L. monocytogenes 10403s was used as the wild-type strain. L. monocytogenes strains were grown at 37°C or 30°C in brain heart infusion (BHI), Luria broth (LB), or minimal defined media (min) supplemented with glucose as the sole carbon source (59). Escherichia coli strains were grown in Luria broth (LB) at 37°C. Antibiotics were used at a concentration of 100 µg/ml carbenicillin, 10 µg/ml chloramphenicol, 2 µg/ml erythromycin, or 30 µg/ml kanamycin when appropriate. For growth of MK-deficient strains in MK-limiting minimal media, MK (Sigma; V9378) was supplemented at 25 ng/ml. For anaerobic growth, bacteria were cultivated on BHI plates placed anaerobic jars carrying a GasPak EZ anaerobe container system (BD; 260678).