The most common etiologic agent of infections associated with prosthetic devices such as artificial heart valves and CSF shunts is which organism?

The most common etiologic agent of infections associated with prosthetic devices such as artificial heart valves and CSF shunts is which organism?

• A. Corynebacterium urealyticum
• B. Staphylococcus capitis
• C. Staphylococcus epidermidis
• D. Streptococcus mutans

Answer: (C)

In device-associated infections, organisms that live on skin and can cling to artificial surfaces and persist there are the usual culprits. Staphylococcus epidermidis fits this scenario best. It’s a coagulase-negative staphylococcus commonly found on the skin and mucous membranes. When a prosthetic device such as an artificial heart valve or a CSF shunt is in place, S. epidermidis readily adheres to the surface and forms a biofilm—a protective, slime-covered community of bacteria. This biofilm shields the bacteria from antibiotics and the immune system, allowing a low-grade, chronic infection around the device. Because of these traits, S. epidermidis is the leading cause of prosthetic device infections. The other organisms listed are less typically involved in this setting: Streptococcus mutans is mainly linked to dental caries, Corynebacterium urealyticum to urinary tract infections, and Staphylococcus capitis, while a skin inhabitant, is not the principal cause of prosthetic device infections.

In device-associated infections, organisms that live on skin and can cling to artificial surfaces and persist there are the usual culprits. Staphylococcus epidermidis fits this scenario best. It’s a coagulase-negative staphylococcus commonly found on the skin and mucous membranes. When a prosthetic device such as an artificial heart valve or a CSF shunt is in place, S. epidermidis readily adheres to the surface and forms a biofilm—a protective, slime-covered community of bacteria. This biofilm shields the bacteria from antibiotics and the immune system, allowing a low-grade, chronic infection around the device. Because of these traits, S. epidermidis is the leading cause of prosthetic device infections. The other organisms listed are less typically involved in this setting: Streptococcus mutans is mainly linked to dental caries, Corynebacterium urealyticum to urinary tract infections, and Staphylococcus capitis, while a skin inhabitant, is not the principal cause of prosthetic device infections.