Fig. 3

Intracellular survival of the LOS mutants in macrophages. Macrophages were incubated with M. marinum strains for 2 h at an MOI of 10. Non-ingested bacteria were extensively washed and killed by gentamycin. Macrophages were either lysed with Triton X-100 or maintained in culture for 2 additional days prior to lysis. Cell lysates were plated onto Middlebrook 7H10 agar supplemented with 10% OADC for CFU determination. The data are presented as fold increase in CFU/ml (number of bacteria 2 days post-infection divided by the number of bacteria after 2-h of phagocytosis), expressed as the mean ± SEM from 6 to 7 separate experiments. Figure describes the difference in intracellular survival between mutants, their complemented counterparts and wild-type M. marinum. Statistical significance: *p ≤ 0.05 (Mann–Whitney U test)