Specimen Submission for Diagnostic Testing
Public health department laboratory staff can forward approved specimens to CDC for specialized testing, including various assays for detecting and characterizing Mycoplasma pneumoniae. CDC uses molecular testing with multiplex real-time polymerase chain reaction (PCR) as the primary laboratory procedure for M. pneumoniae identification. CDC does not use culture or serological testing as routine diagnostic methods. Refer to the M. pneumoniae Diagnostic Methods for more information.
Listed below is information about providing specimens to the CDC laboratory for M. pneumoniae diagnostic testing. Note: certain tests, PCR and culture in particular, have better yields if specimen collection occurs before antimicrobial treatment starts.
Approved Specimen Types
CDC’s laboratory accepts any of the following types of specimens* for M. pneumoniae testing from public health department laboratories:
- Combined nasopharyngeal (NP) and oropharyngeal (OP) swabs in viral transfer media (VTM) or universal transfer media (UTM)
- NP swabs in VTM/UTM
- OP swabs in VTM/UTM
- NP aspirates
- Bronchial lavage (BAL) fluid
- Bronchial washings
- Cerebrospinal fluid (CSF)
- Purified nucleic acid
- Bacterial isolates
* Only if the specimen type does not fall within the category of “specimen rejection criteria” as outlined below
Specimen Rejection Criteria
CDC’s laboratory most commonly rejects specimens for M. pneumoniae testing for the following reasons:
- Specimens collected using calcium alginate swabs, cotton swabs, or swabs with wooden shafts
- Use only sterile Dacron, rayon, or nylon swabs with plastic shafts; if available, use flocked swabs
- Specimens not stored or transported at proper temperature
- Refer to Specimen Submission for shipment requirements
- Specimens with insufficient volume for testing
- 200 µL specimen volume is required for completion of diagnostic testing; additional volume is preferred for further testing such as isolate typing
- Inappropriate specimen type
- Specimens arriving with no, insufficient, or erroneous documentation
- Refer to Specimen Submission for required documentation
Specimen Collection Protocol
CDC’s Specimen Collection Guidelines Cdc-pdf[8 pages] detail how to collect tissue specimens, as well as upper (NP, OP) and lower (sputum, bronchial lavage fluid) respiratory tract specimens.
Request permission to swab patients for M. pneumoniae and other respiratory pathogen testing who meet at least one of the following criteria:
- Cough for ≥ 3 days and fever ≥ 100.0°F (reported or documented)
- Chest x-ray confirmed pneumonia
- Erythema multiforme, Stevens-Johnson syndrome, or toxic epidermal necrolysis
Collect an OP and NP swab specimen
Use only sterile Dacron, rayon, or nylon swabs with plastic shafts. If available, use flocked swabs. DO NOT use calcium alginate swabs or swabs with wooden sticks, as they may contain substances that inactivate some agents and inhibit some molecular assays.
For OP swab specimens:
Insert swab into the posterior pharynx and tonsillar areas. Rub swab over both tonsillar pillars and posterior oropharynx and avoid touching the tongue, teeth, and gums.
For NP swab specimens:
Insert flexible shaft swab through the nares parallel to the palate (not upwards) until it contacts the nasopharynx. Indications of contact include encountering resistance and the distance equaling that from the ear to the patient’s nostril. Gently rub and roll the swab.
During the Collecting a Nasopharyngeal Swab Clinical Specimen video the clinician collects samples by swabbing the posterior nasopharynx. While this video is not specific to M. pneumoniae, the swabbing technique is the same.
View information about how to submit specimens to CDC , including a test directory, submission forms, and shipping information.
For additional information on investigating unidentified respiratory disease outbreaks, visit the Unexplained Respiratory Disease Outbreaks website.