Functional analysis of a novel virulence factor RatA contributing to the pathogenesis of fowl typhoid

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K05926
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 42020:Veterinary medical science-related
• Research Institution: Obihiro University of Agriculture and Veterinary Medicine
• Principal Investigator: Okamura Masashi 帯広畜産大学, 畜産学部, 教授 (70374775)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: サルモネラ / 病原因子 / 家禽チフス

Outline of Final Research Achievements

The pathogenicity of SGΔratA, which lacks ratA, one of the genes of SG that is strongly expressed in chicken biology, was significantly reduced compared to the wild type, indicating that ratA contributes to the pathogenicity of SG. However, the pathogenicity of its complementary strain in chickens did not return to wild-type levels. Therefore, we focused on the possibility of suppressing the expression of ratB and shdA, which are downstream genes of ratA. We also examined the pathogenicity of SGΔratB and SGΔshdA lacking each gene in chickens, and found that the pathogenicity of both genes was not reduced as much as in the SGΔratA mutant strain. In other words, the involvement of these two genes in pathogenicity was considered to be partial compared to ratA.

Free Research Field

獣医微生物学

Academic Significance and Societal Importance of the Research Achievements

同じサルモネラ属菌のネズミチフス菌（ST）では、ratAが STのマウス腸管腔内での生存に関わることが分かっている。しかし、本研究成果により、同じ遺伝子が宿主と血清型の組み合わせによって発症機序において果たす機能が異なることが分かった。このことは、発症機序に関わる新たな病原機構を標的とする家禽チフスの新規予防法の開発につながるだけでなく、サルモネラ感染症全般の発症機序解明の端緒となり、それらの新規予防法の開発に向けた基盤となる。