Wound Culture, Mycobacterium

CPT CODE: 87206; 87015; 87116
TEST INFORMATION: Test includes culture and acid-fast stain (if specimen volume is adequate). Culture includes decontamination and concentration. If a mycobacterial species is isolated, the organism will be definitely identified. Susceptibility testing will be performed depending upon the isolate identification.
TURNAROUND TIME: Smear results: 24 hours after receipt of the specimen in the laboratory. Preliminary culture reports are available after 1 week or when a mycobacterial isolate is detected. Negative cultures with negative smears will be finalized after 8 weeks. Negative cultures with positive smears will be finalized after 12 weeks. Completion of culture reports may require additional time when mycobacteria are isolated and/or susceptibility testing is performed.
SPECIAL INSTRUCTIONS: The specific anatomic site of the specimen MUST be specified on the requisition.
CONTAINER TYPE: Copan® II swab, sealed sterile container
COLLECTION: The specimen of choice is an aspirate or tissue, NOT a swab. Specimens are to be collected from a site prepared utilizing aseptic technique. Overlying and adjacent areas must be carefully prepared to eliminate surface (normal flora) organisms. Ideally, material is obtained by needle aspiration through an intact surface, which has been cleaned with antiseptic. Sampling of open lesions is enhanced by deep aspiration using a sterile plastic catheter. Curetting of the base of an open lesion is optimal. If irrigation is necessary, nonbacteriostatic sterile saline may be used. When a syringe is used to obtain the specimen, ALL air should be expelled after which the specimen should be injected into a sealed sterile container. Swabs should be used as a last resort due to the small volume of specimen obtainable by this method. If a swab must be used, sample the advancing margin of the lesion and abscess walls firmly. Do NOT sample pus or exudate ONLY. Contamination with normal flora from skin or other body sources MUST be avoided since colonizing bacteria not involved in the infectious process may be introduced into the sample.
SPECIMEN REQUIREMENTS: Pus or other purulent fluid material appropriately obtained from a wound.
REJECTION CRITERIA: Inappropriate specimen container, insufficient specimen volume, specimen received in a preservative. Only three specimens per body site with negative acid-fast smears will be processed. Subsequent specimens will be rejected. Specimens from known positive patients will be accepted only once a week for culture and smear per body site.
MINIMUM VOLUME: 0.5 mL or two swabs
HANDLING INSTRUCTIONS: Specimen should be transported as soon as possible. When transportation is delayed, refrigerate.
REFERENCE RANGE: No acid-fast bacilli observed on smear or isolated in culture
LIMITATIONS OF TEST: A single negative smear does not rule out the presence of mycobacterial infection.
METHODOLOGY: Acid-fast smear: fluorochrome stain. Culture: inoculation of conventional culture media and a rapid medium for automated continuous analysis.

ADDITIONAL INFORMATION: DNA probes may be incorporated to aid with more rapid identification of mycobacterial isolates. This will generate an additional charge(s). Susceptibility testing will be performed only on the first Mycobacterium isolate from each specimen type per patient. Additional susceptibilities may be performed after a period of 4 weeks for patients with suspected treatment failure. Susceptibility testing is performed routinely only for M. tuberculosis complex, M. kansasii, M. chelonae complex, and M. fortuitum. Susceptibility testing for other Mycobacterium species is performed by special request only. The battery of drugs routinely tested will vary by isolate and/or physician request. Patients from whom M. tuberculosis is isolated in culture are reported to the City of Chicago Board of Health. This is mandated by law.
TEST SYNONYM(S):AFB Culture, Wound; Mycobacterium Culture, Wound