Specimen Requirements

For diagnostic purposes, clinical specimens should be collected before the initiation of therapy since even a few days of treatment may render the culture negative.

 

Submit only 1 of the following specimens:

 

Abscess Contents, Aspirated Pus, Wounds
1. Aseptically aspirate as much material as possible into a screw-capped, sterile container. (Specimen submitted in formalin is not acceptable.)

2. A second set of cultures should be submitted for Mycobacterium which grow at lower temperatures.
3. Label container with patient’s name (first and last), date and actual time of collection, and type of specimen.
4. Maintain sterility and forward promptly.
Note:  Specimen source is required on request form for processing.

 

Body Fluids
1. Disinfect site with alcohol if collecting by needle and syringe.
2. Aseptically collect >3 mL of fluid by aspiration or during surgical procedure in a screw-capped, sterile container or in a syringe with a Luer-tip cap.

3. Label container with patient’s name (first and last), date and actual time of collection, and type of specimen.
4. Maintain sterility and forward promptly.
Note:  Specimen source is required on request form for processing.

 

Bronchial Aspirate, Bronchial Lavage, or Bronchial Washings
1. Aseptically collect >1 mL of bronchial aspirate in a sterile sputum trap or bronchial lavage or bronchial washings in a screw-capped, sterile container.
2. Avoid contaminating bronchoscope with tap water.
3. Saprophytic mycobacteria may produce false-positive culture or smear results.
4. Label container with patient’s name (first and last), date and actual time of collection, and type of specimen.
5. Maintain sterility and forward promptly.
Note:  Specimen source is required on request form for processing.

 

Bronchial Brushings
1. Submit bronchial brushings in a screw-capped, sterile container.
2. Label container with patient’s name (first and last), date and actual time of collection, and type of specimen.
3. Maintain sterility and forward promptly.
Note:  Specimen source is required on request form for processing.

 

Gastric Lavage Fluids
1. Gastric lavage specimens should be reserved for those circumstances where specimens cannot be obtained by other methods, such as pediatric patients.
2. Collect a fasting, early-morning specimen on 3 consecutive days at least 8 hours after the patient has eaten or taken oral drugs as follows:
A. Obtain 5 mL to 10 mL of gastric lavage fluid in a screw-capped, sterile container in the morning soon after patient awakes in order to obtain sputum swallowed during sleep.
B. Using sterile saline, adjust to neutral pH with 1.5 mL of 40% anhydrous disodium phosphate per 35 mL to 50 mL of gastric washing immediately following collection. (Specimen that has not been neutralized is not acceptable. Long-term exposure to acid is detrimental to mycobacteria.)
3. Label container with patient’s name (first and last), date and actual time of collection, and type of specimen.
4. Maintain sterility and forward promptly.
Note:  Specimen source is required on request form for processing.

 

Sputum

Specimen must arrive within 2 hours of collection.

Expectorated
1. Under direct supervision of a nurse or physician, collect an early-morning specimen on at least 3 consecutive days in a screw-capped, sterile container as instructed below. (Pooled sputum specimens are not acceptable.)

A. Instruct patient to brush his/her teeth and/or rinse mouth well with water to minimize contaminating specimen with food particles, mouthwash, or oral drugs which may inhibit the growth of mycobacteria.

B. Have patient remove dentures.

C. Instruct patient to take a deep breath, hold it momentarily, then cough deeply and vigorously into container, and collect 5 mL to 10 mL of discharged material.
2. Label container with patient’s name (first and last), date and actual time of collection, and type of specimen.
3. Maintain sterility and forward promptly.
Note:  Specimen source is required on request form for processing.

 

Induced
1. Collect an early-morning specimen on at least 3 consecutive days in a screw-capped, sterile container.

2. Instruct patient to brush his/her teeth and/or rinse mouth well with water to minimize contaminating specimen with food particles, mouthwash, or oral drugs which may inhibit the growth of mycobacteria.

3. With the aid of nebulizer, have patient inhale 25 mL of 3% to 10% sterile saline.

4. Collect induced sputum in a screw-capped, sterile container.

5. Avoid sputum contamination with nebulizer reservoir water.

6. Saprophytic mycobacteria in tap water may produce false-positive culture or smear results.
7. Label container with patient’s name (first and last), date and actual time of collection, and type of specimen.
8. Maintain sterility and forward promptly.
Note:  1. Indicate on request form if specimen is induced sputum, as these watery specimens resemble saliva and risk rejection as inadequate.
2. Specimen source is required on request form for processing.

 

Stool
1. 1 g of stool in a screw-capped, sterile, wax-free, disposable container as follows:
A. Collect specimen directly into container or transfer from bedpan or plastic wrap stretched over toilet bowel.
B. Wax from container may produce a false-positive smear.
2. Label container with patient’s name (first and last), date and actual time of collection, and type of specimen.
3. Maintain sterility and forward promptly.
Note:  1. Utility of culturing stool for AFB remains controversial.
2. Specimen source is required on request form for processing.

 

Tissue (Lymph Node, Skin, Other Body Material)
1. Aseptically collect 1 g of tissue, if possible, in a screw-capped, sterile container without fixative or preservative avoiding indigenous microbiota. (Specimen submitted in formalin is not acceptable.) Select caseous portion if available.
2. Do not immerse in saline or other fluid or wrap in gauze.
3. Label container with patient’s name (first and last), date and actual time of collection, and type of specimen.
4. Maintain sterility and forward promptly at ambient temperature only. Freezing decreases yield.
Note:  1. Minute amounts of biopsy may be immersed in small amounts of saline.

2. Specimen source is required on request form for processing.

 

Urine
Collect first-morning specimen on 3 consecutive days for the clean-catch specimen. Only 1 specimen/day will be accepted. Organisms accumulate in bladder overnight, so first-morning void provides the best yield. Specimens collected at other times are dilute and are not optimal.
 
1. Collect a clean-catch, midstream urine specimen as follows:

 

Males
A. Prepare obstetrical Towelettes® by opening packages (do not remove Towelettes® until ready to use), and place them on sink. Take top off of plastic urine container, and set it on edge of sink. Set Towelettes® and container so that they can be reached while urinating.
B. Holding back foreskin with 1 hand, if necessary, use first Towelette® to wash end of penis. Discard the first Towelette® in wastebasket.
C. Continue holding back foreskin; and gently rinse end of penis using second and third Towelette®, discarding them in wastebasket when done.
D. Continue holding back foreskin, and begin to urinate into the toilet.
 
Females
A. Prepare obstetrical Towelettes® by opening packages (do not remove Towelettes® until ready to use), and place them on sink. Take top off of plastic urine container, and set it on edge of sink. Set Towelettes® and container so that they can be reached while urinating.

B. Pull panties below the knees so they will not interfere with urine collection. With 2 fingers of 1 hand, hold outer folds of vagina apart. With other hand, gently wash vaginal area from front to back, using first Towelette®. After this step, throw away first Towelette® in wastebasket.
C. Still holding outer vaginal skin away from opening through which urination takes place, rinse area from front to back using Towelette® #2, discard, and then repeat with Towelette® #3.

D. Continue holding outer vaginal folds apart and begin to urinate into toilet. Lean slightly forward so that urine flows directly down without running along skin.

2. After first few teaspoons, place screw-capped, sterile container under stream of urine; and collect as much urine as possible (minimum:  50 mL). (Specimen <40 mL, unless larger volume is not obtainable, is not acceptable.)
3. After finishing, tighten cap on container securely; and wash any spilled urine from outside of container.
4. Label container with patient’s name (first and last), date and actual time of collection, and type of specimen.
5. Send specimen refrigerated. Maintain sterility and forward promptly.

Note:  1. 24-Hour urine specimen is not acceptable.
2. Specimen source is required on request form for processing.