SEROLOGICAL DIAGNOSIS OF BOVINE CORONAVIRUS IN CALVES USING A DEVELOPMENT NATIVE ELISA PREPARATION

Rania S El-Mohamady

doi:10.21608/avmj.2021.177854

Abstract

Bovine coronavirus (BCoV) infection has found worldwide among cattle of all ages, causing diarrhea in newborn calves, winter dysentery in adult cattle and respiratory tract diseases results in major economic losses in dairy herds. The objective of this study was to establish an ELISA kits as patent prepared in Lab. with assessment its applicability in the field samples. Sixty-five pneumonic calves 2- to 4-month-old, used in this study to detect BCoV antibodies in serum of infected calves, where it assayed against BCoV antibodies by using prepared ELISA plates and SNT. The results were positive for BCoV antibody 72.3% and 53.9% by ELISA and SNT respectively. The prepared ELISA showed high sensitivity of over SNT, where sensitivity, specificity and correlation were 91.4%, 50% and 72.3% respectively, and there is a positive correlation between both tests. The test has been successfully used in longitudinal field studies on virus dynamics and evaluation of management routines. In conclusion the patent prepared ELISA is more sensitive, accurate and specific assay than SNT for detection of BCoV antibodies, in addition to saving time and commercial kits cost.

Highlights

In the dairy industry worldwide, bovine coronavirus (BCoV) is a widely spread pathogen causing disease and economic losses
The results showed by Checkerboard titration finding for the prepared BCoV viral antigen and antibody optimization of enzyme linked immunosorbant assay (ELISA) are that the optimal amount of tissue culture polyethylene glycol concentration antigen coating level at 8 μg/well and the working dilution in case of serum is 1:40
BCoV is usually associated with the occurrence of diarrhea in calves and adult cattle, but it is responsible for respiratory distress, being implicated as an etiological agent of bovine respiratory disease (BRD) (Bok et al, 2015; Johnson and Pendell, 2017)

Summary

Introduction

In the dairy industry worldwide, bovine coronavirus (BCoV) is a widely spread pathogen causing disease and economic losses. BCoV has been associated with gastrointestinal and respiratory diseases in cattle including diarrhea in neonatal calves, winter dysentery and respiratory tract illness (Storz et al, 2000). In dairy and beef calves, BCoV can cause enteritis in healthy and diarrheal calves, BCoV can often be identified, that complicating the assessment of its role as a primary pathogen (Bartels et al, 2010). BCoV infects the upper, lower respiratory tract and intestine It is not unexpected that cattle would have a coronavirus with tropism for the respiratory tract. Coronaviruses infect the respiratory tract of other species including pigs, turkeys, and chickens. This virus has a role in both respiratory tract disease and enteric diseases (Fulton, 2009). BCoV was associated with the occurrence of respiratory distress in calves and adults (Lathrop et al, 2002)

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