Characterization of BoHV-5 field strains circulation and report on transient specific subtype of bovine herpesvirus 5 in Argentina

MAIDANA, S.S; LADELFA, M.F; PÉREZ, S; LOMÓNACO, P; DEL MÉDICO ZAJAC, M. P; ODEÓN, A; BLANCO VIERA, F.J; COMBESSIES, G; FONDEVILA, N; PALACIOS, M; THIRY, J; MUYLKENS, B; THIRY, E; ROMERA, S.A

BMC VETERINARY RESEARCH

BIOMED CENTRAL LTD

Lugar: London; Año: 2011 vol. 7 p. 1 - 8

1746-6148

BACKGROUND: Bovine herpesvirus 5 (BoHV-5) is a member of the subfamily Alphaherpesvirinae responsible for meningo-encephalitis in young cattle. The first case of bovine meningo-encephalitis associated with a herpesvirus infection was reported in Australia. The current geographical distribution of BoHV-5 infection is mainly restricted to South America, especially Brazil and Argentina. Outbreaks of BoHV-5 are regularly observed in Argentina suggesting the circulation of the virus in the bovine population. RESULTS: Seventeen field strains of BoHV-5 isolated from 1984 to now were confirmed by differential PCR and subjected to restriction endonuclease analysis (REA). Viral DNA was cleaved with BstEII which allows differentiation among subtypes a, b and non a, non b. According to the REA with BstEII, only one field strain showed a pattern similar to the Argentinean A663 strain (prototype of BoHV-5b). All other isolates showed a clear pattern similar to the Australian N569 strain (prototype of BoHV-5a) consistent with the subtypes observed in Brazil, the other South-American country where BoHV-5 is known to be prevalent. The genomic region of subtype b responsible for the distinct pattern was determined and amplified by PCR; specifically a point mutation was identified on the restriction site of BstEII, which generates the profile specific of BoHV-5b. CONCLUSIONS: This is the first report of circulation of BoHV-5a in Argentina as the prevailing subtype. Therefore the circulation of BoHV-5b was restricted to a few years in Argentina, speculating that this subtype was not able to be maintained in the bovine population. The mutation in the gB gene is associated with a difference in the restriction patterns between subtypes "a" and "b".