An ELISA to Detect Antibodies to Bovine Alphaherpesviruses 1 and 5 and Bubaline Alphaherpesvirus 1 in Cattle Sera.

Bovine alphaherpesvirus 1 (subtypes 1.1, 1.2a, and 1.2b), type 5 (subtypes 5a, 5b, and 5c), and bubaline herpesvirus 1 (BuHV-1) induce highly, though not fully cross-reactive serological responses. Most types and subtypes of these viruses circulate particularly in countries of the southern hemisphere, notably Brazil and Argentina. Therefore, the detection of infected animals is important in defining prevention and control strategies, particularly when flocks are destined for international trade. Identification of infected herds is most often achieved by assays that detect antibodies, such as enzyme immunoassays (ELISAs). However, to date, no ELISA has been evaluated in its capacity to detect antibodies to these alphaherpesviruses. Here, an ELISA was developed to detect antibodies to all currently recognized BoAHV-1, BoAHV-5, and BuAHV-1 types/subtypes, and its sensitivity and specificity were determined. Six hundred bovine sera were screened in serum neutralization tests (SN) against the seven viruses. ELISAs prepared with each of the viruses were compared to SN. Subsequently, a combined assay with multiple antigens LISA was prepared by mixing five viral antigens, chosen for their highest sensitivity in the preparative assays. In comparison to SN, the mAgELISA sensitivity was 96.5% with 96.1% specificity (κ = 0.93; PPV = 95.0%; NPV = 97.3%). The findings reveal that the mAgELISA developed here is highly suitable for the detection of antibodies, comparable in sensitivity and specificity to that of SN when performed with all known types and subtypes of bovine and bubaline alphaherpesviruses.

Torque teno sus virus 1 (TTSuV1) and 2 (TTSuV2) viral loads in serum of postweaning multisystemic wasting syndrome (PMWS)-affected and healthy pigs in Brazil.

Associations between Torque teno sus viruses (TTSuVs) and the occurrence of postweaning multisystemic wasting syndrome (PMWS) have been reported with controversial results. Currently, no studies have been performed comparing simultaneously viral loads of TTSuVs and PCV2. To examine the role for TTSuVs in PMWS-affected animals, a SYBR Green-based quantitative PCR (qPCR) was designed to detect and quantify TTSuV1, TTSuV2 and PCV2 genomes in swine sera. TTSuV1 genome loads were significantly higher in healthy adults than in young and SPF animals (p<0.05) suggesting that the prevalence of TTSuV1 infection increases with age and bears no association with PMWS. Regarding TTSuV2, no significant variation was detected in viral loads within any of the groups. As expected, PCV2 genome loads were higher in PMWS-affected swine than in healthy or SPF animals (p<0.001). These findings provide clear evidence to indicate that neither TTSuV1 nor TTSuV2 viral loads have any correlation with the occurrence of PMWS.

Full-Genome Sequence of a Reassortant H1N2 Influenza A Virus Isolated from Pigs in Brazil.

In this study, the full-genome sequence of a reassortant H1N2 swine influenza virus is reported. The isolate has the hemagglutinin (HA) and neuraminidase (NA) genes from human lineage (H1-δ cluster and N2), and the internal genes (polymerase basic 1 [PB1], polymerase basic 2 [PB2], polymerase acidic [PA], nucleoprotein [NP], matrix [M], and nonstructural [NS]) are derived from human 2009 pandemic H1N1 (H1N1pdm09) virus.

Guinea pigs experimentally infected with vaccinia virus replicate and shed, but do not transmit the virus

The origin of vaccinia viruses (VACV) associated with vesicular disease in cattle and humans in Southeast Brazil remains uncertain, yet the role of wild species in virus transmission has been suggested. This study investigated the susceptibility and transmission potential by guinea pigs (Cavia porcellus) - phylogenetically close to an abundant Brazilian rodent (Cavia aperea) - to two VACV strains (P1V and P2V) isolated from an outbreak of cutaneous disease in horses in Southern Brazil. Eight guinea pigs inoculated intranasally with P1V and P2V (10(6) TCID50.ml-1) did not develop clinical signs, but six animals shed virus in nasal secretions (day 1 to 9 post-inoculation - pi), developed viremia (between days 1 and 10 pi) and seroconverted to VACV. In spite of virus replication and shedding, the virus was not transmitted to sentinel animals by direct or indirect contact (aerosols) or through food and water contaminated with virus. These results demonstrate that, in spite of replicating and shedding the virus, guinea pigs do not transmit the virus upon experimental inoculation. This finding makes unlikely a possible participation of related species in VACV maintenance and transmission in nature.

A origem dos vírus vaccínia (VACV), envolvidos em surtos de doença vesicular em bovinos e humanos no Sudeste do Brasil, permanece desconhecida, e a participação de espécies silvestres na manutenção e transmissão do vírus tem sido sugerida. O objetivo deste trabalho foi investigar a susceptibilidade e o potencial de transmissão por cobaias (Cavia porcellus) - filogeneticamente relacionada a uma espécie de roedor, conhecido por preá (Cavia aperea), bastante abundante no país - a duas cepas de VACV (P1V e P2V) isoladas de um surto de doença cutânea em equinos no Rio Grande do Sul. Oito cobaias inoculadas pela via intranasal com uma mistura das amostras P1V e P2V (10(6) DICC50.ml-1) não apresentaram sinais clínicos, porém seis animais excretaram o vírus nas secreções nasais (1 a 9 dias pós-inoculação - pi), desenvolveram viremia (1 a 10 dias pi) e soroconverteram ao VACV. Apesar da replicação e excreção viral, o vírus não foi transmitido a sentinelas por contato direto, indireto (aerossóis) ou por água e alimentos contaminados com fezes deliberadamente contaminadas com o vírus. Esses resultados demonstram que, apesar de replicar e excretar o vírus, as cobaias não transmitem o VACV nas condições estudadas. Esses achados tornam pouco provável a participação de espécies relacionadas na manutenção e transmissão do VACV na natureza.

Guinea pigs experimentally infected with vaccinia virus replicate and shed, but do not transmit the virus

The origin of vaccinia viruses (VACV) associated with vesicular disease in cattle and humans in Southeast Brazil remains uncertain, yet the role of wild species in virus transmission has been suggested. This study investigated the susceptibility and transmission potential by guinea pigs (Cavia porcellus) - phylogenetically close to an abundant Brazilian rodent (Cavia aperea) - to two VACV strains (P1V and P2V) isolated from an outbreak of cutaneous disease in horses in Southern Brazil. Eight guinea pigs inoculated intranasally with P1V and P2V (10(6) TCID50.ml-1) did not develop clinical signs, but six animals shed virus in nasal secretions (day 1 to 9 post-inoculation - pi), developed viremia (between days 1 and 10 pi) and seroconverted to VACV. In spite of virus replication and shedding, the virus was not transmitted to sentinel animals by direct or indirect contact (aerosols) or through food and water contaminated with virus. These results demonstrate that, in spite of replicating and shedding the virus, guinea pigs do not transmit the virus upon experimental inoculation. This finding makes unlikely a possible participation of related species in VACV maintenance and transmission in nature.

A origem dos vírus vaccínia (VACV), envolvidos em surtos de doença vesicular em bovinos e humanos no Sudeste do Brasil, permanece desconhecida, e a participação de espécies silvestres na manutenção e transmissão do vírus tem sido sugerida. O objetivo deste trabalho foi investigar a susceptibilidade e o potencial de transmissão por cobaias (Cavia porcellus) - filogeneticamente relacionada a uma espécie de roedor, conhecido por preá (Cavia aperea), bastante abundante no país - a duas cepas de VACV (P1V e P2V) isoladas de um surto de doença cutânea em equinos no Rio Grande do Sul. Oito cobaias inoculadas pela via intranasal com uma mistura das amostras P1V e P2V (10(6) DICC50.ml-1) não apresentaram sinais clínicos, porém seis animais excretaram o vírus nas secreções nasais (1 a 9 dias pós-inoculação - pi), desenvolveram viremia (1 a 10 dias pi) e soroconverteram ao VACV. Apesar da replicação e excreção viral, o vírus não foi transmitido a sentinelas por contato direto, indireto (aerossóis) ou por água e alimentos contaminados com fezes deliberadamente contaminadas com o vírus. Esses resultados demonstram que, apesar de replicar e excretar o vírus, as cobaias não transmitem o VACV nas condições estudadas. Esses achados tornam pouco provável a participação de espécies relacionadas na manutenção e transmissão do VACV na natureza.