Teste de eficiência de vacinas antiaftosa. I. Redução da variação do índice C pelo aumento do número de cobaias (Cavia cavia)

Two foot and mouth disease vaccines were submitted to the “C Index” efficiency test with six replicates each using four guinea pigs per viral dilution for titration. The values obtained, when transformed into quality of the vaccine, demonstrated that the same vaccine could be scored as “rejected regular”, “approved good” or “approved very good”, indicating that the random variation in the results may prevent a classification of the immunogen. To determine whether these variations are due to the small number of guinea pigs used, one vaccine was submitted to six replicates using five guinea pigs per viral dilution in the “C Index” test. Analyses of the results using 2 by 2, 3 by 3, 4 by 4 and 5 by 5 arrangements from the data corresponding to all possible combinations when 5, 10, 20, 25 or 30 guinea pigs were used per viral dilution demonstrated that the plus or minus (±) 0.5 log10 variation with 95% confidence limits corresponds to 15 guinea pigs.Duas vacinas antiaftosa foram submetidas a seis repetições cada, à prova de eficiência, “índice C”, usando-se para titulação, quatro cobaias por diluição de vírus. Os valores encontrados, quando transformados em qualidade de vacina, demonstraram que uma mesma vacina poderia ser enquadrada como sendo “reprovada regular”, “aprovada boa” ou “aprovada muito boa”, indicando que a variação dos resultados, dependendo do caso, pode indefinir a classificação do imunógeno. Para verificar se tais variações são devidas ao pequeno número de cobaias, uma vacina foi submetida a seis repetições, usando-se cinco cobaias por diluição do vírus na prova “índice C”. Os arranjos 2 a 2, 3 a 3, 4 a 4, 5 a 5, realizados a partir dos resultados correspondentes a todas as combinações possíveis quando são usadas 5, 10, 15, 20, 25 ou 30 cobaias por diluição viral, demonstraram que a variação de mais ou menos 0,5 logaritmo com 95% de segurança, corresponde a 15 cobaias

Teste de eficiência de vacinas antiaftosa. II. Relação entre o Índice C em cobaias e o Índice Proteção Camundongos

O exame da eficiência de seis vacinas antiaftosa, realizado com os testes “Indice Proteção Camundongos” e "Índice C” utilizando 15 ou mais cobaias por diluição de vírus na titulação, demonstrou a presença de boa correlação e alta significância entre os resultados das duas provas. O valor do índice Proteção Camundongos foi aproximadamente o dobro do valor do índice C. Assim, o índice Proteção Camundongos pode ser recomendado como teste de eficiência de vacinas antiaftosa. principalmente quando se necessita um grande número de provas, devido a seu baixo custo e facilidade de execução, por usar exclusivamente camundongos.The efficiency of six foot and mouth disease vaccines was examined by the Mouse Protection Index and C Index tests using 15 or more guinea pigs per viral dilution for titration. A good correlation and high significance were obtained between the tests. The value of the Mouse Protection Index was approximately double the C Index value. Thus, in view of its low cost and easy execution due to the exclusive use of mice, the Mouse Protection Index can be recommended for testing the efficiency of foot and mouth disease vaccines, especially when a large number of tests is needed

Pesquisa de anticorpos anti-Listeria monocytogenes em soros de bovinos da região de Ribeirão Preto, no Estado de São Paulo, Brasil

Serological examinations were carried out for Listeria monocytogenes antibodies in 1000 cattle serum of the county of Ribeirão Preto, in the state of São Paulo, Brazil. The serum assay was carried out by serum agglutination test in tubes with somatic antigens from serotypes L 1, L2, L3, L4a and L4b. It was considered to be reagent all sera reacting in a titer of 1:20 being positive only the sera with 1:320 or above. According to this criteria 193 (19,3%) serum samples were positive for the serotypes L1, L2, and L4b. The serotype L4b was the more frequent. All 16 positive serum and 32 of the 193 reacting serum from agglutination reaction were submit to the complement fixation test. It was found that high titer in complement fixation test corresponded to high titer observed in the serum agglutination reaction.Exames sorológicos para Listeria monocytogenes foram realizados em 1000 amostras de soros bovinos da região de Ribeirão Preto, Estado de São Paulo, Brasil, tendo-se utilizado da prova de soro-aglutinação lenta com antígenos somáticos dos sorotipos L1, L2, L3, L4a e L4b. Foram considerados reagentes todos os soros com títulos superiores a 1:20 e como positivos somente os soros com títulos iguais ou superiores a 1:320. Com base nesse critério, 193 (19,3%) soros foram reagentes e 16 (1,6%) soros positivos para os sorotipos L1, L2 e L4b tendo o sorotipo L4b apresentado a maior frequência. Todos os 16 soros positivos e 32 dos 193 soros reagentes à prova de soro-aglutinação foram submetidos à prova de fixação do complemento. Títulos elevados nas provas de fixação do complemento correspondiam a títulos também elevados na prova de soro-aglutinação

Doença de Newcastle. I. Estudo experimental da resposta imune às estirpes vacinais B1 e La Sota

Broiler chicks from a commercial flocks of immunized matrix were used to study the lentogcnic vaccine prepared with both B1 and La Sota strains of the Newcastle virus disease. B1 and La Sota strains were equally efficient (P<0,01) in protecting animals against the effects produced by 107.52/0,1 ml EID50 of a velogenic viscerotropic sample given by eye drop instillation. Further, the haemagglutination inhibition antibody titre (HI) observed after vaccination, increased until the 21st day, being most effective for La Sota strain (P<0,05).Foram utilizados pintos de corte de linhagem comercial, procedentes de matrizes imunizadas, para o estudo de vacinas lentogênicas preparadas com as estirpes B1 e La Sota, do vírus da doença de Newcastle. As estirpes vacinais B1 e La Sota, estatisticamente ao nível de 1% de probabilidade, foram igualmente eficientes no teste de proteção ao desafio, realizado com 107,52 /0,1 ml EID50 de uma mostra velogênica viscerotrópica de campo administrada pela via ocular. O título de anticorpos inibidores hemoaglutinação (HI) aumentou até 21º dia após a vacinação, sendo significamente maiores para a estirpe La Sota, ao nível de 5% de probabilidade

Experimental infection with Brazilian Newcastle disease virus strain in pigeons and chickens

AbstractThis study was designed with the goal of adding as much information as possible about the role of pigeons (Columba livia) and chickens (Gallus gallus) in Newcastle disease virus epidemiology. These species were submitted to direct experimental infection with Newcastle disease virus to evaluate interspecies transmission and virus-host relationships. The results obtained in four experimental models were analyzed by hemagglutination inhibition and reverse transcriptase polymerase chain reaction for detection of virus shedding. These techniques revealed that both avian species, when previously immunized with a low pathogenic Newcastle disease virus strain (LaSota), developed high antibody titers that significantly reduced virus shedding after infection with a highly pathogenic Newcastle disease virus strain (São Joao do Meriti) and that, in chickens, prevent clinical signs. Infected pigeons shed the pathogenic strain, which was not detected in sentinel chickens or control birds. When the presence of Newcastle disease virus was analyzed in tissue samples by RT-PCR, in both species, the virus was most frequently found in the spleen. The vaccination regimen can prevent clinical disease in chickens and reduce viral shedding by chickens or pigeons. Biosecurity measures associated with vaccination programs are crucial to maintain a virulent Newcastle disease virus-free status in industrial poultry in Brazil

Detecção de Chlamydophila felis e Herpesvirus felino tipo 1 em felídeo não doméstico no Brasil

Little is known about the occurrence of feline upper respiratory tract disease agents, namely Feline Herpesvirus type 1 (FHV-1) and Chlamydophila felis, and co-infection of these agents with Feline Immunodeficiency virus (FIV) and Feline Leukemia Virus (FeLV) in non-domestic felids in Brazil. Between 2009 and 2010, 72 conjunctival swab and serum samples were collected from eight non-domestic felid species (Leopardus pardalis, Leopardus tigrinus, Panthera leo, Panthera tigris, Puma concolor, Puma yagouaroundi, Oncifelis colocolo, and Panthera onca) maintained in captivity in Brazilian zoos. DNA extracted from conjunctival swabs were used in PCR assays for the detection of Chlamydophila sp, FHV-1, and retrovirus DNA, respectively. Antibodies to FIV and FeLV antigen were detected in non-domestic felid serum samples using a commercial ELISA kit. Antibodies to FIV were found only in five (6.9%) felids. No sampled non-domestic felid was positive for FeLV antigen detection. One (1.3%) out of 72 non-domestic felid conjunctival swab samples was positive for Chlamydophilasp. and Feline Herpesvirus-1 in PCR. This felid was an ocelot and was negative for FIV and FeLV. The results of this survey showed the occurrence of co-infection with C. felis and FHV-1 in an ocelot (Leopardus pardalis) in Brazil. Poucos trabalhos descrevem a ocorrência dos agentes do complexo respiratório felino, Herpesvírus Felino tipo 1 (FHV-1) e Chlamydophila felis, e a coinfecção com o vírus da imunodeficiência felina (FIV) e leucemia viral felina (FeLV) em felinos não domésticos no Brasil. Entre 2009 e 2010, 72 amostras de swab de conjuntiva e de soro foram coletados de oito espécies de felinos não domésticos (Leopardus pardalis, Leopardus tigrinus, Panthera leo, Panthera tigris, Puma concolor, Puma yagouaroundi, Oncifelis colocolo, and Panthera onca) mantidos em cativeiro em zoológicos brasileiros. O DNA foi extraído das amostras de swab de conjuntiva para detecção de Chlamydophila sp e FHV-1 pela PCR. Anticorpos para FIV e antígeno para FeLV foram determinados pelo kit comercial de ELISA. Anticorpos para FIV foram detectados em cinco felídeos (6,9%). Nenhuma amostra foi positiva para a presença de antígeno de FeLV. Um (1,3%) dos 72 felinos não domésticos apresentou fragmentos de DNA de Chlamydophila sp e FHV-1 pela PCR. Este felino era uma jaguatirica que não apresentou anticorpos para FIV e nem antígeno para FelV. Estes resultados demonstram a ocorrência de coinfecção de C. felis e FHV-1 em uma jaguatirica (Leopardus pardalis) no Brasil

Pesquisa de anticorpos anti antígeno VIA (“Virus-infection associated” ) do virus da febre aftosa em búfalos (Bubalus bubalis, Linnaeus, 1758), ovinos e caprinos de alguns municípios do Estado de São Paulo, Brasil

The results of experiments to investigate antibody to virus-infection-associated (VIA) antigen in 157 sera samples from Indian buffalos (Bubalus bubalis), 370 sera from sheep and 180 sera from goats from some cities of São Paulo State, Brazil, are reported. Antibody against virus-infection-associated (VIA) antigen was found in 52 per cent of Indian buffalos, in 5,4 per cent of sheep and in 11 per cent of goats. These studies were done with sera from animals with well-documented pre-and postexposure histories of foot-and-mouth disease and vaccination.Foi realizado um estudo sorológico em 157 amostras de soros de búfalos indianos (Bubalus bubalis), em 370 soros de ovinos e em 180 soros de caprinos de algumas propriedades do Estado de São Paulo, Brasil. Os resultados encontrados revelam que 52% dos búfalos, 5,4% dos ovinos e 11% dos caprinos continham anticorpos anti antígeno VIA do vírus da febre aftosa. Esse estudo foi realizado em animais cujo histórico de vacinação e de exposição ao vírus da febre aftosa era conhecido

Persistência de anticorpos colostrais antiantígeno via ("Virus-Infection - Associated") e anticorpos soroneutralizantes induzidos por infecção natural pelo vírus da febre aftosa em bezerros búfalos indianos (Bubalus bubalis)

Antibody against virus-infection-associated (VIA) antigen and neutralizing serum antibody to foot-and-mouth disease virus were studied in 32 non vaccinated Indian buffalo calves. Antibody levels against VIA antigen were detected by double immunodifusion in 76.5% of the animals at 3 + ½, 30% at 4 + ½ and 6.2% at 5 + ½ months of age. Antibody against VIA antigen was no longer detectable at 7 + ½, 8 + ½ and 9 + ½ months of age. Neutralizing serum antibody levels were studied in 12 of 32 animals. At 3 = ½ months of age neutralizing serum antibody for O1, A24, and C3 virus were found respectively in 83.3%m 83.3% ans 65.6% of samples. At 5 + ½ months of age neutralizing serum antibody was present against the three types only in 20% of the animals and was not detected at 7 + ½ months of age. Twenty one days after the outbreak in cattle when the buffalo calves were 12 + ½ months old antibody against VIA antigen was again detected in 20 of 32 (62.5%) of the animals. Neutralizing serum antibody was found in up to 63.3% of the animals against type A and 16.6% against type O1 and C3.Anticorpos anti-antigeno VIA e anticorpos soroneutralizantes foram estudados em 32 bezerros búfalos indianos não vacinados, a partir de 3 + ½ meses de idade até 1 ano. Esses anticorpos foram detectados até os 5 = ½ meses de idade dos animais, até sofrerem infecção natural do vírus da febre aftosa, o que ocorreu aos 12 + ½ meses de idade. O significados destes achados em relação a susceptibilidade dos bubalinos a essa doença é discutido

Doença de Newcastle. II. Estudo comparativo entre diferentes métodos de administração de vacina preparada com a estirpe vacinal B1

The influence of different methods of application of vaccines prepared with B1 strain of Newcastle virus were studied in young birds obtained from immune matrixes. Their response was evaluated both by haemagglutination inhibition test (HI) and by the protection against a challenge test. Young birds, 14 days old, were primary vaccinated through aerosol, eye drop instillation or oral routes. Results showed that the aerosol method induced the most effective response on HI test (P<0,05). No differences were found between the eye drop instillation and the aerosol methods concerning protection against the challenge test. Further it was also observed that maternally derived antibodies declined quickly after birth being not detected in animals between 14 and 21 days old.Foram relatados os resultados do experimento entre diferentes métodos de aplicação de vacina preparada com a estirpe B1 do vírus da doença de Newcastle, realizado em pintos protegidos passivamente por anticorpos maternais, procedentes de matrizes imunizadas. A resposta imune foi avaliada pela reação de inibição da hemaglutinação (Hl) e pelo teste de proteção ao desafio. A primeira vacinação em pintos de 14 dias foi realizada pelas vias aerógena, ocular e oral. O método aerossol induziu melhor resposta de anticorpos inibidores da hemaglutinação, com significância ao nível de 5% de probabilidade, entretanto, sem diferenças significativas com ocular, no teste de proteção ao desafio. Os anticorpos maternos declinaram rapidamente depois do nascimento, não sendo detectados entre o 14º e o 21º dia

Pesquisa de Chlamydophila psittaci em ranfastídeos cativos no Estado de São Paulo, Brasil

Chlamydophila psittaci (C. psittaci) has been detected in 460 avian species, among them the most frequent are the Psittaciformes, Columbiformes, Anseriformes and raptors. In Brazil, the main avian species recognized as healthy carriers belong to the order Psittaciformes and Columbiformes, but very few studies have been done in other bird families. Reports of the occurrence of this disease in the clinical form are rare in the Ramphastids; consequently, they are not commonly evaluated for this agent. The present study reports the investigation of C. psittaci in 25 captive ramphastids from a zoological park in São Paulo State, Brazil. Swabs samples from the cloaca were submitted to semi-nested polymerase chain reaction (semi-nested PCR) for direct detection of the microorganism. Additionally, blood samples obtained from these birds were submitted to the Complement Fixation Test (CFT) for detection of antibodies anti-C. psittaci. The presence of C. psittaci was not detected in the cloacal swab samples tested by the PCR. Nevertheless, 16% (4/25) of the bird's sera were positive by the CFT. Among the species with positive results, there are the saffron toucanet (Pteroglossus bailloni) and black-necked-aracari (Pteroglossus aracari), two species with no descriptions of the survey of C. psittaci published in the literature. Intermittent elimination of C. psittaci is a feature of chronically infected birds; however the absence of a positive-antigen sample did not guarantee that the bird is Chlamydophila-free. The serological results obtained show that the ramphastids tested were previously exposed to the pathogen and developed immune response, but showed no clinical signs of the disease and didn't eliminate regularly the organism in their feces in the moment of the sample collection