The mRNA levels of (a) TGF-β1, (b) CTGF and (c) IGF1 expression in the colon (upper panels) and caecum (lower panels) was determined 3 weeks post AIEC infection. Data were normalized to 18s RNA and expressed as fold-change relative to the uninfected control. Quantification of (d) collagen type I (Col1a2) and (e) collagen type III (Col3a1) was determined by quantitative RT–PCR. Data were normalized to 18s RNA and expressed as fold-change relative to the uninfected PBS-treated control. Data are expressed as the means with s.e. from four mice per group, representative of two independent experiments. *P<0.05, **P<0.005, ***P<0.001 compared with uninfected PBS-treated controls (one-way analysis of variance with Dunnett’s post test).