迟钝爱德华氏菌黏附及侵袭特性的研究

Invasion and virulence of pathogenic bacterium Edwardsiella tarda

将引发养殖大菱鲆Scophthalmus maximus出血性败血症的病原菌迟钝爱德华氏菌Edwardsiella tarda(L-49231)接种于体外培养细胞——人上皮角质层形成细胞(HaCaT-cell),观察其对细胞的黏附性和侵袭性,研究了不同作用时间下以及用不同因素处理菌体后,细菌对HaCaT细胞黏附性及侵袭性的影响。结果表明:L-49231菌株能黏附HaCaT细胞,2 h后即可侵入细胞;随着作用时间的延长,细菌黏附细胞与侵入细胞的数量增加。分别用甲醛、戊二醛、盐酸、胰蛋白酶处理L-49231菌体,细菌的黏附力及侵袭力均有所下降;用蔗糖、甘露糖处理L-49231菌体时,细菌的黏附力变化不大;用葡萄糖处理时,能够促进细菌对细胞的黏附作用。用甘露糖和葡萄糖处理菌体时,能促进细菌对细胞的侵袭;用蔗糖处理菌体时,能部分抑制细菌对细胞的侵袭作用。用抗体处理L-49231菌体后,细菌的黏附力及侵袭力均明显下降。说明L-49231菌株对HaCaT细胞具明显的侵袭性,其主要黏附因子为胞外蛋白质成分,无确切的糖受体。

A strain isolated from the diseased turbot Scophthalmus maximus was proved to be the pathogenic bacteria by an artificial infection test. The strain was identified as Edwardsiella tarda numbered as L -49231 strain. The adhesion and invasion of strain L - 49231 to HaCaT cell was observed by being inoculated in 24 - well cell culture plates. The adhesion and invasion of the L - 49231 strain contacted to HaCaT cell during different period and trans- acted with different factors were studied. The results showed that the L -49231 was found to attach to the HaCaT ceil and to invade into 2 hours after administration. The quantity of bacteria adhered and invaded to the cell increased with the increase in action period. The adhesive and invasion capability of L -49231 strain declined after treatment with Formaldehyde, Glutaraldehyde, Hydrochloric acid, and Trypsase. The adhesive capability varied little in disposal of Sucrose and D - mannose, but increased with Glucose. The results on invasion capability indi- cated that the invasion to the cell enhanced when the strain L- 49231 was exposed to Glucose and D -mannose. The invasion of the L - 49231 was exposed to Sucrose was partially restrained, but both its adhesion and invasion ability declined distinctly when the L-49231 was exposed to the antibody.