Studies On The Effects Of Bacillus Amyloliquefaciens In Prevention And Treatment Of Rotavirus Infective Suckling Mice

Rotavirus disease,caused by rotavirus,is a infectious disease which leads to the newborn animals diarrhea and dehydration.At present,there is no specific drug for the treatment of rotavirus disease.Therefore,it’s particularly important to find the safe and effective agents to prevent and treat this disease.Studies have shown that the individual Bacillus species could produce the antiviral substances.So this experiment to obtain with antibacterial and antiviral activity of probiotic bacillus strains, and to expand the function of micro ecological preparation laid a certain foundation.Twenty soil samples were collected from different locations.Four strains Bacillus were screened from twenty soil samples by coating plate method with Staphylococcus aureus and Escherichia coli as the indicator bacteria.These Bacillus were respectively named YI-1,YI-3, YI-7,YI-8. By mouse toxicity test,artificial gastric acid and artificial intestinal fluid test rescreened the four strains found that the YI-1 strain had the characteristics of safety and resistance of artificial gastric acid and artificial intestinal fluid.Through molecular biological identification the YI-1 strain was identified as Bacillus amyloliquefaciens.Cultured the rotavirus with MA-104 cells and determined the virus drops.Six-day-old suckling mouse were randomly divided into 5 groups,the negative control group,the positive control group,namely the treatment group,prevention group,bacteria and viruses in vitro group.The suckling mouse were daily observed their mental state and defecation after inoculated rotavirus.After virus inoculation in 48 h,96h and 168 h,two mouse of each group were randomly selected to execute and observe their gastrointestinal condition.At the same time their jejunum and ileum were taken with formalin fixed for making the paraffin sections.Then measured the length of the jejunum and ileum after HE staining.The results has showed that 96 h after inoculation the suckling mouse’s rate of diarrhea for the 5 groups were 0%,100%,66.7%, 28.5% and 0%.The autopsy results showed that the jejunum and ileum of the ill mouse were full of gas.The intestinal wall became thinner and the intestinal mucosal was shedding,The observation of the paraffin sections displayed that the intestinal wall of the ill suckling mouse was dropsical an dcongestive,the mucosal was shedding and the connection between intestinal epithelial cells was destroyed, the villi shortened and the microvilli arranged in disorder.Analyzed the height of the jejunal and ileum villi with the statistical software SPSS17.0 and found that the difference o f villi height between the groups were significant.