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[Construction of attenuated Salmonella choleraesuis vaccine strain expressing recombinant antigen of Shiga-like toxin Escherichia coli].

OBJECTIVE
To construct an attenuated Salmonella choleraesuis vaccine strain expressing the gene SLT-IIeB and FedF of Shiga-like toxin Escherichia coli (SLTEC) O138 with balanced lethal system.


METHODS
The gene of SLT-IIeB and FedF of SLTEC O138 was amplified, and then recombined with a vector pYA3493 (Asd+). The recombinant was electroporated into attenuated Salmonella choleraesuis C500 (Asd-). The expression of SLT-IIeB and FedF was analyzed by SDS-PAGE. The stability of the vaccine strains was studied by generation culture in vitro.


RESULTS
The stable attenuated Salmonella choleraesuis vaccine strain expressing SLT-IIeB and FedF of SLTEC O138 was constructed with balanced lethal system. The expressed products with protein quality 37000 could react with the antibody of FedF and SLT-IIeB.


CONCLUSION
The attenuated Salmonella choleraesuis vaccine strain could probably serve as a vaccine against edema disease and piglets paratyphoid.