Infectious Disease and Microbiology – Corynebacterium jeikeium

Overview

Corynebacterium jeikeium is an uncommon aerobic Gram-positive bacillus that acts mainly as an opportunistic pathogen. Infection is seen most often in patients with significant immunosuppression, particularly those with neutropenia or advanced HIV infection.

Microbiologic Characteristics

C. jeikeium is an aerobic, Gram-positive bacillus belonging to the genus Corynebacterium.

It is generally considered a low-frequency pathogen but can cause serious invasive disease in susceptible hosts.

Epidemiology

C. jeikeium infection is rare and occurs worldwide.

The organism is encountered primarily in hospitalized or immunocompromised patients, especially those with impaired host defenses or indwelling vascular devices.

Risk Groups

Clinically significant infection is most strongly associated with immunosuppression.

Important risk groups include:

• Patients with neutropenia

• Patients with advanced HIV infection

• Patients with prolonged hospitalization

• Patients with central venous catheters or other intravascular devices

Clinical Infections

C. jeikeium can cause several serious infections in vulnerable patients.

Sepsis

Bloodstream infection may progress to sepsis, particularly in severely immunocompromised patients.

Patients may present with fever, hypotension, systemic inflammatory findings, and other signs of invasive infection.

Endocarditis

C. jeikeium may cause infective endocarditis, especially in patients with underlying risk factors such as prosthetic material, prolonged bacteremia, or intravascular devices.

Central Venous Catheter-Associated Infection

Central venous catheters are an important potential source of infection.

Catheter-associated disease may present with:

• Persistent fever

• Positive blood cultures

• Local catheter-site inflammation

• Bacteremia or sepsis

Removal of an infected catheter may be required in addition to antimicrobial therapy.

Pneumonia

C. jeikeium can occasionally cause pneumonia, particularly in immunosuppressed patients.

Clinical manifestations may include fever, cough, dyspnea, hypoxemia, and pulmonary infiltrates.

Meningitis

Although uncommon, C. jeikeium can cause meningitis, particularly in patients with severe immune compromise.

This represents a serious invasive manifestation requiring prompt antimicrobial treatment.

Diagnosis

Diagnosis is made by culture from the appropriate clinical specimen.

Potential specimens include:

• Blood

• Catheter-related samples

• Cerebrospinal fluid

• Respiratory specimens

• Other normally sterile-site samples

Because corynebacteria may sometimes be dismissed as contaminants, repeated isolation of C. jeikeium in a compatible clinical setting should be taken seriously.

Treatment

Vancomycin is the principal treatment for serious C. jeikeium infection.

This is particularly important because the organism may show resistance to multiple other antimicrobial classes.

Additional Treatment

An alternative regimen described in older sources is:

Penicillin G combined with an antipseudomonal aminoglycoside

However, treatment should ideally be guided by antimicrobial susceptibility testing, especially in severe invasive disease.

High-Yield Clinical Pattern

Immunocompromised or neutropenic patient

• ●

Central venous catheter or prolonged hospitalization

• ●

Gram-positive bacillus in blood cultures

→ Consider Corynebacterium jeikeium

Exam Essentials

Organism: Corynebacterium jeikeium

Type: Aerobic Gram-positive bacillus

Epidemiology: Rare, worldwide infection

Major risk groups: Neutropenic and immunosuppressed patients

Important infections: Sepsis, endocarditis, catheter-associated infection, pneumonia, meningitis

Diagnosis: Culture

First-line treatment: Vancomycin

Alternative: Penicillin G plus an antipseudomonal aminoglycoside

Key clinical pearl: Corynebacterium jeikeium should not automatically be dismissed as a contaminant when isolated from a seriously immunocompromised patient, particularly when bacteremia or a central venous catheter infection is suspected.