Figure 5. Assessing the abundance, colonization and localization of small intestinal microbiota in mice with or without Bacteroidales–E. coli oral exposure.
(a) The total adherent anaerobic colony-forming units (c.f.u.'s) per gram of washed jejunal tissue in BG-exposed or unexposed malnourished and control mice. Data are pooled from two independent experiments (n=8), and bars indicate median values (*P<0.05, Mann–Whitney U-test). Real-time qPCR analysis of (b) the total Eubacteria 16S rDNA copies, (c) mouse intestinal Bacteroidetes-specific 16S rDNA and (d) Enterobacteriaceae-specific 16S rDNA, in each gram of jejunal tissue. Analysis was performed on DNA extracted from washed jejunum tissue of BG-exposed or unexposed malnourished and control mice. All data in b–d are pooled from two independent experiments (n=8), and bars indicate the mean with s.e.m. (*P<0.05, one-way analysis of variance with post hoc Tukey's test). (e) Carnoy's-fixed jejunal tissues were probed for total 16S rDNA (Eub338) and γ-Proteobacteria-specific 16S rDNA (Gam42a) abundance using FISH. Images are representative of BG-exposed or unexposed malnourished and control mice. Actin is stained in green (488-Phalloidin), cell nuclei in blue (4,6-diamidino-2-phenylindole) and bacteria in red (Eub338 and Gam42a). Scale bars, 100 μm length, and white arrows point towards the presence of tissue-associated bacteria or bacteria within the villi. CON, control; MAL, malnourished.