Biofilm - forming characteristics of vancomycin - resistant <em>Enterococcus faecium vanA</em> of the epidemic clonal complex 17 isolated in a university hospital of southern Brazil
Características dos biofilmes formados por <em>Enterococcus faecium</em> resistente à vancomicina <em>vanA</em> do complexo clonal epidêmico 17 isolado em um hospital universitário do sul do Brasil
Keywords:rep-PCR fingerprinting, sequence types, adhesion, polystyrene
Vancomycin-resistant Enterococcus faecium (VREfm) is an important etiologic agent of healthcare-associated infections worldwide. The present study aimed to characterize the vanA-carrying VREfm isolates according to their genetic relatedness, multilocus sequence typing (MLST), biofilm-forming characteristics, and the occurrence of putative genes involved in adhesion, biofilm formation, and pili assembly. High genetic diversity among the ten vanA VREfm isolated from inpatients was observed using the rep-PCR analysis. According to the MLST analyses, four different STs were detected among the vanA VREfm isolates, with ST 412 being the most prevalent. Most of the STs detected in this study belong to Clonal Complex 17 (CC 17), a high-risk clone adapted to the hospital environment. All VREfm were capable of forming biofilm on a polystyrene surface. However, significant differences in biofilm biomass were observed among the different isolates, including those with the same ST. Scanning electron microscopy analyses of the 24-h biofilms revealed the presence of sessile cells surrounded by an extracellular polymeric substance. All VREfm harbored the atlA gene, and nine were positive for the ecbA gene. The acm, scm, and ebpC genes were detected in six isolates. Finally, the fms21/pilA gene was detected in seven isolates.