scholarly journals In Vivo Characterization of a Bank Vole-Derived Cowpox Virus Isolate in Natural Hosts and the Rat Model

Viruses ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 237
Author(s):  
Saskia Weber ◽  
Kathrin Jeske ◽  
Rainer G. Ulrich ◽  
Christian Imholt ◽  
Jens Jacob ◽  
...  

Cowpox virus (CPXV) belongs to the genus Orthopoxvirus in the Poxviridae family and is endemic in western Eurasia. Based on seroprevalence studies in different voles from continental Europe and UK, voles are suspected to be the major reservoir host. Recently, a CPXV was isolated from a bank vole (Myodes glareolus) in Germany that showed a high genetic similarity to another isolate originating from a Cotton-top tamarin (Saguinus oedipus). Here we characterize this first bank vole-derived CPXV isolate in comparison to the related tamarin-derived isolate. Both isolates grouped genetically within the provisionally called CPXV-like 3 clade. Previous phylogenetic analysis indicated that CPXV is polyphyletic and CPXV-like 3 clade represents probably a different species if categorized by the rules used for other orthopoxviruses. Experimental infection studies with bank voles, common voles (Microtus arvalis) and Wistar rats showed very clear differences. The bank vole isolate was avirulent in both common voles and Wistar rats with seroconversion seen only in the rats. In contrast, inoculated bank voles exhibited viral shedding and seroconversion for both tested CPXV isolates. In addition, bank voles infected with the tamarin-derived isolate experienced a marked weight loss. Our findings allow for the conclusion that CPXV isolates might differ in their replication capacity in different vole species and rats depending on their original host. Moreover, the results indicate host-specific differences concerning CPXV-specific virulence. Further experiments are needed to identify individual virulence and host factors involved in the susceptibility and outcome of CPXV-infections in the different reservoir hosts.

Viruses ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1075 ◽  
Author(s):  
Kathrin Jeske ◽  
Saskia Weber ◽  
Florian Pfaff ◽  
Christian Imholt ◽  
Jens Jacob ◽  
...  

Cowpox virus (CPXV) is a zoonotic orthopoxvirus (OPV) that infects a wide range of mammals. CPXV-specific DNA and antibodies were detected in different vole species, such as common voles (Microtus arvalis) and bank voles (Myodes glareolus). Therefore, voles are the putative main reservoir host of CPXV. However, CPXV was up to now only isolated from common voles. Here we report the detection and isolation of a bank vole-derived CPXV strain (GerMygEK 938/17) resulting from a large-scale screening of bank voles collected in Thuringia, Germany, during 2017 and 2018. Phylogenetic analysis using the complete viral genome sequence indicated a high similarity of the novel strain to CPXV clade 3 and to OPV “Abatino” but also to Ectromelia virus (ECTV) strains. Phenotypic characterization of CPXV GerMygEK 938/17 using inoculation of embryonated chicken eggs displayed hemorrhagic pock lesions on the chorioallantoic membrane that are typical for CPXV but not for ECTV. CPXV GerMygEK 938/17 replicated in vole-derived kidney cell lines but at lower level than on Vero76 cell line. In conclusion, the first bank vole-derived CPXV isolate provides new insights into the genetic variability of CPXV in the putative reservoir host and is a valuable tool for further studies about CPXV-host interaction and molecular evolution of OPV.


2015 ◽  
Vol 89 (21) ◽  
pp. 10959-10969 ◽  
Author(s):  
Donata Hoffmann ◽  
Annika Franke ◽  
Maria Jenckel ◽  
Aistė Tamošiūnaitė ◽  
Julia Schluckebier ◽  
...  

ABSTRACTThe incidence of human cowpox virus (CPXV) infections has increased significantly in recent years. Serological surveys have suggested wild rodents as the main CPXV reservoir. We characterized a CPXV isolated during a large-scale screening from a feral common vole. A comparison of the full-length DNA sequence of this CPXV strain with a highly virulent pet rat CPXV isolate showed a sequence identity of 96%, including a large additional open reading frame (ORF) of about 6,000 nucleotides which is absent in the reference CPXV strain Brighton Red. Electron microscopy analysis demonstrated that the vole isolate, in contrast to the rat strain, forms A-type inclusion (ATI) bodies with incorporated virions, consistent with the presence of completeatiandp4cgenes. Experimental infections showed that the vole CPXV strain caused only mild clinical symptoms in its natural host, while all rats developed severe respiratory symptoms followed by a systemic rash. In contrast, common voles infected with a high dose of the rat CPXV showed severe signs of respiratory disease but no skin lesions, whereas infection with a low dose led to virus excretion with only mild clinical signs. We concluded that the common vole is susceptible to infection with different CPXV strains. The spectrum ranges from well-adapted viruses causing limited clinical symptoms to highly virulent strains causing severe respiratory symptoms. In addition, the low pathogenicity of the vole isolate in its eponymous host suggests a role of common voles as a major CPXV reservoir, and future research will focus on the correlation between viral genotype and phenotype/pathotype in accidental and reservoir species.IMPORTANCEWe report on the first detection and isolation of CPXV from a putative reservoir host, which enables comparative analyses to understand the infection cycle of these zoonotic orthopox viruses and the relevant genes involved.In vitrostudies, including whole-genome sequencing as well asin vivoexperiments using the Wistar rat model and the vole reservoir host allowed us to establish links between genomic sequences and thein vivoproperties (virulence) of the novel vole isolate in comparison to those of a recent zoonotic CPXV isolated from pet rats in 2009. Furthermore, the role of genes present only in a reservoir isolate can now be further analyzed. These studies therefore allow unique insights and conclusions about the role of the rodent reservoir in CPXV epidemiology and transmission and about the zoonotic threat that these viruses represent.


Viruses ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1069 ◽  
Author(s):  
Michelitsch ◽  
Tews ◽  
Klaus ◽  
Bestehorn-Willmann ◽  
Dobler ◽  
...  

Tick-borne encephalitis is the most important tick-transmitted zoonotic virus infection in Eurasia, causing severe neurological symptoms in humans. The causative agent, the tick-borne encephalitis virus (TBEV), circulates between ticks and a variety of mammalian hosts. To study the interaction between TBEV and one of its suspected reservoir hosts, bank voles of the Western evolutionary lineage were inoculated subcutaneously with either one of eight TBEV strains or the related attenuated Langat virus, and were euthanized after 28 days. In addition, a subset of four strains was characterized in bank voles of the Carpathian linage. Six bank voles were inoculated per strain, and were housed together in groups of three with one uninfected in-contact animal each. Generally, most bank voles did not show any clinical signs over the course of infection. However, one infected bank vole died and three had to be euthanized prematurely, all of which had been inoculated with the identical TBEV strain (Battaune 17-H9, isolated in 2017 in Germany from a bank vole). All inoculated animals seroconverted, while none of the in-contact animals did. Viral RNA was detected via real-time RT-PCR in the whole blood samples of 31 out of 74 inoculated and surviving bank voles. The corresponding serum sample remained PCR-negative in nearly all cases (29/31). In addition, brain and/or spine samples tested positive in 11 cases, mostly correlating with a positive whole blood sample. Our findings suggest a good adaption of TBEV to bank voles, combining in most cases a low virulence phenotype with detectable virus replication and hinting at a reservoir host function of bank voles for TBEV.


2019 ◽  
Author(s):  
Tomas Strandin ◽  
Teemu Smura ◽  
Paula Ahola ◽  
Kirsi Aaltonen ◽  
Tarja Sironen ◽  
...  

AbstractOrthohantaviruses are globally emerging zoonotic pathogens. Human infections are characterized by an overt immune response that is efficient at counteracting virus replication but can also cause severe tissue damage. In contrast, orthohantavirus infections in rodent reservoir hosts are persistent and asymptomatic. The mechanisms facilitating asymptomatic virus persistence in reservoir hosts are not well understood but could help to guide therapeutic strategies for human infections. Here we report on a study using in vivo and in vitro experiments to investigate immune responses associated with persistent Puumala orthohantavirus (PUUV) infections in the bank vole (Myodes glareolus), its reservoir host. We examined adaptive cellular and humoral responses by quantifying changes in T-cell related gene expression in the spleen and immunoglobulin (Ig) responses in blood, respectively. Since existing Vero E6-cell adapted hantavirus isolates have been demonstrated to have lost their wild-type infection characteristics, infections were conducted with a novel PUUV strain isolated on a bank vole cell line. Whole virus genome sequencing revealed that only minor sequence changes occurred during the isolation process, and critically, experimental infections of bank voles with the new isolate resembled natural infections. In vitro infection of bank vole splenocytes with the novel isolate demonstrated that PUUV promotes immunoregulatory responses by inducing interleukin-10, a cytokine strongly associated with chronic viral infections. A delayed virus-specific humoral response occurred in experimentally infected bank voles, which is likely to allow for initial virus replication and the establishment of persistent infections. These results suggest that host immunoregulation facilitates persistent orthohantavirus infections in reservoir hosts.ImportanceOrthohantaviruses are a group of global pathogens that regularly spillover from rodent reservoirs into humans and can cause severe disease. Conversely, infections in reservoir hosts do not cause obvious adverse effects. The mechanisms responsible for persistent asymptomatic reservoir infections are unknown, and progress has been hindered by the absence of an adequate experimental system. Knowledge on these mechanisms could help provide strategies to treat human infections. We developed and validated an experimental system based on an orthohantavirus isolated in cells of its vole reservoir host. Using animal and cell culture experiments in the reservoir host system, we demonstrated that infection suppresses immunity in the vole reservoir via specific mechanisms, likely allowing the virus to take hold and preventing immune responses that can cause self-damage.


Parasitology ◽  
2017 ◽  
Vol 145 (3) ◽  
pp. 393-407 ◽  
Author(s):  
A. DUBOIS ◽  
G. CASTEL ◽  
S. MURRI ◽  
C. PULIDO ◽  
J.-B. PONS ◽  
...  

SUMMARYEcoevolutionary processes affecting hosts, vectors and pathogens are important drivers of zoonotic disease emergence. In this study, we focused on nephropathia epidemica (NE), which is caused by Puumala hantavirus (PUUV) whose natural reservoir is the bank vole,Myodes glareolus. We questioned the possibility of NE emergence in a French region that is considered to be NE-free but that is adjacent to a NE-endemic region. We first confirmed the epidemiology of these two regions and we demonstrated the absence of spatial barriers that could have limited dispersal, and consequently, the spread of PUUV into the NE-free region. We next tested whether regional immunoheterogeneity could impact PUUV chances to circulate and persist in the NE-free region. We showed that bank voles from the NE-free region were sensitive to experimental PUUV infection. We observed high levels of immunoheterogeneity between individuals and also between regions. Antiviral gene expression (TnfandMx2) reached higher levels in bank voles from the NE-free region. During experimental infections, anti-PUUV antibody production was higher in bank voles from the NE-endemic region. These results indicated a lower susceptibility to PUUV for bank voles from this NE-free region, which might limit PUUV persistence and therefore, the risk of NE.


Viruses ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 44 ◽  
Author(s):  
Jenni Kesäniemi ◽  
Anton Lavrinienko ◽  
Eugene Tukalenko ◽  
Tapio Mappes ◽  
Phillip C. Watts ◽  
...  

Bank voles (Myodes glareolus) are host to many zoonotic viruses. As bank voles inhabiting areas contaminated by radionuclides show signs of immunosuppression, resistance to apoptosis, and elevated DNA repair activity, we predicted an association between virome composition and exposure to radionuclides. To test this hypothesis, we studied the bank vole virome in samples of plasma derived from animals inhabiting areas of Ukraine (contaminated areas surrounding the former nuclear power plant at Chernobyl, and uncontaminated areas close to Kyiv) that differed in level of environmental radiation contamination. We discovered four strains of hepacivirus and four new virus sequences: two adeno-associated viruses, an arterivirus, and a mosavirus. However, viral prevalence and viral load, and the ability to cause a systemic infection, was not dependent on the level of environmental radiation.


2017 ◽  
Author(s):  
Audrey Rohfritsch ◽  
Maxime Galan ◽  
Mathieu Gautier ◽  
Karim Gharbi ◽  
Gert Olsson ◽  
...  

AbstractInfectious pathogens are major selective forces acting on individuals. The recent advent of high-throughput sequencing technologies now enables to investigate the genetic bases of resistance/susceptibility to infections in non-model organisms. From an evolutionary perspective, the analysis of the genetic diversity observed at these genes in natural populations provides insight into the mechanisms maintaining polymorphism and their epidemiological consequences. We explored these questions in the context of the interactions between Puumala hantavirus (PUUV) and its reservoir host, the bank vole Myodes glareolus. Despite the continuous spatial distribution of M. glareolus in Europe, PUUV distribution is strongly heterogeneous. Different defence strategies might have evolved in bank voles as a result of co-adaptation with PUUV, which may in turn reinforce spatial heterogeneity in PUUV distribution. We performed a genome scan study of six bank vole populations sampled along a North/South transect in Sweden, including PUUV endemic and non-endemic areas. We combined candidate gene analyses (Tlr4, Tlr7, Mx2 genes) and high throughput sequencing of RAD (Restriction-site Associated DNA) markers. We found evidence for outlier loci showing high levels of genetic differentiation. Ten outliers among the 52 that matched to mouse protein-coding genes corresponded to immune related genes and were detected using ecological associations with variations in PUUV prevalence. One third of the enriched pathways concerned immune processes, including platelet activation and TLR pathway. In the future, functional experimentations should enable to confirm the role of these these immune related genes with regard to the interactions between M. glareolus and PUUV.


2017 ◽  
Vol 44 (1) ◽  
pp. 72 ◽  
Author(s):  
E. Notz ◽  
C. Imholt ◽  
D. Reil ◽  
J. Jacob

Context Live traps are regularly used in field and enclosure studies with mammals. In some scenarios, such as, for example, when the focus is on temporal patterns or to minimise the time animals are contained inside the trap for animal-ethics reasons, it can be highly useful to be alerted immediately when an individual is trapped. Aims In the present study, an automated system was trialed that is designed to automatically send a signal to a receiving device (pager, computer, mobile phone) when the body heat or movement of a trapped small mammal is registered by an infrared sensor (ERMINEA permanent monitoring system for rodent detection). Methods Sensors were attached to Ugglan multiple-capture traps and used in laboratory conditions and in semi-natural outdoor enclosures with common voles (Microtus arvalis) and bank voles (Myodes glareolus), as well as in the field with bank voles, Apodemus species and common voles. Sensor readings were compared to visual observation and trapping results. Key results In enclosure and field conditions, 100% and 98.7% of traps recorded captured animals correctly. There were no sensor signals when rodents moved along the outside or in the entrance compartment of the traps. Rodents sitting on the trap door triggered the sensor in 50% of cases when there was no bedding in the trap; however, there were no sensor signals if bedding was present. In laboratory trials, 20–70% of traps were falsely triggered by large insects (crickets), depending on ambient temperature and whether bedding was in the trap. Conclusions Generally, the system was a reliable, flexible and easy-to-handle tool to monitor live captures. To minimise false negatives (animals trapped without signal), testing sensor function in the pre-baiting phase and software adjustments are recommended. Implications The sensors are compatible with various trapping and other monitoring devices, providing the potential to be used in a wide range of applications. Their use is likely to optimise study designs, especially when temporal patterns are recorded or animals or samples need to be obtained soon after capture, and to minimise stress of trapped animals because they can be removed shortly after capture.


2009 ◽  
Vol 138 (1) ◽  
pp. 91-98 ◽  
Author(s):  
E. BENNETT ◽  
J. CLEMENT ◽  
P. SANSOM ◽  
I. HALL ◽  
S. LEACH ◽  
...  

SUMMARYPuumala virus (PUUV) is a zoonotic rodent-borne hantavirus in continental Europe. Its reservoir host, the bank vole (Myodes glareolus), is ubiquitous in Great Britain (GB); however, there has been no reported incidence of virus in either animals or humans. In northwest Europe, increases in bank vole numbers, stimulated by increases in production of beech/oak crops (mast), are associated with outbreaks of nephropathia epidemica (NE) in humans. These so-called ‘mast years’ are determined by sequential climatic events. This paper investigates the contribution of a number of ecological and environmental factors driving outbreaks of PUUV in northwest Europe and assesses whether such factors might also permit enzootic PUUV circulation in GB. Analysis of GB climate data, using regression models, confirms that mast years in GB are stimulated, and can be predicted, by the same climatic events as mast years in PUUV-endemic regions of northwest Europe. A number of other possible non-climatic constraints on enzootic cycles are discussed.


Open Biology ◽  
2017 ◽  
Vol 7 (9) ◽  
pp. 170135 ◽  
Author(s):  
Grace M. Loxley ◽  
Jennifer Unsworth ◽  
Michael J. Turton ◽  
Alexandra Jebb ◽  
Kathryn S. Lilley ◽  
...  

The urine of bank voles ( Myodes glareolus ) contains substantial quantities of a small protein that is expressed at much higher levels in males than females, and at higher levels in males in the breeding season. This protein was purified and completely sequenced at the protein level by mass spectrometry. Leucine/isoleucine ambiguity was completely resolved by metabolic labelling, monitoring the incorporation of dietary deuterated leucine into specific sites in the protein. The predicted mass of the sequenced protein was exactly consonant with the mass of the protein measured in bank vole urine samples, correcting for the formation of two disulfide bonds. The sequence of the protein revealed that it was a lipocalin related to aphrodisin and other odorant-binding proteins (OBPs), but differed from all OBPs previously described. The pattern of secretion in urine used for scent marking by male bank voles, and the similarity to other lipocalins used as chemical signals in rodents, suggest that this protein plays a role in male sexual and/or competitive communication. We propose the name glareosin for this novel protein to reflect the origin of the protein and to emphasize the distinction from known OBPs.


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