PESQUISA VETERINÁRIA BRASILEIRA

Abstract in English:

ABSTRACT.- Dezengrini R., Silva S.C., Weiss M., Kreutz L.C., Weiblen R. & Flores E.F. 2010. [Activity of three antiviral drugs against bovine herpesviruses 1, 2 and 5 in cell culture.] Atividade de três drogas antivirais sobre os herpesvírus bovino tipos 1, 2 e 5 em cultivo celular. Pesquisa Veterinária Brasileira 30(10):855-860. Setor de Virologia, Departamento de Medicina Veterinária Preventiva, Centro de Ciências Rurais, Universidade Federal de Santa Maria, Av. Roraima 1000, Camobi, Santa Maria, RS 97105-900, Brazil. E-mail: eduardofurtadoflores@gmail.com The activity of three anti-herpetic drugs (Acyclovir [ACV], Gancyclovir [GCV] and Foscarnet [PFA]) was tested against bovine herpesvirus 1 (BoHV-1), 2 (BoHV-2) and 5 (BoHV-5) in vitro using the plaque reduction assay. Different drug concentrations were tested against one hundred 50% tissue culture infectious dose (TCID50) of the respective viruses. Drug concentrations lower than 200µg/mL resulted in viability rates of more than 80% for MDBK and Hep2 cells in the MTT test (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide). The selectivity index (IS) of the drugs was calculated dividing the concentration of the drug that is cytotoxic for 50% of the cells (CC50) by the concentration of the drug that was effective in reducing by 50% the number of viral plaques (EC50) for the three herpesviruses. Thus, ACV was shown to be moderately active against BoHV-1 (EC50: 112.9mg/mL; IS: 4.5), BoHV-2 (EC50: 114.2mg/mL; IS: 4.5) and BoHV-5 (EC50: 96.9mg/mL; IS: 5.3). GCV was effective against BoHV-2 (EC50: 33.5mg/mL; IS: 16.6), moderately effective against BoHV-5 (EC50: 123.2mg/mL; IS: 4.5) and poorly active against BoHV-1 (EC50: 335.8mg/mL; IS: 1.7). PFA exhibited the highest antiviral activity, being the only drug that, at concentration of 100mg/mL, completely inhibited plaque formation by all three viruses. PFA was the most effective in vitro against BoHV-1 (EC50: 29.5mg/mL; IS: 42.2), BoHV-2 (EC50: 45.2mg/mL; IS: 27.6) and BoHV-5 (EC50: 7.8mg/mL; IS: 160.6). Thus, the results indicate that PFA is a promising candidate for experimental therapeutic testing in vivo against bovine herpesviruses.

• Antivirals BoHV-1 BoHV-2 BoHV-5 Foscarnet Gancyclovir Acyclovir antivirais Ganciclovir Aciclovir

Abstract in Portuguese:

RESUMO.- Dezengrini R., Silva S.C., Weiss M., Kreutz L.C., Weiblen R. & Flores E.F. 2010. [Activity of three antiviral drugs against bovine herpesviruses 1, 2 and 5 in cell culture.] Atividade de três drogas antivirais sobre os herpesvírus bovino tipos 1, 2 e 5 em cultivo celular. Pesquisa Veterinária Brasileira 30(10):855-860. Setor de Virologia, Departamento de Medicina Veterinária Preventiva, Centro de Ciências Rurais, Universidade Federal de Santa Maria, Av. Roraima 1000, Camobi, Santa Maria, RS 97105-900, Brazil. E-mail: eduardofurtadoflores@gmail.com A atividade de três fármacos antivirais (Aciclovir [ACV], Ganciclovir [GCV] e Foscarnet [PFA]) foi testada in vitro frente aos herpesvírus bovino tipos 1 (BoHV-1), 2 (BoHV-2) e 5 (BoHV-5). Para isso, utilizou-se o teste de redução de placas virais em cultivo celular, testando-se diferentes concentrações dos fármacos frente a 100 doses infectantes para 50% dos cultivos celulares (DICC50) dos respectivos vírus. Pelo teste de MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide), verificou-se que concentrações inferiores a 200µg/mL dos três antivirais resultaram em índices de viabilidade de células MDBK e Hep2 superiores a 80%. Com base na concentração citotóxica para 50% das células (CC50) e na concentração dos fármacos efetiva para inibir em 50% o número de placas virais (EC50), calculou-se o índice de seletividade (IS) dos antivirais para os três herpesvírus. Assim, o ACV demonstrou ser moderadamente ativo frente ao BoHV-1 (EC50: 112,9mg/mL e IS: 4,5), ao BoHV-2 (EC50: 114,2 mg/mL e IS: 4,5) e BoHV-5 (EC50: 96,9mg/mL e IS: 5,3). O GCV apresentou atividade moderada frente ao BoHV-2 (EC50: 33,5mg/mL e IS: 16,6) e, em menor grau, contra o BoHV-5 (EC50: 123,2mg/mL e IS: 4,5), sendo ineficaz frente ao BoHV-1 (EC50: 335,8mg/mL e IS: 1,7). O PFA apresentou atividade antiviral mais pronunciada, sendo o único fármaco que, na concentração de 100µg/mL, inibiu completamente a produção de placas pelos três vírus testados. O PFA foi o mais efetivo in vitro frente ao BoHV-1 (EC50: 29,5mg/mL e IS: 42,2), ao BoHV-2 (EC50: 45,2mg/mL e IS: 27,6) e ao BoHV-5 (EC50: 7,8mg/mL e IS: 160,6). Portanto, os resultados obtidos indicam que o PFA pode se constituir em um candidato para terapia experimental de infecções pelos herpesvírus de bovinos in vivo.

Abstract in English:

ABSTRACT.- Dezengrini R., Silva S.C., Weiss M., Oliveira M.S., Traesel C.K., Weiblen R. & Flores E.F. 2010. [Effects of Foscarnet on the infection by bovine herpesviruses 1 and 5 in rabbits.] Efeitos do Foscarnet sobre a infecção pelos herpesvírus bovino tipos 1 e 5 em coelhos. Pesquisa Veterinária Brasileira 30(8):623-630. Setor de Virologia, Departamento de Medicina Veterinária Preventiva, Centro de Ciências Rurais, Universidade Federal de Santa Maria, Av, Roraima 1000, Camobi, Santa Maria, RS 97105-900, Brazil. E-mail: eduardofurtadoflores@gmail.com The activity of Foscarnet (PFA) against three bovine herpesviruses (BoHVs) was previously demonstrated in cell culture. Herein we evaluated the effects of PFA on the infection and disease by BoHV-1 and BoHV-5 in a rabbit model. Rabbits inoculated with BoHV-5 in the conjunctival sac (IC) and treated with PFA (100 mg/kg/day) from day 1 to 17 post-inoculation (pi) shed less virus between days 2 and 6 pi comparing to untreated controls; this difference was significant at day 3 pi [F(9,108) = 2,23; P<0.03]. The morbidity and mortality rates of rabbits inoculated with BoHV-5 IC or intranasally (IN) were also significantly reduced in PFA-treated rabbits (50%; 11/22) comparing to untreated controls (95.4%; 21/22) (P<0.0008). In rabbits inoculated IC with BoHV-1, a reduction in virus shedding was observed in PFA-treated animals between days 1 and 4 pi; 6 and 7 pi. In addition, PFA-treated rabbits presented a longer incubation period and a shorter clinical course comparing to untreated controls (P<0.005 and P<0.04, respectively). The frequency and severity of ocular signs were also reduced in the PFA-treated group. These results demonstrate that PFA is effective against BoHV-1 and BoHV-5 in vivo and open the way towards its use in experimental therapy of herpetic infections in domestic animals.

• Antivirals BoHV-1 BoHV-5 PFA bovine herpesviruses 1 bovine herpesviruses 5 Foscarnet herpesvírus bovino tipo 1 herpesvírus bovino tipo 5

Abstract in Portuguese:

RESUMO.- Dezengrini R., Silva S.C., Weiss M., Oliveira M.S., Traesel C.K., Weiblen R. & Flores E.F. 2010. [Effects of Foscarnet on the infection by bovine herpesviruses 1 and 5 in rabbits.] Efeitos do Foscarnet sobre a infecção pelos herpesvírus bovino tipos 1 e 5 em coelhos. Pesquisa Veterinária Brasileira 30(8):623-630. Setor de Virologia, Departamento de Medicina Veterinária Preventiva, Centro de Ciências Rurais, Universidade Federal de Santa Maria, Av, Roraima 1000, Camobi, Santa Maria, RS 97105-900, Brazil. E-mail: eduardofurtadoflores@gmail.com

Abstract in English:

Spilki F.R, Esteves P.A., Lima M., Franco A.C., Chiminazzo C., Flores E.F., Weiblen R., Driemeier D. & Roehe P.M. 2004. Comparative pathogenicity of bovine herpesviruses type 1 (BHV-1) subtypes 1 (BHV-1.1) and 2a (BHV-1.2a). Pesquisa Veterinária Brasileira 24(1):43-49. Centro de Pesquisas Desidério Finamor, Fepagro Saúde Animal, Cx. Postal 47, Eldorado do Sul, RS 92990-000, Brazil. E-mail: proehe@ufrgs.br The study aimed to examine the capacity of two bovine herpesvirus type 1 (BHV-1) isolates of different subtypes (EVI 123/96, BHV-1.1; SV265/98, BHV-1.2a) to induce respiratory disease in calves. These two isolates are representative of the BHV-1 subtypes prevalent in Brazil. Viral subtypes were confirmed by monoclonal antibody analysis and by restriction enzyme digestion of viral genomes. The viruses were inoculated intranasally into seven 3 months old calves (four with BHV-1.1, three with BHV-1.2a). Three other calves of identical age and condition were kept as uninfected controls. In both groups of infected calves, the clinical signs observed were consistent with typical infectious bovine rhinothracheitis (IBR), including pyrexia, apathy, anorexia, nasal and ocular mucopurulent discharges, erosions on the nasal mucosa, conjunctivitis, lachrymation, redness of nasal mucosa, dyspnoea, coughing, tracheal stridor and enlargement of retropharingeal, submandibular and cervical lymphnodes. No significant differences were observed between the clinical scores attributed to both groups. Virus shedding in nasal and ocular secretions were also similar, apart from a significant difference in nasal virus shedding on day 1 to 3 post-inoculation, which was higher for BHV-1.1 than for BHV-1.2a. Following corticosteroid induced reactivation of the latent infection, recrudescence of clinical signs was also observed, with no significant differences on both groups. It was concluded that both subtypes BHV-1.1 and BHV-1.2a were able to induce clinically undistinguishable respiratory disease in calves, either subsequent to a primary infection or following reactivation.

• Infectious bovine rhinotracheitis IBR BHV-1.1 BHV-1.2a subtypes pathogenicity.

Abstract in Portuguese:

Spilki F.R, Esteves P.A., Lima M., Franco A.C., Chiminazzo C., Flores E.F., Weiblen R., Driemeier D. & Roehe P.M. 2004. Comparative pathogenicity of bovine herpesviruses type 1 (BHV-1) subtypes 1 (BHV-1.1) and 2a (BHV-1.2a). Pesquisa Veterinária Brasileira 24(1):43-49. Centro de Pesquisas Desidério Finamor, Fepagro Saúde Animal, Cx. Postal 47, Eldorado do Sul, RS 92990-000, Brazil. E-mail: proehe@ufrgs.br The study aimed to examine the capacity of two bovine herpesvirus type 1 (BHV-1) isolates of different subtypes (EVI 123/96, BHV-1.1; SV265/98, BHV-1.2a) to induce respiratory disease in calves. These two isolates are representative of the BHV-1 subtypes prevalent in Brazil. Viral subtypes were confirmed by monoclonal antibody analysis and by restriction enzyme digestion of viral genomes. The viruses were inoculated intranasally into seven 3 months old calves (four with BHV-1.1, three with BHV-1.2a). Three other calves of identical age and condition were kept as uninfected controls. In both groups of infected calves, the clinical signs observed were consistent with typical infectious bovine rhinothracheitis (IBR), including pyrexia, apathy, anorexia, nasal and ocular mucopurulent discharges, erosions on the nasal mucosa, conjunctivitis, lachrymation, redness of nasal mucosa, dyspnoea, coughing, tracheal stridor and enlargement of retropharingeal, submandibular and cervical lymphnodes. No significant differences were observed between the clinical scores attributed to both groups. Virus shedding in nasal and ocular secretions were also similar, apart from a significant difference in nasal virus shedding on day 1 to 3 post-inoculation, which was higher for BHV-1.1 than for BHV-1.2a. Following corticosteroid induced reactivation of the latent infection, recrudescence of clinical signs was also observed, with no significant differences on both groups. It was concluded that both subtypes BHV-1.1 and BHV-1.2a were able to induce clinically undistinguishable respiratory disease in calves, either subsequent to a primary infection or following reactivation.

Abstract in English:

ABSTRACT.- Souza V.F, Melo S.V., Esteves P.A., Schmidt C.S.R., Gonçalves D.A., Schaefer R., Silva T.C., Almeida R.S., Vicentini F., Franco A.C., Oliveira E.A., Spilki F.R., Weiblen R., Flores E.F., Lemos R.A., Alfieri A.A., Pituco E.M. & Roehe P.M. 2002. [Monoclonal antibody characterization of bovine herpesviruses types 1 (BHV-1) and 5 (BHV-5).] Caracterização de herpesvírus bovinos tipos 1 (BHV-1) e 5 (BHV-5) com anticorpos monoclonais. Pesquisa Veterinária Brasileira 22(1):13-18,-Depto Microbiologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, and Centro de Pesquisas Universitárias Desidério Finamor, Estrada do Conde 6000, Eldorado do Sul, RS 90001-970, Brazíl. E-mail: proehe@vottex.ufrgs.br The antigenic profile of 45 herpesviruses (44 viruses from cattle, including six reference BHV-1 strains and 15 putative BHV-1; three reference BHV-5 strains and 20 putative BHV-5) and one butfalo isolate (BuHV) were examined with a panei of monoclonal antibodies (Mabs) prepared against bovine herpesvirus antigens. Tests were performed by immunoperoxidase (IPX) on infected cell cultures, with the Mabs as primary antibodies. lmmunostaining allowed the differentiation between types 1 and 5 viruses. Ali isolates from cases of encephalitis displayed BHV-5 profiles. Four BHV-5 isolates obtained from geographically distinct áreas displayed different and highly variable IPX patterns of reactivity. Two viruses with BHV-5 antigenic profile were isolated from semen of asymptomatic bulis. The results showed that the antigenic characterization with the Mab panei employed here is useful for typing BHV-1 and BHV-5 isolates.

• Bovine herpesvirus BHV-1 BHV-5 monoclonal antibodies immunoperoxidase Herpesvírus bovino 1 herpesvírus bovino 5 anticorpos monoclonais imunoperoxidase.

Abstract in Portuguese:

RESUMO.- Souza V.F, Melo S.V., Esteves P.A., Schmidt C.S.R., Gonçalves D.A., Schaefer R., Silva T.C., Almeida R.S., Vicentini F., Franco A.C., Oliveira E.A., Spilki F.R., Weiblen R., Flores E.F., Lemos R.A., Alfieri A.A., Pituco E.M. & Roehe P.M. 2002. [Monoclonal antibody characterization of bovine herpesviruses types 1 (BHV-1) and 5 (BHV-5).] Caracterização de herpesvírus bovinos tipos 1 (BHV-1) e 5 (BHV-5) com anticorpos monoclonais. Pesquisa Veterinária Brasileira 22(1):13-18,-Depto Microbiologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, and Centro de Pesquisas Universitárias Desidério Finamor, Estrada do Conde 6000, Eldorado do Sul, RS 90001-970, Brazíl. E-mail: proehe@vottex.ufrgs.br O perfil antigénico de 45 herpesvírus (44 de bovinos, sendo seis amostras de referência de BHV-1 e 15 prováveis BHV-1; três amostras de referência de BHV-5 e 20 prováveis BHV-5) e uma amostra de herpesvírus bubalino (BuHV) foi examinado com um painel de anticorpos monoclonais (Acms) produzidos contra antígenos de herpesvírus bovinos. Para os exames, foi utilizada a prova de imunoperoxidase (IPX) sobre cultivas de células infectadas, tendo os Acms como anticorpos primários. A determinação dos padrões de reatividade das amostras de vírus frente aos Acms permitiu a diferenciação entre os tipos 1 e 5. Todas as amostras isoladas de casos de encefalite apresentaram perfil de BHV-5. Quatro amostras de BHV-5 isoladas de áreas geograficamente distintas apresentaram perfis de reatividade diferenciados em relação às demais amostras do tipo 5. Duas amostras de vírus com perfil antigénico de BHV-5 foram isoladas de sêmen de animais infectados. Estes resultados comprovam a utilidade da caracterização antigénica com este painel de Acms na tipagem de amostras de BHV-1 e BHV-5.

Abstract in English:

ABSTRACT.- Roehe P.M., Silva T.C., Nardi N.B., Oliveira L.G. & Rosa J.C.A. 1997. [Monoclonal antibody differentiation between bovine herpesviruses type 1 and 5.] Diferenciação entre os vírus da rinotraqueíte infecciosa bovina (BHV-1) e herpesvírus da encefalite bovina (BHV-5) com anticorpos monoclonais. Pesquisa Veterinária Brasileira 17(1):41-44. Centro de Pesquisas Veterinárias Desidério Finamor, Caixa Postal 2076, Porto Alegre, RS 90001-970, Brazil. Bovine Herpesviruses (BHV) type 1 (BHV-1) and type 5 (BHV-5) were analysed by immunoperoxidase staining with a panei of monoclonal antibodies (Mabs) prepared against BHV antigens. One of the Mabs recognized ali BHV isolates tested. The remainder four mabs recognized only BHV-1 samples, including standard laboratory strains. Ali isolates associated with clinical cases of encephalitis (BHV-5) displayed a pattern of reactivity distinct from that of viruses isolated from syndromes associated with BHV-1 infections. The results obtained indicate that such Mabs allowed the differentiation between BHV-1 and BHV-5, with a perfect correlation between the clinical pictures and the patterns of reactivity in vitro.

• Bovine herpesviruses infectious bovine rhinotracheitis virus IBR IPV bovine encephalitis virus BHV-1 BHV-5 Herpesvírus bovinos rinotraqueíte infecciosa bovina encefalite bovina.

Abstract in Portuguese:

SINOPSE.- Roehe P.M., Silva T.C., Nardi N.B., Oliveira L.G. & Rosa J.C.A. 1997. [Monoclonal antibody differentiation between bovine herpesviruses type 1 and 5.] Diferenciação entre os vírus da rinotraqueíte infecciosa bovina (BHV-1) e herpesvírus da encefalite bovina (BHV-5) com anticorpos monoclonais. Pesquisa Veterinária Brasileira 17(1):41-44. Centro de Pesquisas Veterinárias Desidério Finamor, Caixa Postal 2076, Porto Alegre, RS 90001-970, Brazil. Amostras de herpesvírus bovinos (BHV) tipo 1 (Virus da Rinotraqueíte Infecciosa BovinaNulvovaginite Pustular Infecciosa; BHV-1) e tipo 5 (Herpesvírus da Encefalite Bovina; BHV-5) tiveram seu perfil de reatividade analisado em testes de imunoperoxidase frente a um painel composto por cinco anticorpos monoclonais (AcM) produzidos contra antígenos de BHV-1. Um dos AcM reconheceu todas as amostras de BHV examinadas. Os quatro AcM restantes reconheceram somente amostras de BHV-1. Todas as amostras isoladas de casos de encefalites (BHV-5) apresentaram um padrão de reação distinto daquelas isoladas de outros síndromes associados à infecção pelo BHV-1. Os resultados obtidos indicam que os AcM avaliados permitem a diferenciação entre amostras de BHV-1 e BHV-5, havendo perfeita correlação entre os quadros clínicos observados com os perfis de reatividade obtidos in vitro.