Influences Of Bacillus Licheniformi On Ileum Histology Of Chickling Necroticans Enteritis And Cytokine Dynamic Variation

This study researched the pathological change and cytokine variable quantity in intestinal tract which infected by Clostridium perfringens and cured by Bacillus licheniformis.In this study, we choose a standard strain of Clostridium perfringens (Cp) as pathogen and a Bacillus licheniformis as the experimental bacterial strain which isolated from healthy chicken intestinal tract. chicken were randomly divided into infection experiment and experiment of prevernted and controlled by probiotics. In infection experiment,60 chicken were randomly divided into 2 groups which were control group and Infection group. Feeling Cp and coccidian according to the Infection model. The control group and infected group fed basal diet 1 from 1 to 14 days, from 15th day, began to fed diet 2 which were in high wheat. On 15th day, the infection group fed coccidian and intragastrically Cp (108,1 mL). The control group fed the same dose of normal saline. Probiotics control experiment,150 healthy chickens were randomly divided into 4 groups, these were normal group (K group), infected group (G group), prevention group (y group), treatment group (Z group). The control group and infected group were fed basal diet, prevention group were fed basic diet I content 0.05%,0.1% and 0.2% probiotics.the treatment group fed basic diet contented 0.05% probiotics from 1 to 20 days and then fed basic diet II content 0.1%, 0.2%,0.4% probiotics after 20th. Infection group, prevention group and treatment group fed coccidian at 15th and Cp (108,1 mL) from 17th to 20th, control group fed the same dose of normal saline.The test shown: 1. Change in the number of peripheral blood leukocyte:infection group's WBC were significantly higher than the control group, prevention group and treatment group (P<0.01 or P<0.05); on 21th,WBC in prevention group higher than control group but lower than infected group; there were no significantly difference between treatment and control group; the control group which content 0.1% probiotics and treatment group which content 2.0% probiotics the amount of WBC were near chose to the control group at every times, and in normal reach. The infected group higher out the normal reach from 21st to 25th (32.6(9.1～56)k/mm3)).2. Clostridium perfringens changes in Ileum:there were no difference before fed Cp. A week after fed Cp and coccidian the number of Clostridium perfringens in Ileum had difference. The infected group significantly higher than others, prevention group higher than control group but lower than infected group(P<0.01). the number of Cp in Ileum and probiotics were inverse correlation, but no marked(P>0.05). More obvious effect of the treatment group, inhibited the exogenous Clostridium perfringens colonization in the ileum, Cp is lower than infected group (P<0.01) and the same as the control group (P> 0.05).3. The changes of cytokine expression in Ileum:the IFN-α, IFN-γ, IL-1β, IL-6 expression had no significant difference between infection group and control group(P >0.05) when 14th day;when 21st day, IFN-γ, IL-1βexpression levels in infection group were significantly higher than the control group(P<0.01), when 23rd day, the infection group's IFN-γ, IL-1β, IL-6 expression levels were significantly higher than the control group (P<0.01) but IFN-α. (P>0.05); when the 25th day, the infection group were only IFN-y higher than the control group (P>0.05), other cytokines were different, but not statistically significant (P> 0.05) and there were no significantly different on 28th day. After fed Bacillus, there were no different amount 4 groups when 14 day (P> 0.05). when 21st day, the IL-1β, IFN-γ, IL-6 of preventive group higher than the control group (P<0.05), except IL-1β,others cytokine and no difference for infection group. when 23rd day, IL-1βreturn to normal levels in preventive group. And IFN-γ, IL-6 were lower than infected group but not significantly. Every cytokines were same level on 28th day (P>0.05).Generally speaking, IL-1β, IFN-γ, IL-6 were lower in treatment group than infected group, especially on 23rd day. but higher than control group (IL-1β,IL-6 P<0.05, IFN-γP<0.01); When 25th day, the expression were less than infection group (P<0.05) and had no significant difference for control group (P> 0.05), there were no significant difference every cytokines on 28th day (P>0.05). the IFN-αexpression levels had no significant regularity in every groups.4. Structural changes of villous histology:Control group of chicken ileum intestinal villus integrity, no bleeding or bleeding phenomena, columnar cells arranged in neat, orderly arrangement of goblet cells; Heal villi of infected group structure is incomplete, there is obvious bleeding or blood stasis phenomenon in villus lamina propria. Disordered arrangement of columnar cells, hair breakage, shedding and autolysis phenomenon. Goblet cells were increased mucus content increased, and the phenomenon of visible broken. intestinal villus of Prevention, treatment group had with integrity of normal structure. The number of goblet cells in Prevention group were between control and between infected group; In treatment group, a large number of lymphocyte proliferation, and increased number of lymphoid nodules, fewer goblet cells than the infected group, and no significant difference with control group.