4.7. Detection of Genes Involved in Biofilm Formation

The PCR assays for amplification of the icaA, icaB, icaC, and icaD genes followed the parameters described by Arciola et al. [75] using the primers shown in Table 6. The mixtures were incubated in thermocyclers using different parameters for each gene. For detection of the icaA gene, the isolates were submitted to 30 cycles of denaturation at 94 °C for 45 s, annealing at 49 °C for 45 s, and extension at 72 °C for 1 min. For the icaB, icaC, and icaD genes, incubation started at a temperature of 94 °C for 5 min, followed by 50 cycles of denaturation at 94 °C for 30 s, annealing at 54 °C for 30 s, and extension at 72 °C for 1 min. The following reference strains were used as positive and negative controls, respectively, in all reactions: S. epidermidis ATCC 35985 (biofilm producer) and S. epidermidis ATCC 12228 (non-biofilm producer).