Protection Against Salmonella by Vaccination with Toxin-Antitoxin Self-Destructive Bacteria.

Area of Science:

• * Veterinary immunology
• * Food safety microbiology
• * Molecular vaccinology

Background:

• * Salmonella is a significant zoonotic pathogen in poultry, posing food safety risks.
• * Current poultry vaccines have limitations in efficacy, safety, and practical application.
• * Novel vaccination strategies are needed to control Salmonella Enteritidis.

Purpose of the Study:

• * To develop and assess an oral vaccine for poultry using inducible toxin-antitoxin (TA) systems.
• * To enhance the safety and immunogenicity of Salmonella Enteritidis vaccines.
• * To engineer TA systems for controlled bacterial self-destruction.

Main Methods:

• * Design and construction of Hok/Sok (HS) and CeaB/CeiB (CC) TA systems.
• * Modification of the Hok toxin promoter to regulate toxin production.
• * In vitro and in vivo evaluation of Salmonella survival and immunogenicity in chickens.
• * Assessment of bacterial persistence and protective immune response.

Main Results:

• * Attenuated Hok toxin promoter enhanced Salmonella survival in vitro.
• * Combined HS and CC TA systems led to complete Salmonella elimination in vitro and in chickens.
• * Vaccinated chickens exhibited high antibody levels and protection against wild-type Salmonella challenge.

Conclusions:

• * Inducible TA systems offer a promising platform for developing safe and effective Salmonella vaccines for poultry.
• * This approach can significantly reduce Salmonella transmission within the food chain.
• * The adaptable TA-based vaccination strategy holds potential for broader applications in animal health.