scholarly journals Myxoma virus jumps species to the Iberian hare

2019 ◽  
Vol 66 (6) ◽  
pp. 2218-2226 ◽  
Author(s):  
Kevin P. Dalton ◽  
José M. Martín ◽  
Inés Nicieza ◽  
Ana Podadera ◽  
Daniel Llano ◽  
...  
Keyword(s):  
Myxoma Virus ◽  
Iberian Hare

scholarly journals First description of a herpesvirus infection in genus Lepus

2020 ◽  
Author(s):  
F.A. Abade dos Santos ◽  
M. Monteiro ◽  
A. Pinto ◽  
C.L. Carvalho ◽  
M.C. Peleteiro ◽  
...  
Keyword(s):  
Stromal Cells ◽  
Inclusion Bodies ◽  
International Committee ◽  
Myxoma Virus ◽  
Sequencing Analysis ◽  
Wild Populations ◽  
Herpesvirus Infection ◽  
Transmission Electron ◽  
The Impact ◽  
Iberian Hare

AbstractDuring the necropsies of Iberian hares obtained in 2018/2019, along with signs of the nodular form of myxomatosis, other unexpected external lesions were also observed. Histopathology revealed nuclear inclusion bodies in stromal cells suggesting the additional presence of a nuclear replicating virus.Transmission electron microscopy further demonstrated the presence of herpesvirus particles in the tissues of affected hares.We confirmed the presence of herpesvirus in 13 MYXV-positive hares by PCR and sequencing analysis. Herpesvirus-DNA was also detected in seven healthy hares, suggesting its asymptomatic circulation.Phylogenetic analysis based on DNA polymerase gene, grouped this virus within the gammaherpesviruses, close to herpesviruses from bats and rodents.We propose to name this new virus Leporid gammaherpesvirus 5 (LeHV-5), according to the International Committee on Taxonomy of Viruses standards.The impact of herpesvirus infection on the reproduction and mortality of the Iberian hare is yet unknown but may aggravate the decline of wild populations caused by the recently emerged natural recombinant myxoma virus.

scholarly journals A Versatile qPCR for Diagnosis of Leporid Gammaherpesvirus 5 Using Evagreen® or Taqman® Technologies

Viruses ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 715
Author(s):  
Fábio A. Abade dos Santos ◽  
Carina L. Carvalho ◽  
Maria C. Peleteiro ◽  
Francisco Parra ◽  
Margarida D. Duarte
Keyword(s):  
Sensitivity And Specificity ◽  
Internal Control ◽  
18S Rrna ◽  
Pcr Amplification ◽  
18S Rrna Gene ◽  
Myxoma Virus ◽  
Rrna Gene ◽  
Molecular Method ◽  
The Real ◽  
Iberian Hare

In late 2019, the first herpesvirus in the genus Lepus, named leporid gammaherpesvirus 5 (LeHV-5) was described. At the time, herpetic typical lesions were observed in hares infected by the myxoma virus, which is known to induce immunosuppression. Though the real impact of LeHV-5 is still poorly understood, since it affects reproduction, it poses an additional threat to the already fragile populations of Iberian hare, demanding prevalence investigations. In this article, we describe the first quantitative molecular method for LeHV-5 detection, using either Taqman or the EvaGreen systems. This method has excellent sensitivity and specificity, it is able to detect 2.1 copies of LeHV-5 DNA and was validated with an internal control targeting the 18S rRNA gene, allowing monitoring extraction and PCR amplification efficiencies.

scholarly journals A Quadruplex qPCR for Detection and Differentiation of Classic and Natural Recombinant Myxoma Virus Strains of Leporids

2021 ◽  
Vol 22 (21) ◽  
pp. 12052
Author(s):  
Fábio A. Abade dos Santos ◽  
Carina L. Carvalho ◽  
Francisco Parra ◽  
Kevin P. Dalton ◽  
Maria C. Peleteiro ◽  
...  
Keyword(s):  
Real Time ◽  
Housekeeping Gene ◽  
Myxoma Virus ◽  
European Rabbit ◽  
Fast Method ◽  
Wild Rabbit ◽  
Viral Dna ◽  
Eukaryotic Organisms ◽  
Virus Strains ◽  
Iberian Hare

A natural recombinant myxoma virus (referred to as ha-MYXV or MYXV-Tol08/18) emerged in the Iberian hare (Lepus granatensis) and the European rabbit (Oryctolagus cuniculus) in late 2018 and mid-2020, respectively. This new virus is genetically distinct from classic myxoma virus (MYXV) strains that caused myxomatosis in rabbits until then, by acquiring an additional 2.8 Kbp insert within the m009L gene that disrupted it into ORFs m009L-a and m009L-b. To distinguish ha-MYXV from classic MYXV strains, we developed a robust qPCR multiplex technique that combines the amplification of the m000.5L/R duplicated gene, conserved in all myxoma virus strains including ha-MYXV, with the amplification of two other genes targeted by the real-time PCR systems designed during this study, specific either for classic MYXV or ha-MYXV strains. The first system targets the boundaries between ORFs m009L-a and m009L-b, only contiguous in classic strains, while the second amplifies a fragment within gene m060L, only present in recombinant MYXV strains. All amplification reactions were validated and normalized by a fourth PCR system directed to a housekeeping gene (18S rRNA) conserved in eukaryotic organisms, including hares and rabbits. The multiplex PCR (mPCR) technique described here was optimized for Taqman® and Evagreen® systems allowing the detection of as few as nine copies of viral DNA in the sample with an efficiency > 93%. This real-time multiplex is the first fast method available for the differential diagnosis between classic and recombinant MYXV strains, also allowing the detection of co-infections. The system proves to be an essential and effective tool for monitoring the geographical spread of ha-MYXV in the hare and wild rabbit populations, supporting the management of both species in the field.

scholarly journals Genetic characterization of a recombinant myxoma virus leap into the Iberian hare (Lepus granatensis)

2019 ◽  
Author(s):  
Ana Águeda-Pinto ◽  
Ana Lemos de Matos ◽  
Mário Abrantes ◽  
Simona Kraberger ◽  
Maria A. Risalde ◽  
...  
Keyword(s):  
Myxoma Virus ◽  
Open Reading Frames ◽  
Lepus Europaeus ◽  
European Rabbit ◽  
New Host ◽  
Tissue Samples ◽  
Lepus Granatensis ◽  
Domestic Rabbits ◽  
Iberian Hare

AbstractMyxomatosis is a lethal disease of wild European and domestic rabbits (Oryctolagus cuniculus) caused by a Myxoma virus (MYXV) infection, a leporipoxvirus that is found naturally in someSylvilagusrabbit species in South America and California. The introduction of MYXV in the early 1950s into feral European rabbit populations in Australia and Europe demonstrate the best documented field example of host-virus coevolution following a cross-species transmission. Recently, a new cross-species jump of MYXV has been suggested in both Great Britain and Spain, where European brown hares (Lepus europaeus) and Iberian hares (Lepus granatensis) were found dead with lesions consistent with those observed in myxomatosis. To investigate the possibility of a new cross-species transmission event by MYXV, tissue samples collected from a wild Iberian hare found dead in Spain (Toledo region) were analyzed and deep sequenced. Our results report a new MYXV strain (MYXV Toledo) in the tissues of this species. The genome of this new strain encodes three disrupted genes (M009L,M036LandM152R) and a novel 2.8 KB recombinant region that resulted from an insertion of four novel poxviral genes towards the 5’ end of its genome. From the open reading frames inserted into the MYXV Toledo strain, a new orthologue of a poxvirus host range gene family member was identified which is related to the MYXV geneM064R. Overall, we confirmed the identity of a new MYXV strain in Iberian hares that we hypothesize was able to more effectively counteract the host defenses in hares and start an infectious process in this new host.

scholarly journals Detection of Recombinant Hare Myxoma Virus in Wild Rabbits (Oryctolagus cuniculus algirus)

Viruses ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 1127
Author(s):  
Fábio A. Abade dos Santos ◽  
Carina L. Carvalho ◽  
Andreia Pinto ◽  
Ranjit Rai ◽  
Madalena Monteiro ◽  
...  
Keyword(s):  
Myxoma Virus ◽  
Virus Infectivity ◽  
Sequencing Analysis ◽  
Wild Rabbit ◽  
Mainland Portugal ◽  
Viral Particles ◽  
Domestic Rabbits ◽  
Virus Strains ◽  
Iberian Hare ◽  
Species Segregation

In late 2018, an epidemic myxomatosis outbreak emerged on the Iberian Peninsula leading to high mortality in Iberian hare populations. A recombinant Myxoma virus (strains MYXV-Tol and ha-MYXV) was rapidly identified, harbouring a 2.8 kbp insertion containing evolved duplicates of M060L, M061L, M064L, and M065L genes from myxoma virus (MYXV) or other Poxviruses. Since 2017, 1616 rabbits and 125 hares were tested by a qPCR directed to M000.5L/R gene, conserved in MYXV and MYXV-Tol/ha-MYXV strains. A subset of the positive samples (20%) from both species was tested for the insert with MYXV being detected in rabbits and the recombinant MYXV in hares. Recently, three wild rabbits were found dead South of mainland Portugal, showing skin oedema and pulmonary lesions that tested positive for the 2.8 kbp insert. Sequencing analysis showed 100% similarity with the insert sequences described in Iberian hares from Spain. Viral particles were observed in the lungs and eyelids of rabbits by electron microscopy, and isolation in RK13 cells attested virus infectivity. Despite that the analysis of complete genomes may predict the recombinant MYXV strains’ ability to infect rabbit, routine analyses showed species segregation for the circulation of MYXV and recombinant MYXV in wild rabbit and in Iberian hares, respectively. This study demonstrates, however, that recombinant MYXV can effectively infect and cause myxomatosis in wild rabbits and domestic rabbits, raising serious concerns for the future of the Iberian wild leporids while emphasises the need for the continuous monitoring of MYXV and recombinant MYXV in both species.

First cases of myxomatosis in Iberian hares (Lepus granatensis) in Portugal

2020 ◽  
Vol 8 (2) ◽  
pp. e001044 ◽  
Author(s):  
Carina Luísa Carvalho ◽  
Fábio Alexandre Abade dos Santos ◽  
Madelena Monteiro ◽  
Paulo Carvalho ◽  
Paula Mendonça ◽  
...  
Keyword(s):  
Body Condition ◽  
Myxoma Virus ◽  
Common Origin ◽  
Lepus Granatensis ◽  
Short Course ◽  
Good Body Condition ◽  
Myxoid Matrix ◽  
Gross Lesions ◽  
Perineal Region ◽  
Iberian Hare

Myxomatosis was detected in Iberian hares (Lepus granatensis) in Portugal, October 2018, following its emergence in Spain 3 months earlier. Here, we describe the epidemiological, molecular and anatomo-histopathological data of the first two cases. Myxoma virus DNA was detected in the eyelids, nose and perineal region in both hares. It was also detected in the lungs of hare 1 and in the spleen and liver of hare 2. The genomic insertion identified in strains from Spain was confirmed in both strains suggesting a common origin for the Iberian viruses. Gross lesions in hare 1 included palpebral oedema and conjunctival mucopurulent discharge, common in both forms of the disease in rabbits. Hare 2 presented eyelid thickening with small diffuse nodules. Histopathology of the eyelids showed extracellular myxoid matrix in hare 1 and purulent dermatitis in hare 2. Both animals exhibited good body condition, suggesting a short course of the disease and higher virulence of the virus towards the Iberian hare.

scholarly journals Genetic Characterization of a Recombinant Myxoma Virus in the Iberian Hare (Lepus granatensis)

Viruses ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 530 ◽  
Author(s):  
Ana Águeda-Pinto ◽  
Ana Lemos de Matos ◽  
Mário Abrantes ◽  
Simona Kraberger ◽  
Maria A. Risalde ◽  
...  
Keyword(s):  
Myxoma Virus ◽  
Open Reading Frames ◽  
Lepus Europaeus ◽  
European Rabbit ◽  
New Host ◽  
Tissue Samples ◽  
Lepus Granatensis ◽  
Domestic Rabbits ◽  
Iberian Hare

Myxomatosis is a lethal disease in wild European and domestic rabbits (Oryctolagus cuniculus), which is caused by a Myxoma virus (MYXV) infection—a leporipoxvirus that is found naturally in some Sylvilagus rabbit species in South America and California. The introduction of MYXV into feral European rabbit populations of Australia and Europe, in the early 1950s, demonstrated the best-documented field example of host–virus coevolution, following a cross-species transmission. Recently, a new cross-species jump of MYXV has been suggested in both Great Britain and Spain, where European brown hares (Lepus europaeus) and Iberian hares (Lepus granatensis) were found dead with lesions consistent with those observed in myxomatosis. To investigate the possibility of a new cross-species transmission event by MYXV, tissue samples collected from a wild Iberian hare found dead in Spain (Toledo region) were analyzed and deep sequenced. Our results reported a new MYXV isolate (MYXV Toledo) in the tissues of this species. The genome of this new virus was found to encode three disruptive genes (M009L, M036L, and M152R) and a novel ~2.8 kb recombinant region, which resulted from an insertion of four novel poxviral genes towards the 3’ end of the negative strand of its genome. From the open reading frames inserted into the MYXV Toledo virus, a new orthologue of a poxvirus host range gene family member was identified, which was related to the MYXV gene M064R. Overall, we confirmed the identity of a new MYXV isolate in Iberian hares, which, we hypothesized, was able to more effectively counteract the host defenses in hares and start an infectious process in this new host.

scholarly journals Detection of Recombinant Hare Myxoma Virus in Wild Rabbits (Oryctolagus cuniculus algirus)

2020 ◽  
Author(s):  
Fábio A. Abade dos Santos ◽  
Carina L. Carvalho ◽  
Andreia Pinto ◽  
Ranjit Rai ◽  
Madalena Monteiro ◽  
...  
Keyword(s):  
Myxoma Virus ◽  
Virus Infectivity ◽  
Wild Rabbit ◽  
R Gene ◽  
Viral Particles ◽  
Domestic Rabbits ◽  
South Portugal ◽  
Iberian Hare ◽  
Continue Monitoring ◽  
Species Segregation

In late 2018, an epidemic myxomatosis outbreak emerged on the Iberian Peninsula leading to high mortality in Iberian hare populations. Soon, a recombinant virus (MYXV-Tol or ha-MYXV) was identified, harboring a 2.8 kb insertion containing evolved duplicates of M060L, M061L, M064L, and M065L from MYXV. Since 2017, 1616 rabbits and 82 hares were tested by a qPCR directed to M000.5L/R gene, conserved in MYXV and MYXV-Tol/ ha-MYXV strains. A subset (20%) of the positive samples was tested for the insert with MYXV being detected in rabbits and recombinant MYXV in hares. Recently, two wild rabbits found dead in South Portugal, showing skin oedema and pulmonary lesions tested positive for the 2.8 Kb insert. Sequencing showed 100% similarity with the insert sequences described in Iberian hares from Spain. Viral particles were observed in the lungs of both rabbits by electron microscopy, and isolation in RK13 cells showed virus infectivity. Despite the analysis of recombinant MYXV genomes may predict its ability to infect rabbit, routine analyses showed species segregation for the circulation of MYXV and recombinant MYXV in wild rabbit and in Iberian hares, respectively. This study demonstrates, however, that recombinant MYXV can effectively infect and cause myxomatosis in wild rabbits and domestic rabbits, which raises serious concerns for the future of the Iberian wild leporids and emphasizes the need to continue monitoring MYXV and recombinant MYXV in both species.

scholarly journals The differential transmissibility of myxoma virus strains of differing virulence grades by the rabbit flea Spilopsyllus cuniculi (Dale)

1975 ◽  
Vol 75 (2) ◽  
pp. 237-247 ◽  
Author(s):  
A. R. Mead-Briggs ◽  
J. A. Vaughan
Keyword(s):  
Host Resistance ◽  
Oryctolagus Cuniculus ◽  
Selective Advantage ◽  
Myxoma Virus ◽  
Laboratory Studies ◽  
Natural Conditions ◽  
Male And Female ◽  
The Mean ◽  
Virus Strains ◽  
Sampling Times

SUMMARYLaboratory studies showed that few rabbit fleas (Spilopsyllus cuniculi (Dale)) transmitted myxomatosis after removal from wild rabbits (Oryctolagus cuniculus (L)) that had been infected for fewer than 10–12 days, irrespective of the virulence of the myxoma virus strain involved. Rabbits infected with fully virulent (Grade I) strains died within 10–15 days and few fleas from these hosts became infective; averaging all the samples taken, 12% of the fleas were infective. Also, few fleas acquired infectivity on individual rabbits which recovered from infection with attenuated strains; the mean was 8% infective. Rabbits which died between 17 and 44 days after infection had higher proportions of infective fleas at all sampling times; the mean was 42% infective. Male and female fleas transmitted virus with equal efficiency.For rabbits infected with any of the attenuated virus strains the mean percentage of infective fleas was inversely related to the survival time of the host. Rabbits infected with moderately attenuated strains (Grades IIIA and IIIB) had, on average, the highest proportion of infective fleas; hence such strains have a selective advantage and have become predominant under natural conditions in Britain. The changes that might occur if there is an increase in host resistance to myxomatosis are discussed.

Myxoma virus and malignant rabbit fibroma virus encode a serpin-like protein important for virus virulence

Virology ◽  
1990 ◽  
Vol 179 (2) ◽  
pp. 618-631 ◽  
Author(s):  
C. Upton ◽  
J.L. Macen ◽  
D.S. Wishart ◽  
G. McFadden
Keyword(s):  
Myxoma Virus
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