Validation of a Commercial Indirect ELISA Kit for the Detection of Bovine alphaherpesvirus1 (BoHV-1)-Specific Glycoprotein E Antibodies in Bulk Milk Samples of Dairy Cows

Abstract

In this study, we validated a commercial indirect enzyme-linked immunosorbent assay (ELISA) to detect antibodies to glycoprotein E (gE) of Bovine alphaherpesvirus 1 (BoHV-1) in bulk milk (BM) samples using the OIE Manual of Diagnostic Tests and Vaccines for Terrestrial Animals. The assay performance characteristics were evaluated using a panel of positive (n = 36) and negative (n = 80) samples with known infectious bovine rhinotracheitis (IBR) status. The assay showed adequate repeatability (within-run and between-run), with a coefficient of variability (CV%) of replicates below 30%; only two 1:40 diluted samples had a CV% above 20%. Additionally, an agreement analysis of the qualitative results of replicates led to a Gwet’s agreement coefficient of 0.99 (95% confidence interval (CI): 0.96–1.00, p < 0.001). The estimated diagnostic sensitivity (DSe) and diagnostic specificity (DSp) were 100% (95% CI: 90.3–100%) and 97.5% (95% CI: 91.3–99.7%), respectively. Overall, a good level of agreement was observed between the assay results and the true IBR status of samples (weighted Cohen’s κ: 0.96, 95% CI: 0.78–1.00). The findings demonstrate that the indirect ELISA kit validated here is an easy-to-use and economical method to differentiate infected and gE-deleted marker vaccine-immunised animals using BM samples.

Genomic Characterization of a Wild-Type Bovine alphaherpesvirus 1 (BoAHV-1) Strain Isolated in an Outbreak in Central Italy

“…In contrast, NA levels were increased up to 1:256 in the absence of viral excretion. These results are consistent with those reported by other authors [20,28] and can be interpreted as an active immune response to viremia.…”

Reference Material Production and Milk Protein Concentration as Elements to Improve Bluetongue Serological Diagnosis in Bulk Tank Milk

“…Moreover, BTM samples diluted at 1:50 simulating pools of 50 BTM did not test positive even in samples from herds with high positivity ( Figure 3 a, BTM Herd-1 1:50). To solve these shortcomings, a milk protein concentration procedure based on similar methods previously developed for BT [ 31 ] and for infectious bovine rhinotracheitis (IBR) [ 47 , 48 ] was evaluated and optimized. Regarding the results from this study ( Figure 3 ), the milk protein concentration treatment produces a high increase in analytical sensitivity, producing positive ELISA results in highly diluted samples with low levels of BTV antibodies ( Figure 3 a), without false positive induction ( Figure 3 b).…”

Humoral Immune Response of Mice against a Vaccine Candidate Composed of a Chimera of gB of Bovine Alphaherpesviruses 1 and 5

“…Infections and damage caused by BoHV-1 have been described in reports around the world [ 24 ]. In the case of BoHV-5, there are recurrent reports in South America and some sporadic ones in North America and Europe [ 25 ]; therefore, it is necessary to improve the success of vaccines to prevent the symptoms produced by both bovine alphaherpesviruses.…”