Infecção experimental e avaliação de vias de transmissão de Clostridium difficile em leitões jovens
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Data
2016-12-16
Autores
Ferroni, Lívia Boarini [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
A infecção por Clostridium difficile é na maioria das vezes de manifestação subclínica em leitões jovens. E como atualmente este agente tem tido grande importância na medicina veterinária e possivelmente potencial zoonótico, o objetivo desta pesquisa foi avaliar a transmissão de C. difficile por via naso-nasal e aerógena em leitões jovens, utilizando analises microbiológicas, histopatológicas e moleculares. Leitões foram divididos em três grupos (Infectado, Sentinela e Controle), e distribuídos em baias isoladoras. Os grupos Infectados receberam inóculo 109 UFC.mL-1 e 108UFC.mL-1 de C. difficile 096 para via de transmissão naso-nasal e aerógena, respectivamente. Suabes anorretais foram colhidos diariamente para análises microbiológicas e moleculares da excreção nas fezes, utilizou-se técnica de PCR com iniciadores oligonucleotídeos que codificam os genes das toxinas TcdB e TcdA de Clostridium difficile para identificação molecular. Realizou-se eutanásia dos leitões, após 18 dias de infecção experimental, para avaliações histopatológicas e microbiológicos de intestino delgado, cólon, fígado, baço, tonsilas palatinas e linfonodos. Os grupos Infectado e Sentinela da via naso-nasal desenvolveram sinais clínicos de enfermidade, enquanto os animais da via aerógena não apresentaram sinais de infecção. Os leitões avaliados por via naso-nasal foram positivos para o gene TcdB nos grupos Infectado e Sentinela, enquanto os leitões desafiados por via aerógena foram positivos para TcdB apenas no grupo Infectado. Nas análises histopatológicas dos leitões da via naso-nasal foram observadas diversas lesões nos órgãos alvos tanto dos animais do grupo Infectado quanto no Sentinela; nos leitões da via aerógena avaliados histologicamente, apenas o grupo Infectado apresentou lesões nos órgãos, sendo que em ambas as vias, as lesões mais notáveis foram no intestino delgado. A transmissão de Clostridium difficile foi confirmada com a técnica de PCR apenas na via naso-nasal, inclusive com sinais clínicos durante período experimental no grupo Sentinela. Com isso, destaca-se a importância do controle preventivo deste agente nas granjas, a fim de minimizar a ocorrência de infecções em leitões jovens. Conclui-se que experimentalmente o Clostridium difficile pode ser transmitido entre leitões jovens pelo contato focinho-focinho, desencadeando doença clínica. Por outro lado, a transmissão pela via aerógena não ocorreu entre suínos jovens em situação experimental.
Clostridium difficile infection is most often of subclinical manifestation in young piglets. As this agent has been of great importance in veterinary medicine and also zoonotic potential, the objective of this research was to evaluate the naso-nasal and aerogenic transmission of C. difficile in young pigs, using microbiological, histopathological and molecular analyzes. Piglets were divided into three groups (Infected, Sentinel and Control), and distributed in isolation bays. The infected group received inoculum 109 CFU.mL-1 and 108 CFU.mL-1 of C. difficile 096 for the naso-nasal and aerogenic transmission route, respectively. Anorectal swabs were harvested for microbiological and molecular analyzes of faecal excretion, a PCR technique was used with primers that encode the TcdB and TcdA toxin genes of Clostridium difficile for molecular identification. Euthanasia of piglets after 18 days of experimental infection was performed for histopathological and microbiological evaluations of small intestine, colon, liver, spleen, palatine tonsils and lymph nodes. The Infected and Sentinel groups of the naso-nasal route developed clinical signs of disease, whereas the animals in the aerogenic showed no signs of infection. The naso-nasal piglets were positive for the TcdB gene in the Infected and Sentinel groups, while the pigs challenged by the aerogenic route were positive for TcdB only in the Infected group. In the histopathological analyzes of piglets of the naso-nasal route, several lesions were observed in the target organs of both the Infected group and the Sentinel; in the piglets of the aerogenic histologically evaluated, only the Infected group presented lesions in the organs, and in both routes, the most notable lesions were in the small intestine. Only the naso-nasal route confirmed transmission of Clostridium difficile, including clinical signs during the experimental period in the Sentinel group. With this, it stands out as a preventive control of this agent in the farms, in order to minimize an occurrence of infections in young piglets. It is concluded that experimentally, Clostridium difficile can be transmitted between young piglets the snout-snout contact, triggering clinical disease. On the other hand, aerial transmission did not occur among young experimental pigs
Clostridium difficile infection is most often of subclinical manifestation in young piglets. As this agent has been of great importance in veterinary medicine and also zoonotic potential, the objective of this research was to evaluate the naso-nasal and aerogenic transmission of C. difficile in young pigs, using microbiological, histopathological and molecular analyzes. Piglets were divided into three groups (Infected, Sentinel and Control), and distributed in isolation bays. The infected group received inoculum 109 CFU.mL-1 and 108 CFU.mL-1 of C. difficile 096 for the naso-nasal and aerogenic transmission route, respectively. Anorectal swabs were harvested for microbiological and molecular analyzes of faecal excretion, a PCR technique was used with primers that encode the TcdB and TcdA toxin genes of Clostridium difficile for molecular identification. Euthanasia of piglets after 18 days of experimental infection was performed for histopathological and microbiological evaluations of small intestine, colon, liver, spleen, palatine tonsils and lymph nodes. The Infected and Sentinel groups of the naso-nasal route developed clinical signs of disease, whereas the animals in the aerogenic showed no signs of infection. The naso-nasal piglets were positive for the TcdB gene in the Infected and Sentinel groups, while the pigs challenged by the aerogenic route were positive for TcdB only in the Infected group. In the histopathological analyzes of piglets of the naso-nasal route, several lesions were observed in the target organs of both the Infected group and the Sentinel; in the piglets of the aerogenic histologically evaluated, only the Infected group presented lesions in the organs, and in both routes, the most notable lesions were in the small intestine. Only the naso-nasal route confirmed transmission of Clostridium difficile, including clinical signs during the experimental period in the Sentinel group. With this, it stands out as a preventive control of this agent in the farms, in order to minimize an occurrence of infections in young piglets. It is concluded that experimentally, Clostridium difficile can be transmitted between young piglets the snout-snout contact, triggering clinical disease. On the other hand, aerial transmission did not occur among young experimental pigs
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Palavras-chave
Desafio, Clostridiose, Suínos, Challenge, Clostridiosis, Swines