Evolutionary barriers to horizontal gene transfer in macrophage associated Salmonella

To investigate which of the intrinsic of a horizontally acquired gene and the environment can be a barrier to HGT, we transferred and expressed 44 E.coli orthologs into S. Typhimurium strain 4/74. Overall design: We estimated relative fitness effects in four infection relevant environments for the 44 Salmonella mutants with changes in gene frequencies estimated using Next-Generation Sequencing. Pooled growth assays for the 44 mutants in four infection relevant environments that are representative of an intra-macrophage environment during an infection.