Enterococcus spp. are a component of the microbiota of humans and animals and are commonly found in the natural environment. They are opportunistic pathogens that can cause infections of various locations. These bacteria rarely cause community-acquired infections. Although they were considered microorganisms with low pathogenic potential, they have become one of the important hospital pathogens recently. Their common occurrence and ability to survive in the hospital environment contribute to the recorded and still increasing frequency of their isolation, also from invasive infections. The species most frequently isolated from infection cases are E. faecalis and E. faecium, which pose therapeutic problems due to their increasing multidrug resistance. Due to the growing clinical importance, mechanisms of natural and acquired resistance to antibiotics, and potential virulence factors, Enterococcus spp. have become the subject of many studies. The aim of the study is to present the current knowledge on the most important virulence factors that may occur in bacteria of the genus Enterococcus, which include: SagA secretory antigen, EfaA protein, Esp surface protein, Ace collagen binding protein, cytolysin, hyaluronidase, hemagglutinin, lipase, serine protease, aggregating substance, extracellular peroxides and gelatinase.
