Is the third emerging mycosis a threat to native snakes?

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K05639
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 39060:Conservation of biological resources-related
• Research Institution: Okayama University of Science
• Principal Investigator: UNE YUMI 岡山理科大学, 獣医学部, 教授 (40160303)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 新興感染症 / 真菌 / 生態系の保全 / ヘビ / Ophidiomycosis / snake fungal disease

Outline of Final Research Achievements

A third emerging pathogen, Ophidiomyces ophiodiicola, was discovered for the first time in Asia and its impact on endemic snakes was evaluated. While Ophidiomycosis had occurred in exotic species distributed domestically, there were no natural outbreaks in endemic species and no infections in infection experiments. However, in vitro experiments showed that Oo infected endemic species. We also discovered the pathogenic fungi Nanniziopsis guarroi and Paranniziopsis spp (Pn), which are closely related to Oo, and established a specific detection method for each fungus to determine the status of domestic invasion. As a result, we confirmed the occurrence of Pn in the Shirohebe, a protected species. The negative impact of pathogenic fungi on endemic species was clarified, indicating the need for countermeasures.

Free Research Field

獣医病理学

Academic Significance and Societal Importance of the Research Achievements

生態系の保全及び種の保存の脅威となる病原真菌の在来種への影響を、自然死した動物の病性鑑定、感染実験およびin vitroの実験と、多角的に評価したこと、併せて、病原真菌の特異的検出法を確立したことから、国内飼育下ヘビにおける各種真菌の浸浸状況の把握と、病原性の評価、治療の評価、予防対策などが可能となった。また、Ophidiomyces ophiodiicolaの近縁真菌を株化できたことから、遺伝子解析、病原性決定因子などの解析が可能となり、生態系保存のみならず、病原体解析のための基盤を作ったこと。