Mycobacterium chimaera

Mycobacterium chimaera is a species of bacteria that belongs to the Mycobacterium avium complex (MAC). It is a slow-growing, non-tuberculous mycobacterium (NTM) that was first identified in 2004.

Characteristics

Mycobacterium chimaera is a Gram-positive, acid-fast bacterium. It is aerobic and non-motile. The bacterium is capable of surviving in a wide range of environments, including water and soil.

Pathogenesis

Mycobacterium chimaera primarily causes lung disease in individuals with pre-existing lung conditions or compromised immune systems. However, it can also cause disseminated disease, affecting multiple organs and systems in the body. The bacterium is resistant to many common antibiotics, making infections difficult to treat.

Transmission

The primary route of transmission for Mycobacterium chimaera is through the inhalation of aerosolized water droplets containing the bacteria. It has been associated with contaminated water sources, including tap water and heater-cooler units used in cardiac surgery.

Diagnosis

Diagnosis of Mycobacterium chimaera infection is typically made through culture of a patient's sputum or tissue samples. The bacterium is slow-growing, so it may take several weeks for it to be detected in culture. Molecular testing methods, such as polymerase chain reaction (PCR), can also be used to identify the bacterium.

Treatment

Treatment of Mycobacterium chimaera infections typically involves a combination of antibiotics over a long period of time, often lasting more than a year. The choice of antibiotics is guided by antimicrobial susceptibility testing.

Epidemiology

Mycobacterium chimaera has been identified in patients worldwide, with notable outbreaks occurring in Europe and North America. The bacterium has been associated with heater-cooler units used in cardiac surgery, leading to infections in patients undergoing these procedures.

See also

• Mycobacterium avium complex
• Non-tuberculous mycobacteria
• Heater-cooler unit

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