Impact of SREC-I on adhesion of <i>S. aureus</i> to CHO epithelial cells and impact of SREC-I on the early phases of nasal colonization in the cotton rat model.

<p><i>S. aureus</i> adhesion to the cell line CHO expressing or not expressing SREC-I assayed in chamber slides under shear stress (A) and under static conditions (B). Attachment of <i>S. aureus</i> wt, <i>tagO</i>, and <i>tagO</i> compl. evaluated microscopically by counting at least 8 visible fields per well or chamber slide containing CHO cells without SREC-I or expressing full length SREC-I (A) or consecutive truncations of the extracellular EGF-like domains (B). Means and SD of 4 independent experiments (static) or 3 independent experiments (flow) are shown. Statistical analysis was performed by one-way ANOVA with Bonferroni's multiple comparison test (A and B). Significant differences are indicated by one (<i>P</i><0.05), two (<i>P</i><0.01), or three (<i>P</i><0.001) asterisks (<b>*</b>). Nasal colonization was assayed in a cotton rat model (C). Bacterial numbers were determined 8 h and 6 days after inoculation. 15 min prior to inoculation cotton rats were pretreated with 2 µg anti-SREC-I Fab₂-fragment per nose. After 8 h and 6 days the noses were dissected and the bacterial CFU was evaluated on <i>S. aureus</i> selective highchrome agar. Statistical analysis was performed by D'Agostino & Pearson omnibus normality test and a subsequent Kruskal-Wallis non-parametric ANOVA with Dunn's Multiple Comparison Test (C). Significant differences between groups are indicated by one (<i>P</i><0.05), two (<i>P</i><0.01), or three (<i>P</i><0.001) asterisks (<b>*</b>).