Staphylococcus Epidermidis Gram Stain Overview

This bacterium has a spherical shape.

This organism stains positive on Gram stain due to thick peptidoglycan layer which absorbs crystal violet.

Characteristically, Staph epidermidisis is catalase-positive, meaning it produces the enzyme catalase. This enzyme allows the bacterium to convert hydrogen peroxide to water and oxygen. This characteristic is helpful in distinguishing Staphylococci from catalase-negative Streptococci and Enterococci.

This bacterium has the ability to produce urease, which hydrolyzes urea in the body to ammonia.

Staph epidermidis can be differentiated from other Staphylococcal organisms, such as Staph aureus, because Staph aureus is coagulase-positive, while Staph epidermidis is coagulase-negative.

Staphylococcus epidermidis is catalase- positive and coagulase-negative, but is sensitive to novobiocin. In comparison, Staphylococcus saprophyticus is novobiocin- resistant, but also catalase-positive and coagulase-negative.

Staphylococcus epidermidis is a gram- positive cocci that is part of the human skin flora.

Staphylococcus epidermidis is also a large concern with patients with catheters or other prosthetic devices, such as heart valves, because it is known to cause adherent biofilms that grow on the devices.

Because this organism is a component of normal skin flora, it is a common contaminant of blood cultures.

Staphylococcus epidermidis is also a large concern with patients with catheters or other prosthetic devices, because it is known to cause adherent biofilms that grow on the devices.