ABSTRACT
VP1 gene encoded by the newly identified caprine enterovirus CEV-JL 14 was amplified and cloned to prokaryotic expression vector pGEX-4T-1.Recombinant GST-VP1 fusion protein was expressed,purified,emulsified with Freund's complete adjuvant and used to immunize the BALB/c mice following a standard procedure.The spleen cells from immunized mice were collected and fused with myeloma cells after its antibody titer reached over 104 times detected by indirect ELISA.Hybridoma cell clones secreting monoclonal antibodies against VP1 were screened and their stability and specificity were further determined.The identified hybridoma cells were injected to mice intraperitoneally and ascites were collected at 7 DPI.Isotypes of the monoclonal antibodies against the recombinant VP1 protein were characterized to be either IgG1 or IgG2b,which showed a high specificity for detection of caprine enterovirus antigens by immunoperoxidase monolayer assay,thus laying a solid basis for future study related to viral pathogenesis,detection and diagnostics for caprine enterovirus infection.
ABSTRACT
Porcine teschovirus (PTV), porcine sapelovirus (PSV), and enterovirus G (EV-G) are infectious agents specific to pig host species that are endemically spread worldwide. This study aimed to investigate the natural infection by these porcine enteric picornaviruses in wild boars (Sus scrofa scrofa) of Paraná state, Brazil, and to evaluate peccaries (Pecari tajacu and Tayassu pecari) as alternative host species for these viruses. Fecal samples (n=36) from asymptomatic wild boars (n=22) with ages ranging from 2 to 7 months old (young, n=14) and 2 to 4 years old (adult, n=8) and from peccaries (6 to 8 months old, n=14) were collected from a farm and a zoo, respectively, both located in Paraná state. Reverse transcription-polymerase chain reaction (RT-PCR) and nested-PCR (n-PCR) assays targeting the 5'non-translated region of the virus genome were used for screening the viruses. Porcine enteric picornaviruses were detected in 12 out of the 22 wild boar fecal samples. According to each of the viruses, EV-G was most frequently (11/22, 50%) detected, followed by PTV (10/22, 45.5%) and PSV (4/22, 18.2%). Regarding the age groups, young wild boars were more frequently (9/14, 64.3%) infected with PTV, PSV, and EV-G than adult animals (3/8, 37.4%). One n-PCR amplified product for each of the viruses was submitted to sequencing analysis and the nucleotide sequences were compared with the related viruses, which showed similarities varying from 97.7% to 100% for PTV, 92.4% to 96.2% for PSV, and 87.1% to 100% for EV-G. Peccaries tested negative for the viruses and in this study they did not represent infection reservoirs. This study is the first to report the molecular detection of PTV, PSV, and EV-G from captive wild boars in a South American country and the first to screen peccaries as alternative host species for porcine enteric picornavirus.
Teschovírus suíno (PTV), sapelovírus suíno (PSV) e enterovírus G(EV-G) são agentes infecciosos específicos da espécie suína que estão endemicamente disseminados em todo o mundo. O objetivo deste estudo foi investigar a infecção natural por estes picornavírus entéricos suínos em javalis (Sus scrofa scrofa) do estado do Paraná, Brasil e avaliar pecaris (Pecari tajacu e Tayassu pecari) como hospedeiros alternativos para estes vírus. Amostras fecais (n=36) de javalis assintomáticos (n=22) com idades de 2 a 7 meses (jovens, n=14) e 2 a 4 anos (adultos, n=8) e de pecaris (6 a 8 meses de idade, n=14) foram coletadas em um cativeiro e zoológico, respectivamente, ambos localizados no estado do Paraná. A transcrição reversa seguida por reações da polimerase em cadeia (RT-PCR) e nested-PCR com alvo na região 5'-não traduzida do genoma viral foram utilizadas para a identificação dos vírus. Picornavírus entéricos suínos foram detectados em 12 das 22 amostras fecais de javalis. De acordo com cada um dos vírus, EV-G foi mais frequentemente (11/22, 50%) detectado, seguido pelo PTV (10/22; 45,5%) e PSV (4/22; 18,2%). Considerando os grupos de idade, javalis jovens foram mais frequentemente (9/14; 64,3%) infectados com PTV, PSV e EV-G do que os javalis adultos (3/8; 37,4%). Um produto amplificado na nested-PCR para cada um dos vírus foi submetido à análise de sequenciamento e as sequências de nucleotídeos foram comparadas com vírus relacionados, o que mostrou que as similaridades variaram entre 97,7% a 100% para o PTV, 92,4% a 96,2% para o PSV e 87,1% a 100% para o EV-G. Os pecaris foram negativos para as viroses investigadas e neste estudo não se apresentaram como hospedeiros alternativos para as infecções. Este estudo é o primeiro a relatar a detecção molecular de PTV, PSV e EV-G em javalis de cativeiro de um país da América Latina e o primeiro a avaliar pecaris como espécie hospedeira alternativa para picornavírus entéricos suínos.