Produced by the National Institute of Allergy and Infectious Diseases (NIAID), under a magnification of 20,000X, this digitally-colorized scanning electron micrograph (SEM) depicts a number of mustard-colored, spheroid-shaped Staphylococcus aureus bacteria that were in the process of escaping their destruction by blue-colored human white blood cells (WBCs). One form of Staphylococcus aureus bacteria known as methicillin-resistant Staphylococcus aureus, or MRSA, causes a range of illnesses, from skin and wound infections to pneumonia and bloodstream infections that can cause sepsis and death. Staph bacteria, including MRSA, are one of the most common causes of healthcare-associated infections. Resistance to methicillin and related antibiotics (e.g., nafcillin, oxacillin) and resistance to cephalosporins are of concern. CDC estimates 80,461 invasive MRSA infections and 11,285 related deaths occurred in 2011. An unknown but much higher number of less severe infections occurred in both the community and in healthcare settings.