Distribution of adhesion and biofilm regulation genes in Staphylococcus aureus

Biofilm formation is an important virulence factor that contributes to the chronicity of the infectious processes caused by Staphylococcus aureus. The proteins on the surface of this bacterium can promote the formation of a biofilm. The distribution of genes encoding adhesion proteins associated with biofilm formation in methicillin-sensitive (MSSA) and methicillin-resistant (MRSA) strains was compared in this study. The analysis of a total of 106 isolates obtained from solid and liquid samples collected from a hospital in Mexico showed that biofilm formation was significantly associated with MRSA strains (83%). The presence of nine adhesine genes (eno, ebps, fnbA, fnbB, fib, clfA, clfB, bbp, cna) and two biofilm regulatory genes (icaA, icaD) was looked for by polymerase chain reaction (PCR). The results evidenced that icaA, icaD, eno, ebps, clfA, and clfB genes were amplified from all strains, while fnbA, fnbB, fib, and bbp genes were non-uniformly distributed among them. Notably, the results showed for the first time that the presence of the cna gene is associated with biofilm non-producing MSSA strains (p<0.05).