Studies On Dynamic Change Of 6 Kinds Of Bacteria In Respiratory Tract And Intestinal Microbial Community Diversity Of Ducklings Infected With Salmonella Enteritidis

S.enteritidis is a common pathogenic bacterium that can result in zoonosis.In this study,FQ-PCR was used to detect the quantity of six kind of bacterium in respiratory tract,ERIC-PCR was used to fingerprint the kinetics of microbial community of fecal samples of S.enteritidis-infected ducklings.The contents are summarized as follows:1.FQ-PCR was used to detect the quantity of six kind of bacterium in respiratory tract. The results indicated that five of the six kind of bacteria in respiratory tract of all ducklings can be well detected except Lactobacillus and the quantity of Bifidobacterium is the least(3.18±0.3—5.06±0.25).The chronologicaol order of Eschenchia coli's quantity crest value is hypodermically inoculated ducklings(8 h p.i.)＞orally inoculated duckling s (24 h p.i.)＞nasally inoculated ducklings(48 h p.i.).The quantity of StaphyLococcus is nasally inoculated ducklings(8.37±0.29—10.54±0.23)＞orally inoculated ducklings (7.41±0.31—9.66±0.24)＞hypodermically inoculated ducklings(7.06±0.41-8.76±0.45).The dynamic changes of the other four kind of bacterium are also hypodermically inoculated ducklings＞orally inoculated ducklings＞nasally inoculated ducklings.So the maladjusted degree of microbial community in respiratory tract was correlative with the infected routes.2.Enterobacterial Repetitive Intergenic Consensus(ERIC)-PCR was applied to analyze the intestinal microbial community diversity and dynamic change of healthy ducklings and 7-day-old ducklings infected with S.enteritidis in different routes.The results indicated that the intestinal microbial community of the control healthy ducklings was steady and the ERIC-PCR band numbers of the control healthy ducklings were the least with rectum and were the most with caecum.The maladjusted degree of intestinal microbial community was correlative with the infected routes and it successively abated in hypodermically inoculated ducklings,orally inoculated ducklings and nasally inoculated ducklings.The intestinal microbial community dynamic change of hypodermically inoculated ducklings was severely maladjusted while it did not change in nasally infected ducklings.The prominent bacteria had changed because of S.enteritidis infection and the DNAstar of staple of ERIC-PCR showed that aerobe and facultative aerobe(Escherichia coli,Shigella,Salmonella) became preponderant bacilli in the intestine of all infected ducklings with S.enteritidis.