USP18 and Salmonella Infections: During Salmonella infection, Usp18-mutant mice are more susceptible to systemic (i.e., typhoid) S. Typhimurium infection. By contrast, in the streptomycin-induced model of typhlocolitis, mutant Usp18 mice display lower pathology scores, low IFN-γ production but upregulated type I IFN signaling compared to control mice, resulting in earlier systemic dissemination of the bacteria and decreased survival