Avibacterium paragallinarum is the etiological agent of infectious coryza, a significant respiratory ailment associated with growth inhibition and diminished egg production in poultry. Given the increasing incidence of antibiotic resistance in bacteria, there is an imperative need for the development of genetically engineered vaccines; however, the lack of effective tools for genetic manipulation in Av. paragallinarum has limited the scope of related research. Herein, we investigat