Colon cancer-associated B2 Escherichia coli colonize gut mucosa and promote cell proliferation

Figure 3 Impact of CEABAC10 mice colonization by B2 Escherichia coli strain on inflammation and cell proliferation. CEABAC10 mice transgenic for human CEACAMs, including CEACAM6, were subjected to 8 consecutive cycles of infection with AIEC LF82 or B2 phylogroup Escherichia coli (E. coli) strain 11G5. Control mice received PBS. A: Quantification of the number of bacteria in the feces of mice at cycle 4 and cycle 8; B: Histopathological scoring for several parameters of inflammation and epithelial damages (see Table 2) was performed at the end of the 8^th cycle. ^aP≤ 0.05 vs control; P = NS vs LF82; C: Hematoxylin/eosin/safran (HES) staining of colonic tissue sections; D: Total RNAs from colons were extracted at the end of the 8th cycle. PCNA and S26 mRNA levels were measured by RT-qPCR. PCNA amount relative to S26 is presented. ^aP≤ 0.05 vs control; ^cP≤ 0.05 vs LF82; E: Immunohistochemistry examination of Ki67 on colonic tissue sections. NS: Not significant.