Development of an Aeromonas hydrophila infection model using the protozoan Tetrahymena thermophila
Development of an Aeromonas hydrophila infection model using the protozoan Tetrahymena thermophila
复制标题
使用原生动物嗜热四膜虫开发嗜水气单胞菌感染模型
DOI：
10.1111/j.1574-6968.2010.02208.x
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发表时间：
2011-03-01
影响因子：
2.1
通讯作者：
Lu, Cheng-Ping
中科院分区：
文献类型：
--
作者：
Li, Jing;Zhang, Xiao-Lu;Lu, Cheng-Ping
嗜水气单胞菌是一种运动细菌，存在于全世界许多淡水栖息地中，并且经常是鱼类和包括人类在内的许多陆生脊椎动物感染的原因。由于嗜水气单胞菌也是健康鱼类正常肠道菌群的组成部分，因此毒力机制尚不清楚。考虑到用于检查与毒力相关的嗜水气单胞菌基因的鱼类模型尚未明确定义，我们使用自由生活的纤毛虫原生动物嗜热四膜虫建立了感染模型。通过逆转录-PCR 评估嗜热丝虫感染后嗜水气单胞菌毒力基因的表达，并证明强毒 J-1 菌株中的气溶素 (aerA) 和 Ahe2 丝氨酸蛋白酶 (ahe2) 基因（无毒力的嗜水气单胞菌 NJ-4 菌株中不存在）在感染后 4 小时上调。此外，嗜热丝虫内完整的嗜水放线菌 J-1 的存在表明这些细菌可能干扰吞噬作用，导致受感染原生动物在感染后 48 小时死亡。相反，受 A. Hydrophila NJ-4 感染的 T.thermophila 在感染后存活下来。这项研究建立了一种新的嗜热嗜热嗜热菌感染模型，该模型将为检查嗜水嗜热嗜热菌毒力机制提供一种新方法。
Aeromonas hydrophila is a motile bacterium present in numerous freshwater habitats worldwide and is frequently the cause of infections in fish and numerous terrestrial vertebrates including humans. Because A. hydrophila is also a component of the normal intestinal flora of healthy fish, virulence mechanisms are not well understood. Considering that fish models used for the examination of A. hydrophila genes associated with virulence have not been well defined, we established an infection model using the free-living, ciliate protozoa Tetrahymena thermophila. The expression of A. hydrophila virulence genes following infection of T. thermophila was assessed by reverse transcription-PCR and demonstrated that the aerolysin (aerA) and Ahe2 serine protease (ahe2) genes (not present in the avirulent A. hydrophila NJ-4 strain) in the virulent J-1 strain were upregulated 4-h postinfection. Furthermore, the presence of intact A. hydrophila J-1 within T. thermophila suggested that these bacteria could interfere with phagocytosis, resulting in the death of the infected protozoan 48-h postinfection. Conversely, A. hydrophila NJ-4-infected T. thermophila survived the infection. This study established a novel T. thermophila infection model that will provide a novel means of examining virulence mechanisms of A. hydrophila.