Capacidade de colonização e expressão imunomoduladora de Salmonella Heidelberg e Salmonella Typhimurium em poedeiras livres de patógenos específicos
Nenhuma Miniatura disponível
Data
2019-06-28
Autores
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Federal de Goiás
Resumo
Laying hens and broilers are potential reservoirs for Salmonella enterica and the zoonotic risk
composes predictive analyses, regarding the attributes for infection and multiplication in
poultry flocks and, consequently, food contamination. The aim of this study was to evaluate
the potential of internal organ colonization, fecal shedding patterns and egg contamination
by Salmonella Heidelberg and Salmonella Typhimurium, and evaluate the influence of
infection by Heidelberg and Typhimurium serovars on TLR-4, IL1β, IL6 and IL10 expression in
spleen, magnus and uterus of experimentally inoculated layers. 28-week-old White Leghorn
laying hens were selected, free of specific pathogens, divided into three groups kept in
isolation units. In the first group, SH, 1.2 x 10 7 CFU of Salmonella Heidelberg was inoculated
orally in each bird, in the second group, ST, 1.0 x 10 7 CFU of Salmonella Typhimurium. In the
control group, birds received equal volume of sterile saline solution. At seven, 14 and 21 days
after inoculation, five layers / group were euthanized and necropsied. Spleen, liver, ovaries,
magnum, isthmus, uterus, small intestine and caecum were collected and destined for
histopathological and bacteriological tests. Eggs were collected daily and excreted every
three days, before and during the period of the experiment and analyzed. qPCR was
performed for expression analysis of TLR-4, IL6, IL10 and IL1B genes in spleen, magnus and
uterus. Results were normalized using constitutive genes RPLP-1 and β-actin and expression
was calculated by the ratio of the mean differences between the control group and the target
gene in challenge groups. None of the layers showed clinical signs after oral inoculation. Fecal
excretion was intermittent and lasted 12 days for both serovars. Heidelberg serovar was
identified in all tissues evaluated seven DPI, as well as Salmonella Typhimurium, identified in
all tissues evaluated, except ovary, seven DPI. Salmonella Heidelberg persisted 14 DPI in the
cecum and spleen, while Typhimurium serovar was not identified in any tissue over the same
period. Experimental inoculation generated infection with 14 DPI resolution in ST layers and
21 DPI in SH layers. Salmonella Heidelberg persisted longer in the host, with microbiological
isolation in the caecum and spleen associated with discrete induction of inflammatory
response in the evaluated organs. Both serovars were able to contaminate the eggs produced
in the post inoculation period, being isolated in shell from three DPI and yolk up to 12 DPI.
The histopathological alterations found were of discrete score, without alterations in the
spleen. There are interactions between the TLR4, IL1B, IL6 and IL10 genes, evidencing the
presence of five functional partner genes STAT3, IL10RA, TRAF6, TICAM1 and LY96. The
results show differences in antigen recognition and immune response determined by mRNA
expression of TLR-4, IL1B, Il6 and IL10 genes in laying hens infected with Salmonella
Heidelberg and Salmonella Typhimurium.
Descrição
Palavras-chave
Citação
RAUECKER, U. N. Capacidade de colonização e expressão imunomoduladora de Salmonella Heidelberg e Salmonella Typhimurium em poedeiras livres de patógenos específicos. 2019. 96 f. Tese (Doutorado em Ciência Animal) - Universidade Federal de Goiás, Goiânia, 2019.