Effects of cold stress and Salmonella Heidelberg infection on bacterial load and immunity of chickens.

Effects of cold stress and Salmonella Heidelberg infection on bacterial load and immunity of chickens. Avian Pathol. 2015 Sep 23;:1-30 Authors: Borsoi A, Quinteiro-Filho WM, Calefi AS, Piantino Ferreira AJ, Astolfi-Ferreira CS, Florio JC, Palermo-Neto J Abstract We analyzed the effects of cold stress (19 ± 1°C, 6 h /day, from the 1(st) to the 7(th) days of life) applied to SPF chickens. On experimental Day 1 (ED1), chicks were divided into four groups: C (not infected and kept under thermoneutral condition); CS (not infected and cold stressed); PC (Salmonella Heidelberg (SH) infected and kept under thermoneutral condition) and PCS (SH infected and cold stressed). High concentrations of corticosterone were found in the cold stressed birds on ED7 and ED21, with a greater increase in birds of the PCS group. Stress or non-stressed SH-infected birds had high levels of norepinephrine on ED21. On ED21, an increased percentage and number of SH were found in birds of the PCS group. On ED7, a decrease in macrophages presenting MHCII, CD8(+) and CD8(+)γδ cells was observed in the chickens of the CS group. Decrease was observed in CD3(+)cells in the birds of the PCS group and increase in macrophages presenting MHCII cells and of the CD4(+)/CD8(+) ratio in chickens of the CS group on ED21. A decrease in CD8(+)γδ cells to birds of the CS group on ED21 and in the CD3(+) and CD8(+)cell numbers in chickens of the PCS group on ED21. Our results ...
Source: Avian Pathology - Category: Pathology Authors: Tags: Avian Pathol Source Type: research