Corynebacterium jeikeium is a type of bacteria commonly found on human skin. While often harmless, it can become a serious threat under specific conditions. This bacterium is opportunistic, typically causing infections when a person’s immune system is weakened or when it gains access to parts of the body where it doesn’t normally reside. Such infections can be challenging to treat.
Understanding Corynebacterium jeikeium
Corynebacterium jeikeium is a rod-shaped, Gram-positive bacterium belonging to the genus Corynebacterium. It is an aerobic organism, requiring oxygen to grow. It is frequently found on human skin, especially in hospitalized individuals.
While typically harmless on the skin, C. jeikeium can become pathogenic under specific circumstances. It is a lipophilic species, requiring lipids for growth, which can sometimes complicate its detection in laboratory settings. The bacterium forms tiny, grayish-white colonies when grown on blood agar in a lab.
Infections Associated with Corynebacterium jeikeium
Corynebacterium jeikeium can cause a range of infections, particularly in susceptible individuals. Bloodstream infections, also known as bacteremia, are common, leading to general symptoms such as fever and chills.
The bacterium is also a known cause of endocarditis, an infection of the heart valves. Symptoms can include fatigue, fever, and heart murmurs. Skin and soft tissue infections may also occur, presenting as redness, swelling, and pain.
Infections related to medical devices are another significant concern. This includes infections of central venous catheters and prosthetic joints. The presence of these foreign bodies provides surfaces for the bacteria to attach and form biofilms, making them particularly difficult to eradicate.
Factors Increasing Risk
Several factors can increase an individual’s susceptibility to Corynebacterium jeikeium infections. People with weakened immune systems are particularly vulnerable, including cancer patients, organ transplant recipients, and individuals with HIV/AIDS. A compromised immune system makes it harder for the body to fight off opportunistic pathogens like C. jeikeium.
Prolonged hospitalization also elevates the risk, as healthcare environments can expose patients to various bacteria. The presence of invasive medical devices, such as central venous catheters, prosthetic heart valves, or shunts, provides a direct pathway for bacteria to enter the body and establish an infection. These devices can serve as surfaces for bacteria to adhere and multiply.
Extensive antibiotic use can disrupt the body’s normal microbial flora, creating an environment where C. jeikeium can overgrow and cause disease. When beneficial bacteria are suppressed, opportunistic pathogens have less competition and can proliferate more easily. Patients in a dormant “non-culturable” state may also acquire resistance to various antibiotics, making them harder to eliminate.
Diagnosis and Management
Diagnosing Corynebacterium jeikeium infections primarily involves laboratory culture of patient samples. Samples such as blood or tissue are collected and then grown in a laboratory to identify the specific bacterium causing the infection. Once the bacterium is isolated, antibiotic susceptibility testing, also known as an antibiogram, is performed. This test determines which antibiotics are effective against the specific strain of C. jeikeium.
Treating C. jeikeium infections can be challenging due to its common resistance to multiple antibiotics. Susceptibility testing is therefore crucial for guiding therapy, ensuring that the chosen antibiotic will be effective against the identified strain. Vancomycin is an antibiotic often found to be effective against C. jeikeium.
In addition to antibiotic therapy, removing infected medical devices is often a significant part of the management strategy. For instance, if a catheter is the source of a bloodstream infection, its removal can greatly aid in clearing the infection. Dormant C. jeikeium cells, which exhibit enhanced resistance to antibiotics, may be eliminated using photodynamic inactivation, a treatment that utilizes light to destroy the bacteria.