽  
The Impact

This book demonstrates how cheetahs are adapted to arid savannahs like the southern Kalahari, and makes comparisons with other areas, especially the Serengeti. Topics dealt with are: demography and genetic status; feeding ecology, i.e. methods used for studying diet, diets of different demographic groups, individual diet specializations of females, prey selection, the impact of cheetah predation on prey populations, activity regimes and distances travelled per day, hunting behaviour, foraging success and energetics; interspecific competition; spatial ecology; reproductive success and the mating system; and conservation. The major findings show that cheetahs are well adapted to arid ecosystems and are water independent. Cheetah density in the study area was stable at 0.7/100 km2 and the population was genetically diverse. Important prey were steenbok and springbok for females with cubs, gemsbok, and adult ostrich for coalition males, and steenbok, springhares, and hares for single animals. Cheetahs had a density-dependent regulatory effect on steenbok and springbok populations. Females with large cubs had the highest overall food intake. Cheetahs, especially males, were often active at night, and competition with other large carnivores, both by exploitation and interference, was slight. Although predation on small cubs was severe, cub survival to adolescence was six times higher than in the Serengeti. There was no difference in reproductive success between single and coalition males. The conservation priority for cheetahs should be to maintain protected areas over a spectrum of landscapes to allow ecological processes, of which the cheetah is an integral part, to proceed unhindered.

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