1. Characteristics of systemic infection and host responses in chickens experimentally infected with Salmonella enterica serovar Gallinarum biovar Gallinarum
- Author
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Takashige Kashimoto, Nana Osawa, Shinjiro Ojima, Akiko Tamura, Takeshi Haneda, Dong-Liang Hu, Masashi Okamura, Hisaya K. Ono, and Kazuki Yoshioka
- Subjects
040301 veterinary sciences ,chicken ,animal diseases ,Biovar ,Inflammation ,Spleen ,Biology ,Serogroup ,Microbiology ,0403 veterinary science ,03 medical and health sciences ,systemic infection ,Immune system ,Interferon ,medicine ,Animals ,Pathogen ,Poultry Diseases ,030304 developmental biology ,fowl typhoid ,Colony-forming unit ,Salmonella Infections, Animal ,0303 health sciences ,Full Paper ,General Veterinary ,Inoculation ,Immunity ,Salmonella enterica ,04 agricultural and veterinary sciences ,biochemical phenomena, metabolism, and nutrition ,bacterial infections and mycoses ,biology.organism_classification ,medicine.anatomical_structure ,Salmonella Gallinarum ,Avian Pathology ,bacteria ,medicine.symptom ,Chickens ,medicine.drug - Abstract
Salmonella enterica serovar Gallinarum biovar Gallinarum (S. Gallinarum) is a host-specific pathogen causing systemic infection in poultry, which leads to significant economic losses due to high mortality. However, little is known about the dynamic process of systemic infection and pathogenic characteristics of S. Gallinarum in chickens. In the present study, we developed an oral infection model that reproduces the pathology of S. Gallinarum and clarified the host immune response of the infected chickens. Chickens at 20 days of age orally inoculated at a dose of 108 colony forming unit (CFU) showed typical clinical signs of fowl typhoid and died between 6 and 10 days post infection. The inoculated S. Gallinarum rapidly disseminated to multple organs and the bacterial counts increased in the liver and spleen at 3 days post infection. Pathological changes associated wirh inflammation in the liver and spleen became apparent at 4 days post infection, and increased expression of interferon (IFN)-γ and interleuikin (IL)-12 in the liver and spleen did not observed until 3 days post infection. These results indicate that S. Gallinarum rapidly spread to entire body through intestine, and the low-level of inflammatory responses in the liver during the early stage of infection may contribute to rapid, systemic dissemination of the bacteria. Our infection model and findings will contribute to the better understanding of the pathogenic mechanism of S. Gallinarum, and provide new insights into the prevention and control of fowl typhoid.
- Published
- 2021
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