| 1. |
- Ling, Jiaxin, et al.
(författare)
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Evolution and postglacial colonization of Seewis hantavirus with Sorex araneus in Finland
- 2018
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Ingår i: Infection, Genetics and Evolution. - : Elsevier BV. - 1567-1348 .- 1567-7257. ; 57, s. 88-97
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Tidskriftsartikel (refereegranskat)abstract
- Hantaviruses have co-existed with their hosts for millions of years. Seewis virus (SWSV), a soricomorph-borne hantavirus, is widespread in Eurasia, ranging from Central Siberia to Western Europe. To gain insight into the phylogeography and evolutionary history of SWSV in Finland, lung tissue samples of 225 common shrews (Sorex araneus) trapped from different parts of Finland were screened for the presence of SWSV RNA. Forty-two of the samples were positive. Partial small (S), medium (M) and large (L) segments of the virus were sequenced, and analyzed together with all SWSV sequences available in Genbank. The phylogenetic analysis of the partial S-segment sequences suggested that all Finnish SWSV strains shared their most recent common ancestor with the Eastern European strains, while the L-segment suggested multiple introductions. The difference between the Land S-segment phylogenies implied that reassortment events play a role in the evolution of SWSV. Of the Finnish strains, variants from Eastern Finland occupied the root position in the phylogeny, and had the highest genetic diversity, supporting the hypothesis that SWSV reached Finland first form the east. During the spread in Finland, the virus has formed three separate lineages, identified here by correlation analysis of genetic versus geographic distance combined with median-joining network analysis. These results support the hypothesis that Finnish SWSV recolonized Finland with its host, the common shrew, from east after the last ice age 12,000-8000 years ago, and then subsequently spread along emerging land bridges towards west or north with the migration and population expansion of its host.
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| 2. |
- Ling, Jiaxin, et al.
(författare)
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Introduction and Dispersal of Sindbis Virus from Central Africa to Europe
- 2019
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Ingår i: Journal of Virology. - : AMER SOC MICROBIOLOGY. - 0022-538X .- 1098-5514. ; 93:16
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Tidskriftsartikel (refereegranskat)abstract
- Bird-hosted viruses have the potential to be transported over large areas of the world and to be transmitted in distant geographical regions. Sindbis virus (SINV) is a mosquito-borne alphavirus that is locally amplified in a bird-mosquito enzootic cycle and distributed all over the Old World and Australia/Oceania. Sindbis virus genotype I (SINV-I) is the cause of disease outbreaks in humans in South Africa as well as in northern Europe. To trace the evolutionary history and potential strain-disease association of SINV-I, we sequenced 36 complete genomes isolated from field material in Europe, as well as in Africa and the Middle East, collected over 58 years. These were analyzed together with 30 additional published whole SINV-I genomes using Bayesian analysis. Our results suggested that SINV-I was introduced only once to northern Europe from central Africa, in the 1920s. After its first introduction to Sweden, it spread east and southward on two separate occasions in the 1960s and 1970s. Another introduction from central Africa to southern/central Europe seems to have occurred, and where these two introductions meet, one recombination event was detected in central Europe. In addition, another recombinant strain was found in central Africa, where the most divergent SINV-I strains also originated. IMPORTANCE This study shows that only a single introduction of SINV into a new geographical area is required for spread and establishment, provided that the requisite vector(s) and reservoir(s) of epizootological and epidemiological importance are present. Furthermore, we present the first report of recombination between two strains of SINV in nature. Our study increases the knowledge on new introductions and dispersal of arboviruses in general and of SINV in particular.
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| 3. |
- Masika, Moses Muia, et al.
(författare)
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Serological Evidence of Exposure to Onyong-Nyong and Chikungunya Viruses in Febrile Patients of Rural Taita-Taveta County and Urban Kibera Informal Settlement in Nairobi, Kenya
- 2022
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Ingår i: Viruses. - : MDPI. - 1999-4915. ; 14:6
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Tidskriftsartikel (refereegranskat)abstract
- Several alphaviruses, such as chikungunya (CHIKV) and Onyong-nyong (ONNV), are endemic in Kenya and often cause outbreaks in different parts of the country. We assessed the seroprevalence of alphaviruses in patients with acute febrile illness in two geographically distant areas in Kenya with no previous record of alphavirus outbreaks. Blood samples were collected from febrile patients in health facilities located in the rural Taita-Taveta County in 2016 and urban Kibera informal settlement in Nairobi in 2017 and tested for CHIKV IgG and IgM antibodies using an in-house immunofluorescence assay (IFA) and a commercial ELISA test, respectively. A subset of CHIKV IgG or IgM antibody-positive samples were further analyzed using plaque reduction neutralization tests (PRNT) for CHIKV, ONNV, and Sindbis virus. Out of 537 patients, 4 (0.7%) and 28 (5.2%) had alphavirus IgM and IgG antibodies, respectively, confirmed on PRNT. We show evidence of previous and current exposure to alphaviruses based on serological testing in areas with no recorded history of outbreaks.
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| 4. |
- Paulsen, Katrine M., et al.
(författare)
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High-throughput sequencing of two European strains of tick-borne encephalitis virus (TBEV), Hochosterwitz and 1993/783
- 2021
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Ingår i: Ticks and Tick-borne Diseases. - : Elsevier. - 1877-959X .- 1877-9603. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- Tick-borne encephalitis virus (TBEV) is a medically important arbovirus, widespread in Europe and Asia. The virus is primarily transmitted to humans and animals by bites from ticks and, in rare cases, by consumption of unpasteurized dairy products. The aim of this study was to sequence and characterize two TBEV strains with amplicon sequencing by designing overlapping primers. The amplicon sequencing, via Illumina MiSeq, covering nearly the entire TBEV genome, was successful: We retrieved and characterized the complete polyprotein sequence of two TBEV strains, Hochosterwitz and 1993/783 from Austria and Sweden, respectively. In this study the previous phylogenetic analysis of both strains was confirmed to be of the European subtypes of TBEV (TBEV-Eu) by whole genome sequencing. The Hochosterwitz strain clustered with the two strains KrM 93 and KrM 213 from South Korea, and the 1993/783 strain clustered together with the NL/UH strain from the Netherlands. Our study confirms the suitability and rapidness of the high-throughput sequencing method used to produce complete TBEV genomes from TBEV samples of high viral load giving high-molecular-weight cDNA with large overlapping amplicons.
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| 5. |
- Ravlo, Erlend, et al.
(författare)
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Boosted production of antibodies which neutralized different SARS-CoV-2 variants in a COVID-19 convalescent following mRNA vaccination - a case study
- 2023
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Ingår i: International Journal of Infectious Diseases. - 1878-3511. ; 137, s. 75-78
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Tidskriftsartikel (refereegranskat)abstract
- Vaccinated convalescents do not develop severe COVID-19 after infection with new SARS-CoV-2 variants. We questioned how mRNA vaccination of convalescents provides protection from emerging virus variant. From the cohort of 71 convalescent plasma donors, we identified a patient who developed immune response to infection with SARS-CoV-2 variant of 20A clade and who subsequently received mRNA vaccine encoding S protein of strain of 19A clade. We showed that vaccination increased the production of immune cells and anti-S antibodies in the serum. Serum antibodies neutralized not only 19A and 20A, but also 20B, 20H, 21J and 21K virus variants. One of the serum antibodies (100F8) completely neutralized 20A, 21J and partially 21K strains. 100F8 was structurally similarly to published Ab188 antibody, which recognized non-conserved epitope on the S protein. We proposed that 100F8 and other serum antibodies of the patient which recognized non- and conserved epitopes of the S protein, could have additive or synergistic effect to neutralize various virus variants. Thus, mRNA vaccination could be beneficial for convalescents because it boosts production of neutralizing antibodies with broad-spectrum activity. -.
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