Keywords enterotoxins;Escherichia coli;bacterial diarrhea;multivalent vaccine;cholera toxin;Salmonella typhi;host_plasmid balancing system;

• 关键词肠毒素类;大肠杆菌;细菌性腹泻;基因工程多价疫苗;霍乱毒素;沙门菌;伤寒;宿主-质粒平衡致死系统;