Kanamycin kn

S. Typhimurium strains and plasmids used in this work are listed in S1 Table. Strains were maintained in Luria-Bertani (LB) broth or on plates with appropriate antibiotics at the following concentrations; ampicillin (Sigma Aldrich), 100 μg.ml^-1; chloramphenicol (Cm, Sigma Aldrich), 12.5 μg.ml^-1; kanamycin (Kn, Sigma Aldrich), 50 μg.ml^-1; tetracycline (Tet, Sigma Aldrich), 15 μg.ml^-1. M9 minimal medium with 0.4% w/v glucose was used where indicated. Oligonucleotide primers were purchased from Sigma Genosys or Illumina.

S. Typhimurium strains and plasmids used in this work are listed in Table 1. Strains were maintained in Luria-Bertani (LB) broth or on plates with appropriate antibiotics at the following concentrations; ampicillin (Sigma Aldrich), 100 µg.ml⁻¹; chloramphenicol (Cm, Sigma Aldrich), 12.5 µg.ml⁻¹; kanamycin (Kn, Sigma Aldrich), 50 µg.ml⁻¹; tetracycline (Tet, Sigma Aldrich), 15 µg.ml⁻¹. M9 minimal medium with 0.4% w/v glucose was used where indicated. Oligonucleotide primers were purchased from Sigma Genosys or Illumina.

Bacterial strains and plasmids used in this study are listed in Table 1. L. acidophilus strains were propagated in de Man Rogosa and Sharpe (MRS) broth (Difco) under ambient atmospheric conditions, statically or on MRS solid medium containing 1.5% (w/v) agar (Difco) under anaerobic conditions at 37°C, or at 42°C where indicated. Recombinant strains were selected in the presence of 2 μg/ml of erythromycin (Em; Sigma–Aldrich) and/or 2–5 μg/ml of chloramphenicol (Cm; Sigma). Escherichia coli strains were grown in brain heart infusion (Difco) medium at 37°C with aeration. E. coli EC101 was grown in the presence of 40 μg/ml kanamycin (Kn; Sigma–Aldrich) while NCK1911 and transformants were grown with 40 μg/ml Kn and 150 μg/ml Em. Counterselection of plasmid-free excision recombinants was performed using 5-fluorouracil-supplemented glucose semi-defined medium, as previously described (Goh et al., 2009 (link)).