The Mechanism Research Of Coinfection Of Eimeria Tenella And Salmonella Enteritidis

The coinfection of a variety of pathogens has been a common phenomenon, studies have shown that the incidence of coinfection of the chickens was 85%. There has been a lot of reports about the coinfection, including parasites, bacteria and a variety of immune suppression of the virus infection cases, epidemiological investigation and the study of coinfection pathogenesis. Studies have confirmed that Eimeria infection can affect the bacterial infection, bacterial infection also can affect Eimeria infection. The coinfection of Eimeria with Salmonella is common clinically, Eimeria infection can lead to serious damage to intestinal mucosa epithelium, greatly improve the susceptibility of Salmonella chicken, and because Eimeria infection are everywhere, under normal conditions may have a significant impact on levels of Salmonella infection spread. Although coinfection phenomenon is very common, but most of the research still focus on in-depth study of a single pathogen, or a limited number of pathogen infection of study, and research on Eimeria and Salmonella infections is relatively less. Given the tender Eimeria tenella and Salmonella enteritidis in the present situation of the popularity of chickens and the lack of the two kinds of pathogen infection of research, this article will tender Eimeria tenella infection with Salmonella enteritidis chicks, test the effect of coinfection of pathogenic host and host changes in the structure of intestinal flora, and from the Angle of the proteomics analysis of the coinfection of pathogenic mechanism. Our studies were divided into the following several parts:1. The pathogenic and interaction of coinfection:The12-day chickens are divided into six groups, and vaccinated Eimeria tenella and Salmonella enteritidis. Evaluate the influence of coinfection from body weight growth rate,mortality rate, immune organ index and T lymphocyte subgroup percentage. The results showed that the weight negative after coinfection, especially the same time infection. The ratio of CD4 / CD8 were lower after infection, indicated that the immune system were damaged seriously. In addition, the mortality caused by coinfection also increased. The above results show that the pathogenic enhance when Eimeria tenella and Salmonella enteritidis coinfection. We analyzed the symptoms, pathological changes of blood scoring and mortality,the results showed that single and coinfection can also cause cecum seriously pathological.We analyzed the positive rates of liver and spleen of salmonella and cecum contents, the results found that Eimeria tenella infection can increase the positive rates of liver and spleen.We think that Eimeria tenella infection has synergism with Salmonella enteritidis. They work together to promote the incidence and severity of inflammation, which make the illness even worse.2. The influence of intestinal flora after coinfection:We collected cecum contents on the fifth day after infection, 16 S r RNA gene sequence-based comparisons of the bacterial communities in the chicken cecal contents are performed. The results showed that the cecal microbiota of chicks up to the age of 18 days was dominated by representatives of the phylum Firmicutes and Bacteroidetes. In contrast with Eimeria tenella or Salmonella enteritidis infection alone, concurrent infection result in Enterobacteriaceae significant increase and Lachnospiraceae significant reduce. Overall, the effects of co-infections of Eimeria tenella and Salmonella enteritidis on cecal microbiota were different with Eimeria tenella or Salmonella enteritidis infection alone.3. The influence of the caecum tonsil protein expression of the host after coinfection:5 days collect each experimental chicken caecum tonsil infection, extraction and purification of proteins, then analysis the two-dimensional electrophoresis and mass spectrometry. We were successfully identified 29 proteins, these proteins mainly involves in the glycolytic pathway, oxidative stress, inflammation, cell structure, etc. some proteins associated with inflammation that up-regulated expression in coinfection, such as Heat shock protein(HSP70), Alpha- enolase(ENO1), Glyceraldehyde 3- phosphate dehydrogenase(GAPDH), showed that coinfection have synergy to the pathogenicity of the host.