Expression of avian beta-defensin and histopathological evaluation of chickens’ gut following salmonella enteritidis δznuabc administration
Autor: | Scaglione, frine Eleonora, Pregel, Paola, Pesciaroli, Michele, Drumo, Rosanna, Pasquali, Paolo, Petrucci, Paola, Greco, Miriam, Pistoia, Claudia, Ammendola, Serena, Battistoni, Andrea, Bollo, Enrico, Lalmanach, Anne-Christine |
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Přispěvatelé: | Università degli studi di Torino (UNITO), Istituto Superiore di Sanità, Università degli Studi di Roma Tor Vergata [Roma], Infectiologie et Santé Publique (UMR ISP), Institut National de la Recherche Agronomique (INRA)-Université de Tours (UT), Institut National de la Recherche Agronomique (INRA)-Université de Tours |
Jazyk: | angličtina |
Rok vydání: | 2019 |
Předmět: | |
Zdroj: | 73. Annual Meeting of the Italian Society for Veterinary Sciences (SISVET) 73. Annual Meeting of the Italian Society for Veterinary Sciences (SISVET), Jun 2019, Olbia, Italy |
Popis: | International audience; Contaminated poultry and eggs are major sources of Salmonella infections in humans. The decrease of Salmonella foodborne infections is dependent on the reduction of Salmonella burden at primary production stages. Defensins are major antimicrobial peptides, effectors of innate immunity playing a key role in the protection of mucosal surfaces of animals and humans through multiple modes of action such as bacterial membrane disruption, chemotactic properties towards leucocytes, and tissue repair [1](Lay and Gallo, 2009). Enteric defensins are also regulators of intestinal microbial ecology [2](Salzamn et al., 2010). The sustained production of defensins in the gut could constitute a valuable mean of control in gut health.Aim of the work was to investigate if the infection of one-day-old chickens with S. Enteritidis deleted of ZnuABC transporter (S. Enteritidis ΔznuABC) used as a vaccine candidate modifies the course of avian β-defensin genes expression during the first 4 weeks of chicken life.Microbiological and histopathological investigations were carried out in order to assess the pathogen colonization of the organs and the effects of vaccination in the intestine.Forty white Leghorn hens were divided into two groups of 20 animals (treated and control group, respectively). One mL of sodium bicarbonate buffer containing105 CFU ofS. Enteritidis ΔznuABC was administered by oral gavage to each animal of the treated group; animals of the control group received 1 mL of sterile sodium bicarbonate buffer. Five animals in each group were sacrificed on day 3, 7, 17, 32 and 86 post-administration. Liver, caecal tonsils and portions of intestine (colon) were aseptically removed and processed for bacteriological, biomolecular and histological analyses.The results of the microbiological analyses showed a decrease in the concentration of Salmonella in the intestine in the first 32 days and a complete disappearance in about 3 months. This result highlights the attenuation of the vaccine strain in the chicken and its possible use in animals with long production cycles, in accordance with the data reported in the literature on attenuated strains of S. Typhimurium [3](Van Immerseel et al., 2005)). The biomolecular analysis showed a pattern already found in several studies for the AvBD1, AvBD2, AvBD4 and AvBD7 genes, not significantly modified by vaccination. In contrast, AvBD9, AvB10 and AvBD14 showed a new pattern of expression in the control group, not observed in treated animals, but without significant differences between the two groups. Histological analysis showed an increase in haemorrhages in the colon and caecal tonsils in treated animals and an activation of lymphoid follicles of the colon at day 7, probably caused by intestinal colonization. These results highlight some possible issue of the vaccine (haemorrhages).Epithelial and haemorrhagic damage was also observed in control group, thus requiring further investigations. |
Databáze: | OpenAIRE |
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