RESUMEN
The coagulase-negative staphylococci are known for their ability to acquire resistance genes, which limits the choice of therapeutic options for the treatment of infections caused by these microorganisms. In this study, the diversity of high-level mupirocin resistance plasmids (Mup(R) ) was investigated in four strains of Staphylococcus haemolyticus belonging to different pulsed-field gel electrophoresis (PFGE) types or subtypes, isolated in a Brazilian hospital. These strains harbor the mupA gene in large plasmids. In addition, the presence of IS257 sequences flanking the mupA gene was also shown. Two isolates belonging to two different PFGE types exhibited a similar polymorphism for a fragment of the mupA gene and the closest proximal flanking copies of the IS257, suggesting horizontal transmission of S. haemolyticus mupirocin resistance plasmids in the environment and a role of this species as a reservoir of the mupA gene.