FIG. 3.

Effects of insertional knockouts on the intracellular replication of L. monocytogenes. Caco-2 cells were infected with either the wild-type strain or insertional mutants as described in Materials and Methods. Mutated genes are in the same order as in Table 2, and putative functions are indicated in parentheses. The number of CFU recovered after 7 hours was determined, and reduced survival of the mutants was calculated as a percentage compared to the control group. The control group comprised 107 insertional mutants whose intracellular growth was not significantly affected. Error bars represent the standard deviations from the mean (n ≥ 3 for insertional mutants; n = 13 for the wild type). The significance level was ≤0.02 according to Student's t test. lmo2434 encodes a glutamate decarboxylase (glutamate decarb.).