Staphylococcus Epidermidis: Symptoms & Treatment

Staphylococcus epidermidis (S. epidermidis) is a gram-positive bacterium that normally lives harmlessly on the skin. Under normal conditions, it stays balanced and does not cause illness.

However, it is considered an opportunistic pathogen because it can cause infections when the immune system is weakened. This is particularly common in hospitalized patients, as the bacterium can grow on medical devices and enter the bloodstream.

Once it spreads through the blood, it may cause symptoms such as fever, headache, and general discomfort. To confirm the infection and determine the best treatment, a doctor may perform tests like a coagulase test or blood culture.

Main symptoms

The main symptoms of Staphylococcus epidermidis infection are:

• High fever.

• Severe tiredness.

• Headache.

• General malaise.

• Low blood pressure.

• Shortness of breath or difficulty breathing.

When bacteria enter the bloodstream through a device such as a joint prosthesis, the person may develop local symptoms like inflammation, redness, and pus around the site of the prosthesis or catheter.

If the bacteria affect a prosthetic heart valve, they can cause infective endocarditis, which often leads to symptoms such as fever, chills, fatigue, night sweats, and shortness of breath.

Is Staphylococcus epidermidis dangerous?

A Staphylococcus epidermidis infection can be dangerous if it is not controlled early.

This is because the bacteria can quickly spread through the bloodstream and reach other organs, causing widespread inflammation that is harder to control and may put the person’s life at risk.

Transmission and spread

Staphylococcus epidermidis is a common skin bacterium that normally exists in small numbers and does not cause disease. However, it can contaminate medical devices such as catheters, prostheses, and cardiac or orthopedic implants.

The Centers for Disease Control and Prevention (CDC) notes that bloodstream infections may occur when microorganisms enter the bloodstream through a central line or another contaminated medical device, highlighting the same risk associated with these instruments.

Once S. epidermidis adheres to a device surface, it can spread into the bloodstream and multiply, especially in people with weakened immune systems.

Confirming a diagnosis

The diagnosis of Staphylococcus epidermidis is made in the laboratory using specific tests, particularly the coagulase test, which helps differentiate it from Staphylococcus aureus. Since S. epidermidis does not produce the coagulase enzyme, it is classified as coagulase-negative. Additional lab tests may be performed to confirm the species identification.

However, detecting S. epidermidis in a blood sample does not always indicate an active infection. Because this bacterium naturally lives on the skin, it can contaminate blood samples during collection. In such cases, the result is considered sample contamination rather than a true bloodstream infection. To ensure an accurate diagnosis, two or more blood cultures are usually collected from different sites to help avoid false results.

A diagnosis of S. epidermidis infection is confirmed when all blood cultures test positive for this microorganism. If only one culture is positive for S. epidermidis while others grow different bacteria, the finding is typically interpreted as contamination.

Antibiotic resistance

In many cases, sample contamination by Staphylococcus epidermidis is mistakenly interpreted by laboratories as a true infection. As a result, healthcare providers may prescribe antibiotics for an “infection” that is not actually present.

According to the World Health Organization (WHO), unnecessary and excessive antibiotic use is a major driver of antimicrobial resistance, which makes future infections harder to treat. Currently, S. epidermidis infections are becoming more common among hospitalized patients, increasing their clinical significance.

This situation stems not only from the overuse of antibiotics but also from the bacterium’s ability to form a biofilm on medical devices. The biofilm supports bacterial growth and further increases resistance to treatment.

Treatment options

Treatment of Staphylococcus epidermidis infection typically involves the use of antibiotics. The choice of antibiotic depends on the specific characteristics of the bacterial strain, as many strains have developed resistance mechanisms.

For this reason, healthcare providers often prescribe antibiotics such as vancomycin or rifampin. Treatment is recommended only when an infection is confirmed. If contamination of the sample is suspected, new samples should be collected to determine whether the finding represents contamination or a true infection.

When S. epidermidis colonizes catheters or prosthetic devices, replacing the affected device is usually necessary. Some hospitals also use antiseptic-coated medical equipment to prevent biofilm formation and limit the growth of S. epidermidis, which helps reduce the risk of infection.