Fig. 4: Lineage 2 and 3 ST34 Salmonella 4,[5],12:i:- demonstrate increased infectivity and replication in human cell lines.

Differentiated THP-1 (human monocyte) cells (A–D), HT-29 (human intestinal epithelial) cells (E, F), or BJ-5ta (human fibroblast) cells (G, H) were infected at an MOI:10 with selected ST34 Salmonella 4,[5],12:i:- and ST34 matched-Lineage 1 biphasic S. Typhimurium isolates (Supplementary Table 1). THP-1 cells were lysed and intracellular bacteria enumerated as CFU/well at times 0, 6, 12, and 24 hpi. HT-29 and BJ-5ta cells were lysed and intracellular bacteria enumerated as CFU/well at times 0 and 24 hpi. Isolates depicted on the x axis correspond to isolates listed in Supplementary Table 1. Each dot represents CFU/well of a biological replicate (performed in technical duplicate), with error bars indicating ±1 standard deviation of n = 3 or 4 biological replicates. Statistical significance was determined by nested one-way ANOVA with Fisher’s uncorrected multiple comparisons test. MOI multiplicity of infection, hpi hours post-infection, CFU colony-forming units.