Development and validation of an indirect ELISA as a confirmatory test for surveillance of infectious bovine rhinotracheitis in vaccinated herds.

Margherita Profiti,Luigi Bertolotti,Laura Lucchese,Stefano Nardelli,Chiara Nogarol,Claudio Caruso,Loretta Masoero,Elvira Muratore,Laura Anfossi,Sergio Rosati

doi:10.1186/s12917-015-0612-5

Abstract

BackgroundBovine herpesvirus 1 (BoHV1) is a member of the viral subfamily of Alphaherpesvirinae that infects various species, including cattle, sheep, and goats. The virus causes infectious bovine rhinotracheitis (IBR), which is included in a European list of diseases that may require control and eradication programs. The lack of confirmatory tests affects the validity of diagnostic tools, especially those used for vaccinated herds. In this study, we report the development and validation of an indirect enzyme-linked immunosorbent assay (ELISA) based on BoHV1 glycoprotein E, which was expressed as a secreted recombinant antigen in a mammalian cell system. The performance of the new rec-gE ELISA was compared with that of commercially available indirect and/or blocking ELISAs.ResultsThe sample set included blood sera from animals from IBR-positive farms, IBR-free farms, and marker-vaccinated farms. The indirect ELISA proposed in this study is based on antibody reactivity against BoHV1 gE, and showed high sensitivity and specificity (98.41 and 99.76 %, respectively).ConclusionsThe ELISA performed well, in terms of both its diagnostic sensitivity and specificity, and as a confirmatory methodology, and therefore should improve the diagnostic protocols used for IBR surveillance.

Highlights

Bovine herpesvirus 1 (BoHV1) is a member of the viral subfamily of Alphaherpesvirinae that infects various species, including cattle, sheep, and goats
We developed and validated an indirect enzyme-linked immunosorbent assay (ELISA) based on BoHV1 glycoprotein E (gE) expressed as a secreted recombinant antigen in a mammalian cell system
We evaluated the performance of the new rec-gE ELISA on pooled blood serum samples, so that the cut-off level could be modified based on the pool size to improve its analytical sensitivity

Summary

Introduction

Bovine herpesvirus 1 (BoHV1) is a member of the viral subfamily of Alphaherpesvirinae that infects various species, including cattle, sheep, and goats. The performance of the new rec-gE ELISA was compared with that of commercially available indirect and/or blocking ELISAs. Bovine herpesvirus 1 (BoHV1) is a member of the viral subfamily of Alphaherpesvirinae that infects different species, including cattle, sheep, and goats. The respiratory syndrome produced in cattle is known as infectious bovine rhinotracheitis (IBR), and genital infections are associated with pustular vulvovaginitis, balanoposthitis, and abortion. Both the respiratory syndrome and genital infection may cause lifelong latent infection. In response to European Union (EU) regulations, several European countries have adopted different strategies for the eradication of IBR, and several countries have achieved an IBR-free status (Sweden, Austria, Denmark, Finland, Switzerland, Norway, the Federal State of Bavaria, and the Province of Bolzano in Italy) and have established trade restrictions for seropositive animals (2004/558/CEE [4])

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Results

Conclusion