Viral replication kinetics and in vitro cytopathogenicity of parental and reassortant strains of bluetongue virus serotype 1, 6 and 8

M.P.A. Coetzee, M. van Vuuren, M. Stokstad, M. Myrmel, H.G.P. van Gennip, P.A. van Rijn, E.H. Venter

Research output: Contribution to journalArticleAcademicpeer-review

10 Citations (Scopus)

Abstract

Bluetongue virus (BTV), a segmented dsRNA virus, is the causative agent of bluetongue (BT), an economically important viral haemorrhagic disease of ruminants. Bluetongue virus can exchange its genome segments in mammalian or insect cells that have been co-infected with more than one strain of the virus. This process, may potentially give rise to the generation of novel reassortant strains that may differ from parental strains in regards to their phenotypic characteristics. To investigate the potential effects of reassortment on the virus’ phenotype, parental as well as reassortant strains of BTV serotype 1, 6, 8, that were derived from attenuated and wild type strains by reverse genetics, were studied in vitro for their virus replication kinetics and cytopathogenicity in mammalian (Vero) cell cultures. The results indicate that genetic reassortment can affect viral replication kinetics, the cytopathogenicity and extent/mechanism of cell death in infected cell cultures. In particular, some reassortants of non-virulent vaccine (BTV-1 and BTV-6) and virulent field origin (BTV-8) demonstrate more pronounced cytopathic effects compared to their parental strains. Some reassortant strains in addition replicated to high titres in vitro despite being composed of genome segments from slow and fast replicating parental strains. The latter result may have implications for the level of viraemia in the mammalian host and subsequent uptake and transmission of reassortant strains (and their genome segments) by Culicoides vectors. Increased rates of CPE induction could further suggest a higher virulence for reassortant strains in vivo. Overall, these findings raise questions in regards to the use of modified-live virus (MLV) vaccines and risk of reassortment in the field. To further address these questions, additional experimental infection studies using insects and/or animal models should be conducted, to determine whether these results have significant implications in vivo
Original languageEnglish
Pages (from-to)53-65
JournalVeterinary Microbiology
Volume171
Issue number1-2
DOIs
Publication statusPublished - 2014

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Bluetongue virus
cytopathogenicity
virus replication
serotypes
kinetics
Viruses
Genome
Insects
Vaccines
Cell Culture Techniques
Bluetongue
Ceratopogonidae
Reverse Genetics
Vero Cells
Viremia
viruses
Ruminants
genome
Virus Diseases
Virus Replication

Keywords

  • genome segment reassortment
  • newcastle-disease virus
  • nonstructural protein
  • mixed infection
  • transplacental transmission
  • culicoides-variipennis
  • genetic reassortment
  • avirulent strains
  • bovine fetuses
  • messenger-rna

Cite this

Coetzee, M.P.A. ; van Vuuren, M. ; Stokstad, M. ; Myrmel, M. ; van Gennip, H.G.P. ; van Rijn, P.A. ; Venter, E.H. / Viral replication kinetics and in vitro cytopathogenicity of parental and reassortant strains of bluetongue virus serotype 1, 6 and 8. In: Veterinary Microbiology. 2014 ; Vol. 171, No. 1-2. pp. 53-65.
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title = "Viral replication kinetics and in vitro cytopathogenicity of parental and reassortant strains of bluetongue virus serotype 1, 6 and 8",
abstract = "Bluetongue virus (BTV), a segmented dsRNA virus, is the causative agent of bluetongue (BT), an economically important viral haemorrhagic disease of ruminants. Bluetongue virus can exchange its genome segments in mammalian or insect cells that have been co-infected with more than one strain of the virus. This process, may potentially give rise to the generation of novel reassortant strains that may differ from parental strains in regards to their phenotypic characteristics. To investigate the potential effects of reassortment on the virus’ phenotype, parental as well as reassortant strains of BTV serotype 1, 6, 8, that were derived from attenuated and wild type strains by reverse genetics, were studied in vitro for their virus replication kinetics and cytopathogenicity in mammalian (Vero) cell cultures. The results indicate that genetic reassortment can affect viral replication kinetics, the cytopathogenicity and extent/mechanism of cell death in infected cell cultures. In particular, some reassortants of non-virulent vaccine (BTV-1 and BTV-6) and virulent field origin (BTV-8) demonstrate more pronounced cytopathic effects compared to their parental strains. Some reassortant strains in addition replicated to high titres in vitro despite being composed of genome segments from slow and fast replicating parental strains. The latter result may have implications for the level of viraemia in the mammalian host and subsequent uptake and transmission of reassortant strains (and their genome segments) by Culicoides vectors. Increased rates of CPE induction could further suggest a higher virulence for reassortant strains in vivo. Overall, these findings raise questions in regards to the use of modified-live virus (MLV) vaccines and risk of reassortment in the field. To further address these questions, additional experimental infection studies using insects and/or animal models should be conducted, to determine whether these results have significant implications in vivo",
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author = "M.P.A. Coetzee and {van Vuuren}, M. and M. Stokstad and M. Myrmel and {van Gennip}, H.G.P. and {van Rijn}, P.A. and E.H. Venter",
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Viral replication kinetics and in vitro cytopathogenicity of parental and reassortant strains of bluetongue virus serotype 1, 6 and 8. / Coetzee, M.P.A.; van Vuuren, M.; Stokstad, M.; Myrmel, M.; van Gennip, H.G.P.; van Rijn, P.A.; Venter, E.H.

In: Veterinary Microbiology, Vol. 171, No. 1-2, 2014, p. 53-65.

Research output: Contribution to journalArticleAcademicpeer-review

TY - JOUR

T1 - Viral replication kinetics and in vitro cytopathogenicity of parental and reassortant strains of bluetongue virus serotype 1, 6 and 8

AU - Coetzee, M.P.A.

AU - van Vuuren, M.

AU - Stokstad, M.

AU - Myrmel, M.

AU - van Gennip, H.G.P.

AU - van Rijn, P.A.

AU - Venter, E.H.

PY - 2014

Y1 - 2014

N2 - Bluetongue virus (BTV), a segmented dsRNA virus, is the causative agent of bluetongue (BT), an economically important viral haemorrhagic disease of ruminants. Bluetongue virus can exchange its genome segments in mammalian or insect cells that have been co-infected with more than one strain of the virus. This process, may potentially give rise to the generation of novel reassortant strains that may differ from parental strains in regards to their phenotypic characteristics. To investigate the potential effects of reassortment on the virus’ phenotype, parental as well as reassortant strains of BTV serotype 1, 6, 8, that were derived from attenuated and wild type strains by reverse genetics, were studied in vitro for their virus replication kinetics and cytopathogenicity in mammalian (Vero) cell cultures. The results indicate that genetic reassortment can affect viral replication kinetics, the cytopathogenicity and extent/mechanism of cell death in infected cell cultures. In particular, some reassortants of non-virulent vaccine (BTV-1 and BTV-6) and virulent field origin (BTV-8) demonstrate more pronounced cytopathic effects compared to their parental strains. Some reassortant strains in addition replicated to high titres in vitro despite being composed of genome segments from slow and fast replicating parental strains. The latter result may have implications for the level of viraemia in the mammalian host and subsequent uptake and transmission of reassortant strains (and their genome segments) by Culicoides vectors. Increased rates of CPE induction could further suggest a higher virulence for reassortant strains in vivo. Overall, these findings raise questions in regards to the use of modified-live virus (MLV) vaccines and risk of reassortment in the field. To further address these questions, additional experimental infection studies using insects and/or animal models should be conducted, to determine whether these results have significant implications in vivo

AB - Bluetongue virus (BTV), a segmented dsRNA virus, is the causative agent of bluetongue (BT), an economically important viral haemorrhagic disease of ruminants. Bluetongue virus can exchange its genome segments in mammalian or insect cells that have been co-infected with more than one strain of the virus. This process, may potentially give rise to the generation of novel reassortant strains that may differ from parental strains in regards to their phenotypic characteristics. To investigate the potential effects of reassortment on the virus’ phenotype, parental as well as reassortant strains of BTV serotype 1, 6, 8, that were derived from attenuated and wild type strains by reverse genetics, were studied in vitro for their virus replication kinetics and cytopathogenicity in mammalian (Vero) cell cultures. The results indicate that genetic reassortment can affect viral replication kinetics, the cytopathogenicity and extent/mechanism of cell death in infected cell cultures. In particular, some reassortants of non-virulent vaccine (BTV-1 and BTV-6) and virulent field origin (BTV-8) demonstrate more pronounced cytopathic effects compared to their parental strains. Some reassortant strains in addition replicated to high titres in vitro despite being composed of genome segments from slow and fast replicating parental strains. The latter result may have implications for the level of viraemia in the mammalian host and subsequent uptake and transmission of reassortant strains (and their genome segments) by Culicoides vectors. Increased rates of CPE induction could further suggest a higher virulence for reassortant strains in vivo. Overall, these findings raise questions in regards to the use of modified-live virus (MLV) vaccines and risk of reassortment in the field. To further address these questions, additional experimental infection studies using insects and/or animal models should be conducted, to determine whether these results have significant implications in vivo

KW - genome segment reassortment

KW - newcastle-disease virus

KW - nonstructural protein

KW - mixed infection

KW - transplacental transmission

KW - culicoides-variipennis

KW - genetic reassortment

KW - avirulent strains

KW - bovine fetuses

KW - messenger-rna

U2 - 10.1016/j.vetmic.2014.03.006

DO - 10.1016/j.vetmic.2014.03.006

M3 - Article

VL - 171

SP - 53

EP - 65

JO - Veterinary Microbiology

JF - Veterinary Microbiology

SN - 0378-1135

IS - 1-2

ER -