Comparison On Immunoprotective Effect Of Bacteriophages Of Vibrio Alginolyticus And Vaccines Of Bacterial Ghost

A new Vibrio alginolyticus phage was isolated and screened from the polluted water Vibrio alginolyticus is one of important pathogenic to aquatic and human beings. In the present Vibrio alginolyticus study aims at the biophysical chemistry characters of the phage and the produce of bccterial Vibrio alginolyticus ghosts. Compares the whole cell vaccine, bacterial ghosts vaccine and phage immune function and preventing the prawn vibrio disease. Our works coverd:1. A new Vibrio alginolyticus was isolated form the pond. The isolation was identified as Vibrio alginolyticus by physiologicaland and biochemical characteristic analysis;2. In this experiment a new phage of Vibrio alginolyticus was isolated from sewage by using Vibrio alginolyticus as its host bacteria. The plaques of the phage which was screen were clear in the center and with haloy around.The plaques were about 1.0～1.2mm diameter in the flat. The potency of the phages was 10¹⁰pfu/mL after amplification.3 .The physiological and biochemical characteristic of the phages indicated that:the RTD of the phage is 106pfu/mL ;the optimum PH value of the phage is about 8.0; Overacidity or overalkalinity environment are not suitable for the survival of phage . The optimum temperature of the phage infected to Vibrio parahaemolyticus is 35℃; the phage has good heat tolerance; the phages were sensitive to upper 60℃. The phages were sensitive to ultraviolet radiation and Triton-X100. The mixed time of phages and hosts affects quantity of plaques. The phages were resistent to chloroform; titer of the phage is remin 17.8% after treatment. It's favorable to the attachment of the phage when Mg²⁺ is in the culture medium.The ability of cleavage of the phages was strong when the salinity of the water is about 25‰. It adapt to the living entironment of phages. The best infect proportion was 0.1¹. The incubation period of the phage is 35min.4. This paper study in how to use the phage to completely pyrolysis hosts. They can be seen from the experimental results: the cultivation period of Vibrio alginolyticus affect the disinfection of phages, between 2 hours and 8 hours the effection is not significant and the change of the amount of Vibrio alginolyticus is uniform that began with a faint rise, four hours later began to fall, after six hours fall more evident and rised after reached the lowest point the splitted ability of phage is reduce to the 10 hours Vibrio alginolyticus .The number of bacteria in 10 hours to reach the lowest ,but is higher than before. In 12 hours with training period after as the host of dissolving algae vibrio, found the quantity change of bacteria phage role smaller. Phages play a smaller role to the change of the bacteria amount when the hosts have growed more than 12 hours. The curve of the number of bacteria is similar with the bacteria growth curve;The change of the amount of Vibrio alginolyticus is different when the amount of the phage is different from the amount of the hosts.When the number of the hosts is larger than the number of the phage , the mumber of hosts is first showed a rising trend, then down and up ;In contrast,the number of bacteria slowly increased but dropped later.When MIO=10, the disinfection dffect is best.The amount of the phages and the ratio of the amount of the hosts to the disinfection effect is not very big, but will lead to reach the minimum amount of bacteria in different time.5. The results of Experiments have found phage can't completely cracking bacteria in laboratory. Using 50μL garlic liquid or 10μLconcentration for 100U/mL of penicillin and 100 muon g/mL streptomycin of PBS can clean the rest of the bacteria.6. The virulence test show: 1×10⁶cfu/mL Vibrio alginolyticus can make the prawn mortality 30%, and 1×10⁷cfu/mL of Vibrio alginolyticus can cause red body disease to the shrimp, 1×10⁸cfu/mL of Vibrio alginolyticus make the prawn mortality achieve 90%. The experiment of bacteria burden of the tissue and apparatus of Litopanaeus vannamei show that the amount of vibrios in the body of prawn is bigger than the control group expecially in hepatopancreas and intestines.7. This experiment showed effects of the immunological indexes after injected whole cell vaccine, bacterial ghosts and phage.The NOS value is the highest when injected bacterial ghosts, and the influence of phage is not obvious,even lower than negative control; PO value of the Litopanaeus vannamei Given 10⁸ the whole cell vaccine is the highest. Hemocyanin is the highest of Litopanaeus vannamei Given 10⁸ phage.8. The virulence test after immunization showed: the immune protective rate of Litopanaeus vannamei injected 10⁸pfu/mL phage is better than others and up to 88.2%. With the concentration decreasing the immune protective rate also fall subsequently but the immune protective rate of Litopanaeus vannamei which injected 10⁶pfu/mL phages is remin 70.6% and higher than 10⁸cfu/mL whole cell vaccines. The immune protective rate of Litopanaeus vannamei injected 10⁸cfu/mL bacterial ghosts is remin 76.5% and higher than 10⁸cfu/mL whole cell vaccine.