Fig. 6: Man-PTS EII knockout mutant produces more CPS and induces more severe infection in mice compared to the WT strain.

a CPS quantification of the wild type (WT), Δman-PTS EII mutant and complemented mutant (C-Δman-PTS EII) strains cultured in LB or Lac-LB. b–d RT-PCR analysis of CPS encoding genes expression (galf, wzi and manC) in the WT, Δman-PTS EII mutant and C-Δman-PTS EII strains cultured in LB and Lac-LB. e Endocytosis rate of the WT and Δman-PTS EII strains by RAW 264.7 macrophages. Data represent the ratio of intracellular bacterial CFU to the input bacteria CFU. f Bacterial loads in liver, spleen, kidney and lung tissues. n = 5/group. g Representative histopathology of liver tissues (Hematoxylin-eosin and MPO staining). Images captured at 200× magnification. h, i Histological and MPO score (n = 3/group). Two tissue sections per sample were scored on a 0 to 3 scale, and cumulative lesion scores were calculated by summing the individual section scores. j–k Serum protein levels of proinflammatory cytokines IL-6 and TNF-α in mice infected with the WT and Δman-PTS EII strains, measured by ELISA. n = 5/group. l Survival curves of mice infected with the WT and Δman-PTS EII strains. Mice (n = 6/group) were intraperitoneally injected with 1 × 10⁴ CFU bacteria and monitored for 3 days. Statistical analysis for panels a-e was performed using one-way ANOVA with Tukey’s post-tests; (f–k) were analyzed using two-sided independent-samples t-test. The survival analysis (l) was performed using the log-rank test. Error bars show the mean ± SD. n indicates the number of biological replicates for all experiments. Source data are provided as a Source Data file.