Isolation And Identification Of Salmonella Pullorum And Development Of Its Bacterin.

The purpose of this study is to prepare a salmonellos pullorosis bacterins with oil emulsion and propolis adjuvant,respectively,in order to prevent chook from pullorum disease. The Salmonella Pullorum for the preparation of bacterin were isolated and identified from sick group regarded as pullorum disease at the 8 pathogenic area in SiChuan province and ChongQing city and from 80 out of 191 chickens struck by pullorum disease whose agglutination assay proved positive. And 21 strains of pullorum disease were isolated from 80 chook. The isolated strains appeared round,edge-regulated, slightly bulging, surface-wetting but smooth, transparent, dew, tiny colony on the s.s agar plate. It could be observed that the colony is amphi-botuse, middle-sizing, arrange-scattered,G" bacillus in the microcope. The colony cultivated in San Tang Tie culture medium assume yellow and can no.t utilize lactose, cane sugar ,but produce H₂S. In addition, it owned lysine decarboxycase and ornithine and fermened glucide. Agglutination was occurred when it was interacted with salmonellos pullorosis multivalencel(A-F)diagnosis serum and with single-factor serum O₁, O₉, O₁₂, whereas not when it was interacted with single-factor serum H_a,H_b,H_c,H_d and H_e. It proved that the 21 strains were all pullorum disease. Three strong violent strains isolated SR_96-1,SC_14-H ,SC_18-L, were screened by assay of violence. Three mentioned challenged chickling. After 12 hours, 95percents of chicken showed weak energy, intolerance of cold, loose bowels, white dejecta like gesso adhered to the vicinity of anus. After 32 to 48 hours,the part began to die.The dying chicken were dissected to show liver putrescence,lung bleeding,caecum dropsy. Meanwhile,After the chicken aged two month and grown chickens were also challenged for six days,they were dissected to unfold needlepoint,different amout of dead tissue on the surface of liver,and intumesce cholecyst,intumesce spleen,incrassated pericardium, manifolded liquor pericardii and agnailed epicardium or dead tissue of cardiac musde,etc, howerer, liver pathology in most grave condition. The LD50 of three isolated strains SR_96-1,SC_14-H ,SC_18-L and standard strain were respectively 2.04×10⁴, 4.43 ×10⁴, 1.38 ×10⁴, 1.39×10⁴. And the ID₅₀ of duckings aged two month,grown chicken were 1.197×10⁸ and 1.897×10⁸. It could be concluded from these results that the violence of isolated strain surpassed or leastly corresponded standard strain. So it was a regional strain so that it could be qualified for the use of vaccine. After three isolated strains and standard strain C_79-13-4 with oil emulsion and propolis adjuvant were checked out by asepsis and security assay, these vaccine injected chicken agedthree days. After 14days, immunity from disease made the protection ratio respectively up to 83.4%with oil emulsion and 75% with propolis, The grown chickens could reach high antibody concentration after injected ten days,whereas reach peak after 20 to 30 days,Few individual could reach l:128,subsequently,the titer of antibody gradually cut down to 1:32 on 35th day. The result of protective test and serology identification of challenged grown chicken showed that salminellos pullorosis could not be isolated from liver, choleoyst, spleen, and ovary of chicken injected by oil emulsion vaccine while isolated from one-third of chicken injected by propolis vaccine. These man-made infected grown chickens injected by oil emulsion vaccine produced antibody ,but the pathogen could be isolated from partial internal organs.