Avaliação da resposta imunológica da mucosa intestinal de frangos de corte desafiados com diferentes sorovares de Salmonella

Abstract

RESUMO.-Objetivou-se com o presente estudo comparar o efeito de diferentes sorovares de Salmonella na resposta imune local da mucosa do intestino de frangos de corte. Aos sete dias de idade, as aves foram desafiadas com os sorovares S. Enteritidis, S. Typhimurium, S. Senftenberg, S. Mbandaka e S. Minnesota. Foi observado que todos os sorovares testados foram capazes de colonizar o intestino das aves sendo possível o isolamento de Salmonella em suabes de cloaca, 48 h após inoculação. De maneira geral, as aves do grupo controle negativo, que não foram desafiados apresentaram quantidade significativamente menor de células imunológicas na mucosa intestinal do que as aves desafiadas. Porém, verificou--se que os sorovares de Salmonella, utilizados neste estudo, apresentaram diferentes efeitos sobre a dinâmica celular da mucosa do íleo e ceco e afetaram de modo diferente o ganho de peso e ganho médio diário das aves demonstrando distintos graus de patogenicidade. Os sorovares Enteritidis e Typhimurium apresentaram um efeito mais intenso tanto no desempenho quanto na mobilização de células imunoló-gicas na mucosa intestinal de frangos de corte. The study was designed to compare the effect of different Salmonella serovars in immune response across the count of CD8+ cells, CD4+ cells, goblet cells and macrophages in the gut mucosa of broilers. During the experimental inoculation at 7 day-old were used Salmonella enterica subspecies enterica sorovars Enteritidis, Typhimurium, Senftenberg, Mbandaka and Minnesota. It was observed that all serovars tested were capable of contaminating the poultry being possible counts of Salmonella in cloacal swabs, 48 h after inoculation and into the crop and cecum, at 14 and 20 day-old. Serovars tested had different effects on broiler performance assessed at 20 days. In the mucosa of the ileum and cecum of broilers, it was observed that some of the serotypes increased CD8 + cells, CD4 + cells, goblet cells and macrophages compared to the negative control group both at 14 and at 20 day-old. S. Enteritidis and S. Typhimurium are the serovars that showed the more intense effect in live performance and in the immune system of birds showing pathogenic characteristic; generally the broilers of the negative control showed significantly less immune cells on the intestinal mucosa than broilers inoculated experimentally. However, it was found that the Salmonella serovars used in this study had different effects on the cellular dynamics of the mucosa of the ileum and cecum and differently affect weight gain and average daily gain of poultry showing different levels of pathogenicity. Avaliação da resposta imunológica da mucosa intestinal

Evaluation of the effectiveness and safety of a genetically modified live vaccine in broilers challenged with Salmonella Heidelberg

“…These results are in agreement with recent studies indicating that various non-typhoidal Salmonella serovars are highly adapted to the host and do not cause a reduction in performance parameters (Setta et al, 2012;Muniz et al, 2015). This asymptomatic behaviour makes the control of these serovars more difficult because contaminated flocks generally are infected without demonstrating clinical signs that are visible to producers.…”

Phenotypic and Genotypic Features of a Salmonella Heidelberg Strain Isolated in Broilers in Brazil and Their Possible Association to Antibiotics and Short-Chain Organic Acids Resistance and Susceptibility

“…No clinical signs were observed after SH UFPR1 oral challenge. Other studies have shown that non-typhoid Salmonella infection in chickens does not result in morbidity or severe clinical signs in spite of intestinal colonization, and liver and spleen bacterial infiltration ( 2 , 3 , 35 ). The SH UFPR1 strain infection produced mild histologic alterations in liver and cecum compared to non-challenged birds, mainly associated with inflammatory processes.…”

“…Despite recent advances in the treatment of infectious diseases, pathogenic microorganisms, including Salmonella , remain an important threat to human and animal health worldwide ( 1 ). Non-typhoid Salmonella serovars are well-known pathogens but they also silently infect animals, particularly poultry, as transient members of the intestinal microbial population without causing disease ( 2 , 3 ). Intestinal colonization of several Salmonella enterica serovars often have no effect on poultry zootechnical performance ( 3 ).…”

“…Non-typhoid Salmonella serovars are well-known pathogens but they also silently infect animals, particularly poultry, as transient members of the intestinal microbial population without causing disease ( 2 , 3 ). Intestinal colonization of several Salmonella enterica serovars often have no effect on poultry zootechnical performance ( 3 ). Kogut et al ( 4 ) described that the infection in chickens caused by Salmonella Enteritidis leads to immune tolerance beginning around 3–4 days post-primary infection.…”

Salmonella Typhimurium Vaccine to Control a Brazilian Salmonella Heidelberg Strain in Broiler Chickens

“…Non-typhoidal Salmonella is a pathogen, but is also a transient member of the intestinal microbiome of animals, without causing disease (BARROW et al, 1987;MUNIZ et al, 2015). Most types of Salmonella enterica does not often affect poultry performance, and as a result, asymptomatic infection may increase the likelihood of zoonotic transmission through the food chain (CARTER et al, 2009).…”