Lb 0.3 m nacl

Salmonella Typhimurium SL1344 (SB300, SmR) was used as WT. The plasmid pM975 (pssaG-GFPmut2) has been previously used.^{15 (link)} For in vivo and tissue culture infections, S.Tm was cultured in LB/0.3 M NaCl (Sigma-Aldrich) with appropriate antibiotics for 12 h before sub-culturing at a 1:20 dilution for 4 h in the same broth without antibiotics. For in vivo infections, the inoculum was reconstituted in PBS (BioConcept), and for tissue culture infections in either DMEM/F12 (Gibco) supplemented with 3% FBS (Gibco), or in complete mouse Intesticult (STEMCELL).

All strains used in this study had a Salmonella enterica serovar Typhimurium SL1344 background (SB300; streptomycin resistant) (74 (link)). Besides the wild type (Salmonella Typhimurium WT), the previously described ΔinvG (64 (link)) and ΔsipA ΔsopBEE2 (referred to here as Salmonella Typhimurium Δ4) mutants (66 (link)) were used. The ΔmotA mutant was generated via transfer of a previously described deletion (75 (link)) from a Salmonella Typhimurium 14028 strain (C1172) to the SL1344 background by P22 transduction. Chloramphenicol-resistant, isogenically tagged Salmonella Typhimurium WT (tags A to C) and Salmonella Typhimurium ΔinvG (tags D to F) strains were used in an earlier study (65 (link)). The pFPV-mCherry (rpsM-mCherry; Addgene plasmid number 20956) (60 (link)), pM975 (pssaG-GFPmut2) (15 (link), 22 (link)), and pZ1400 (puhpT-GFP) (18 (link)) reporter plasmids were previously used and validated. For infections, Salmonella Typhimurium cultures were grown overnight for 12 h in LB–0.3 M NaCl (Sigma-Aldrich) with appropriate antibiotics, followed by subculturing in the same medium without antibiotics at a 1:20 dilution for 4 h. Prior to microinjection, the inoculum was reconstituted in antibiotic-free complete human or mouse IntestiCult medium (StemCell) at a concentration of 5 × 10⁸ to 1 × 10⁹ CFU/ml.

Salmonella enterica serovar Typhimurium, SL1344 (SB300), was used in this study [82 (link)]. For IEC monolayer infections, Salmonella was grown in LB/0.3 M NaCl (Sigma-Aldrich) for 12 h overnight, supplemented with Streptomycin (100 μg/ml). The following day, a 1:20 dilution was subcultured in LB/0.3 M NaCl without antibiotics for 4 h. For IEC monolayer infections, the 4 h sub-culture was diluted in DMEM/F-12 without antibiotics for a final MOI of 10 (50 μl inoculum volume).