Pathology

Mycobacteria Concentrated Culture
AFB Smear

Mycobacterial [AFB] culture; AFB smear reported.

Sputum early morning deep cough to produce lower respiratory specimen; bronchioalveolar lavage; stool, urine, CSF, tissues, body fluids, gastric aspirates
For blood, see AFB blood cultures.

Transport at ambient temperature to Microbiology Laboratory within one hour.

Phone report of isolation of acid fast organisms.

Use of non sterile container; delay in transport; improper labeling; leaking container; swab specimen; insufficient quantity

Preliminary negative reports at end of weeks 2 and 4. Final negative report at 6 weeks. Positive reports with isolation and with identification.

Specimens are currently sent to reference laboratory for concentration, smear (non-STAT) and culture. AFB isolates are identified at reference laboratory.

Suspected mycobacterial infection.

GASTRIC ASPIRATES (Pediatric patients only) must arrive in the lab within one hour of collection to allow for appropriate neutralization. Specimens received greater than one hour will be rejected.

Online ordering

Observe for complications of collection procedure.

SPUTUM [EXPECTORATE] See Collection Guidelines for Common Specimens. SPUTUM [INDUCED] The patient should rinse their mouth with water after brushing gums and tongue. With the aid of a nebulizer, have the patient inhale about 25 mL of 3 10% sterile saline. This should produce a deep coughing. Collect the specimen into a sterile container. PEDIATRIC patients may require collection by suction; contact Respiratory Care. TRACHEAL ASPIRATES Collected through a tracheostomy or endotracheal tube. Pass a catheter through the site and into the trachea. Aspirate material from the trachea using a syringe or suction device. Remove the catheter and disengage the syringe or suction device. Place the specimen in a sterile container. STOOL Pass directly into clean dry container. Do not contaminate with urine. Select portions containing pus, blood, or mucus. Submit a second specimen on a separate day to increase probability of isolation of pathogen. CLEAN CATCH URINE See Collection Guidelines.

No acid fast bacilli isolated

Not all mycobacteria will grow on routine media. Notify laboratory if M. bovis or BCG, M. haemophilum or M. leprae is suspected, as these may require extended incubation and/or special media. Certain microorganisms may overgrow the media, preventing successful culture.

Reference laboratory performs susceptibility test of initial M. tuberculosis isolates automatically. For other mycobacterial susceptibility tests, contact the Microbiology Laboratory. Three first morning sputums are recommended to adequately exclude pulmonary tuberculosis.