Avibacterium paragallinarum attenuated mutant strain and application thereof

Abstract

The invention discloses an avibacterium paragallinarum attenuated mutant strain and application thereof, and belongs to the field of microorganisms and the technical field of veterinary biological preparations. The avibacterium paragallinarum attenuated mutant strain is C-N118 and is preserved in the China Center for Type Culture Collection on July 2, 2025, and the preservation number of the avibacterium paragallinarum attenuated mutant strain is CCTCC NO: M 20251506. Compared with a parent strain 2020 / JS74, the avibacterium paragallinarum attenuated mutant strain C-N118 obtained by mutagenesis of 1-methyl-3-nitro-1-nitrosoguanidine has the advantages that the biofilm forming capability and the adhesion invasion capability are reduced, the pathogenicity is obviously reduced, and any clinical symptoms and lesions of SPF (specific pathogen free) chickens are not caused after the avibacterium paragallinarum attenuated mutant strain C-N118 is inoculated with the avibacterium paragallinarum attenuated mutant strain C-N118. The C-N118 is immunized in a nasal drop mode, the immunizing dose is 10 < 7 > CFU / duck, the C-type avibacterium paragallinarum 2020 / JS74 is attacked after 14 days, the dose is 10 < 2 > CFU / duck, and the protection rate is 100%. It is proved that the avibacterium paragallinarum attenuated mutagenic strain C-N118 can be used as a candidate strain of a chicken infectious rhinitis attenuated live vaccine, is used for vaccine research and has a great application prospect.

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