Bovine respiratory syncytial virus infection

Abstract

-Bovine respiratory syncytial virus (BRSV) belongs to the pneumovirus genus within the family Paramyxoviridae and is a major cause of respiratory disease in young calves. BRSV is enveloped and contains a negative sense, single-stranded RNA genome encoding 11 proteins. The virus replicates predominantly in ciliated respiratory epithelial cells but also in type II pneumocytes. It appears to cause little or no cytopathology in ciliated epithelial cell cultures in vitro, suggesting that much of the pathology is due to the host's response to virus infection. RSV infection induces an array of pro-inflammatory chemokines and cytokines that recruit neutrophils, macrophages and lymphocytes to the respiratory tract resulting in respiratory disease. Although the mechanisms responsible for induction of these chemokines and cytokines are unclear, studies on the closely related human (H)RSV suggest that activation of NF-κB via TLR4 and TLR3 signalling pathways is involved. An understanding of the mechanisms by which BRSV is able to establish infection and induce an inflammatory response has been facilitated by advances in reverse genetics, which have enabled manipulation of the virus genome. These studies have demonstrated an important role for the non-structural proteins in anti-interferon activity, a role for a virokinin, released during proteolytic cleavage of the fusion protein, in the inflammatory response and a role for the SH and the secreted form of the G protein in establishing pulmonary infection. Knowledge gained from these studies has also provided the opportunity to develop safe, stable, live attenuated virus vaccine candidates.

Evidence of respiratory syncytial virus and parainfluenza-3 virus in Mexican sheep

“…This reveals that lambs are in contact with RSV and PI3V and develop a humoral immune response [17]. Passive immunity in calves has been reported to last from 4 months through 6 months, and calves develop their own humoral response only after 12 months of age [8,45]. Lambs that ingest enough calostrum are protected against diseases.…”

Blood dendritic cells in cattle infected with bovine leukemia virus (BLV): isolation and phenotyping

“…They belong to the most conservative proteins both in HRSV and BRSV, showing 81% identity for glycoprotein F and 93% for nucleoprotein N at the amino acid sequence level (Valarcher and Taylor 2007). It has been shown that monoclonal antibodies to HRSV cross-react with most of the epitopes of F and N proteins of BRSV (Stine et al 1997, Fogg et al 2001.…”

“…The morbidity Correspondence to: J. Rola, e-mail: jrola@piwet.pulawy.pl, tel. : +48 81 889 30 69 is high (60 to 80%), whereas the mortality rate seldom exceeds 5-10%, although occasionally in some outbreaks it can reach up to 20% (Valarcher and Taylor 2007). Clinical signs observed during acute disease may raise the suspicion of BRSV infection but to make a definitive diagnosis laboratory confirmation is needed.…”

Detecção molecular e análise filogenética de vírus respiratório sincicial bovino (BRSV) em swabs e tecido pulmonar de bovinos adultos

“…O vírus respiratório sincicial bovino (BRSV), um membro do gênero Morbillivirus, subfamília Pneumovirinae, famí-lia Paramyxoviridae, ordem Mononegavirales, é associado a pneumonias em bovinos jovens (Easton et al 2004, Valarcher et al 2007. A caracterização de isolados de BRSV com monoclonais e por ϐilogenia molecular permite classiϐicá-las em 3 subgrupos nomeados A, B e AB (Furze ate al., 1994).…”

“…Em vacas leiteiras foram relacionadas com quedas na produção leiteira e a vacinação prévia ao período de lactação interfere positivamente na produção e nos valores de pico de lactação dos animais (Van der Poel et al 1995, Beaudeau et al 2010. Todavia, a maioria das infecções com sinais clínicos mais evidentes e quadros graves ocorre no primeiro ano de vida e apenas excepcionalmente após a entrada na fase adulta (Uttenthal et al 2000, Hägglund et al 2006, Valarcher et al 2007, Brodersen et al 2010.…”