RESUMEN
Mycoplasma hyopneumoniae (M. hyopneumoniae) is a primary agent of porcine enzootic pneumonia, a disease that causes significant economic losses to pig farming worldwide. Commercial vaccines induce partial protection, evidencing the need for a new vaccine against M. hyopneumoniae. In our work, three chimeric proteins were constructed, composed of potentially immunogenic domains from M. hyopneumoniae proteins. We designed three chimeric proteins (Q1, Q2, and Q3) based on bioinformatics analysis that identified five potential proteins with immunogenic potential (MHP418, MHP372, MHP199, P97, and MHP0461). The chimeric proteins were inoculated in the murine model to evaluate the immune response. The mice vaccinated with the chimeras presented IgG and IgG1 against proteins of M. hyopneumoniae. There was induction of IgG in mice immunized with Q3 starting from 30 days post-vaccination, and groups Q1 and Q2 showed induction at 45 days. Mice of the group immunized with Q3 showed the production of IgA. In addition, the mice inoculated with chimeric proteins showed a proinflammatory cytokine response; Q1 demonstrated higher levels of TNF, IL-6, IL2, and IL-17. In contrast, animals immunized with Q2 showed an increase in the concentrations of TNF, IL-6, and IL-4, whereas those immunized with Q3 exhibited an increase in the concentrations of TNF, IL-6, IL-10, and IL-4. The results of the present study indicate that these three chimeric proteins can be used in future vaccine trials with swine because of the promising antigenicity.
Asunto(s)
Mycoplasma hyopneumoniae , Animales , Porcinos , Ratones , Mycoplasma hyopneumoniae/genética , Interleucina-4 , Interleucina-6 , Vacunas Bacterianas/genética , Inmunoglobulina G , Proteínas Recombinantes de Fusión/genéticaRESUMEN
Demyelination is among the most conspicuous neurological sequelae of SARS-CoV-2 infection (COVID-19) in both the central (CNS) and peripheral (PNS) nervous systems. Several hypotheses have been proposed to explain the mechanisms underlying demyelination in COVID-19. However, none have considered the SARS-CoV-2's effects on the renin-angiotensin-aldosterone system (RAAS). Therefore, our objective in this review is to evaluate how RAAS imbalance, caused by direct and indirect effects of SARS-CoV-2 infection, could contribute to myelin loss in the PNS and CNS. In the PNS, we propose that demyelination transpires from two significant changes induced by SARS-CoV-2 infection, which include upregulation of ADAM-17 and induction of lymphopenia. Whereas, in the CNS, demyelination could result from RAAS imbalance triggering two alterations: (1) a decrease in angiotensin type II receptor (AT2R) activity, responsible for restraining defense cells' action on myelin; (2) upregulation of ADAM-17 activity, leading to impaired maturation of oligodendrocytes and myelin formation. Thus, we hypothesize that increased ADAM-17 activity and decreased AT2R activity play roles in SARS-CoV-2 infection-mediated demyelination in the CNS.
RESUMEN
Chagas disease (CD), caused by the protozoan Trypanosoma cruzi (T. cruzi), is a neglected disease endemic to some Latin American countries, including Brazil. Soon after infection, individuals develop an acute phase, which in most cases is asymptomatic and may go undetected. However, when CD is detected early, notification in the Notifiable Diseases Information System (SINAN), is mandatory. This study aimed to evaluate the information registered in the SINAN database and to determine the epidemiological profile of acute CD in Northeast Brazil, an endemic region, from 2001 to 2021. According to this survey, 1,444 cases of acute CD were reported in the Northeastern region of Brazil during this period. During the first six years, referred to as period 1, 90.24% of the notifications were registered, while the number of notifications significantly decreased in the subsequent years, referred to as period 2. Most individuals diagnosed with acute CD were Afro-Brazilian adults. All known routes of infection by the parasite were reported. Vector-borne transmission was predominant during period 1 (73.29%) and oral transmission during period 2 (58.87%). All nine states in Northeast Brazil reported cases in both periods. A higher incidence of disease was reported in Rio Grande do Norte (RN) during period 1, and in Maranhão (MA) during period 2. Our results show that CD remains a significant public health challenge.
Asunto(s)
Enfermedad de Chagas , Enfermedad de Chagas/epidemiología , Enfermedad de Chagas/transmisión , Brasil/epidemiología , Humanos , Masculino , Adulto , Femenino , Persona de Mediana Edad , Adolescente , Niño , Preescolar , Adulto Joven , Notificación de Enfermedades/estadística & datos numéricos , Lactante , Anciano , Incidencia , Trypanosoma cruzi , Enfermedad Aguda/epidemiología , Recién Nacido , Anciano de 80 o más AñosRESUMEN
BACKGROUND: Schistosomiasis continues to represent a serious public health problem in Brazil. With the coronavirus disease 2019 (COVID-19) pandemic, several control strategies were suspended, probably compromising the goals of eradicating the disease in the country. We aimed to assess the impact of the COVID-19 pandemic on Schistosomiasis Control Program (PCE) actions in all endemic states of Brazil. METHODS: We performed an ecological study using spatial analysis techniques. The PCE variables assessed were the population surveyed, the number of Kato-Katz tests, positive cases of schistosomiasis and the percentage of cases treated between 2015 and 2021. The percent change was calculated to verify if there was an increase or decrease in 2020 and 2021, along with time trend analyses provided by the Joinpoint model. Spatial distribution maps were elaborated considering the percent change. RESULTS: The surveyed population decreased in 2020 (-65.38%) and 2021 (-37.94%) across Brazil. There was a proportional reduction in the number of Kato-Katz tests (2020, -67.48%; 2021, -40.52%), a decrease in the percentage of positive cases (2020, -71.16%; 2021, -40.5%) and a reduction in the percentage of treated cases (2020, -72.09%; 2021, -41.67%). Time trend analyses showed a decreasing trend in most PCE variables. CONCLUSIONS: The PCE activities were impacted by the COVID-19 pandemic in Brazil and PCE strategies must be urgently reviewed, focusing on investments in all endemic areas.
Asunto(s)
COVID-19 , SARS-CoV-2 , Esquistosomiasis , Humanos , COVID-19/epidemiología , COVID-19/prevención & control , Brasil/epidemiología , Esquistosomiasis/epidemiología , Esquistosomiasis/prevención & control , Pandemias/prevención & control , Análisis Espacial , Control de Enfermedades Transmisibles/organización & administración , Control de Enfermedades Transmisibles/métodosRESUMEN
The COVID-19 pandemic has severely affected global health, leading to the suspension of numerous routine healthcare services and posing challenges in efforts to control other diseases, such as HIV/AIDS. This study aimed to assess the impact of the COVID-19 pandemic on HIV/AIDS diagnoses and mortality rates in Brazil during 2020 and 2021. The percentage change was calculated to determine whether there was an increase or decrease in HIV/AIDS diagnoses and mortality, considering the average numbers from the last 5 years. Additionally, a Joinpoint regression model and an interrupted time series analysis were applied to assess time trends before and after the onset of the pandemic. Lastly, choropleth maps were prepared. We observed a reduction of 22.4% (2020) and 9.8% (2021) in the diagnosis of HIV/AIDS in Brazil. Conversely, there was a significant increase in the percentage change of late diagnosis of AIDS deaths in 2020 (6.9%) and 2021 (13.9%), with some states showing an increase of over 87%. Decreasing time trends in the diagnosis of HIV/AIDS were identified before the pandemic in Brazil, especially in the Southeast and South regions, and then time trends stabilized after including the pandemic years. Along with the dissemination of COVID-19, there was a reduction in the diagnosis of HIV/AIDS and an increase in late diagnosis AIDS deaths, signaling a serious impact of the pandemic on HIV/AIDS control strategies in Brazil. Therefore, we highlight the need for continuous efforts to control both diseases, that is, maintaining regular health services even in crisis situations.
Asunto(s)
Síndrome de Inmunodeficiencia Adquirida , COVID-19 , Infecciones por VIH , Humanos , Síndrome de Inmunodeficiencia Adquirida/diagnóstico , Síndrome de Inmunodeficiencia Adquirida/epidemiología , Pandemias , Diagnóstico Tardío , Brasil/epidemiología , COVID-19/diagnóstico , COVID-19/epidemiología , Infecciones por VIH/diagnóstico , Infecciones por VIH/epidemiología , Prueba de COVID-19RESUMEN
Bovine herpesvirus 1 (BoHV-1) is an important bovine pathogen that is responsible for causing respiratory diseases and reproductive failures. The presence of BoHV-1 in an in vitro embryo production system affects fertilization, maturation, and embryonic development. The objective of this study was to evaluate the developmental capacity of oocytes from naturally infected cows with no reproductive history. Moreover, this study investigated the presence of viral DNA in cumulus oophorus complexes (COCs). Experimental groups were differentiated by titrating the antibodies detected through seroneutralization assays, establishing three groups: seronegative animals (titer lower than 2), low titer (2 to 8), and animals with a titer above or equal to 16. COCs were obtained from 15 donors during 22 sessions of ultrasound-guided follicular aspiration. DNA was extracted from a pool of COCs obtained from all aspirations from the same donor as well as from whole blood and nested PCR reactions were performed. Only COCs with a compact layer of cumulus cells, an intact zona pellucida, and homogeneous cytoplasm were selected for in vitro culture and evaluation of nuclear maturation rate. After culturing for 24 hours, the oocytes were fixed and stained to evaluate the meiotic cell cycle stage. Oocytes that showed a chromosomal configuration in metaphase II were considered to have reached nuclear maturation. Compared with the other groups, the oocyte nuclear maturation rate in animals with a titer greater than or equal to 16 (50%) was compromised (P<0.05). However, the viral titer did not influence the maturation rate of bovine oocytes in animals exhibiting low titration (62.2%) when compared with the control group (76.7%). Viral DNA was not observed in the blood samples but was detected in the COC pool from three seropositive donors. In view of the results obtained, we conclude that natural infections by the BoHV-1 virus can compromise the nuclear maturation rate in cows, depending on the titration levels of antibodies against the virus. Moreover, viral DNA could be present in COCs, contradicting the hypothesis that seropositive animals with no history of clinical symptomatology pose a negligible risk of transmitting BoHV-1 by COCs.(AU)
Herpesvírus bovino 1 (BoHV-1) é um importante patógeno bovino, responsável por causar doenças respiratórias e falhas reprodutivas. A presença do BoHV-1 em sistema de produção in vitro de embriões afeta a fertilização, a maturação e o desenvolvimento embrionário. O objetivo deste estudo foi avaliar a capacidade de desenvolvimento de ovócitos oriundos de vacas infectadas naturalmente sem histórico reprodutivo. Além disso, este estudo investigou a presença do DNA viral em Complexos Cumulus Ooforus (COCs). Os tratamentos foram definidos a partir do título de anticorpos detectados pelos ensaios de soroneutralização, sendo estabelecidos três grupos: animais soronegativos (título menor do que 2), título baixo (2 a 8) e animais com título maior ou igual a 16. Os COCs foram obtidos de 15 doadoras durante 22 sessões de aspiração folicular guiada por ultrassom. A extração do DNA foi realizada em um pool de COCs de todas as aspirações de uma mesma doadora e no sangue total para a realização das reações de Nested-PCR. Para avaliação da taxa de maturação nuclear, foram selecionados para o cultivo in vitro somente os COCs com camada compacta de células do cumulus, zona pelúcida íntegra e citoplasma homogêneo. Após 24 horas de cultivo, os ovócitos foram fixados e corados em lâmina para a avaliação do estádio do ciclo celular meiótico. Os ovócitos que apresentaram configuração cromossômica em metáfase II foram considerados como tendo alcançado a maturação nuclear. Verificou-se comprometimento na taxa de maturação nuclear ovocitária (P<0.05) nos animais de título maior ou igual a 16 (50%). No entanto, não houve influência do título viral na taxa de maturação de ovócitos bovinos em animais que apresentaram titulação baixa (62,2%) quando comparados com o grupo controle (76,7%). O DNA viral não foi identificado nas amostras de sangue, mas foi detectado no pool de COCs de três doadoras soropositivas. Diante dos resultados encontrados conclui-se que vacas infectadas naturalmente pelo vírus BoHV-1 apresentam comprometimento na taxa de maturação nuclear, dependendo do grau de titulação de anticorpos contra o vírus. Ademais, o DNA viral pode estar presente em COCs contrariando a hipótese de que animais sorologicamente positivos e sem histórico de sintomatologia clínica oferecem risco negligível de transmissão do BoHV-1 por COCs.(AU)
Asunto(s)
Animales , Femenino , Bovinos , Oocitos/patología , Oocitos/virología , Infecciones por Herpesviridae/veterinaria , Herpesvirus Bovino 1 , Rinotraqueítis Infecciosa Bovina , Técnicas de Maduración In Vitro de los Oocitos/veterinariaRESUMEN
BACKGROUND Gene reporter-fluorescent cells have emerged as alternative method for drug screening. OBJECTIVE Achievement of constitutive expression of fluorescent protein GFP by Leishmania braziliensis as alternative method for drug screening. METHODS L. braziliensis-GFP was generated using Leishmania tarentolae pLEXSY-egfp for constitutive expression of GFP. Fluorescent cells were selected and subjected to standardisation tests of anti-promastigote and anti-intracellular amastigote assays. FINDINGS Our results showed that L. braziliensis-GFP method is faster and more sensitive than Allamar Blue-resazurin. MAIN CONCLUSION Transfected parasites maintained stable fluorescence after successive in vitro passages and pLEXSY system can be used to achieve non-L. tarentolae fluorescent cells.
Asunto(s)
Animales , Leishmania braziliensis/efectos de los fármacos , Anfotericina B/farmacología , Proteínas Fluorescentes Verdes/farmacología , Evaluación Preclínica de Medicamentos/métodos , Antiprotozoarios/farmacología , Factores de Tiempo , Microscopía FluorescenteRESUMEN
CONTEXT AND OBJECTIVE: Mycobacterium avium subsp. paratuberculosis (MAP) has attracted the interest of researchers because of similarities between paratuberculosis and Crohn's disease (CD). The aim of this study was to evaluate the frequency of MAP through cultures, histology and polymerase chain reaction (PCR) on intestinal biopsies from Brazilian CD patients. Quantitative real time PCR (qRT-PCR) was performed on positive samples. DESIGN AND SETTING: Analytical cross-sectional study with control group at two federal universities. METHODS: Fresh samples were collected from 25 patients; five with CD, eight with ulcerative colitis (UC) and 12 controls with non-inflammatory bowel disease (nIBD). Formalin-fixed paraffin-embedded (FFPE) samples from 143 patients were also collected: 44 CD, 49 UC and 56 nIBD. RESULTS: None of the fresh samples was positive for MAP. Five FFPE samples (one CD, two UC and two nIBD) and three fresh samples (one in each group) were positive through IS900-PCR. qRT-PCR was performed on these eight samples. Among the FFPE samples, there were 192.12 copies/μl in the CD group, 72.28 copies/μl in UC and 81.43 copies/μl in nIBD. Among the fresh samples, there were 432.99 copies/μl, 167.92 copies/μl and 249.73 copies/μl in the CD, UC and nIBD groups, respectively. The highest bacterial load was in the CD group. CONCLUSION: This study does not provide evidence for a role of MAP in the etiology of CD, although MAP DNA was detected in all three patient groups. This is the first report of MAP presence in human intestinal biopsies in Brazil.
CONTEXTO E OBJETIVO: Mycobaterium avium subsp. paratuberculosis (MAP) tem atraído o interesse de pesquisadores devido às semelhanças entre a paratuberculose e a doença de Crohn (CD). Este estudo objetivou avaliar a frequência de MAP por meio de cultura, histologia e reação da polimerase em cadeia (PCR), em biópsias intestinais de pacientes brasileiros com CD. PCR quantitativa em tempo real (qRT-PCR) foi realizada nas amostras positivas. TIPO DE ESTUDO E LOCAL: Estudo transversal analítico com grupo controle realizado em duas universidades federais. MÉTODOS: Amostras frescas foram coletadas de 25 pacientes; cinco com CD, oito com colite ulcerativa (UC) e 12 controles sem doença inflamatória intestinal (nIBD). Também foram coletadas 149 amostras fixadas em parafina (FFPE): 44 CD, 49 UC e 56 nIBD. RESULTADOS: Nenhuma das amostras frescas foi positiva para MAP. Cinco amostras FFPE (uma CD, duas UC e duas nIBD) e três amostras frescas (uma de cada grupo) foram positivas por IS900-PCR. qRT-PCR foi realizada nessas oito amostras. Nas amostras FFPE, havia 192,12 cópias/μl no grupo CD, 72,28 cópias/μl no UC e 81,43 cópias/μl no nIBD. Nas amostras frescas, havia 432,99 cópias/μl, 167,92 cópias/μl e 249,73 cópias/μl nos grupos CD, UC e nIBD, respectivamente. A maior carga bacteriana foi encontrada no grupo CD. CONCLUSÃO: Este estudo não fornece evidências do papel de MAP na etiologia da CD, embora DNA de MAP tenha sido detectado em pacientes dos três grupos. Este é o primeiro relato da presença de MAP em biópsias intestinais humanas no Brasil.
Asunto(s)
Humanos , Masculino , Femenino , Preescolar , Niño , Adolescente , Adulto , Persona de Mediana Edad , Anciano , Anciano de 80 o más Años , Adulto Joven , Enfermedades Inflamatorias del Intestino/microbiología , Colitis Ulcerosa/microbiología , Enfermedad de Crohn/microbiología , Mycobacterium avium subsp. paratuberculosis/aislamiento & purificación , Estudios de Casos y Controles , Reacción en Cadena de la Polimerasa/métodos , Estudios Transversales , Mycobacterium avium subsp. paratuberculosis/patogenicidad , Análisis de Secuencia de ADN/métodosRESUMEN
Mycobacterium avium subspecies paratuberculosis (MAP) can infect ruminants and remain subclinical for long periods within herds. The identification of organs that are more susceptible to infection and the evaluation of cytokine expression at the site of infection are important to understand the pathogenesis of MAP. In this study, the probability of detection of MAP-DNA and the expression of cytokines in organs of C57BL/6 mice infected intraperitoneally for 120 days were evaluated. Among the evaluated organs, the spleen (85%), colon (75%) and liver (60%) had the highest frequency of positivity. When compared these frequencies between organs, it has been found that the spleen had 1.54 times as likely to be positive in relation to the ileum, and 2.0 times more likely in relation to the Peyer's patches. In addition, at 60 days post-infection, the spleen and the liver were responsible for upregulation of IFN-γ , and the ileum by TNF-α and IL-4. The results indicate that the spleen is the best organ for evaluating an experimental infection by MAP, especially in the initial stages of the infection. Moreover, it showed that the spleen, liver and ileum have a direct role in the inflammatory response in experimental models.
Mycobacterium avium subespécie paratuberculosis (MAP) pode infectar ruminantes e permanecer subclínica por longos períodos nos rebanhos. A identificação de órgãos mais susceptíveis à infecção e a avaliação da expressão das citocinas no local da infecção são importantes para compreender a patogênese de MAP. Neste estudo foi avaliada a probabilidade de detecção de DNA de MAP e a expressão de citocinas em órgãos de camundongos C57BL/6 infectados por via intraperitoneal durante 120 dias. Dentre os órgãos avaliados, o baço (85%), cólon (75%) e fígado (60%) tiveram as maiores frequências de positividade. Quando comparadas essas frequências entre os órgãos, verificou-se que o baço teve 1,54 vezes mais probabilidade de ser positivo em relação ao íleo, e 2,0 vezes mais probabilidade em relação às placas de Peyer. Além disso, aos 60 dias pós infecção, o baço e o fígado foram responsáveis pela maior expressão de IFN-γ e o íleo pela TNF-α e IL-4. Os resultados indicam que o baço é o melhor órgão para avaliar uma infecção experimental por MAP, principalmente nos períodos iniciais da infecção. Além disso, demonstrou que o baço, fígado e íleo têm importância direta na resposta inflamatória de modelos experimentais.
Asunto(s)
Animales , Femenino , Cobayas , Ratones , Citocinas/análisis , Citocinas/genética , Mycobacterium avium subsp. paratuberculosis/patogenicidad , Paratuberculosis/diagnóstico , Infecciones Asintomáticas , Bazo/virología , Infecciones/veterinaria , Reacción en Cadena en Tiempo Real de la Polimerasa/veterinaria , Reacción en Cadena de la Polimerasa/veterinaria , Técnicas Histológicas/veterinariaRESUMEN
The aim of this study was to investigate the presence of neutralizing antibodies against bovine herpesvirus 1 (BoHV-1) in 722 non-vaccinated animals from eight properties that use different farming systems (extensive, semi-confinement and confinement). Serum samples were subjected to neutralization tests in order to search for anti-BoHV-1 antibodies. Serological results were categorized as negative, low titer, intermediate titer or high titer. One property showed no positive samples; while other properties presented frequency of positive samples ranging from 17.95% to 86.96%. For animals raised under confinement, the number of positive samples and neutralizing antibody titers were lower compared to others, possibly due to good sanitary practices adopted by this type of system. Altogether, our results can contribute towards the understanding of the endemic infection in Brazil.
Este trabalho teve por objetivo avaliar a distribuição de anticorpos neutralizantes contra o herpesvirus bovino 1 (BoHV-1) em 722 animais não vacinados pertencentes a oito propriedades que utilizam diferentes sistemas de criação (extensivo, semi-confinamento e confinamento). As amostras sorológicas foram submetidas ao teste de soroneutralização para pesquisa de anticorpos anti-BoHV-1. Os resultados foram classificados em títulos negativo, baixo, médio e alto. Uma propriedade não apresentou amostras positivas, enquanto que nas demais propriedades a frequência de amostras positivas variou de 17,95% a 86,96%. Os animais do sistema de criação por confinamento apresentaram menor número de amostras positivas quando comparado aos animais do outros sistemas de criação, possivelmente devido às boas práticas sanitárias adotadas por esse sistema. Dessa forma, nossos resultados podem contribuir para o entendimento dessa infecção endêmica no Brasil.
Asunto(s)
Herpesvirus Bovino 1 , Anticuerpos Neutralizantes , Rinotraqueítis Infecciosa BovinaRESUMEN
Twenty-nine lactic acid bacteria (LAB) isolates were submitted for identification using Biolog, API50CHL, 16S rDNA sequencing, and species-specific PCR reactions. The identification results were compared, and it was concluded that a polyphasic approach is necessary for proper LAB identification, being the molecular analyzes the most reliable.
RESUMEN
Porcine circovirus-2 (PCV-2) infection is currently considered an important disease of swine. The pathogenic agent was first described in Brazil in 2000. This study detected the PCV-2 DNA in four Brazilian pig tissues collected between 1978 and 1979. This observation is the oldest description of this virus in Brazil.
Asunto(s)
Animales , Infecciones por Circoviridae , Circovirus , Técnicas y Procedimientos Diagnósticos , Reacción en Cadena de la Polimerasa , Porcinos , Métodos , MétodosRESUMEN
Porcine circovirus 2 (PCV2) is generally associated with the porcine circovirosis syndrome, which is considered an important disease of swine and has potentially serious economic impact on the swine industry worldwide. This article describes the construction of a recombinant plasmid expressing the PCV2 structural protein and the evaluation of cellular and humoral immune responses produced by this recombinant vaccine in BALB/c mice. The vaccine candidate was obtained and analyzed in vivo, in an effort to determine the ability to induce a specific immune response in mice. DNA was extracted from a Brazilian PCV2 isolate and the gene coding for Cap protein was amplified by PCR and inserted into an expression plasmid. Groups of BALB/c mice were inoculated intra-muscularly and intradermally in a 15-day interval, with 100 µg and 50 µg of the vaccine construct, respectively. Another group was inoculated intramuscularly with 100 µg of empty plasmid, corresponding to the control group. Seroconversion and cellular response in BALB/c mice were compared and used for vaccine evaluation. Seroconversion was analyzed by ELISA. After a series of 3 immunizations the spleen cells of the immunized animals were used to perform lymphocyte proliferation assays. Seroconversion to PCV2 was detected by ELISA in the animals inoculated with the vaccine construct when compared with control groups. Lymphocyte proliferation assays showed a stronger cell proliferation in the inoculated animals compared with the control group. Thus, the vaccine candidate construct demonstrated to be able to induce both humoral and cellular responses in inoculated mice.
O circovírus suíno 2 (PCV2) é geralmente associado à síndrome da circovirose suína, que é considerada uma importante doença de suínos e possui um sério impacto econômico na suinocultura mundial. Este trabalho descreve a construção de um plasmídeo recombinante que expressa a proteína estrutural do PCV2 e a avaliação das respostas imune humoral e celular por meio de vacinação em camundongos BALB/c. O candidato vacinal foi submetido a análises in vivo, determinando a capacidade de induzir resposta imune específica em camundongos. O DNA de um isolado brasileiro de PCV2 foi extraído e o gene que codifica para a proteína do capsídeo foi amplificado por PCR e inserido num plasmídeo de expressão. Grupos de camundongos BALB/c foram inoculados por via intramuscular e intradérmica a cada 15 dias, com 100µg e 50µg da construção vacinal, respectivamente. Outro grupo foi inoculado com 100µg do plasmídeo original, correspondente ao grupo controle. A soroconversão e a resposta celular dos grupos de camundongos BALB/c vacinados foram comparados como parâmetros de avaliação vacinal. A soroconversão foi avaliada por um teste de ELISA. Após 3 imunizações, as células esplênicas dos animais imunizados foram utilizadas nos ensaios de linfoproliferação. A soroconversão para o PCV2 foi detectada por ELISA nos animais inoculados com a construção vacinal quando comparados com o grupo controle. Nos ensaios de linfoproliferação foi observada uma grande proliferação celular nos animais inoculados comparados ao grupo controle. Portanto, o candidato vacinal demonstrou ser capaz de induzir tanto uma resposta humoral e celular nos camundongos inoculados.
Asunto(s)
Animales , Circovirus/aislamiento & purificación , Ensayo de Inmunoadsorción Enzimática , Ratones , Vacunas de ADN/efectos adversosRESUMEN
O herpesvírus bovino 5 (BoHV-5) é o agente da menigoencefalite herpética bovina. A doença neurológica, associada à infecção pelo BoHV-5, apresenta altas taxas de letalidade em bovinos jovens e está disseminada no Brasil. A prevenção das perdas causadas pela infecção pelo herpesvírus está baseada, principalmente, na imunização dos animais. Nesse sentido, foi delineada uma comparação entre isolados de BoHV-5, buscando selecionar o isolado mais antigênico para a formulação de vacinas. As formulações inativadas foram produzidas com os isolados ISO9898292, SV507, SV163, 1807 e EVI145 e administradas a cinco grupos de 10 ovelhas cada, que receberam duas doses vacinais por via intramuscular com intervalo de 21 dias. Foram realizadas coletas de sangue para análise de presença de anticorpos por soroneutralização e acompanhamento dos animais até o 63° dia após a primo-vacinação. Foram observados dois picos na curva de anticorpos, o primeiro no dia 14, após a vacinação, quando os títulos médios de anticorpos variaram entre 23,1 e 138,6. O segundo pico foi observado 14 dias após a revacinação, quando os títulos médios variaram entre 301,3 e 1017,5. No 42° dia após a revacinação, foi observada variação de título entre 82,4 e 305,9. A diferença entre as médias de títulos de anticorpos de cada grupo de animais sugere uma menor antigenicidade do isolado ISO9898292 em relação aos demais, demonstrando uma possível variação antigênica entre os isolados. Todos os isolados, com exceção do ISO9898292, mostraram-se imunogênicos para a indução de anticorpos.
Herpesvirus bovine 5 (BoHV-5) is the agent of bovine herpetic menigoencephalitis. The neurological disease associated with the infection is highly lethal in young cattle and it is widespread in Brazil. Control of the clinical signs caused by herpesviruses is based mainly on the immunization of cattle. A comparative study was performed among Brazilian BoHV-5 isolates to select the more antigenic virus. Inactivated vaccines were formulated using isolates ISO9898292, SV507, SV163, 1807 and EVI145 and administered to five groups of 10 sheep, each animal receiving two intramuscular doses with a 21 days interval. Blood collection for serology by virusneutralization were performed until the 63rd day after the first vaccination, two peaks in the curve of antibodies were observed, the first on day 14, ranged from 23.l to 138.6. The second peak was observed 14 days after the booster, and ranged from 301.3 to 1017.5. In the 42nd day after the booster, it was observed a titer variation from 82.4 to 305.9. The differences among antibody titers of each group of suggests a lower antigenicity of isolate ISO9898292 in comparison with the others, demonstrating a possible antigenic variation among the isolates. Thus, all isolates, with exception of ISO9898292, were immunogenic for the induction of neutralizing antibodies.