What Factors Contribute to the Virulence of Staph aureus?

Jeff Boyd, PhD, assistant professor of Biochemistry and Microbiology at Rutgers School of Environmental and Biological Sciences, examines the virulence factors of Staphylococcus aureus.

Interview Transcript (slightly modified for readability).

“Some factors that would contribute to virulence and Staphylococcus aureus include different things such as the ability to form a capsule. A capsule [is] a layer, or a slime layer, on the outside of the cell which prevents phagocytosis by white blood cells or prevents recognition by antibodies.

Staph makes another protein called “Protein A,” which binds to human antibodies on the outside of the cell, and it masks and coats it with human antibodies so the immune system can’t recognize it. Staph aureus has the ability to make a number of different toxins which can lice white blood cells [and] red blood cells. It has the ability to acquire nutrients that might be hard or limiting in the human body, such as iron. Staph can produce a toxin which will lice red blood cells and then it has a mechanism to get heme out of hemoglobin and use that iron as a source of iron for the cell to grow.

Staph aureus also has the ability to produce a number of superantigens. One you might have heard of include toxic shock syndrome toxin. These will stimulate or cause the human immune system to overreact to the presence of Staph aureus, or the presence of this toxin, and can cause the body to have a number of global metabolic defects and ultimately, if untreated, will lead to death.”