Uso da sílica nanoestruturada SBA-15 como adjuvante de vacina oral para controle de Mycoplasma hyopneumoniae na produção de suínos
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2023-12-10
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Universidade Estadual Paulista (Unesp)
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Mycoplasma hyopneumoniae é uma bactéria de difícil controle, uma vez que vacinas comerciais não impedem a colonização e excreção do agente. O presente estudo teve como objetivo avaliar o desempenho de uma vacina de administração oral, composta por antígenos extraídos de Mycoplasma hyopneumoniae e incorporados à sílica mesoporosa ordenada tipo SBA-15, que possui função adjuvante-carreador, visando potencializar a ação da vacina intramuscular comercial. A vacina oral foi administrada em leitões nascidos de fêmeas nulíparas desafiadas com M. hyopneumoniae, com o propósito de promover um incremento na resposta imune contra o patógeno a partir do estímulo do tecido linfoide associado às mucosas (MALT), com início na mucosa intestinal. No total 60 leitões foram divididos em 4 grupos (n=15) submetidos a diferentes protocolos vacinais da seguinte forma, Grupo 1: SBA15 pela via oral + vacina comercial aos 24 dias no desmame, G2: vacina oral ao terceiro dia de vida + vacina comercial aos 24 dias, G3: vacina comercial aos 24 dias e G4: vacina comercial + vacina oral aos 24 dias. No primeiro dia, os leitões foram pesados e a partir do 3º dia, submetidos a colheitas de sangue, para detecção e quantificação de IgG anti Mycoplasma hyopneumoniae, bem como suabes nasais, para o monitoramento de IgA por ELISA, e de suabe orofaríngeo para avaliação da carga bacteriana por qPCR. As colheitas de amostras biológicas foram realizadas periodicamente até o 73º dia a partir do terceiro dia de vida. Aos 41 dias de vida, 15 indivíduos de mesma idade, experimentalmente desafiados com inóculo contendo M. hyopenumoniae foram inseridos na baia dos animais dos grupos (1 a 4) de forma a elevar a pressão de infecção durante período de creche. Ao final do estudo, aos 73 dias, todos os leitões foram eutanasiados e necropsiados para avaliação dos pulmões e colheita de amostras para estimativa de carga bacteriana por qPCR, e para a avaliação histopatológica. Também foram colhidas amostras de lavado traqueobrônquico, submetidas ao teste de qPCR. Os dados quantitativos obtidos nos exames clínicos, físicos e laboratoriais foram submetidos a avaliação dos pressupostos de normalidade e homocedasticidade pelos testes de Shapiro-Wilk e Bartlett, previamente à realização de testes estatísticos paramétricos ou não paramétricos.
Mycoplasma hyopneumoniae is a difficult-to-control bacterium since commercial vaccines do not prevent colonization and excretion. The present study aimed to evaluate the performance of an orally administered vaccine, composed of antigens extracted from Mycoplasma hyopneumoniae and incorporated into mesoporous silica (SBA-15), which has an adjuvant-carrier function, aiming to potentiate the action of the commercial intramuscular vaccine. The oral vaccine was administered to piglets born to nulliparous females challenged with M. hyopneumoniae, to promote an increase in the immune response against the pathogen from the stimulation of the mucosa-associated lymphoid tissue (MALT), starting in the intestinal mucosa. A total of 60 piglets were divided into four groups (n=15) submitted to different vaccination protocols as follows, Group 1: oral SBA15 + commercial vaccine at 24 days after weaning, G2: oral vaccine on the third day of life + vaccine commercial vaccine at 24 days, G3: commercial vaccine at 24 days and G4: commercial vaccine + oral vaccine at 24 days. On the first day, the piglets were weighed and, from the 3rd day onwards, submitted to blood collections for the detection and quantification of anti-Mycoplasma hyopneumoniae IgG. Nasal swabs were collected for monitoring IgA by ELISA, and oropharyngeal swabs were for assessing the bacterial load by qPCR. Biological samples were collected periodically from the third day of life until the 73rd day. At 41 days of life, 15 individuals of the same age, experimentally challenged with an inoculum containing M. hyopneumoniae, were inserted into the pen with the animals from groups (1 to 4) to increase the infection pressure during the nursery period. At the end of the study, at 73 days, all piglets were euthanized and necropsied for evaluation of the lungs and collection of lung samples for estimation of bacterial load by qPCR and histopathological evaluation. Tracheobronchial lavage samples were also collected and submitted to the qPCR test. Quantitative data obtained from physical parameters and laboratory investigation were analyzed regarding assumptions of normality and homoscedasticity using the Shapiro-Wilk and Bartlett tests, before performing parametric or non-parametric statistical tests.
Mycoplasma hyopneumoniae is a difficult-to-control bacterium since commercial vaccines do not prevent colonization and excretion. The present study aimed to evaluate the performance of an orally administered vaccine, composed of antigens extracted from Mycoplasma hyopneumoniae and incorporated into mesoporous silica (SBA-15), which has an adjuvant-carrier function, aiming to potentiate the action of the commercial intramuscular vaccine. The oral vaccine was administered to piglets born to nulliparous females challenged with M. hyopneumoniae, to promote an increase in the immune response against the pathogen from the stimulation of the mucosa-associated lymphoid tissue (MALT), starting in the intestinal mucosa. A total of 60 piglets were divided into four groups (n=15) submitted to different vaccination protocols as follows, Group 1: oral SBA15 + commercial vaccine at 24 days after weaning, G2: oral vaccine on the third day of life + vaccine commercial vaccine at 24 days, G3: commercial vaccine at 24 days and G4: commercial vaccine + oral vaccine at 24 days. On the first day, the piglets were weighed and, from the 3rd day onwards, submitted to blood collections for the detection and quantification of anti-Mycoplasma hyopneumoniae IgG. Nasal swabs were collected for monitoring IgA by ELISA, and oropharyngeal swabs were for assessing the bacterial load by qPCR. Biological samples were collected periodically from the third day of life until the 73rd day. At 41 days of life, 15 individuals of the same age, experimentally challenged with an inoculum containing M. hyopneumoniae, were inserted into the pen with the animals from groups (1 to 4) to increase the infection pressure during the nursery period. At the end of the study, at 73 days, all piglets were euthanized and necropsied for evaluation of the lungs and collection of lung samples for estimation of bacterial load by qPCR and histopathological evaluation. Tracheobronchial lavage samples were also collected and submitted to the qPCR test. Quantitative data obtained from physical parameters and laboratory investigation were analyzed regarding assumptions of normality and homoscedasticity using the Shapiro-Wilk and Bartlett tests, before performing parametric or non-parametric statistical tests.
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Adjuvante, Doenças infecciosas, Doenças respiratórias, Imunologia, Vacinas orais, Saude animal, Immunology, Infectious diseases, Oral vaccines, Respiratory diseases, Adjuvant