Salmonella enterica serovar Typhi (S. Typhi) is the cause of typhoid fever, a life-threatening systemic disease that kills hundred thousands of people every year. In contrast to other Salmonella enterica serovars, S. Typhi is a human-restricted pathogen. Although it is believed that genome reduction has played a central role in narrowing S. Typhi host range, the molecular mechanisms behind S. Typhi host-restriction are still mostly unknown. We recently identified a novel antimicrobial pathway that controls the growth of S. Typhi in mouse macrophage and contributes to S. Typhi host-restriction. This pathway depends on the trafficking regulator Rab32 and its guanine nucleotide exchange factor Biogenesis of Lysosome-related Organelle Complex (BLOC)-3. A S. Typhi strain that delivers a type III secretion effector that targets Rab32 survives in mouse tissues and colonize mice. Several observations suggest that the Rab32 pathway kills S. Typhi by delivering an unknown antimicrobial activity to the S. Typhi vacuole.