AFB Culture & Stain
Test Mnemonic
AFC
CPT Codes
- 87116 - QTY (1)
- 87206 - QTY (1)
- 87015 - QTY (1)
Aliases
- Acid-fast Bacilli Culture and Stain
- TB Culture and stain
Performing Laboratory
Cleveland Clinic Laboratories
Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|---|---|---|---|---|
| 10 mL | Bronchoscopy specimen | Sterile container | Ambient | Larger volumes improve recovery. Collect BAL, wash, or aspirate into sputum trap or sterile cup. Volume: at least 10 mL (preferred). Place bronchial brush in sterile, leak-proof tube or cup with enough non-bacteriostatic sterile saline to cover the brush (1-10 ml). Transfer temperature is ambient. Refrigeration is preferred if transport is delayed longer than 2 hours. | |
| 10 mL | Aspirate, tracheal | Sterile container | Ambient | Larger volumes improve recovery. Refrigeration is preferred if transport is delayed longer than 2 hours. Volume 5-10 mL (preferred). | |
| 1 - 5 g | Tissue | Sterile container | Ambient | Biopsy material from the periphery of a cutaneous lesion. Tissue may be kept moist with a small amount (1-3 ml) of sterile saline. Send a separate portion for histopathology using sterile technique. Tissue in formalin is unacceptable for culture. Transport temperature is ambient. Refrigeration is preferred if transport is delayed longer than 2 hours. | |
| 5 mL | Sputum | Sterile container | Refrigerated | Sputum may be expectorated or induced. Collection of 3 sputum specimens at least 8 hours apart with at least one first morning specimen is recommended. Refrigeration is preferred if transport is delayed longer than 2 hours. Volume: 5 mL (preferred); 1 mL minimum. | |
| 10 mL | Fluid, body | Sterile container | Ambient | Aspirate pleural, pericardial, peritoneal, or synovial fluid using sterile technique after skin disinfection or during surgical procedure. Transfer fluid to sterile tube or cup. Transport temperature is ambient. Refrigeration is preferred if transport is delayed longer than 2 hours. Volume: 10-15 mL (preferred); 1 mL minimum. | |
| Unspecified | Aspirate(s) | Sterile container | Ambient | Larger volumes improve recovery. Aspirate from closed abscess to surface using sterile technique after skin disinfection. Aspirate from both the center and wall of the abscess. For open wounds remove exudate by rinsing with sterile saline. Collect specimen from margin of lesion or abscess using a syringe. If specimen volume is small, instilling a small volume of sterile, non-bacteriostatic saline into the lesion may aid collection. Transfer specimen to sterile tube or submit in syringe after removing needle and capping. Swabs are unacceptable. Refrigeration is preferred if transport is delayed longer than 2 hours. | |
| Unspecified | Skin | Sterile container | Refrigerated | Skin scraping in sterile petri dish or sterile container with blade used to obtain specimen. | |
| 5 mL | Aspirate, gastric | Sterile container | Refrigerated | Patient must be fasting. Transport to Laboratory for receipt within 4 hours of collection. If specimen not received in lab within 4 hours, neutralize with (100 mg) sodium bicarbonate (pH 7). For increased sensitivity, collect specimens on 3 consecutive days. Refrigeration is preferred if transport is delayed longer than 2 hours. Volume: 5-10 mL (preferred). | |
| 40 mL | Urine, random | Sterile container | Ambient | Submit entire first morning void in sterile container without preservative. 40 mL preferred. For increased sensitivity, collect specimens on 3 consecutive days. Twenty-four hour collections are unacceptable. Patient Preparation: Usual preparation for clean-catch mid-void urine collection. Transport temperature is ambient. Refrigeration is preferred if transport is delayed longer than 2 hours. | |
| 5 mL | Cerebrospinal fluid (CSF) | Sterile container | Ambient | Culture yield is increased with larger specimen volumes. Specimen volumes between 0.5 and 2 mL will be processed with a disclaimer. Do not refrigerate if routine bacterial culture is performed on same CSF specimen. | |
| 1 g | Stool | Sterile container | Ambient | Pass stool and collect as for bacterial culture. Submit in sterile, leak-proof container, without preservatives. Transport temperature is ambient. Refrigeration is preferred if transport is delayed longer than 2 hours. |
Stability
| Environmental Condition | Description |
|---|---|
| Ambient | 24 hours |
| Refrigerated | 1 week |
| Frozen | Unacceptable |
Days Performed
Sun - Sat
Turnaround Time
7 weeks
Methodology
| Name | Description |
|---|---|
| Culture | |
| Stain | |
| DNA Probe Hybridization | |
| DNA Sequencing | |
| Matrix-assisted Laser Desorption Ionization Time-of-Flight (MALDI-TOF) Mass Spectrometry |
Reference Range
| AFB Culture | |||||
|---|---|---|---|---|---|
| Sex | Age From | Age To | Type | Range | Range Unit |
| Freetext | Negative for Mycobacteria Growth | ||||
| AFB Stain | |||||
| Sex | Age From | Age To | Type | Range | Range Unit |
| ~ | Freetext |
Special Info
Specimen collection methods should minimize contamination with respiratory, skin or urogenital flora. To prevent overgrowth of flora organisms, if specimen transport is delayed by more than 2 hours, specimens should be refrigerated. Frozen specimens are unacceptable. When sputum, stool or urine is collected in the outpatient setting, patients should be sent home with pre-labeled containers and instructed to record the collection time and date on the container and refrigerate until submission. Avoid use of tap water during specimen collection or transport as environmental mycobacteria present in water will cause false positive results. Tissue or fluid material is preferred to specimen collected with a swab. The hydrophobic mycobacterial cell wall may became trapped in swab fibers, preventing release into culture medium. Swabs provide a suboptimal volume of material and are only accepted with medical director approval.
Clinical Info
Culture is performed to identify an infection due to a mycobacterium. A single negative culture does not rule out the presence of a mycobacterial infection. Mycobacterial culture includes an acid fast stain and culture in liquid and on solid media. Stain results are reported within 24 hours of specimen receipt. Providers are notified of initial positive smear or culture results and any identification of M. tuberculosis. For AFB stain-positive sputum samples, PCR for detection of M. tuberculosis and rifampin resistance (rpoB) will be performed automatically. Rifampin resistant and indeterminate results require confirmatory sequencing; additional charges may apply. PCR for M. tuberculosis vs. non-tuberculous mycobacteria may be performed if AFB stain is positive when indicated from BAL, fresh tissue and other sample types. Cultures for mycobacteria are incubated for 6 weeks and updated, if negative, on a weekly basis. Extended incubation or other special requests must be approved in consultation with a medical director. Specimens from all skin sites and wounds, fluid, and tissues of the extremities are cultured at both 35°C and 30°C to optimize recovery of M. marinum, M. chelonae, M. haemophilum and M. ulcerans. If these species are otherwise suspected, please notify the laboratory. Mycobacteria grown in culture are identified to species. Susceptibility testing is performed automatically for M. tuberculosis and by request for other species. Multiple identification procedures may be required, with the following CPT codes billed as applicable: Cepheid PCR 87556 87798, MALDI-TOF 87118, DNA Probe 87149, Sequencing 87153, and Susceptibility Testing 87186.