This illustration depicts a three-dimensional (3D) computer-generated image of a cluster of sphere-shaped vancomycin-resistant Staphylococcus aureus (VRSA) bacteria. The artistic recreation was based upon scanning electron micrographic imagery. Staphylococcus aureus is a common type of bacteria that is found on the skin. During medical procedures when patients require catheters or ventilators, or undergo surgical procedures, S. aureus can enter the body and cause infections. When S. aureus becomes resistant to vancomycin, there are few treatment options available because vancomycin-resistant S. aureus bacteria identified to date were also resistant to methicillin and other classes of antibiotics. A total of 13 cases of vancomycin-resistant Staphylococcus aureus (VRSA) have been identified in the United States since 2002. VRSA infection continues to be a rare occurrence. A few existing factors seem to predispose case patients to VRSA infection, including: - Prior MRSA and enterococcal infections or colonization - Underlying conditions (such as chronic skin ulcers and diabetes) - Previous treatment with vancomycin