Bacterial Proteins/metabolism; Gene Expression Regulation, Bacterial; Pneumococcal Vaccines; Protein Sorting Signals/physiology; Recombinant Fusion Proteins; Salmonella typhimurium/metabolism; Animals; Antibodies, Bacterial/blood; Bacterial Proteins/chemistry; Bacterial Proteins/genetics; Female; Humans; Immunoglobulin G/blood; Immunoglobulin G/classification; Immunoglobulin Isotypes; Mice; Mice, Inbred BALB C; Plasmids; Pneumococcal Infections/immunology; Pneumococcal Infections/mortality; Pneumococcal Infections/prevention & control; Pneumococcal Vaccines/administration & dosage; Pneumococcal Vaccines/genetics; Pneumococcal Vaccines/immunology; Pneumococcal Vaccines/metabolism; Recombinant Fusion Proteins/genetics; Recombinant Fusion Proteins/metabolism; Salmonella typhimurium/genetics; Time Factors; Vaccines, Attenuated/genetics; Vaccines, Attenuated/metabolism; Vaccines, Synthetic/genetics; beta-Lactamases/chemistry