Figure 6
Quantitative and qualitative assessment of fecal STEC shedding. Animals were grouped according to their vaccination status (VAC+ = rStxMUT-vaccinated; VAC− = placebo control) and the supplementation of vitamin E (VitEH = high supplementation; VitEM = moderate supplementation). A Fecal cultures (n = 191) were screened for stx1/stx2 by PCR and grouped into stx-negative, stx1-positive, stx2-positive and stx1 plus stx2-positive. B Samples detected by stx-PCR of fecal cultures as stx 1 and stx 2 negative samples were not further analyzed (white part of the bar). Nylon membrane blots of agar plates of positively tested feces samples were hybridized with stx1/stx2 probes. Single colonies tested positive by hybridization (up to 10 per blot) were picked and further analyzed by PCR. A STEC profile is defined as single colony testing positive for stx (stx 1 and/or stx 2 ) plus facultative eae and/or ehxA. Different STEC profiles are illustrated with differently colored bars. Samples with no detectable stx1-/stx2-positive signal by hybridization (dark grey bars) and samples with single colonies positive detected by hybridization but negative signal by multiplex PCR (bright grey bars) are illustrated as such.