Comparison of bovine coronavirus isolates associated with neonatal calf diarrhoea and winter dysentery in adult dairy cattle in Quebec

Abstract

Cytopathic coronaviruses were isolated in HRT-18 cells from bloody faecal samples collected from cows in Qurbec dairy herds having experienced typical outbreaks of winter dysentery (WD). The formation of polykaryons in the infected cell cultures was found to be dependent on the presence of trypsin in the medium. The WD isolates differed from the prototype Mebus strain of bovine enteropathogenic coronavirus (BCV.Meb) in respect to haemagglutination inhibition (HI), haemagglutination patterns at 4 °C and 37 °C, and receptor destroying enzyme activity with rat erythrocytes. Other field strains of BCV associated with outbreaks of neonatal calf diarrhoea (NCD) also differed from the BCV.Meb strain by demonstrating differences in HI. In all cases, no differences were detected by virus neutralization and Western immunoblotting. Analysis and comparison of the nucleotide and deduced amino acid sequences of the PCR-amplified haemagglutinin esterase (HE) genes of one representative WD strain (BCQ.2590) and two highly cytopathic NCD strains (BCQ.3 and BCQ.571) revealed high degrees of similarities (nt and aa sequence homologies > 98 %) with the BCV.Meb strain. The putative esterase active site FGDS was conserved among these four BCV strains, indicating that this domain is probably not a determinant for BCV virulence. Six amino acid substitutions occurred between the HE glycoproteins of BCV.Meb and BCQ.2590 strains; two proline substitutions occurred respectively in the signal peptide (at aa 5) and near the sequences of the putative esterase domain (at aa 53).

Recent Progress in Studies of Arterivirus- and Coronavirus-Host Interactions

“…An infection or outbreak can cause severe economic losses from the death of young offspring, lifelong impact on the yield of animal produce such as eggs and milk, weight losses and the general health of the population. Bovine coronavirus (BCV), for example, causes Winter Dysentery (WD) in adult cows and diarrhea in young calves [12]. …”

Characterization of bovine coronavirus isolates/from eight different states in the USA

“…Cytopathic effects produced by BCV isolates have no correlation with the clinical condition but depends on the presence of trypsin in the medium (Dea et al, 1995). Similarly, no differences were observed in CPE among calf diarrhea and winter dysentery isolates by another group (Tsunemitsu and Saif, 1995).…”

“…Veterinary Microbiology 67 (1999) 221±230 The current modified, live BCV vaccine is not clinically effective (Thurber et al, 1977) and lack of clinical efficacy of the vaccine may be due to antigenic differences among the vaccine and field isolates of BCV. Minor antigenic and biological differences have been observed among BCV isolates from calf diarrhea and winter dysentery cases from the USA (Tsunemitsu and Saif, 1995) and Canada (Dea et al, 1995). To further understand the molecular epidemiology of BCV, 94 BCV isolates from eight states of the USA were compared.…”

“…Isolates of BCV from calf diarrhea and winter dysentery differ in cytopathology, some isolates are non fusogenic while others are weakly or highly fusogenic (Dea et al, 1995).…”

Reação de hemi-nested RT-PCR dirigida ao gene da hemaglutinina-esterase do Coronavírus Bovino

“…Adult cattle, mainly cows, present an enteric disease known as winter dysentery, first described in the USA, and also caused by a bovine coronavirus similar to that found in neonatal diarrhea 12,13,14 . As HE is a polymorphic protein that functions as a secondary receptor binder 3 , surveys on the diversity of HE gene might allow insights on BCoV evolution and host-parasite interactions.…”