嗜水气单胞菌侵袭力与宿主细胞信号转导和骨架的关系

嗜水气单胞菌(Aeromonas hydrophila，Ah)是淡水鱼暴发性败血症的主要病原，该菌能够引致淡水鱼等的败血症和人的腹泻等^1]。嗜水气单胞菌有多种致病因子，如毒素、蛋白酶、S层蛋白等^2]，还发现它具有侵袭作用，有报道嗜水气单胞菌粪分离株能侵袭HEp-2细胞^3]，但对于鱼源菌株的侵袭特性知之甚少。仅有一些报道认为嗜水气单胞菌能引致细胞病变^4,5]。

Invasion of Aeromonas hydrophila in Cells Involving Signal Transduction and Cytoskeleton

Invasion of Aeromonas hydrophila strain Ah J-1 isolated from diseased fish to cultured HEp-2cells monolayer was evaluated by the recovery of gentamincin-resistant (Gm') bacteria from Triton X-100 cell lysates. The invasive efficiency (IE) could reach to 0.2% at 37 degrees C. In addition, potential signal transduction pathways that precede bacterial internalization were studied by using signal transduction inhibitors. Bacterial internalization of Ah J-1 involved microfilaments and protein tyrosine kinase since cytochalasin D (an inhibitor of microfilament polymerization) and genistein (an inhibitor of protein tyrosine kinase) prevented internalization. Staurosporine (a protein kinase C inhibitor) and Sodium orthovanadate (a protein tyrosine phosphatase inhibitor) accelerated internalization of Ah J-1 into HEp-2 cells.