Phylogenetic analysis for O7 group of Salmonella and identification of the factors for antimicrobial resistance and virulence

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K14980
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 42020:Veterinary medical science-related
• Research Institution: National Agriculture and Food Research Organization
• Principal Investigator: Arai Nobuo 国立研究開発法人農業・食品産業技術総合研究機構, 動物衛生研究部門, 研究員 (20885008)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: Salmonella Choleraesuis / Salmonella 7:c:- / 全ゲノム解析 / 薬剤耐性

Outline of Final Research Achievements

Phylogenetic analysis based on whole genome sequence revealed that there were five distinctive clades in Salmonella Choleraesuis (SC, antigenic formula; 7:c:1,5) and 7:c:-. Biovar Choleraesuis and Kunzendorf (SCK) were summarized in clade1 and 2, and clade 3 to 5, respectively. All 7:c:- strains, which were isolated from Japan, belong to clade 5. Thus, it was indicated that the domestic 7:c:- was the monophasic variant of SCK. Through the antibiotic susceptibility testing and the invasion assay for INT407, we identified the high-risk clade that showed multidrug resistance and high invasiveness.

Free Research Field

獣医細菌学

Academic Significance and Societal Importance of the Research Achievements

我が国においてサルモネラ血清型Choleraesuis（SC）は豚のサルモネラ症の主要な原因菌であるが、その遺伝学的全体像および7:c:-との関連は不明であった。本研究は、SCにおける国内外の主要系統を明らかにし、国内に分布する7:c:-がSCの単相変異株であること、薬剤耐性および病原性の観点から注視すべき系統（クレード2）を特定した。本成果は、7:c:-がSCと本質的に同等であることを支持するデータであり、本菌の畜産行政上の取り扱いを検討する際の重要な知見になり得る。