@article { , title = {Experimental infection of chickens by a flagellated motile strain of Salmonella enterica serovar Gallinarum biovar Gallinarum}, abstract = {Salmonella enterica subsp. enterica serovar Gallinarum biovar Gallinarum (SG) causes fowl typhoid (FT), a septicaemic disease which can result in high mortality in poultry flocks. The absence of flagella in SG is thought to favour systemic invasion, since bacterial recognition via Toll-like receptor (TLR)-5 does not take place during the early stages of FT. In the present study, chicks susceptible to FT were inoculated with a wild type SG (SG) or its flagellated motile derivative (SG Fla+). In experiment 1, mortality and clinical signs were assessed, whereas in experiment 2, gross pathology, histopathology, systemic invasion and immune responses were evaluated. SG Fla+ infection resulted in later development of clinical signs, lower mortality, lower bacterial numbers in the liver and spleen, and less severe pathological changes compared to SG. The CD8+ T lymphocyte population was higher in the livers of chicks infected with SG at 4 days post-inoculation (dpi). Chicks infected with SG had increased expression of interleukin (IL)-6 mRNA in the caecal tonsil at 1 dpi and increased expression of IL-18 mRNA in the spleen at 4 dpi. In contrast, the CD4+ T lymphocyte population was higher at 6 dpi in the livers of birds infected with SG Fla+. Therefore, flagella appeared to modulate the chicken immune response towards a CD4+ T profile, resulting in more efficient bacterial clearance from systemic sites and milder infection.}, doi = {10.1016/j.tvjl.2016.05.006}, eissn = {1090-0233}, issn = {1090-0233}, journal = {Veterinary Journal}, note = {Embargo expired. OL 23.08.2017}, publicationstatus = {Published}, publisher = {Elsevier}, url = {https://nottingham-repository.worktribe.com/output/797788}, volume = {214}, keyword = {Domestic fowl , Fowl typhoid , Salmonella enterica biovar Gallinarum , Pathogenicity , Immune response}, year = {2016}, author = {Lopes, P.D. and Freitas Neto, O.C. and Batista, D.F.A. and Denadai, J. and Alarcon, M.F.F. and Almeida, A.M. and Vasconcelos, R.O. and Setta, A. and Barrow, P.A. and Berchieri, A.} }