Extra-intestinal dissemination of SEE1.

<p>Bacterial burden of the liver (A) and spleen (B) from three experiments was taken and normalized with corresponding controls, and analyzed by Tukey’s post-test of one-way ANOVA, and significance of <i>p</i><0.05 is indicated by *. There were five mice per group in the first two experiments and four mice per group in the last experiment. Mice that received the same treatment in each of the three experiments were considered one group for final data analysis.</p

Biometrics of the ceca.

<p>The overall size (A), weight (B), and pathology-driven morphological changes (C1-C3) were determined for the mice infected with SEE1 from the three sources. There were four mice in each experimental group and three mice in each control group. Measurements of the ceca from the last experiment were taken and normalized with corresponding controls, yielding the changes in size and weight. SEE1 grown in egg yolk appears to cause greater pathological changes in the ceca as compared to SEE1 grown in LB broth (C1) or passed through mice (C3). For A and B, significance was determined by one-way ANOVA Tukey’s pairwise comparison test, and significance was set at <i>p<</i>0.05; indicated by *.</p

Overall histopathology scores of ceca.

<p>The primary site of colonization for SE in mice is the cecum; so the histopathology of the ceca of three mice from each control group and four mice from each infection group was determined. Statistical significance was determined by one-way ANOVA Tukey’s pairwise comparison test, and significance was set at <i>p</i><0.05; indicated by *.</p

Gross pathological changes in mice.

<p>Overall changes in the mice internal organs from the third experiment were photographed and analyzed. Mice infected with SEE1 grown in egg yolk (B) appear to have greater outward pathology than the mice infected with SEE1 from LB broth (A) or from mouse feces (C). Major changes in gross pathology and organs of interest are indicated by the arrows and Roman numerals. I, The liver displaying marked paling, and prominent blood vessels. II, The small intestine showing signs of paling compared to the small intestine in A and C. III, The cecum that is emptied and shriveled. IV, The colon section of the large intestine that is extremely pale and empty. V, Fluid build-up in the visceral tissues. There were four mice in each experimental group and three mice in each control group.</p

Cytokine analysis of ceca of mice infected with SEE1 from three sources.

<p>Pro-inflammatory and anti-inflammatory cytokine profiles had been determined by ELISA for ceca of mice infected with SEE1 from egg yolk (four mice), LB broth (four mice), and passed through mice (four mice) as well as corresponding controls for each source used (three mice each). Results were normalized with corresponding controls and analyzed through one-way ANOVA and subsequent Tukey’s Pairwise Comparison Test. Significance of <i>p</i><0.05 is indicated by *.</p

Genome map of SS17.

<p>Larger circle depicts chromosomal DNA with the smaller circles representing the two plasmids. <b>SS17</b>: From inner circle: percent GC (teal); tRNA (green arrowheads); rRNA (purple arrowheads); ORFs (forward direction-dark blue, reverse-light blue); location of phage (black bars) and LEE operons (pink); Shiga toxin II genes (red arrowheads); <b>pSS17</b>: percent GC (teal); ORFs (blue); <b>pO157</b>: percent GC (teal); ORFs (blue); hemolysin genes (purple), <i>toxB</i> gene (green) and <i>etp</i> operon (pink).</p

Mauve alignments of SS17 with the four reference genomes.

<p>(A) Alignment of SS17 with the four reference strains (TW14359, EC4115, EDL933, and Sakai) reveal six blocks of homology each of varying length ranging from ~50kb to ~2280kb. Each block is a different color with lines connecting corresponding homologous blocks, with the white regions indicating non-homology. (B) Part of block 4 corresponding to phage region 11 is enlarged indicating the differences in the varying colors between SS17 and the reference strains which can also be seen in the annotations (white bars underneath).</p

Adherence patterns of O157 strains SS17, EDL933, and 86–24-Sm^R to RSE cells.

<p>(A) Quantification of SS17, EDL933, and 86–24-SmR adherence to RSE and HEp-2 cells in the presences of D+Mannose. SS17 displays a strong adherence to RSE cells and only moderate adherence to HEp-2 cells. (B) Immunofluorescence stained slides reveled that both SS17 and EDL933 displayed an aggregative adherence pattern on RSE cells while 86–24 displayed a diffuse pattern. All strains demonstrated a diffuse adherence pattern on HEp-2 cells (not shown). (C) Average of adherence levels for nine super-shedder isolates, which all displayed strong, aggregative adherence to RSE cells, that can be seen in the representative immunofluorescence stained slide. Arrows point to adherent bacteria (green). Slides are shown at 40x magnification with RSE cytokeratin (red) and nuclei (blue).</p

Histopathology scoring system.

<p>Histopathology scoring system.</p

Bacterial burden in the intestinal tract and fecal shedding.

<p>Above are the results of the bacterial burden in the mouse intestines after infecting with SEE1 from different sources. Bacterial counts of the small intestine (A), cecum (B), colon (C) as well as fecal shedding differences (D) were taken from three experiments, normalized with corresponding controls, and the results analyzed by one-way ANOVA with a Tukey’s post-test (A-C) or Kruskall-Wallis test (D) and * represents <i>p</i><0.05. There were five mice per group in the first two experiments and four mice per group in the last experiment. Mice that received the same treatment in each of the three experiments were considered one group for final data analysis.</p