RESUMO
Bovine respiratory syncytial virus (BRSV) affects both beef and dairy cattle, reaching morbidity and mortality rates of 60-80% and 20%, respectively. The aim of this study was to obtain a recombinant MVA expressing the BRSV F protein (MVA-F) as a vaccine against BRSV and to evaluate the immune response induced by MVA-F after systemic immunization in homologous and heterologous vaccination (MVA-F alone or combined with a subunit vaccine), and after intranasal immunization of mice. MVA-F administered by intraperitoneal route in a homologous scheme elicited levels of neutralizing antibodies similar to those obtained with inactivated BRSV as well as better levels of IFN-γ secretion. In addition, nasal administration of MVA-F elicited local and systemic immunity with a Th1 profile. This study suggests that MVA-F is a good candidate for further evaluations combining intranasal and intramuscular routes, in order to induce local and systemic immune responses, to improve the vaccine efficacy against BRSV infection.
Assuntos
Administração Intranasal , Camundongos Endogâmicos BALB C , Vírus Sincicial Respiratório Bovino , Animais , Vírus Sincicial Respiratório Bovino/imunologia , Camundongos , Feminino , Bovinos , Proteínas Virais de Fusão/imunologia , Proteínas Virais de Fusão/genética , Proteínas Virais de Fusão/administração & dosagem , Vacinas contra Vírus Sincicial Respiratório/imunologia , Vacinas contra Vírus Sincicial Respiratório/administração & dosagem , Vetores Genéticos , Infecções por Vírus Respiratório Sincicial/prevenção & controle , Infecções por Vírus Respiratório Sincicial/imunologia , Infecções por Vírus Respiratório Sincicial/veterinária , Vaccinia virus/imunologia , Vaccinia virus/genética , Anticorpos Antivirais/sangue , Imunidade nas Mucosas , Anticorpos Neutralizantes/sangue , Anticorpos Neutralizantes/imunologia , Imunização/métodos , Vacinas de Subunidades Antigênicas/imunologia , Vacinas de Subunidades Antigênicas/administração & dosagemRESUMO
The human respiratory syncytial virus (hRSV) constitutes a major health burden, causing millions of hospitalizations in children under five years old worldwide due to acute lower respiratory tract infections. Despite decades of research, licensed vaccines to prevent hRSV are not available. Development of vaccines against hRSV targeting young infants requires ruling out potential vaccine-enhanced disease presentations. To achieve this goal, vaccine testing in proper animal models is essential. A recombinant BCG vaccine that expresses the Nucleoprotein of hRSV (rBCG-N-hRSV) protects mice against hRSV infection, eliciting humoral and cellular immune protection. Further, this vaccine was shown to be safe and immunogenic in human adult volunteers. Here, we evaluated the safety, immunogenicity, and protective efficacy of the rBCG-N-hRSV vaccine in a neonatal bovine RSV calf infection model. Newborn, colostrum-replete Holstein calves were either vaccinated with rBCG-N-hRSV, WT-BCG, or left unvaccinated, and then inoculated via aerosol challenge with bRSV strain 375. Vaccination with rBCG-N-hRSV was safe and well-tolerated, with no systemic adverse effects. There was no evidence of vaccine-enhanced disease following bRSV challenge of rBCG-N-hRSV vaccinated animals, suggesting that the vaccine is safe for use in neonates. Vaccination increased virus-specific IgA and virus-neutralization activity in nasal fluid and increased the proliferation of virus- and BCG-specific CD4+ and CD8+ T cells in PBMCs and lymph nodes at 7dpi. Furthermore, rBCG-N-hRSV vaccinated calves developed reduced clinical disease as compared to unvaccinated control calves, although neither pathology nor viral burden were significantly reduced in the lungs. These results suggest that the rBCG-N-hRSV vaccine is safe in neonatal calves and induces protective humoral and cellular immunity against this respiratory virus. These data from a newborn animal model provide further support to the notion that this vaccine approach could be considered as a candidate for infant immunization against RSV.
Assuntos
Vacina BCG/imunologia , Doenças dos Bovinos/prevenção & controle , Imunogenicidade da Vacina , Infecções por Vírus Respiratório Sincicial/veterinária , Vacinas contra Vírus Sincicial Respiratório/imunologia , Vírus Sincicial Respiratório Bovino/imunologia , Animais , Animais Recém-Nascidos , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Vacina BCG/administração & dosagem , Vacina BCG/efeitos adversos , Bovinos , Doenças dos Bovinos/imunologia , Doenças dos Bovinos/virologia , Citocinas/metabolismo , Modelos Animais de Doenças , Imunização , Testes de Neutralização , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Vacinação , Eliminação de Partículas ViraisRESUMO
Abstract Bovine respiratory syncytial virus (BRSV) is one of the most relevant agents responsi-ble for respiratory disease in cattle from both dairy and beef farms. BRSV is spread by horizontalcontact causing a constant presence of seropositive animals that favors viral circulation throughout the year. Moreover, reinfections with BRSV are frequent between animals regardless of theirage as BRSV does not confer long-lasting protective immunity. Several studies have demonstrated the circulation of BRSV in cattle from different regions of the world; however, little isknown about the dynamics of BRSV infection in cows before and after they begin lactation. Theaim of this work was to study the dynamics of BRSV neutralizing antibodies from birth up to36 months of age in a closed dairy herd of Argentina specifically around the lactation period. Passive maternal antibodies against BRSV started to decrease monthly and became almost undetectable at 8 months of age. We detected two potential infection points at months 11 and 27after birth, in which 30% and 45% of the animals showed seroconversion, respectively. Specifically, an increase in the proportion of seropositive cows after the start of lactation suggests thatthey became reinfected around the time they began lactating. We demonstrate the importanceof understanding BRSV dynamics in a closed dairy herd to review the vaccination schedule ofthe animals to achieve protection against BRSV infection.
Resumen El virus respiratorio sincitial bovino (Bovine respiratory syncytial virus, [BRSV]) es uno de los principales agentes responsables de la enfermedad respiratoria en bovinos, tanto de tambos como de cría. El virus se transmite horizontalmente y causa la presencia constante de animales seropositivos, lo cual favorece la circulación viral a lo largo del ano. A su vez, las reinfecciones por BRSV son frecuentes entre animales independientemente de su edad, dado que el virus no confiere inmunidad protectora a largo plazo. Numerosos estudios han demostrado la circulación de BRSV en bovinos de diferentes regiones del mundo, sin embargo, poco se conoce acerca de la dinámica de infección en vacas antes y después del inicio de la fase de lactancia. El objetivo de este trabajo fue estudiar la dinámica de anticuerpos neutralizantes anti- BRSV en vacas lecheras desde el nacimiento hasta los 36 meses de vida en un tambo cerrado de Argentina, específicamente, en el período de lactancia. Los anticuerpos pasivos específicos para BRSV comenzaron a declinar mensualmente hasta ser casi indetectables a los 6 meses. Detectamos dos potenciales puntos de infección a los meses 11 y 27 luego del nacimiento, momentos en los que el 30 y el 45% de los animales mostraron seroconversión, respectivamente. El incremento en la proporción de vacas seropositivas luego del comienzo de la lactancia sugiere que estas se reinfectaron en el inicio de dicha etapa. Demostramos la importancia de entender la dinámica de circulación del BRSV en un tambo cerrado, a fin de revisar el esquema de vacunación de los animales para que estén protegidos frente a la posible infección por este virus.
Assuntos
Animais , Bovinos , Vírus Sincicial Respiratório Bovino , Anticorpos Neutralizantes , Argentina , Doenças dos Bovinos/virologia , Vírus Sincicial Respiratório Bovino/imunologiaRESUMO
Bovine respiratory syncytial virus (BRSV) is one of the most relevant agents responsible for respiratory disease in cattle from both dairy and beef farms. BRSV is spread by horizontal contact causing a constant presence of seropositive animals that favors viral circulation throughout the year. Moreover, reinfections with BRSV are frequent between animals regardless of their age as BRSV does not confer long-lasting protective immunity. Several studies have demonstrated the circulation of BRSV in cattle from different regions of the world; however, little is known about the dynamics of BRSV infection in cows before and after they begin lactation. The aim of this work was to study the dynamics of BRSV neutralizing antibodies from birth up to 36 months of age in a closed dairy herd of Argentina specifically around the lactation period. Passive maternal antibodies against BRSV started to decrease monthly and became almost undetectable at 8 months of age. We detected two potential infection points at months 11 and 27 after birth, in which 30% and 45% of the animals showed seroconversion, respectively. Specifically, an increase in the proportion of seropositive cows after the start of lactation suggests that they became reinfected around the time they began lactating. We demonstrate the importance of understanding BRSV dynamics in a closed dairy herd to review the vaccination schedule of the animals to achieve protection against BRSV infection.
El virus respiratorio sincitial bovino (Bovine respiratory syncytial virus, [BRSV]) es uno de los principales agentes responsables de la enfermedad respiratoria en bovinos, tanto de tambos como de cría. El virus se transmite horizontalmente y causa la presencia constante de animales seropositivos, lo cual favorece la circulación viral a lo largo del año. A su vez, las reinfecciones por BRSV son frecuentes entre animales independientemente de su edad, dado que el virus no confiere inmunidad protectora a largo plazo. Numerosos estudios han demostrado la circulación de BRSV en bovinos de diferentes regiones del mundo, sin embargo, poco se conoce acerca de la dinámica de infección en vacas antes y después del inicio de la fase de lactancia. El objetivo de este trabajo fue estudiar la dinámica de anticuerpos neutralizantes anti- BRSV en vacas lecheras desde el nacimiento hasta los 36 meses de vida en un tambo cerrado de Argentina, específicamente, en el período de lactancia. Los anticuerpos pasivos específicos para BRSV comenzaron a declinar mensualmente hasta ser casi indetectables a los 6 meses. Detectamos dos potenciales puntos de infección a los meses 11 y 27 luego del nacimiento, momentos en los que el 30 y el 45% de los animales mostraron seroconversión, respectivamente. El incremento en la proporción de vacas seropositivas luego del comienzo de la lactancia sugiere que estas se reinfectaron en el inicio de dicha etapa. Demostramos la importancia de entender la dinámica de circulación del BRSV en un tambo cerrado, a fin de revisar el esquema de vacunación de los animales para que estén protegidos frente a la posible infección por este virus.
Assuntos
Anticorpos Neutralizantes , Vírus Sincicial Respiratório Bovino , Animais , Argentina , Bovinos , Doenças dos Bovinos/virologia , Vírus Sincicial Respiratório Bovino/imunologiaRESUMO
The etiology and pathologic findings of bovine respiratory disease (BRD) in adult dairy cows (n = 35) from a commercial dairy herd in Southern Brazil were investigated. Pulmonary samples were examined for histopathologic patterns and specific features within these patterns, while immunohistochemical (IHC) assays were designed to detect the intralesional antigens of viral infectious disease agents and Mycoplasma bovis. Pneumonia was diagnosed in 91.4% (32/35) of these cases; neither pneumonia nor any of the infectious disease pathogens evaluated occurred in three cows. The presence of multiple respiratory pathogens in 75% (24/32) of these cases indicated the complex origin of pneumonia in cattle. Interstitial pneumonia, necrosuppurative bronchopneumonia and suppurative bronchopneumonia were the principal patterns of pulmonary disease identified by histopathology. The most frequent pathogens identified by IHC were bovine viral diarrhea virus (BVDV; n = 18), M. bovis (n = 16) and bovine alphaherpesvirus type 1 (BoHV-1; n = 14), followed by bovine respiratory syncytial virus (BRSV; n = 11) and bovine parainfluenza virus type 3 (BPIV-3; n = 5). Obliterative bronchiolitis and peribronchial lymphocytic cuffings were the characteristic histopathologic features associated with M. bovis. Necrohemorrhagic bronchitis with bronchial angiogenesis was associated with BoHV-1. Necrotizing bronchitis and bronchiolitis were associated with BVDV, BoHV-1 and BRSV. Ballooning degeneration of the bronchial and bronchiolar epithelia was associated with BRSV and BoHV-1. This is the first report from Brazil that correlated the histopathologic findings of BRD with the associated infectious disease agents by immunohistochemistry. M. bovis was frequently detected in the tissues of cows with fatal pulmonary disease during this study and may be a possible primary disease pathogen associated with the development of BRD in dairy cows. Additionally, the histopathologic features identified within patterns of pulmonary disease during this investigation may be an efficient diagnostic tool to associate histopathologic findings with specific agents of BRD in dairy cows.
Assuntos
Complexo Respiratório Bovino/virologia , Herpesvirus Bovino 1/isolamento & purificação , Infecções por Mycoplasma/microbiologia , Mycoplasma bovis/isolamento & purificação , Vírus da Parainfluenza 3 Bovina/isolamento & purificação , Vírus Sincicial Respiratório Bovino/isolamento & purificação , Animais , Anticorpos Antivirais/sangue , Complexo Respiratório Bovino/diagnóstico , Brasil , Bovinos , Ensaio de Imunoadsorção Enzimática/veterinária , Feminino , Herpesvirus Bovino 1/imunologia , Infecções por Mycoplasma/diagnóstico , Vírus da Parainfluenza 3 Bovina/imunologia , Transtornos Respiratórios/veterinária , Vírus Sincicial Respiratório Bovino/imunologiaRESUMO
A cross-sectional study was carried out, from November 2007 to March 2008, to estimate the prevalence of and to determine risk factors associated with bovine syncytial respiratory virus (BRSV) and parainfluenza 3 virus (PIV3) in dual-purpose herds in Colima, México. One hundred and seventy-six sera from 33 herds for PIV3 and 232 sera from 44 herds for BRSV were used. Sera were analyzed by indirect ELISA for the detection of antibodies against BRSV and PIV3 in cattle herds to determine the seroprevalence of respiratory diseases. The apparent and true prevalences for PIV3 were 60.8% and 54.4% and for BRSV 52.2% and 50.8%, respectively. The percentage of herds showing at least one positive animal was 78.7% for PIV3, and 93.2% for BRSV. Age (≤ 12, 13-48, and >48 months old) and respiratory signs (no, yes) showed significant association (P < 0.05) with PIV3 and age with BRSV. This study showed that animals were exposed to both viruses and that age was the main risk factor. The need to establish new vaccination plans to effectively protect cattle against those infections in the state of Colima, Mexico is suggested.
Assuntos
Anticorpos Antivirais/sangue , Doenças dos Bovinos/epidemiologia , Vírus da Parainfluenza 3 Bovina/isolamento & purificação , Infecções por Vírus Respiratório Sincicial/veterinária , Vírus Sincicial Respiratório Bovino/isolamento & purificação , Infecções por Respirovirus/veterinária , Animais , Bovinos , Doenças dos Bovinos/microbiologia , Estudos Transversais , Ensaio de Imunoadsorção Enzimática/veterinária , México/epidemiologia , Vírus da Parainfluenza 3 Bovina/imunologia , Prevalência , Infecções por Vírus Respiratório Sincicial/epidemiologia , Infecções por Vírus Respiratório Sincicial/microbiologia , Vírus Sincicial Respiratório Bovino/imunologia , Infecções por Respirovirus/epidemiologia , Infecções por Respirovirus/microbiologia , Fatores de Risco , Estudos SoroepidemiológicosRESUMO
A cross-sectional study was carried out to determine the seroprevalence and risk factors associated with bovine respiratory syncytial virus (BRSV) infection in non-vaccinated dairy and dual-purpose cattle herds from Ecuador. A total of 2,367 serum samples from 346 herds were collected from June 2008 to February 2009. A questionnaire, which included variables related to cattle, health, management measures, and the environment, was filled out in each herd. Presence of antibodies against BRSV was analyzed using a commercial indirect ELISA test. A logistic regression model was used to determine risk factors associated with BRSV at herd level. The individual seroprevalence against BRSV in non-vaccinated herds in Ecuador was 80.48% [1,905/2,367; 95% confidence interval (CI) = 78.9-82.1]. The herd prevalence was 91.3% (316/346; 95% CI = 88.3-94.3), and the intra-herd prevalence ranged between 25% and 100% (mean, 90.47%). The logistic regression model showed that the existence of bordering cattle farms, the dual-purpose farms, and the altitude of the farm (more than 2,338 m above sea level) were risk factors associated with BRSV infection. This is the first study about BRSV prevalence in Ecuador. It shows the wide spread of the BRSV infection in the country. The risk factors found will help to design effective control strategies.
Assuntos
Anticorpos Antivirais/sangue , Doenças dos Bovinos/epidemiologia , Infecções por Vírus Respiratório Sincicial/veterinária , Vírus Sincicial Respiratório Bovino/isolamento & purificação , Animais , Bovinos , Doenças dos Bovinos/microbiologia , Estudos Transversais , Indústria de Laticínios , Equador/epidemiologia , Ensaio de Imunoadsorção Enzimática/veterinária , Feminino , Modelos Logísticos , Prevalência , Infecções por Vírus Respiratório Sincicial/epidemiologia , Infecções por Vírus Respiratório Sincicial/microbiologia , Vírus Sincicial Respiratório Bovino/imunologia , Fatores de Risco , Estudos SoroepidemiológicosRESUMO
Caracterizou-se o efeito citopático produzido pela amostra de vírus respiratório sincicial bovino (BRSV) RC-98, isolada na Argentina, por meio de imunocitoquímica em cultivos de células da linhagem Hep-2. Um soro policlonal anti-BRSV foi utilizado para a imunocitoquímica em células Hep-2 infectadas. Sinais específicos do virus foram observados no citoplasma de um grande número de células, consistindo em inclusões citoplasmáticas e células sinciciais. Efeitos citopáticos distintos foram observados, com frequência, no núcleo das células infectadas, aparecendo como sinais específicos fortes, podendo corresponder a inclusões intranucleares. A presença de sinais intranucleares pode consistir uma característica particular da amostra RC98 do BRSV. (AU)
Assuntos
Efeito Citopatogênico Viral , Vírus Sincicial Respiratório Bovino/imunologia , Vírus Sincicial Respiratório Bovino/isolamento & purificação , Vírus Sincicial Respiratório Bovino/patogenicidade , Corpos de Inclusão Viral , ArgentinaRESUMO
We collected blood samples from 756 > or =2-year-old cattle in 54 herds in Yucatan, Mexico, and used all of those to determine the antibody seroprevalences (in an indirect enzyme-linked inmunosorbance assay) to bovine respiratory syncytial virus (BRSV) and risk factors for animal-level seropositivity. We used 728 of the same samples (from 52 of the same herds) to do the same for parainfluenza virus-3 (PIV3). Cattle were selected by two-stage cluster sampling. Herd-level and animal-level risk factors were obtained through a personal interview. We analyzed the data by using a random-effects multivariable logistic regression model for clustered observations. All herds had at least 3 (BRSV) or 5 (PIV3) seropositive animals. The animal-level true seroprevalences were: 90.8% (86.5, 95.2%) and 85.6% (80.9, 90.4%) for BRSV and PIV3, respectively. Animals in large herds and old animals had the highest odds of being seropositives to BRSV, and those risk factors plus animals born on the farm for PIV3 infection.
Assuntos
Doenças dos Bovinos/epidemiologia , Vírus da Parainfluenza 3 Bovina/isolamento & purificação , Infecções por Vírus Respiratório Sincicial/veterinária , Vírus Sincicial Respiratório Bovino/isolamento & purificação , Infecções por Respirovirus/veterinária , Animais , Anticorpos Antivirais/análise , Bovinos , Doenças dos Bovinos/sangue , Doenças dos Bovinos/etiologia , Doenças dos Bovinos/prevenção & controle , Doenças dos Bovinos/virologia , Ensaio de Imunoadsorção Enzimática/veterinária , Carne , México/epidemiologia , Vírus da Parainfluenza 3 Bovina/imunologia , Infecções por Vírus Respiratório Sincicial/epidemiologia , Vírus Sincicial Respiratório Bovino/imunologia , Infecções por Respirovirus/epidemiologia , Fatores de Risco , Estudos SoroepidemiológicosRESUMO
Samples from 17 free-ranging hunter-killed grey brocket deer (Mazama gouazoubira) in the Gran Chaco, Bolivia, were collected during June-August 1999. All 17 deer appeared to be in good condition at the time of death. Gross necropsies were performed, serum was collected for serologic evaluation of selected infectious disease agents, and feces and ectoparasites were collected for evaluation of internal and external parasites. Serologic tests were positive for antibodies against bovine respiratory syncytial virus and four Leptospira interrogans serovars, with questionable results for epizootic hemorrhagic disease virus serotypes 1 and 2. No antibodies were detected to Anaplasma marginale, Babesia bigemina, Babesia bovis, Babesia odocoilei, bluetongue virus (serotypes 2, 10, 11, 13, and 17), bovine viral diarrhea virus, Brucella abortus, foot-and-mouth disease virus, infectious bovine rhinotracheitis virus, Mycobacterium avium subsp. paratuberculosis, and parainfluenza-3 virus. Sixty-four percent (7/11) of the deer had endoparasites. Amblyomma spp. ticks were found on seven deer, flies of the family Hippoboscidae on six deer, and lice on six deer.