Heat stress decreases expression of the cytokines, avian beta-defensins 4 and 6 and Toll-like receptor 2 in broiler chickens infected with Salmonella Enteritidis

Author(s)

Quinteiro-Filho, W. M. ; Calefi, A. S. ; Cruz, D. S. G. ; Aloia, T. P. A. ; Zager, A. ; Astolfi-Ferreira, C. S. ; Piantino Ferreira, J. A. ; Sharif, S. ; Palermo-Neto, J.

• Document type: Journal article
• Source: VETERINARY IMMUNOLOGY AND IMMUNOPATHOLOGY; v. 186, p. 19-28, APR 2017.
• Web of Science Citations: 16

Abstract

A high ambient temperature is a highly relevant stressor in poultry production. Heat stress (HS) has been reported to reduce animal welfare, performance indices and increase Salmonella susceptibility. Salmonella spp. are major zoonotic pathogen that cause over 1 billion of human infections worldwide annually. Therefore, the current study was designed to analyze the effect of heat stress on Salmonella infection in chickens through modulation of the immune responses. Salmonella Enteritidis was inoculated via gavage at one day of age (10(6) cfu/mL). Heat stress 31 +/- 1 degrees C was applied from 35 to 41 days of age. Broiler chickens were divided into the following groups of 12 chickens: control (C); heat stress (HS31 degrees C); S. Enteritidis positive control (PC); and S. Enteritidis + heat stress (PHS31 degrees C). We observed that heat stress increased corticosterone serum levels. Concomitantly heat stress decreased (1) the IgA and IFN-gamma plasmatic levels; (2) the mRNA expression of IL-6, IL-12 in spleen and IL-113, IL-10, TGF-beta in cecal tonsils; (3) the mRNA expression of AvBD4 and AvBD6 in cecal tonsils; and (4) the mRNA expression of TLR2 in spleen and cecal tonsils of chickens infected with S. Enteritidis (PHS31 degrees C group). Heat stress also increased Salmonella colonization in the crop and caecum as well as Salmonella invasion to the spleen, liver and bone marrow, showing a deficiency in the control of S. Enteritidis induced infection. Together, the present data suggested that heat stress activated hypothalamus-pituitary-adrenal (HPA) axis, as observed by the increase in the corticosterone levels, which in turn presumably decreases the immune system activity, leading to an impairment of the intestinal mucosal barrier and increasing chicken susceptibility to the invasion of different organs by S. Enteritidis. 2017 Elsevier B.V. All rights reserved. (AU)

• FAPESP's process: 11/23391-0 - Effects of heat stress on cytokine expression in broiler chicken infected with Salmonella Enteritidis
• Grantee: Wanderley Moreno Quinteiro Filho
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• FAPESP's process: 13/13736-5 - Effects of Lactobacillus salivarius on immunity and intestinal commensal microbiota of heat-stressed broiler chickens infected with Salmonella Enteritidis
• Grantee: Wanderley Moreno Quinteiro Filho
• Support Opportunities: Scholarships in Brazil - Post-Doctoral