26584 Mycoplasma (Mycoplasmoides) pneumoniae Macrolide (Azithromycin) Resistance Prediction, Molecular Detection, PCR, Varies (RPMPM)

Mycoplasma pneumoniae, Mycoplasmoides pneumoniae​​

​Predicting macrolide susceptibility in Mycoplasma (Mycoplasmoides) pneumoniae

​Specimen source is required; include the specific anatomic source. 

This test should only be ordered on specimens that have tested positive for Mycoplasma (Mycoplasmoides) pneumoniae. This assay predicts M pneumoniae macrolide (Azithromycin) resistance only.

Swab Collection Instructions: 

1. Collect specimen by swabbing back and forth over mucosa surface to maximize recovery of cells.

2. Place swab back into swab cylinder. ​

Cotton or calcium alginate-tipped swab, wooden shaft swab, transport swab containing gel or charcoal

Port-a-Cul tube

Anaerobic fluid vials

Dry swab (no pledget or sponge)

Respiratory fluid specimens placed in viral transport medium (VTM) or placed on a swab and then into VTM (M4-RT, M4, or M5)

Body fluid specimens placed in viral transport medium (VTM) or placed on a swab and then in VTM (M4-RT, M4, or M5)​

​​This assay should only be used for testing of respiratory tract specimens (throat swabs, nasopharyngeal swabs, tracheal secretions, sputum, and bronchoalveolar lavage fluid) and pleural/chest fluid, pericardial fluid, and cerebrospinal fluid that has already tested positive for Mycoplasma (Mycoplasmoides)pneumoniae using a nucleic acid amplification test.

Test results should be used as an aid in the diagnosis. The single assay should not be used as the only criterion to form a treatment decision; results of this test should be correlated with clinical presentation and results of other laboratory tests. A negative result does not negate the presence of the organism or active disease.

Rarely encountered Mycoplasma species may be detected with this assay when present at high concentrations, however this assay is intended to be used as reflex for previously identified M pneumoniae positive samples. Therefore, cross reactivity with other Mycoplasma species is not a major concern.

This assay examines the two most common 23S ribosomal RNA single point variants associated with high-level macrolide resistance. Other mechanisms of macrolide resistance are not assessed nor are mechanisms of resistance to non-macrolide antimicrobial agents.

​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. 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.

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. 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. In a study performed at Mayo Clinic, 10% of M pneumoniae detections were associated with macrolide resistance.

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.

​A macrolide resistance predicted or not predicted result indicates the presence of Mycoplasma (Mycoplasmoides) pneumoniae 23S ribosomal RNA (rRNA) gene and indicates whether one of the 2 most common 23S rRNA gene single nucleotide variations (A2064G and A2063G) associated with high-level macrolide resistance is predicted.

An "unable to assess" result for M pneumoniae macrolide resistance indicates the absence of detectable M pneumoniae 23S rRNA DNA but does not negate the presence of the organism and may occur due to inhibition of the polymerase chain reaction, sequence variability underlying primers or probes, or the presence of M pneumoniae 23S rRNA DNA in quantities less than the limit of detection of the assay.