Intestinal Tract Probiotics Disassociation And Identification And Antiviral Activity Of TGEV And IBV

In the experiments, Bolting and identify three strains probiotics from cecum of healthy chicken and young swine, apply MTT and cytopathic effect(CPE) method in vitro CEF and PK-15 cell preliminary assessment the effect of the inhibition rate of probiotics to TGEV and IBV, then to draw the antiviral activity of three probiotics and to analyze the possible mechanism.In experiments, first to utilize Gram staining, biochemistry essay, 16Sr RNA , bacteriostasis essay and so on bolting and identify three strains probiotics is Lactobacillus.delbrueckiisubsp. delbrueckii(L1);Lactobacillus.delbrueckiisubsplactis(L2);Lactobacillus.delbrueckiisubsp.Bulgaricus (L3) .We determined the cell viability after treated by probiotics using MTT and analyzed the largest non-toxic concentration of 1011cfu/ml Lactobacillus casei, 1012cfu/ml of Lactobacillus acidophilus and 1:2 diluted probiotics metabolites, inactivated probiotics and broken products in the experimental concentrations had not appear cell toxicity phenomena.we selected the highest sensitivity antibiotics(gentamicin) on the three probiotics by sensitivity test.According to the experimental results, we had the anti-virus research of probiotics in cells. Experimental groups as follows: group 1: Pre-treatment of cells with probiotics; Group 2: Cells infected with the virus and then added probiotics; Group 3: Co-incubation of probiotics and NDV; Group 4: Probiotics control; Group 5: Virus control; Group 6: Cells control.The results showed:We determined the cell activity after probiotics and TGEV and IBV treated by MTT method,and alculated the viral inhibition rate by formula .The results showed that, whether in the PK-15 cell, or in the CEF, probiotics componentcould and different add methods significantly rise the inhibition rate of TGEV and IBV, and had a relationship with concentrations and time.Cytopathic effect(CPE) of probiotics-cell- virus interaction showed that probiotics and their metabolites added to cells with TGEV and IBV at the same time can reduce the titer of TGEV and IBV significantly, and it indicated that it may have a direct role in killing virus .In the experiment, we studied the antiviral ability of probiotics, metabolites, inactivated probiotics and broken components, results showed that the probiotics in various forms all have some antiviral effect, but there are some differences may be due to the different mechanisms of its antiviral activity .The result of TGEV and IBV inhibition rate rose when pre-treatment of cells with probiotics reflected that the probiotics may block the adsorption of TGEV and IBV on cells; from the phenomenon probiotics and virus added to cells at the same time reduced the harm of virus on cells,we can see that probiotics can play a direct role of damage the virus structure; the phenomenon of lowest inhibition rate of TGEV and IBV when cells infected with TGEV and IBV before probiotics added showed that after the cells infected the probiotics will hard to have effect on virus.In summary, in the experiment of probiotics on the TGEV and IBV titer in vitro, three probiotics separated and its metabolites were significantly reduced the titer of TGEV and IBV, but there are some differences between strains; the three probiotics separated and their metabolites did not affect the titer of TGEV and IBV, the results indicated that probiotics may have a direct role in destruction of the virus and have strain-specific probiotics not only has a direct role in destruction of the virus, but also can block the virus infected the cells and inhibit the proliferation of virus in cells.