The percentage of bacterial survival and number of colony-forming units per milliliter of bacteria recovered from (A) neutrophil killing and (B) whole-blood killing assays, respectively, were significantly reduced for Salmonella enterica serotype Newport CSF and blood isolates pretreated with 1/4 MIC of ceftriaxone (CRO) and 1/4 MIC of CRO + 1/4 MIC of ciprofloxacin (CIP) but not 1/4 MIC of CIP alone. Data are plotted as mean ± SEM and represent the percentage of bacterial survival remaining following 15 min of neutrophil exposure compared to the initial inoculum or CFU per milliliter recovered following 60 min of exposure to whole blood. **, P < 0.005, ***, P < 0.0005, and n.s., no statistical significance, by two-way ANOVA and comparing pretreated bacteria to untreated bacteria.