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Peter P. C. Mertens - One of the best experts on this subject based on the ideXlab platform.

  • Quantitative RT-PCR assays for identification and typing of the Equine Encephalosis Virus
    Brazilian Journal of Microbiology, 2019
    Co-Authors: Sushila Maan, Manjunatha N. Belaganahalli, Narender Singh Maan, Abraham C. Potgieter, Peter P. C. Mertens
    Abstract:

    Equine Encephalosis (EE) is an acute, arthropod-borne, noncontagious, febrile disease of equids. The clinical signs of EE are similar to milder forms of African horse sickness (AHS) and the two diseases can be easily confused. The Equine Encephalosis Virus (EEV) is a distinct Virus species within the genus OrbiVirus , family Reoviridae , with ten linear segments of dsRNA genome. Seven distinct serotypes of EEV have been recognised on the basis of sequence analyses of Seg-2. The need for differential diagnosis of similar forms of EE and AHS warranted the development of molecular diagnostic methods for specific detection and identification of EEV. We report the development of quantitative real-time RT-PCR assay for detection of any member of the EEV species targeting the highly conserved EEV Seg-9. Similar serotype-specific qRT-PCR assays were designed for each of the seven EEV serotypes targeting genome Seg-2, encoding the serotype determining VP2 protein. These assays were evaluated using different EEV serotypes and other closely related orbiViruses. They were shown to be EEV Virus species–specific, or EEV type–specific capable of detecting 1 to 13 copies of viral RNA in clinical samples. The assays failed to detect RNA from closely related orbiViruses, including AHSV and Peruvian horse sickness Virus (PHSV) isolates.

  • quantitative rt pcr assays for identification and typing of the Equine Encephalosis Virus
    Brazilian Journal of Microbiology, 2019
    Co-Authors: Sushila Maan, Narender S. Maan, Peter P. C. Mertens, Manjunatha N. Belaganahalli, Abraham C. Potgieter
    Abstract:

    Equine Encephalosis (EE) is an acute, arthropod-borne, noncontagious, febrile disease of equids. The clinical signs of EE are similar to milder forms of African horse sickness (AHS) and the two diseases can be easily confused. The Equine Encephalosis Virus (EEV) is a distinct Virus species within the genus OrbiVirus, family Reoviridae, with ten linear segments of dsRNA genome. Seven distinct serotypes of EEV have been recognised on the basis of sequence analyses of Seg-2. The need for differential diagnosis of similar forms of EE and AHS warranted the development of molecular diagnostic methods for specific detection and identification of EEV. We report the development of quantitative real-time RT-PCR assay for detection of any member of the EEV species targeting the highly conserved EEV Seg-9. Similar serotype-specific qRT-PCR assays were designed for each of the seven EEV serotypes targeting genome Seg-2, encoding the serotype determining VP2 protein. These assays were evaluated using different EEV serotypes and other closely related orbiViruses. They were shown to be EEV Virus species–specific, or EEV type–specific capable of detecting 1 to 13 copies of viral RNA in clinical samples. The assays failed to detect RNA from closely related orbiViruses, including AHSV and Peruvian horse sickness Virus (PHSV) isolates. Electronic supplementary material The online version of this article (10.1007/s42770-018-0034-1) contains supplementary material, which is available to authorized users.

  • Specificity of AHSV Virus-species-specific assays (Seg-1 and Seg-3).
    2014
    Co-Authors: Katarzyna Bachanek-bankowska, Sushila Maan, Carrie Batten, Narender Singh Maan, Abraham C. Potgieter, Javier Castillo-olivares, Nicola M. Manning, Antonello Di Nardo, Geoff Sutton, Peter P. C. Mertens
    Abstract:

    Representatives of different serotypes and topotypes from five different OrbiVirus species (AHSV, EEV, PHSV, EHDV and BTV) were tested to confirm the specificity of assays for AHSV dsRNA. Further details on these isolates can be obtained from ORC http://www.reoviridae.org/dsRNA_Virus_proteins/ReoID/Viruses-at-iah.htm[61]. EEV  =  Equine Encephalosis Virus; PHSV  =  Peruvian horse sickness Virus; EHDV  =  Epizootic haemorrhagic disease Virus; BTV  =  Bluetongue Virus. RSA  =  Republic of South Africa.

  • Percent amino acid and nucleotide identities of WALV (AUS1978/09), MUDV (AUS1982/03) and WARV (AUS1969/01) with other orbiViruses in VP1(Pol), T2 and T13 protein/genes.
    2014
    Co-Authors: Manjunatha N. Belaganahalli, Houssam Attoui, Sushila Maan, Narender S. Maan, Ian Pritchard, Peter D. Kirkland, Joe Brownlie, Peter P. C. Mertens
    Abstract:

    BTV =  Bluetongue Virus; BTV1e  =  BTV-1 eastern topotype; BTV8w  =  BTV-8 western topotype; EHDV =  Epizootic haemorrhagic disease; EHDV1w  =  EHDV-1 western topotype; EHDV2e  =  EHDV-2 eastern topotype; PATAV  =  Pata Virus; EUBV  =  Eubenangee Virus; TILV  =  Tilligerry Virus; WALV  =  Wallal Virus; MUDV  =  Mudjinbarry Virus; WARV  =  Warrego Virus; AHSV  =  African horse sickness Virus; CHUV  =  Chuzan Virus; EEV  =  Equine Encephalosis Virus; PHSV  =  Peruvian horse sickness Virus; YUOV  =  Yunnan orbiVirus; UMAV  =  Umatilla Virus; SLOV  =  Stretch Lagoon orbiVirus; CORV  =  Corriparta Virus; SVIV  =  Sathuvachari Virus; TRBV  =  Tribec Virus; KEMV  =  Kemorovo Virus; GIV  =  Great Island Virus; SCRV  =  St Croix river Virus.The highest identities were written in bold font.Percent amino acid and nucleotide identities of WALV (AUS1978/09), MUDV (AUS1982/03) and WARV (AUS1969/01) with other orbiViruses in VP1(Pol), T2 and T13 protein/genes.

  • Maximum likelihood (ML) trees showing phylogenetic comparisons of T2 protein amino acid sequences (a) and nucleotide sequences of Seg-3 (b) of WALV, MUDV and WARV, aligned with those of other OrbiVirus species.
    2014
    Co-Authors: Manjunatha N. Belaganahalli, Houssam Attoui, Sushila Maan, Narender S. Maan, Ian Pritchard, Peter D. Kirkland, Joe Brownlie, Peter P. C. Mertens
    Abstract:

    One thousand bootstrap replicates were used for construction of the phylogenetic trees. The WALV, MUDV and WARV isolates characterised in this study are marked with green circle. BTV =  Bluetongue Virus; AHSV =  African Horse sickness Virus; EHDV =  Epizootic Haemorrhagic Disease Virus; CHUV =  Chuzan Virus; EUBV =  Eubenangee Virus; TILV =  Tilligerry Virus; PATAV =  Pata Virus; EEV =  Equine Encephalosis Virus; WARV =  Warrego Virus; WALV =  Wallal Virus; MUDV =  Mudjinbarry Virus; CORV =  Corriparta Virus; UMAV =  Umatilla Virus; SLOV =  Stretch Lagoon orbiVirus; SVIV =  Sathuvachari Virus; YUOV =  Yunnan orbiVirus; PHSV =  Peruvian horse sickness Virus; TRBV =  Tribec Virus; TRBVh =  another isolate of Tribec Virus; LIPV =  Lipovnik Virus; LIPV =  Lipovnik Virus isolate CzArLip 91; KEMV =  Kemerovo Virus; KEMVh =  Kemerovo Virus isolate EgAn 1169-61; GIV =  Great Island Virus; SCRV =  St Croix river Virus. Virus isolates and accession numbers of polymerase sequences used for comparative analysis are listed in Table S1 in File S1. ‘e’ and ‘w’ after serotype number indicate eastern and western strains, respectively.

A J Guthrie - One of the best experts on this subject based on the ideXlab platform.

  • the sero prevalence and sero incidence of african horse sickness and Equine Encephalosis in selected horse and donkey populations in zimbabwe
    Onderstepoort Journal of Veterinary Research, 2017
    Co-Authors: Stuart J G Gordon, A J Guthrie, P. S. Mellor, Charlotte F Bolwell, C W Rogers, Godfrey Musuka, P J Kelly, C. Hamblin
    Abstract:

    Sentinel herds and samples submitted by private Equine practitioners were used to determine the sero-prevalence and sero-incidence of African horse sickness Virus (AHSV) and Equine Encephalosis Virus (EEV) in horse and donkey populations in the Highveld region of Zimbabwe. The sero-prevalence and sero-incidence of antibodies against these Viruses were determined using the competitive enzyme-linked immunosorbent assay (ELISA) for the detection of serum antibodies. In donkeys, the median sero-prevalence of AHSV antibodies, across the three rainy seasons under study, was 75% (inter quartile range [IQR] 67–83), with a seasonal median sero-incidence of 45% (IQR 40–63). In horses, the median sero-prevalence of EEV antibodies was 63% (IQR 21–73), with a median seasonal sero-incidence of 10.5% (IQR 10–14), while in donkeys the median sero-prevalence of EEV antibodies was 80% (IQR 67–90), with a median seasonal sero-incidence of 50% (IQR 40–60). This study highlighted the significant levels of exposure of donkeys to AHSV and horses and donkeys to EEV in Zimbabwe despite Equine Encephalosis remaining unreported by Zimbabwean veterinarians to date. Most seroconversions in sentinel herd animals to AHSV and EEV occurred towards the end of the rainy season in March, April and May corresponding to the time of the year when the  Culicoides vectors are in high abundance. In order to determine the clinical significance of these infections, blood and spleen samples, submitted by private Equine veterinary practitioners over a 5-year period, from horses showing characteristic clinical signs of African horse sickness were tested for the presence of viral antigen using the antigen capture ELISA. The median sero-prevalence of AHSV antigen in horses recorded from these samples was 38% (IQR 33–88). The predominant AHSV antigen from these samples was serotype 7 (33%) followed by serotype 2 (26%) and serotypes 4 and 8 (16% each). African horse sickness Virus serotypes 3 and 9, identified in this study, had not been previously reported in Zimbabwe.

  • *Corresponding author:
    2016
    Co-Authors: J E Crafford, A J Guthrie, M. Van Vuuren, P.p.c. Mertens, J.n. Burroughs, C. Hamblin, C. A. Batten
    Abstract:

    detection of antibodies to Equine Encephalosis Virus (EEV) was developed. The assay measures the competition between a specific guinea pig antiserum and a test serum, for a pre-titrated EEV antigen. The C-ELISA detected antibodies to the seven known EEV serotypes. Reference antisera raised against other arboViruses did not cross react with EEV antigen. Negative sera from horses in the United Kingdom were used to establish the baseline for a negative population. Negative and positive populations of South African horses, selected on the basis of Virus neutralisation were assayed subsequently. Optimal test parameters, where sensitivity @ specificity @ 100%, were calculated by two-graph receiver operator characteristic (TG-ROC) analysis to be at a cut-off value of 29.5% inhibition. Results show the EEV C- ELISA described to be sensitive, specific and reliable. Used in conjunction with ELISAs available for African horse sickness Virus (AHSV), differential serological diagnosis between EEV and AHSV can be achieved

  • re emergence of bluetongue african horse sickness and other orbiVirus diseases
    Veterinary Research, 2010
    Co-Authors: James N Maclachlan, A J Guthrie
    Abstract:

    Arthropod-transmitted Viruses (ArboViruses) are important causes of disease in humans and animals, and it is proposed that climate change will increase the distribution and severity of arboviral diseases. OrbiViruses are the cause of important and apparently emerging arboviral diseases of livestock, including bluetongue Virus (BTV), African horse sickness Virus (AHSV), Equine Encephalosis Virus (EEV), and epizootic hemorrhagic disease Virus (EHDV) that are all transmitted by haematophagous Culicoides insects. Recent changes in the global distribution and nature of BTV infection have been especially dramatic, with spread of multiple serotypes of the Virus throughout extensive portions of Europe and invasion of the south-eastern USA with previously exotic Virus serotypes. Although climate change has been incriminated in the emergence of BTV infection of ungulates, the precise role of anthropogenic factors and the like is less certain. Similarly, although there have been somewhat less dramatic recent alterations in the distribution of EHDV, AHSV, and EEV, it is not yet clear what the future holds in terms of these diseases, nor of other potentially important but poorly characterized OrbiViruses such as Peruvian horse sickness Virus.

  • prevalence of serotype specific antibody to Equine Encephalosis Virus in thoroughbred yearlings in south africa 1999 2004
    Onderstepoort Journal of Veterinary Research, 2008
    Co-Authors: P G Howell, J P Nurton, Daleen Nel, Carina W Lourens, A J Guthrie
    Abstract:

    Cohorts of yearlings were sampled over a period of 6 years in a retrospective serological survey to establish the annual prevalence of serotype specific antibody to Equine Encephalosis Virus on Thoroughbred stud farms distributed within defined geographical regions of South Africa. Seasonal seroprevalence varied between 3.6% and 34.7%, revealing both single and multiple serotype infections in an individual yearling. During the course of this study serotypes 1 and 6 were most frequently and extensively identified while the remaining serotypes 2, 3, 4, 5 and 7 were all identified as sporadic and localized infections affecting only individual horses. This study of the seasonal prevalence of Equine Encephalosis Virus has a corollary and serves as a useful model in the seasonal incidence of the serotypes of African horse sickness and bluetongue in regions where the respective diseases are endemic.

  • molecular epidemiology of the african horse sickness Virus s10 gene
    Journal of General Virology, 2008
    Co-Authors: Melvyn Quan, Moritz Van Vuuren, P G Howell, Daleen Groenewald, A J Guthrie
    Abstract:

    Between 2004 and 2006, 145 African horse sickness Viruses (AHSV) were isolated from blood and organ samples submitted from South Africa to the Faculty of Veterinary Science, University of Pretoria. All nine serotypes were represented, with a range of 3–60 isolates per serotype. The RNA small segment 10 (S10) nucleotide sequences of these isolates were determined and the phylogeny investigated. AHSV, bluetongue Virus (BTV) and Equine Encephalosis Virus (EEV) all formed monophyletic groups and BTV was genetically closer to AHSV than EEV. This study confirmed the presence of three distinct S10 phylogenetic clades (α, β and γ). Some serotypes (6, 8 and 9 in α; 3 and 7 in β; 2 in γ) were restricted to a single clade, while other serotypes (1, 4 and 5) clustered into both the α and γ clades. Strong purifying selection was evident and a constant molecular clock was inappropriate. The S10 gene is the second most variable gene of the AHSV genome and the use of S10 in molecular epidemiology was illustrated by an AHS outbreak in the Western Cape in 2004. It was shown that two separate AHSV were circulating in the area, even though AHSV serotype 1 was the only isolate from the outbreak. The small size of the gene (755–764 bp) and conserved terminal regions facilitate easy and quick sequencing. The establishment of an S10 sequence database is important for characterizing outbreaks of AHS. It will be an essential resource for elucidating the epidemiology of AHS.

Sushila Maan - One of the best experts on this subject based on the ideXlab platform.

  • Quantitative RT-PCR assays for identification and typing of the Equine Encephalosis Virus
    Brazilian Journal of Microbiology, 2019
    Co-Authors: Sushila Maan, Manjunatha N. Belaganahalli, Narender Singh Maan, Abraham C. Potgieter, Peter P. C. Mertens
    Abstract:

    Equine Encephalosis (EE) is an acute, arthropod-borne, noncontagious, febrile disease of equids. The clinical signs of EE are similar to milder forms of African horse sickness (AHS) and the two diseases can be easily confused. The Equine Encephalosis Virus (EEV) is a distinct Virus species within the genus OrbiVirus , family Reoviridae , with ten linear segments of dsRNA genome. Seven distinct serotypes of EEV have been recognised on the basis of sequence analyses of Seg-2. The need for differential diagnosis of similar forms of EE and AHS warranted the development of molecular diagnostic methods for specific detection and identification of EEV. We report the development of quantitative real-time RT-PCR assay for detection of any member of the EEV species targeting the highly conserved EEV Seg-9. Similar serotype-specific qRT-PCR assays were designed for each of the seven EEV serotypes targeting genome Seg-2, encoding the serotype determining VP2 protein. These assays were evaluated using different EEV serotypes and other closely related orbiViruses. They were shown to be EEV Virus species–specific, or EEV type–specific capable of detecting 1 to 13 copies of viral RNA in clinical samples. The assays failed to detect RNA from closely related orbiViruses, including AHSV and Peruvian horse sickness Virus (PHSV) isolates.

  • quantitative rt pcr assays for identification and typing of the Equine Encephalosis Virus
    Brazilian Journal of Microbiology, 2019
    Co-Authors: Sushila Maan, Narender S. Maan, Peter P. C. Mertens, Manjunatha N. Belaganahalli, Abraham C. Potgieter
    Abstract:

    Equine Encephalosis (EE) is an acute, arthropod-borne, noncontagious, febrile disease of equids. The clinical signs of EE are similar to milder forms of African horse sickness (AHS) and the two diseases can be easily confused. The Equine Encephalosis Virus (EEV) is a distinct Virus species within the genus OrbiVirus, family Reoviridae, with ten linear segments of dsRNA genome. Seven distinct serotypes of EEV have been recognised on the basis of sequence analyses of Seg-2. The need for differential diagnosis of similar forms of EE and AHS warranted the development of molecular diagnostic methods for specific detection and identification of EEV. We report the development of quantitative real-time RT-PCR assay for detection of any member of the EEV species targeting the highly conserved EEV Seg-9. Similar serotype-specific qRT-PCR assays were designed for each of the seven EEV serotypes targeting genome Seg-2, encoding the serotype determining VP2 protein. These assays were evaluated using different EEV serotypes and other closely related orbiViruses. They were shown to be EEV Virus species–specific, or EEV type–specific capable of detecting 1 to 13 copies of viral RNA in clinical samples. The assays failed to detect RNA from closely related orbiViruses, including AHSV and Peruvian horse sickness Virus (PHSV) isolates. Electronic supplementary material The online version of this article (10.1007/s42770-018-0034-1) contains supplementary material, which is available to authorized users.

  • Specificity of AHSV Virus-species-specific assays (Seg-1 and Seg-3).
    2014
    Co-Authors: Katarzyna Bachanek-bankowska, Sushila Maan, Carrie Batten, Narender Singh Maan, Abraham C. Potgieter, Javier Castillo-olivares, Nicola M. Manning, Antonello Di Nardo, Geoff Sutton, Peter P. C. Mertens
    Abstract:

    Representatives of different serotypes and topotypes from five different OrbiVirus species (AHSV, EEV, PHSV, EHDV and BTV) were tested to confirm the specificity of assays for AHSV dsRNA. Further details on these isolates can be obtained from ORC http://www.reoviridae.org/dsRNA_Virus_proteins/ReoID/Viruses-at-iah.htm[61]. EEV  =  Equine Encephalosis Virus; PHSV  =  Peruvian horse sickness Virus; EHDV  =  Epizootic haemorrhagic disease Virus; BTV  =  Bluetongue Virus. RSA  =  Republic of South Africa.

  • Percent amino acid and nucleotide identities of WALV (AUS1978/09), MUDV (AUS1982/03) and WARV (AUS1969/01) with other orbiViruses in VP1(Pol), T2 and T13 protein/genes.
    2014
    Co-Authors: Manjunatha N. Belaganahalli, Houssam Attoui, Sushila Maan, Narender S. Maan, Ian Pritchard, Peter D. Kirkland, Joe Brownlie, Peter P. C. Mertens
    Abstract:

    BTV =  Bluetongue Virus; BTV1e  =  BTV-1 eastern topotype; BTV8w  =  BTV-8 western topotype; EHDV =  Epizootic haemorrhagic disease; EHDV1w  =  EHDV-1 western topotype; EHDV2e  =  EHDV-2 eastern topotype; PATAV  =  Pata Virus; EUBV  =  Eubenangee Virus; TILV  =  Tilligerry Virus; WALV  =  Wallal Virus; MUDV  =  Mudjinbarry Virus; WARV  =  Warrego Virus; AHSV  =  African horse sickness Virus; CHUV  =  Chuzan Virus; EEV  =  Equine Encephalosis Virus; PHSV  =  Peruvian horse sickness Virus; YUOV  =  Yunnan orbiVirus; UMAV  =  Umatilla Virus; SLOV  =  Stretch Lagoon orbiVirus; CORV  =  Corriparta Virus; SVIV  =  Sathuvachari Virus; TRBV  =  Tribec Virus; KEMV  =  Kemorovo Virus; GIV  =  Great Island Virus; SCRV  =  St Croix river Virus.The highest identities were written in bold font.Percent amino acid and nucleotide identities of WALV (AUS1978/09), MUDV (AUS1982/03) and WARV (AUS1969/01) with other orbiViruses in VP1(Pol), T2 and T13 protein/genes.

  • Maximum likelihood (ML) trees showing phylogenetic comparisons of T2 protein amino acid sequences (a) and nucleotide sequences of Seg-3 (b) of WALV, MUDV and WARV, aligned with those of other OrbiVirus species.
    2014
    Co-Authors: Manjunatha N. Belaganahalli, Houssam Attoui, Sushila Maan, Narender S. Maan, Ian Pritchard, Peter D. Kirkland, Joe Brownlie, Peter P. C. Mertens
    Abstract:

    One thousand bootstrap replicates were used for construction of the phylogenetic trees. The WALV, MUDV and WARV isolates characterised in this study are marked with green circle. BTV =  Bluetongue Virus; AHSV =  African Horse sickness Virus; EHDV =  Epizootic Haemorrhagic Disease Virus; CHUV =  Chuzan Virus; EUBV =  Eubenangee Virus; TILV =  Tilligerry Virus; PATAV =  Pata Virus; EEV =  Equine Encephalosis Virus; WARV =  Warrego Virus; WALV =  Wallal Virus; MUDV =  Mudjinbarry Virus; CORV =  Corriparta Virus; UMAV =  Umatilla Virus; SLOV =  Stretch Lagoon orbiVirus; SVIV =  Sathuvachari Virus; YUOV =  Yunnan orbiVirus; PHSV =  Peruvian horse sickness Virus; TRBV =  Tribec Virus; TRBVh =  another isolate of Tribec Virus; LIPV =  Lipovnik Virus; LIPV =  Lipovnik Virus isolate CzArLip 91; KEMV =  Kemerovo Virus; KEMVh =  Kemerovo Virus isolate EgAn 1169-61; GIV =  Great Island Virus; SCRV =  St Croix river Virus. Virus isolates and accession numbers of polymerase sequences used for comparative analysis are listed in Table S1 in File S1. ‘e’ and ‘w’ after serotype number indicate eastern and western strains, respectively.

P G Howell - One of the best experts on this subject based on the ideXlab platform.

  • A competitive ELISA for the detection of group-specific antibody to Equine Encephalosis Virus
    Journal of Virological Methods, 2011
    Co-Authors: Jan Ernst Crafford, P G Howell, Carrie Batten, Alan John Guthrie, M. Van Vuuren, P.p.c. Mertens, J.n. Burroughs, C. Hamblin
    Abstract:

    Abstract A polyclonal antibody-based, group-specific, competitive ELISA (C-ELISA) for the detection of antibodies to Equine Encephalosis Virus (EEV) was developed. The assay measures the competition between a specific guinea pig antiserum and a test serum, for a pre-titrated EEV antigen. The C-ELISA detected antibodies to the seven known EEV serotypes. Reference antisera raised against other arboViruses did not cross react with EEV antigen. Negative sera from horses in the United Kingdom were used to establish the baseline for a negative population. Negative and positive populations of South African horses, selected on the basis of Virus neutralisation were assayed subsequently. Optimal test parameters, where sensitivity ≅ specificity ≅ 100%, were calculated by two-graph receiver operator characteristic (TG-ROC) analysis to be at a cut-off value of 29.5% inhibition. Results show the EEV C-ELISA described to be sensitive, specific and reliable. Used in conjunction with ELISAs available for African horse sickness Virus (AHSV), differential serological diagnosis between EEV and AHSV can be achieved.

  • prevalence of serotype specific antibody to Equine Encephalosis Virus in thoroughbred yearlings in south africa 1999 2004
    Onderstepoort Journal of Veterinary Research, 2008
    Co-Authors: P G Howell, J P Nurton, Daleen Nel, Carina W Lourens, A J Guthrie
    Abstract:

    Cohorts of yearlings were sampled over a period of 6 years in a retrospective serological survey to establish the annual prevalence of serotype specific antibody to Equine Encephalosis Virus on Thoroughbred stud farms distributed within defined geographical regions of South Africa. Seasonal seroprevalence varied between 3.6% and 34.7%, revealing both single and multiple serotype infections in an individual yearling. During the course of this study serotypes 1 and 6 were most frequently and extensively identified while the remaining serotypes 2, 3, 4, 5 and 7 were all identified as sporadic and localized infections affecting only individual horses. This study of the seasonal prevalence of Equine Encephalosis Virus has a corollary and serves as a useful model in the seasonal incidence of the serotypes of African horse sickness and bluetongue in regions where the respective diseases are endemic.

  • molecular epidemiology of the african horse sickness Virus s10 gene
    Journal of General Virology, 2008
    Co-Authors: Melvyn Quan, Moritz Van Vuuren, P G Howell, Daleen Groenewald, A J Guthrie
    Abstract:

    Between 2004 and 2006, 145 African horse sickness Viruses (AHSV) were isolated from blood and organ samples submitted from South Africa to the Faculty of Veterinary Science, University of Pretoria. All nine serotypes were represented, with a range of 3–60 isolates per serotype. The RNA small segment 10 (S10) nucleotide sequences of these isolates were determined and the phylogeny investigated. AHSV, bluetongue Virus (BTV) and Equine Encephalosis Virus (EEV) all formed monophyletic groups and BTV was genetically closer to AHSV than EEV. This study confirmed the presence of three distinct S10 phylogenetic clades (α, β and γ). Some serotypes (6, 8 and 9 in α; 3 and 7 in β; 2 in γ) were restricted to a single clade, while other serotypes (1, 4 and 5) clustered into both the α and γ clades. Strong purifying selection was evident and a constant molecular clock was inappropriate. The S10 gene is the second most variable gene of the AHSV genome and the use of S10 in molecular epidemiology was illustrated by an AHS outbreak in the Western Cape in 2004. It was shown that two separate AHSV were circulating in the area, even though AHSV serotype 1 was the only isolate from the outbreak. The small size of the gene (755–764 bp) and conserved terminal regions facilitate easy and quick sequencing. The establishment of an S10 sequence database is important for characterizing outbreaks of AHS. It will be an essential resource for elucidating the epidemiology of AHS.

  • Correspondence
    2008
    Co-Authors: Alan J Guthrie, P G Howell, Daleen Groenewald, Moritz Van Vuuren, Melvyn Quan
    Abstract:

    Pretoria. All nine serotypes were represented, with a range of 3–60 isolates per serotype. The RNA small segment 10 (S10) nucleotide sequences of these isolates were determined and the phylogeny investigated. AHSV, bluetongue Virus (BTV) and Equine Encephalosis Virus (EEV) all formed monophyletic groups and BTV was genetically closer to AHSV than EEV. This study confirmed the presence of three distinct S10 phylogenetic clades (a, b and c). Some serotypes (6

  • Molecular epidemiology of the African horse sickness Virus S10 gene.
    The Journal of general virology, 2008
    Co-Authors: Melvyn Quan, P G Howell, Daleen Groenewald, Moritz Van Vuuren, Alan J Guthrie
    Abstract:

    Between 2004 and 2006, 145 African horse sickness Viruses (AHSV) were isolated from blood and organ samples submitted from South Africa to the Faculty of Veterinary Science, University of Pretoria. All nine serotypes were represented, with a range of 3-60 isolates per serotype. The RNA small segment 10 (S10) nucleotide sequences of these isolates were determined and the phylogeny investigated. AHSV, bluetongue Virus (BTV) and Equine Encephalosis Virus (EEV) all formed monophyletic groups and BTV was genetically closer to AHSV than EEV. This study confirmed the presence of three distinct S10 phylogenetic clades (alpha, beta and gamma). Some serotypes (6, 8 and 9 in alpha; 3 and 7 in beta; 2 in gamma) were restricted to a single clade, while other serotypes (1, 4 and 5) clustered into both the alpha and gamma clades. Strong purifying selection was evident and a constant molecular clock was inappropriate. The S10 gene is the second most variable gene of the AHSV genome and the use of S10 in molecular epidemiology was illustrated by an AHS outbreak in the Western Cape in 2004. It was shown that two separate AHSV were circulating in the area, even though AHSV serotype 1 was the only isolate from the outbreak. The small size of the gene (755-764 bp) and conserved terminal regions facilitate easy and quick sequencing. The establishment of an S10 sequence database is important for characterizing outbreaks of AHS. It will be an essential resource for elucidating the epidemiology of AHS.

Narender S. Maan - One of the best experts on this subject based on the ideXlab platform.

  • quantitative rt pcr assays for identification and typing of the Equine Encephalosis Virus
    Brazilian Journal of Microbiology, 2019
    Co-Authors: Sushila Maan, Narender S. Maan, Peter P. C. Mertens, Manjunatha N. Belaganahalli, Abraham C. Potgieter
    Abstract:

    Equine Encephalosis (EE) is an acute, arthropod-borne, noncontagious, febrile disease of equids. The clinical signs of EE are similar to milder forms of African horse sickness (AHS) and the two diseases can be easily confused. The Equine Encephalosis Virus (EEV) is a distinct Virus species within the genus OrbiVirus, family Reoviridae, with ten linear segments of dsRNA genome. Seven distinct serotypes of EEV have been recognised on the basis of sequence analyses of Seg-2. The need for differential diagnosis of similar forms of EE and AHS warranted the development of molecular diagnostic methods for specific detection and identification of EEV. We report the development of quantitative real-time RT-PCR assay for detection of any member of the EEV species targeting the highly conserved EEV Seg-9. Similar serotype-specific qRT-PCR assays were designed for each of the seven EEV serotypes targeting genome Seg-2, encoding the serotype determining VP2 protein. These assays were evaluated using different EEV serotypes and other closely related orbiViruses. They were shown to be EEV Virus species–specific, or EEV type–specific capable of detecting 1 to 13 copies of viral RNA in clinical samples. The assays failed to detect RNA from closely related orbiViruses, including AHSV and Peruvian horse sickness Virus (PHSV) isolates. Electronic supplementary material The online version of this article (10.1007/s42770-018-0034-1) contains supplementary material, which is available to authorized users.

  • Percent amino acid and nucleotide identities of WALV (AUS1978/09), MUDV (AUS1982/03) and WARV (AUS1969/01) with other orbiViruses in VP1(Pol), T2 and T13 protein/genes.
    2014
    Co-Authors: Manjunatha N. Belaganahalli, Houssam Attoui, Sushila Maan, Narender S. Maan, Ian Pritchard, Peter D. Kirkland, Joe Brownlie, Peter P. C. Mertens
    Abstract:

    BTV =  Bluetongue Virus; BTV1e  =  BTV-1 eastern topotype; BTV8w  =  BTV-8 western topotype; EHDV =  Epizootic haemorrhagic disease; EHDV1w  =  EHDV-1 western topotype; EHDV2e  =  EHDV-2 eastern topotype; PATAV  =  Pata Virus; EUBV  =  Eubenangee Virus; TILV  =  Tilligerry Virus; WALV  =  Wallal Virus; MUDV  =  Mudjinbarry Virus; WARV  =  Warrego Virus; AHSV  =  African horse sickness Virus; CHUV  =  Chuzan Virus; EEV  =  Equine Encephalosis Virus; PHSV  =  Peruvian horse sickness Virus; YUOV  =  Yunnan orbiVirus; UMAV  =  Umatilla Virus; SLOV  =  Stretch Lagoon orbiVirus; CORV  =  Corriparta Virus; SVIV  =  Sathuvachari Virus; TRBV  =  Tribec Virus; KEMV  =  Kemorovo Virus; GIV  =  Great Island Virus; SCRV  =  St Croix river Virus.The highest identities were written in bold font.Percent amino acid and nucleotide identities of WALV (AUS1978/09), MUDV (AUS1982/03) and WARV (AUS1969/01) with other orbiViruses in VP1(Pol), T2 and T13 protein/genes.

  • Maximum likelihood (ML) trees showing phylogenetic comparisons of T2 protein amino acid sequences (a) and nucleotide sequences of Seg-3 (b) of WALV, MUDV and WARV, aligned with those of other OrbiVirus species.
    2014
    Co-Authors: Manjunatha N. Belaganahalli, Houssam Attoui, Sushila Maan, Narender S. Maan, Ian Pritchard, Peter D. Kirkland, Joe Brownlie, Peter P. C. Mertens
    Abstract:

    One thousand bootstrap replicates were used for construction of the phylogenetic trees. The WALV, MUDV and WARV isolates characterised in this study are marked with green circle. BTV =  Bluetongue Virus; AHSV =  African Horse sickness Virus; EHDV =  Epizootic Haemorrhagic Disease Virus; CHUV =  Chuzan Virus; EUBV =  Eubenangee Virus; TILV =  Tilligerry Virus; PATAV =  Pata Virus; EEV =  Equine Encephalosis Virus; WARV =  Warrego Virus; WALV =  Wallal Virus; MUDV =  Mudjinbarry Virus; CORV =  Corriparta Virus; UMAV =  Umatilla Virus; SLOV =  Stretch Lagoon orbiVirus; SVIV =  Sathuvachari Virus; YUOV =  Yunnan orbiVirus; PHSV =  Peruvian horse sickness Virus; TRBV =  Tribec Virus; TRBVh =  another isolate of Tribec Virus; LIPV =  Lipovnik Virus; LIPV =  Lipovnik Virus isolate CzArLip 91; KEMV =  Kemerovo Virus; KEMVh =  Kemerovo Virus isolate EgAn 1169-61; GIV =  Great Island Virus; SCRV =  St Croix river Virus. Virus isolates and accession numbers of polymerase sequences used for comparative analysis are listed in Table S1 in File S1. ‘e’ and ‘w’ after serotype number indicate eastern and western strains, respectively.

  • Serotype Specific Primers and Gel-Based RT-PCR Assays for ‘Typing ’ African Horse Sickness Virus: Identification of Strains from Africa
    2013
    Co-Authors: Narender S. Maan, Sushila Maan, Kyriaki Nomikou, Manjunatha N. Belaganahalli, Katarzyna Bachanek, Peter P. C. Mertens
    Abstract:

    African horse sickness is a devastating, transboundary animal disease, that is ‘listed ’ by the Office International des Epizooties (OIE). Although attenuated, inactivated and subunit vaccines have been developed for African horse sickness Virus (AHSV), these are serotype-specific and their effective deployment therefore relies on rapid and reliable identification of Virus type. AHSV serotype is controlled by the specificity of interactions between neutralising antibodies, and components of the outer-capsid, particularly protein VP2 (encoded by AHSV genome segment 2 (Seg-2)). We report the development and evaluation of novel gel based reverse transcription-PCR (RT–PCR) assays targeting AHSV Seg-2, which can be used to very significantly increase the speed and reliability of detection and identification (compared to Virus neutralisation tests) of the nine serotypes of AHSV. Primer sets were designed targeting regions of Seg-2 that are conserved between strains within each of the AHSV serotype (types 1 to 9). These assays were evaluated using multiple AHSV strains from the orbiVirus reference collection at IAH (www.reoviridae.org/dsRNA_Virus_proteins/ReoID/AHSV-isolates.htm). In each case the Seg-2 primers showed a high level of specificity and failed to cross-amplify the most closely related heterologous AHSV types, or other related orbiViruses (such as bluetongue Virus (BTV), or Equine Encephalosis Virus (EEV)). The assays are rapid and sensitive, and can be used to detect and type viral RNA in blood, tissue samples, or cultivated viral suspensions within 24 h. They were used to identify AHSV strains from recent outbreaks in sub-Saharan African countries. Thes

  • Neighbour-joining tree showing relationships between VP7[T13] from KUW2010/02 with other orbiViruses.
    2013
    Co-Authors: Sushila Maan, Houssam Attoui, Narender S. Maan, Kyriaki Nomikou, Manjunatha N. Belaganahalli, Katarzyna Bachanek-bankowska, Eva Veronesi, Peter P. C. Mertens
    Abstract:

    KUW2010/02 showed between 69.2%/80.8% to 81.2%/97.7% nt/aa identity in Seg-7/VP7[T13] to other BTV isolates, confirming its identity as a member of the Bluetongue Virus species. Accession numbers and further detail of the sequence and Viruses used are included in Table 1. Epizootic haemorrhagic disease Virus (EHDV), Bluetongue Virus (BTV), Equine Encephalosis Virus (EEV), African horse sickness Virus (AHSV), Chuzan Virus (CHUV), St. Croix River Virus (SCRV), Yunnan orbiVirus (YUOV), Peruvian horsesickness Virus (PHSV), Broadhaven Virus (BRDV) and California mosquito pool Virus (CMPV). Seg-7 accession numbers used for comparative analyses: AM745023, AM744983, AM745013, AM745063, AM745033, AM745043, AM745073, AM745003, AM744993, AM745053, AM745083, FJ183391, AY078469, FJ183371, HM035361, HM035392, AF545433, M87876, NC 007754, NC 007663, NC 006004, ACF22097, AY485667, AM498057, FJ437558, AY841352, GQ506542, GQ506502, AF172829, AF188660, X53740, AY493692, M63417, AJ277802, AF172826, AF172825, AF188674, AF188673, AF172831, EU839843, L11724, DQ465027, DQ465028, DQ465026.