The Isolation And Identification Of Pathogens That Caused Embryo Diseases

The study mainly focused on the bacteria isolation and identification from chicken embryos which died on two breeding chicken farms in Shandong Province. Firstly, bacteria was isolated five times for 90 Hailan he chicken embryos from a poultry breeding company in Tan an City, which died at the age of 18-20 day. Based on the frequency of bacteria isolated, two types of bacteria were selected. Subsequent experiment primarily determines these two bacteria are Salmonella pullorum and Escherichia coli mainly through colony morphology, staining characteristics, biochemical characteristics, etc. Animal testing was then performed to validate the pathogenencity, by inoculating the Kunming white mice and the two-day-old Hailan he chicks. Our results show that Salmonella pullorum has a weak pathogenicity for mice, as the mice inoculated showed no obvious clinical symptoms, and there is only one case from which Salmonella pullorum was isolated. But the bacteria are highly pathogenic for chickens, in that among 18 chicks inoculated, 15 died after three days, with the mortality rate 83.3%, and Salmonella pullorum was isolated from dead chickens. Escherichia coli pathogenicity in mice is also very weak, and the vaccinated mice did not show obvious clinical symptoms, with three cases from which E. coli was isolated. Bacteria are highly pathogenic for chickens, and among 50 chicks inoculated, 35 died after three days, with a death rate of 70.0%, and the isolation of E. coli from chickens. Results from the sensitivity test for the two types of bacteria obtained showed that the isolated Salmonella are sensitive to tobramycin, sulfonamide compound, moderately sensitive to rifampin, chloramphenicol, amikacin, streptomycin, oxygen Piperacillin, cefoperazone, ampicillin, ceftazidime, with a low sensitivity to vancomycin, oxygen piperazine acid, oxacillin, and they are not sensitive to Cefotaxime, carbenicillin penicillin, cephalosporin quinoline, ceftriaxone. The isolated E. coli are moderately sensitive to chloramphenicol, tobramycin, amikacin, ceftriaxone, with a lower sensitivity to the compound sulfamethoxazole, rifampicin, chloramphenicol, vancomycin, oxygen piperazine acid, ceftazidime, cefoperazone, whereas they are not sensitive tcefotaxime, carbenicillin penicillin, cephalosporin quinoline, Ceftriaxone hydrochloride, streptomycin, oxacillin. This article established the chicken embryo-derived Salmonella and E. coli in Shandong Province have a broad drug resistance, and mainly with multiple drug resistance. The study can provide theory basis for Salmonella disease prevention and treatment, in terms of its sensitivity to drugs.Bacteria isolation and identification was performed on chicken embryos from a breeding chicken farm in Shandong Boshan, which were dead at the age of 10-20 day. Through the colony morphology and staining characteristics, one of the bacteria was selected for the study. Through the biochemical tests, we primarily determined the bacteria is leuconostoc mesenteroides, which belongs to the Leuconostoc spp. Through the sensitivity test, this type of lactic acid bacteria is sensitive to chloramphenicol, and moderately sensitive to vancomycin, cefotaxime, carbenicillin penicillin, cephalosporin quinoline, amikacin, ceftriaxone, tobramycin, oxygen piperazine acid, ceftazidime, ampicillin, oxacillin, Cefoperazone, Piperacillin, with a low sensitivity to the compound of rifampicin, and it is not sensitive to streptomycin. This article first proposed that lactic acid bacteria such as Leuconostoc mesenteroides can break down yolk film structural components of the chick embryo, and thereby affecting the growth and development of chick embryos, which is the main cause of the death of the chicken embryos.