title: In vitro-generated interspecific recombinants between bovine herpesviruses 1 and 5 show attenuated replication characteristics and establish latency in the natural host.
abstract: BACKGROUND
  Interspecific recombinant viruses R1ΔgC and R2ΔgI were isolated after in vitro co-infection with BoHV-1 and BoHV-5, two closely related alphaherpesviruses that infect cattle. The genetic characterization of R1ΔgC and R2ΔgI showed that they are composed of different sections of the parental genomes. The aim of this study was the characterization of the in vivo behavior of these recombinants in the natural host.
  
  
  RESULTS
  Four groups of four 3-month-old calves of both genders were intranasally inoculated with either the recombinant or parental viruses. A control group of two animals was also included. Viral excretion and clinical signs were monitored after infection. Histopathological examination of the central nervous system (CNS) was performed and the establishment of latency in trigeminal ganglia was analyzed by PCR. The humoral response was also evaluated using ELISA tests. Three out of four animals from the BoHV-5 infected group excreted virus for 4-10 days. Two calves shed R1ΔgC virus for one day. In R2ΔgI and BoHV-1.2ΔgCΔgI groups, infectious virus was isolated only after two or three blind passages. None of the infected animals developed neurological signs, although those infected with BoHV-5 showed histopathological evidence of viral infection. Latent viral DNA was detected in at least one calf from each infected group. Serum and/or mucosal antibodies were detected in all groups.
  
  
  CONCLUSIONS
  Both BoHV-1/-5 recombinants and the BoHV-1 parental strain are attenuated in calves, although they are able to replicate in animals at low rates and to establish latent infections.
authors: Virology Institute, Veterinary and Agricultural Science Research Center, National Institute of Agricultural Technology, Hurlingham, Buenos Aires, Argentina.
authors: Maria P
authors: MP
authors: Del Medico Zajac
authors: Sonia A
authors: SA
authors: Romera
authors: María F
authors: MF
authors: Ladelfa
authors: Fiorella
authors: F
authors: Kotsias
authors: Fernando
authors: F
authors: Delgado
authors: Julien
authors: J
authors: Thiry
authors: François
authors: F
authors: Meurens
authors: Günther
authors: G
authors: Keil
authors: Etienne
authors: E
authors: Thiry
authors: Benoît
authors: B
authors: Muylkens
references: Microbiol Immunol. 2005;49(2):167-79
references: 15722602
references: Vet Microbiol. 2006 Mar 31;113(3-4):293-302
references: 16337098
references: Vaccine. 1998 May;16(8):802-9
references: 9627937
references: Rev Med Virol. 2005 Mar-Apr;15(2):89-103
references: 15546129
references: Vet Immunol Immunopathol. 1995 Jun;46(3-4):267-83
references: 7502487
references: Comp Immunol Microbiol Infect Dis. 2005 May;28(3):187-96
references: 15857658
references: Res Vet Sci. 2006 Dec;81(3):327-34
references: 16540133
references: J Vet Med B Infect Dis Vet Public Health. 2001 Oct;48(8):613-21
references: 11708680
references: J Virol. 2006 Apr;80(8):4047-60
references: 16571821
references: Am J Vet Res. 1991 Jun;52(6):820-5
references: 1652903
references: Vet Rec. 1996 Oct 26;139(17):416-21
references: 8923716
references: Vaccine. 2006 Apr 12;24(16):3313-20
references: 16480790
references: Vet Microbiol. 2009 Oct 20;139(1-2):67-73
references: 19560292
references: Vet Microbiol. 1999 Apr 19;66(3):187-95
references: 10227121
references: Clin Microbiol Rev. 2003 Jan;16(1):79-95
references: 12525426
references: Vet J. 2010 May;184(2):138-45
references: 19409823
references: J Virol. 2004 Sep;78(18):9828-36
references: 15331717
references: J Gen Virol. 1987 May;68 ( Pt 5):1435-40
references: 3033143
references: Vet Res. 2007 Mar-Apr;38(2):181-209
references: 17257569
references: J Virol Methods. 2009 Oct;161(1):75-83
references: 19501619
references: Science. 1986 Nov 7;234(4777):746-8
references: 3022376