几株益生菌的体外抗新城疫病毒作用

Effect of Probiotics on Newcastle Disease Virus

【目的】探讨益生菌的抗新城疫病毒(NDV)作用并分析其可能的机制。【方法】采用NDV血凝试验和MTT比色法,分别在体外和鸡胚成纤维细胞(CEF)上评价益生菌对NDV血凝价和抑制率的影响。【结果】所选择的5株益生菌及其代谢产物都极显著地降低了NDV的血凝价,而2株致病菌及其代谢产物对NDV的血凝价均没有影响,这一结果说明益生菌可能对NDV具有直接破坏的作用,并且具有菌株特异性。益生菌可以显著地提高CEF对NDV的抑制率,并且这种作用具有量效关系(P<0.01)。益生菌与细胞作用后再感染病毒,对NDV抑制率升高的结果反映了益生菌对NDV吸附细胞的阻断作用;从益生菌与病毒同时接入细胞后降低病毒对细胞侵害的现象,可以看出益生菌可能对病毒具有直接破坏作用;在细胞感染病毒后再接入益生菌对NDV抑制率极低的现象说明,病毒感染后益生菌再很难起作用。【结论】益生菌对NDV既具有直接破坏的作用,又可以阻断NDV对细胞的感染、抑制其在细胞内的增殖。

[Objective]We studied the antiviral activity of probiotics and possible mechanism thereof.[Methods]With hemagglutination in vitro and 3-（4,5-Dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide（MTT） of chicken embryo fibroblast（CEF）,the hemagglutination titers and virus inhibition rate were respectively determined to evaluate the impact of probiotics on Newcastle Disease Virus（NDV）.[Results]Five probiotics and their metabolites could reduce the viral titer of NDV,but the two pathogenic bacteria and their metabolites could not.These results indicated that probiotics may destruct the structure of NDV directly and this effect was strain-specific.Probiotics could inhibit the replication rate of NDV significantly in a dose-dependent manner（P 0.01）.The inhibitory rate increased when the cells were pre-treated with probiotics,which indicated that the probiotics might block NDV adsorbing to the cells.The fact that addition of probiotics and NDV at the same time reduced the cytopathic effect（CPE） of cells suggested that probiotics could destruct the viral structure directly;the lower inhibitory rate of viral replication when cells infected with NDV before addition of probiotics to the cells suggested that the probiotics worked hardly after the cells were infected.[Conclusion]Probiotics can not only destruct the virus,but also block the virus infection of the cells and inhibit the viral proliferation in the cells.