The biofilm formation of clinical S. epidermidis isolates. (A) Adhesion index, determined with the CV assay, of the clinical S. epidermidis strains isolated from the peripheral blood (Group A), catheters (Group B), or wounds (Group C) in different growth media as indicated. Data are represented with dot-plots showing the median value of at least three independent experiments of each isolate grown in BHI ± SUC and TSB ± GLU. Statistical significance analyzed with one-way ANOVA was reported (* p < 0.05, ** p < 0.01). (B) Percentage and number of strains classified according to the adhesion index (AI) value in strong biofilm-producers (AI > 1; purple), moderate biofilm-producers (0.2 < AI < 1; white), and non-producers (AI > 1; light gray) among the S. epidermidis clinical isolates derived from peripheral blood (Group A), catheters (Group B), or wounds (Group C). Statistical analysis performed with Fisher’s exact test for each condition was reported (* p < 0.05).