Clinical Information

Mycoplasma (Mycoplasmoides) pneumoniae is a small bacterium transmitted via organism-containing droplets. It is a cause of upper respiratory infection, pharyngitis, and tracheobronchitis, particularly in children, and has been associated with approximately 20% of cases of community acquired pneumonia.(1) Central nervous system and cardiac manifestations are some of the extrapulmonary complications of infections due to M pneumoniae. The disease is usually self-limited although severe disease may occur, including in patients who are immunocompromised.(2)

Macrolide resistance in M pneumoniae has steadily increased since the early 2000s. Reports suggest over 90% of M pneumoniae isolates are now macrolide resistant in areas of Japan and China, with macrolide resistance also noted in other countries.(3) Macrolides are a common treatment for respiratory tract infections and M pneumoniae. Resistance in M pneumoniae typically corresponds to single point mutations in the 23S ribosomal RNA of the 50S bacterial ribosomal subunit. Among the reported point mutations, mutations at positions 2064 and 2063 are the most common and confer to high-level macrolide resistance.(3) In a study performed at Mayo Clinic, 10% of M pneumoniae detections were associated with macrolide resistance.(4)

Culture, serologic testing, and molecular-based techniques can be used to detect M pneumoniae infection. While detection of macrolide resistance may be determined through culture methods (with antimicrobial susceptibility testing), it is impractical due to the organism’s slow and fastidious growth requirements. Real-time polymerase chain reaction testing can be used to assess for common mutations associated with macrolide resistance in M pneumoniae.