Elizabethkingia meningoseptica

Elizabethkingia meningoseptica is a species of bacteria that is predominantly associated with hospital-acquired infections (HAIs), particularly among immunocompromised patients. This bacterium is named after the American bacteriologist Elizabeth O. King, who first described it in the mid-20th century. E. meningoseptica is known for its resistance to multiple antibiotics, making infections difficult to treat and leading to significant morbidity and mortality rates in affected populations.

Characteristics

E. meningoseptica is a Gram-negative, rod-shaped, non-motile bacterium. It is also oxidase-positive and catalase-positive, characteristics that are used in laboratory identification. This bacterium can be found in various environmental reservoirs, including soil, water, and hospital environments, where it can colonize medical devices such as ventilators and intravenous catheters.

Pathogenesis

The pathogenic mechanisms of E. meningoseptica are not fully understood, but the bacterium is capable of causing a wide range of infections. These include meningitis, especially in newborns; bacteremia; pneumonia; and soft tissue infections. Its ability to form biofilms on medical devices significantly contributes to its pathogenicity and resistance to antibiotics.

Clinical Manifestations

Infections caused by E. meningoseptica can present with a variety of symptoms depending on the site of infection. Meningitis caused by this bacterium is characterized by fever, headache, stiff neck, and altered mental status. Bacteremia may present with fever and signs of sepsis, while pneumonia can lead to cough, fever, and difficulty breathing.

Diagnosis

The diagnosis of E. meningoseptica infections involves the isolation of the bacterium from clinical specimens such as blood, cerebrospinal fluid, or respiratory secretions. Identification is based on the bacterium's characteristic growth on culture media and its biochemical properties. Molecular methods, such as PCR, can also be used for rapid identification.

Treatment

Treatment of E. meningoseptica infections is challenging due to its intrinsic resistance to many commonly used antibiotics, including beta-lactams, aminoglycosides, and fluoroquinolones. Combination therapy with antibiotics to which the bacterium is susceptible, such as rifampicin and minocycline, may be effective. The choice of antibiotics should be guided by susceptibility testing.

Prevention

Prevention of E. meningoseptica infections in healthcare settings involves adherence to strict infection control practices, including hand hygiene, sterilization of medical devices, and the use of sterile water for the preparation of solutions. Surveillance and prompt identification of outbreaks are also crucial for preventing the spread of this bacterium.

Epidemiology

E. meningoseptica is a relatively rare cause of infections but has been reported worldwide, with outbreaks occurring in hospital settings. Immunocompromised patients, including those with cancer, diabetes, or undergoing transplantation, are at higher risk of developing infections.