鳗鲡外周血白细胞体外吞噬嗜水气单胞菌数量模型的建立

Establishment of quantitative model on eel peripheral blood leukocytes phagocytosing Aeromonas hydrophilain vitro

为建立鳗鲡外周血白细胞体外吞噬嗜水气单胞菌的数量模型,研究了感染时间一定、感染复数变化的情况下鳗鲡外周血白细胞吞噬的细菌数量和白细胞的存活率,同时还研究了感染复数一定、感染时间变化的情况下鳗鲡外周血白细胞吞噬的细菌数量和白细胞的存活率。结果发现,鳗鲡外周血白细胞对嗜水气单胞菌有较强的吞噬作用,在感染复数为100∶1、感染时间为30min时细胞吞噬的细菌量达到饱和,而细胞本身仍可维持较高活性。表明100∶1的感染复数及30min的感染时间,是研究鳗鲡外周血白细体外吞噬嗜水气单胞菌数量模型的最佳参数。本研究还通过检测吞噬速率和杀菌速率评估建立起来的数量模型发现,鳗鲡外周血白细胞吞噬嗜水气单胞菌的速率较吞噬大肠杆菌的速率快,但杀灭该菌的速率却均显著低于杀灭大肠杆菌和金黄色葡萄球菌的速率,进一步证明建立的数量模型具有良好的可行性。

In order to establish the quantitative model on eel peripheral blood leukocytes phagocytosing Aeromonas hydrophila in vitro, we first examined the variation of the number of bacteria phagocytosed by eel peripheral blood leukocytes and the survival ratio of the leukocytes when the infection time was unvaried and the infection multiplicity was changed, as well as when the infection multiplicity was stable and the infection time was changed. It was found that the phagocytosis of eel peripheral blood leukocytes against A. hydrophila was significant. When the infection multiplicity was 100 ： 1 and the infection time was 30 min, the number of the bac teria that phagocytosed by eel peripheral blood leukocytes reached saturation while the leuko- cytes still maintained high activity, indicating that 100 ： 1 and 30 min was the optimal infectionmultiplicity and infection time. In addition, the quantitative model was validated by detecting predation velocity and sterilization velocity. It was found that the phagocytosis velocity for eel peripheral blood leukocytes against A. hydrophila was faster than that against Escherichia co li, while the velocity for killing A. hydrophila was significantly lower than that for killing E. coli and Staphylococcus aureus, which shows that the established quantitative model can be used for further study on intracellular survival mechanism of A. hydrophila.