What test result is positive for S. epidermidis, indicating a particular metabolic ability?

Staphylococcus epidermidis is known for its unique metabolic abilities, one of which is the ability to produce urease. A positive urease test indicates the organism can hydrolyze urea to ammonia and carbon dioxide, which raises the pH of the medium. This is particularly relevant in the context of distinguishing S. epidermidis from other Staphylococcus species that do not exhibit urease activity.

Understanding the metabolic capabilities of S. epidermidis can help identify and differentiate it from other bacteria in clinical settings. This is crucial because coagulase-negative staphylococci like S. epidermidis are often associated with infections related to implanted medical devices due to their ability to form biofilms. In contrast, the other tests listed pertain to different metabolic activities: the catalase test assesses the organism’s ability to break down hydrogen peroxide, the coagulase test distinguishes between S. aureus and other Staphylococcus species, and lactose fermentation is more commonly associated with the identification of enteric bacteria rather than staphylococci. Thus, the positive urease result in S. epidermidis specifically indicates its metabolic proficiency in utilizing urea.