Preparation and evaluation of inactivated vaccine against sheep Mannheimia hae-molytica type A1
10.16303/j.cnki.1005-4545.2024.11.07
- VernacularTitle:羊源溶血性曼氏杆菌A1型灭活疫苗的制备及免疫效果评价
- Author:
Zihan XIA
1
;
Yan LI
;
Yuan MA
;
Huanrong ZHANG
;
Falong YANG
Author Information
1. 西南民族大学畜牧兽医学院,四川 成都 610041
- Keywords:
sheep;
Mannheimia haemolytica;
inactivated vaccine;
immunization studies
- From:
Chinese Journal of Veterinary Science
2024;44(11):2356-2362
- CountryChina
- Language:Chinese
-
Abstract:
Mannheimia haemolytica is an important pathogen causing respiratory diseases in sheep,and the development of an inactivated vaccine of sheep origin against Mannheimia haemolytica is an effective means of prevention and control of this pathogen.In this study,Mannheimia haemo-lytica isolated from the diseased material collected from a sheep farm was screened for the most suitable vaccine strain by mouse pathogenicity test,and the inactivated vaccine was prepared by combining four antigenic amounts(106,107,108,109 CFU/mL)with three adjuvants(ISA 201 ad-juvant,ISA 206 adjuvant,and aluminum adjuvant),which were used in immunization and attack protection tests,and then screened for immunity and attack protection tests.Immunization and at-tack protection tests were conducted to screen the optimal antigen amount and adjuvants for inacti-vated vaccine preparation.Finally,the vaccine was prepared under the optimal conditions and the dynamic changes of antibody levels in immunized sheep were observed.The results showed that a total of 24 strains of Mannheimia haemolytica of sheep origin were isolated,among which 12 strains of serotype A1 were the dominant serotypes for the infection in this sheep farm;one strain of Mannheimia haemolytica of sheep origin of type A1(Mh1)was screened and obtained as the strain for vaccine preparation.Its LD50 for mice was 3.16 × 107 CFU/mL,with strong pathogenici-ty,and could cause pathological damage such as inflammatory cell infiltration of varying degrees in heart,liver,spleen,lung and kidney tissues;the results of the immunization and attack protection test showed that the optimal antigenic amount of the inactivated vaccine was 109CFU/mL,and the most suitable adjuvant was ISA 201,which stimulated the production of the highest antibody level and provided 100％protection for the mice.The protection rate of mice reached 100％,and good humoral immunity could be induced after immunizing sheep.The inactivated Mannheimia haemo-lytica type A1 vaccine prepared in this study has good immunoprotection effect,and lays a good foundation for the further development of commercial vaccine against Mannheimia haemolytica of sheep origin.
