A gel-based PCR method to differentiate sheeppox virus field isolates from vaccine strains

Tesfaye Rufael Chibssa; Reingard Grabherr; Angelika Loitsch; Tirumala Bharani K. Settypalli; Eeva Tuppurainen; Nick Nwankpa; Karim Tounkara; Hafsa Madani; Amel Omani; Mariane Diop; Giovanni Cattoli; Adama Diallo; Charles Euloge Lamien

doi:10.1186/s12985-018-0969-8

Virology Journal (Apr 2018)

A gel-based PCR method to differentiate sheeppox virus field isolates from vaccine strains

Tesfaye Rufael Chibssa,
Reingard Grabherr,
Angelika Loitsch,
Tirumala Bharani K. Settypalli,
Eeva Tuppurainen,
Nick Nwankpa,
Karim Tounkara,
Hafsa Madani,
Amel Omani,
Mariane Diop,
Giovanni Cattoli,
Adama Diallo,
Charles Euloge Lamien

Affiliations

Tesfaye Rufael Chibssa: Animal Production and Health Laboratory, Joint FAO/IAEA Agricultural and Biotechnology laboratory, Division of Nuclear Techniques in Food and Agriculture, Department of Nuclear Sciences and Applications, International Atomic Energy Agency
Reingard Grabherr: Institute of Biotechnology, University of Natural Resources and Life Sciences (BOKU)
Angelika Loitsch: Institute for Veterinary Disease Control, Austrian Agency for Health and Food Safety (AGES)
Tirumala Bharani K. Settypalli: Animal Production and Health Laboratory, Joint FAO/IAEA Agricultural and Biotechnology laboratory, Division of Nuclear Techniques in Food and Agriculture, Department of Nuclear Sciences and Applications, International Atomic Energy Agency
Eeva Tuppurainen: Capripoxvirus Reference Laboratory, Pirbright Institute
Nick Nwankpa: Pan African Veterinary Vaccine Centre, African Union (PANVAC)
Karim Tounkara: Pan African Veterinary Vaccine Centre, African Union (PANVAC)
Hafsa Madani: Institut National de la Médecine Vétérinaire, Laboratoire Central Vétérinaire d’Alger
Amel Omani: Institut National de la Médecine Vétérinaire, Laboratoire Central Vétérinaire d’Alger
Mariane Diop: Laboratoire National de l’Elevage et de Recherches Vétérinaires, Institut Sénégalais de Recherches Agricoles Route du Front de Terre Hann
Giovanni Cattoli: Animal Production and Health Laboratory, Joint FAO/IAEA Agricultural and Biotechnology laboratory, Division of Nuclear Techniques in Food and Agriculture, Department of Nuclear Sciences and Applications, International Atomic Energy Agency
Adama Diallo: Laboratoire National de l’Elevage et de Recherches Vétérinaires, Institut Sénégalais de Recherches Agricoles Route du Front de Terre Hann
Charles Euloge Lamien: Animal Production and Health Laboratory, Joint FAO/IAEA Agricultural and Biotechnology laboratory, Division of Nuclear Techniques in Food and Agriculture, Department of Nuclear Sciences and Applications, International Atomic Energy Agency

DOI: https://doi.org/10.1186/s12985-018-0969-8
Journal volume & issue: Vol. 15, no. 1
pp. 1 – 7

Abstract

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Abstract Background Sheeppox (SPP) and goatpox (GTP) caused by sheeppox virus (SPPV) and goatpox virus (GTPV), respectively of the genus Capripoxvirus in the family Poxviridae, are severely afflicting small ruminants’ production systems in Africa and Asia. In endemic areas, SPP and GTP are controlled using vaccination with live attenuated vaccines derived from SPPV, GTPV or Lumpy skin disease virus (LSDV). Sometimes outbreaks occur following vaccination. In order to successfully control the spread of the virus, it is essential to identify whether the animals were infected by the field strain and the vaccine did not provide sufficient protection. Alternatively, in some cases the vaccine strain may cause adverse reactions in vaccinated animals or in rare occasions, re-gain virulence. Thus, diagnostic tools for differentiation of virulent strains from attenuated vaccine strains of the virus are needed. The aim of this study was to identify an appropriate diagnostic target region in the capripoxvirus genome by comparing the genomic sequences of SPPV field isolates with those of the most widely used SPP vaccine strains. Results A unique 84 base pair nucleotide deletion located between the DNA ligase gene and the VARV B22R homologue gene was found only in SPPV vaccines derived from the Romanian and Yugoslavian RM/65 strains and absent in SPPV field isolates originated from various geographical locations of Asia and Africa. In addition, we developed and evaluated a conventional PCR assay, exploiting the targeted intergenic region to differentiate SPPV vaccine virus from field isolates. The assay produced an amplicon size of 218 bp for the vaccine strains, while the SPPV field isolates resulted in a 302 bp PCR fragment. The assay showed good sensitivity and specificity, and the results were in full agreement with the sequencing data of the PCR amplicons. Conclusion The developed assay is an improvement of currently existing diagnostic tools and, when combined with a capripox virus species-specific assay, will enhance SPP and GTP diagnosis and surveillance and facilitate epidemiological investigations in countries using live attenuated SPP vaccines. In addition, for laboratories with limited resources, the assay provides a simple and cost-effective alternative for sequencing.

Published in Virology Journal

ISSN: 1743-422X (Online)
Publisher: BMC
Country of publisher: United Kingdom
LCC subjects: Medicine: Internal medicine: Infectious and parasitic diseases
Website: http://virologyj.biomedcentral.com

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