Acid-Fast (Mycobacteria) Broth-Based Culture and Smear
Acid-Fast (Mycobacteria) Broth-Based Culture and Smear
    
Number
182402
CPT
87015; 87116; 87206
Related Information
  • Acid-Fast (Mycobacteria) Antibiotic Susceptibilities
  • Organism Identification, Mycobacteria
    • Synonyms
    Blood Mycobacteria Culture ; Culture, Acid-Fast (Sputum, Tissue, Urine, and Gastric Contents) ; Culture, Blood, Mycobacteria ; Mycobacteria Culture (Sputum, Tissue, Urine, and Gastric Contents)
    Test Includes
    Mycobacteria culture (AFB) and smear when appropriate; smears are not performed on blood or when there is less than 2 mL of cerebrospinal fluid. Culture and identification (additional charges/CPT code[s] may apply). CPT coding for microbiology and virology procedures often cannot be determined before the culture is performed.
    Special Instructions
    Request test specifically. Not part of routine blood culture.
    Specimen
    First morning sputum (not saliva) (three separate specimens from three separate days are recommended), fasting gastric aspirate, induced sputum, whole blood, tissue, biopsy, bronchial aspirate, urine, skin, cerebrospinal fluid, bone marrow, body fluid, stool. Swabs of exudate from skin sources are acceptable, otherwise, swab specimens should not be submitted; collect an aspirate using sterile, nonbacteriostatic saline or other noninhibitory medium. Do not send syringe. It will be rejected.
    Volume
    5 mL sputum or respiratory aspirate, 5 mL gastric aspirate, 10 mL whole blood, 2 cm3 tissue, 50 mL urine, 5 mL CSF, 5 cc bone marrow, 50 mL body fluid, 10 mL stool, biopsy of skin
    Container
    Sterile container with tight screw-cap seal or green-top (heparin) tube or Isolator™
    Storage Instructions
    Refrigerate. If sample is to be split for other tests, specimen should be divided at the time of collection so that each portion is transported at the appropriate temperature.
    Causes for Rejection
    Inadequate quantity of specimen, including swab specimens without visible evidence of tissue present; inappropriate transport device, including syringes with attached needles; specimen received after leaking out of transport container into the specimen bag. Trach-suction devices will often leak if the cap with tubing is not removed and replaced by a solid cap. Specimen received after prolonged delay (usually more than 72 hours).
    Reference Interval
    No acid-fast organisms recovered
    Use
    Isolate and identify mycobacteria
    Limitations

    Biopsy or body fluid: Transbronchial biopsy cultures may be of assistance in diagnosing tuberculosis in sputum smear negative cases; however, sputum and bronchial washing cultures have a higher yield.1,2 In one study, only 2 out of 12 (16%) transbronchial biopsies were positive and in those cases the biopsy was not the only source of culture positive material.1

    Mycobacterium marinum may cause a localized cutaneous lesion that may be nodular, verrucous, ulcerative, or sporotrichoid, and which may rarely involve deeper structures. If it is suspected, the laboratory must be notified so that the culture may be incubated at an appropriate temperature (30°C).3 Mycobacterium marinum infection occurs in patients who have been exposed to the organism following cutaneous abrasion or penetrating injury while cleaning aquariums, clearing barnacles, and with other aquatic exposures.

    Likewise, there are two additional mycobacterial pathogens requiring special conditions for laboratory culture. Mycobacterium haemophilum, which causes a cutaneous, joint, or pulmonary infection in immunocompromised patients and lymphadenitis in children, requires special growth media and incubation temperature. Mycobacterium genavense has been recovered from disseminated infections in AIDS patients. It requires special acidulated media and extended incubation conditions. If either of these mycobacteria is suspected, the laboratory must be notified so that appropriate cultivation conditions can be initiated.

    Sputum: Bronchial washings are frequently diluted with topical anesthetics and irrigating fluids, but bronchoscopy still provides a high yield of positive specimens. Postbronchoscopy expectorated specimens may provide a better yield of organisms than those obtained during the procedure. Gastric aspirates yield organisms in <50% of cases of M. tuberculosis infection in children. Acid-fast stain of gastric aspirate has a sensitivity of 30% and provides a useful clinical diagnosis if positive.4 The yield of prebronchoscopy sputum was 75%, bronchial washings 66%, and postbronchoscopy sputum 58%. Bronchoscopy can, however, be an important adjunct to serial sputum collection in the definitive diagnosis of pulmonary infection due to mycobacteria.5,6

    Urine: Positive acid-fast stained smears with low numbers of organisms are not diagnostic, because of the presence of Mycobacterium smegmatis in genital secretions of normal patients.

    Stool: M. avium complex is commonly isolated from the stool of patients with AIDS and may contribute to diarrheal disease, but other agents must also be ruled out. Stool is rarely the specimen of choice for the primary diagnosis of mycobacterial infection.

    Methodology
    Broth-based (Bactec® or MGIT®) and conventional agar-based LJ culture. Culture is held for 6 weeks before negative is reported. Organisms are identified by conventional biochemicals, HPLC, and/or DNA probes. Concentrated smears are stained with auramine/rhodamine and read by fluorescence microscopy.

    Key (AFB = acid-fast bacilli):

    • Negative: no AFB observed in 300 fields at 400x magnification
    • Doubtful (±): 1-2 AFB per 300 fields at 400x magnification
    • 1+: 4-36 AFB per 100 fields at 400x magnification
    • 2+: 4-36 AFB per 10 fields at 400x magnification
    • 3+: 4-36 AFB per field at 400x magnification
    • 4+: >36 AFB per field at 400x magnification
    Additional Information

    Biopsy or body fluid: Occult infections with nontuberculous mycobacteria, particularly Mycobacterium avium and Mycobacterium intracellulare, occur in patients with acquired immune deficiency syndrome (AIDS).7 In some institutions, the incidence of isolation of non-Mycobacterium tuberculosis species, specifically M. avium complex, may exceed the rate of isolation of M. tuberculosis. Mycobacteria have been recovered from culture of Kaposi sarcoma and bone marrow specimens, in which the characteristic granulomatous reaction has been absent.8,9 Optimal isolation of mycobacteria from tissue is accomplished by processing as much tissue as possible for culture. Swabs should not be submitted.

    Tuberculous spondylitis represents 50% to 60% of all cases of skeletal tuberculosis. It is seen in children in developing countries and adults older than 50 years of age in the United States and Europe. Frequently, several vertebrae are involved and adjacent psoas muscle abscesses or paravertebral abscesses are not uncommon (“cold abscesses”). Colony counts obtained from bone biopsies are low; however, >90% are culture positive. The diagnosis of vertebral tuberculosis should be considered in all cases of unexplained spondylitis.

    Cases of sternal wound infection, early prosthetic valve endocarditis, infections complicating mammary augmentation surgery, and other cutaneous/subcutaneous infections have been attributed to rapidly growing mycobacteria.10,11 M. fortuitum is the most commonly implicated Mycobacterium in these infections, which are thought to be caused by local environmental strains rather than contaminated commercial surgical materials or devices. Rapidly growing mycobacteria often grow on routine bacterial culture media within the time allotted to incubating routine bacterial cultures. Such organisms may be misidentified as “diphtheroids” and disregarded as contaminants.

    Pleural effusions frequently yield positive cultures in cases of pulmonary tuberculosis. The diagnosis of peritoneal tuberculosis is difficult and is usually made at laparotomy or after a considerable delay. Tuberculosis should be considered in any patient with ascitic fluid and chronic abdominal pain.12 Peritoneal tuberculosis accounted for 11% of a series of cases of extrapulmonary tuberculosis reported by Alvarez and McCabe.13 Pericardial tuberculosis accounts for <5% of extrapulmonary tuberculosis and frequently requires biopsy for diagnosis. See table.

    Predisposing Clinical Conditions and Site of Involvement of Non-M. tuberculosis Mycobacterial Infections


    Site Predisposing Clinical Conditions Species 
    Disseminated Immunodeficiency / malignancy M. avium complex 
    M. kansasii 
    Gastrointestinal tract / disseminated Acquired immunodeficiency syndrome M. avium complex 
    Lung Chronic pulmonary disease M. avium complex 
    M. kansasii 
    Lymph nodes Pediatric age group M. avium complex 
    M. scrofulaceum 
    Peritonitis Chronic ambulatory peritoneal dialysis M. fortuitum 
    M. chelonae 
    Skeleton Immunodeficiency / malignancy M. avium complex 
    M. kansasii 
    Skin and soft tissue Percutaneous trauma / abrasion M. fortuitum 
    M. chelonae 
    Immunodeficiency / malignancy M. haemophilum 

    Sputum: Tuberculosis decreased in incidence in the United States in the 1970s and 1980s, but the incidence of tuberculosis in the United States increased from 1986-1994. High incidence populations exist in depressed inner city areas, some rural areas, amongst new immigrants, in prison inmates, and in HIV-positive patients. The emergence of M. tuberculosis and M. avium complex infections complicating the acquired immunodeficiency syndrome has been striking. When tuberculosis occurs as a first or case-defining opportunistic infection, 75% to 100% of patients of HIV-positive patients have pulmonary disease. After the diagnosis of AIDS has been made, 25% to 70% of HIV-associated tuberculosis patients have an extrapulmonary site of infection.14

    In an ambulatory inner city population, two specimens processed for acid-fast stain and culture identified all cases of active tuberculosis within the time required for culture. The most infectious cases were identified immediately by the acid-fast stain. Tuberculin tests and chest x-rays were also performed but did not significantly increase the number of cases identified in this population.15

    M. kansasii is uncommon as an environmental contaminant. Implication of M. avium complex as a pathogen usually requires at least one of the following criteria:

    • clinical evidence of a disease process that can be explained by nontuberculous mycobacterial infection
    • repeated isolation of the same mycobacterial species from sputum over a period of weeks to months
    • exclusion of other possible etiologies
    • biopsy demonstrating acid-fast bacilli or diagnostic histopathologic changes16

    Endobronchial tuberculosis has been increasingly recognized because of its incidence in association with the acquired immunodeficiency syndrome and because it may mimic carcinoma.17,18

    Nosocomial transmission of multidrug-resistant Mycobacterium tuberculosis has been noted to occur from patient to patient and from patient to healthcare worker. Acid-fast bacilli isolation precautions and adherence to appropriate infection control procedures is recommended until at least three smears from specimens collected on different days are negative.19,20

    While M. tuberculosis is contagious and is usually transmitted from person to person, most of the other disease-causing mycobacteria are not characterized by person-to-person spread, are found in the environment, and are considered opportunistic pathogens. They may be called potentially pathogenic environmental (PPE) mycobacteria. They include M. avium, M. intracellulare, M. asiaticum, M. flavescens, M. fortuitum complex, M. haemophilum, M. kansasii, M. malmoense, M. marinum, M. scrofulaceum, M. simiae, M. genavense, and M. xenopi. They are correlated with HIV.16,21

    Urine: Although it has been thought that tuberculosis of the urinary tract should be suspected when hematuria and pyuria (sterile pyuria) occur without recovery by routine culture of usual urinary tract pathogens, concomitant infections with ordinary pathogens are not rare. Mycobacteria cultures of the urine are approximately 90% sensitive. The kidney is the most frequent site of infection; prostate, salpinx, and endometrial involvement also occurs. Continuing tuberculous bacilluria may cause cystitis with frequency. Genitourinary infections with PPE mycobacteria, particularly M. kansasii and M. avium complex, occur.22 Recovery of M. bovis BCG from urine of patients undergoing BCG treatment for bladder cancer can be expected.

    Stool: The increasing recognition of mycobacterial infections in patients with the acquired immunodeficiency syndrome (AIDS) has resulted in increased awareness of the potential to recover clinically significant mycobacteria from stool. Seven of 132 AIDS patients studied for intestinal infection were found to harbor M. avium complex.23 Isolation of mycobacteria from stool indicates disseminated disease, and cultures from blood, bone marrow, and lymph nodes are usually also positive for the same mycobacterial isolate.24

    Footnotes
    1. Stenson W, Aranda C, and Bevelaqua FA, “Transbronchial Biopsy Culture in Pulmonary Tuberculosis,” Chest, 1983, 83(6):883-4.
    2. Jett JR, Cortese DA, and Dines DE, “The Value of Bronchoscopy in the Diagnosis of Mycobacterial Disease. A Five-Year Experience,” Chest, 1981, 80(5):575-8.
    3. Brown JW III and Sanders CV, “Mycobacterium marinum Infections: A Problem of Recognition, Not Therapy?” Arch Intern Med, 1987, 147(5):817-8.
    4. Klotz SA and Penn RL, “Acid-Fast Staining of Urine and Gastric Contents Is An Excellent Indicator of Mycobacterial Disease,” Am Rev Respir Dis, 1987, 136(5):1197-8.
    5. Stager CE, Libonati JP, Siddigi SH, et al, “Role of Solid Media When Using in Conjunction With the Bactec® System for Mycobacterial Isolation and Identification,” J Clin Microbiol, 1991, 29(1):154-7.
    6. Kolk AH, Schuitema AR, Kuijper S, et al, “Detection of Mycobacterium tuberculosis in Clinical Samples by Using Polymerase Chain Reaction and a Nonradioactive Detection System,” J Clin Microbiol, 1992, 30(10):2567-75.
    7. Hawkins CC, Gold JW, Whimbey E, et al, “Mycobacterium avium Complex Infections in Patients With the Acquired Immunodeficiency Syndrome,” Ann Intern Med, 1986, 105(2):184-8.
    8. Cohen RJ, Samoszuk MK, Busch D, et al, “Occult Infections With M. intracellulare in Bone Marrow Biopsy Specimens From Patients With AIDS,” N Engl J Med, 1983, 308(24):1475-6.
    9. Croxson TS, Ebanks D, and Mildvan D, “Atypical Mycobacteria and Kaposi's Sarcoma in the Same Biopsy Specimens,” N Engl J Med, 1983, 308(24):1476.
    10. Wallace RJ, Musser JM, Hull SI, et al, “Diversity and Sources of Rapidly Growing Mycobacteria Associated With Infections Following Cardiac Surgery,” J Infect Dis, 1989, 159(4):708-16.
    11. Wallace RJ, Steele LC, Labidi A, et al, “Heterogeneity Among Isolates of Rapidly Growing Mycobacteria Responsible for Infections Following Augmentation Mammoplasty Despite Case Clustering in Texas and Other Southern Coastal States,” J Infect Dis, 1989, 160(2):281-8.
    12. Martin RE and Bradsher RW, “Elusive Diagnosis of Tuberculosis Peritonitis,” South Med J, 1986, 79(9):1076-9.
    13. Alvarez S and McCabe WR, “Extrapulmonary Tuberculosis Revisited: A Review of Experience at Boston City and Other Hospitals,” Medicine (Baltimore), 1984, 63(1):25-55.
    14. Chaisson RE and Slutkin G, “Tuberculosis and Human Immunodeficiency Virus Infection,” J Infect Dis, 1989, 159(1):96-100.
    15. Tenover FC, Crawford JT, Huebner RE, et al, “The Resurgence of Tuberculosis: Is Your Laboratory Ready?” J Clin Microbiol, 1993, 31(4):767-70.
    16. Wayne LG and Sramek HA, “Agents of Newly Recognized or Infrequently Encountered Mycobacterial Diseases,” Clin Microbiol Rev, 1992, 5(1):1-25.
    17. Smith LS, Schillaci RF, and Sarlin RF, “Endobronchial Tuberculosis. Serial Fiberoptic Bronchoscopy and Natural History,” Chest, 1987, 91(5):644-7.
    18. Maguire GP, Delorenzo LJ, and Brown RB, “Endobronchial Tuberculosis Simulating Bronchogenic Carcinoma in a Patient With the Acquired Immunodeficiency Syndrome,” Am J Med Sci, 1987, 294(1):42-4.
    19. Pearson ML, Jereb JA, Frieden TR, et al, “Nosocomial Transmission of Multidrug-Resistant Mycobacterium tuberculosis. A Risk to Patients and Healthcare Workers,” Ann Intern Med, 1992, 117(3):191-6.
    20. Iseman MD, “A Leap of Faith. What Can We Do to Curtail Intrainstitutional Transmission of Tuberculosis?” Ann Intern Med, 1992, 117(3):251-3.
    21. Böttger EC, Teske A, Kirschner P, et al, “Disseminated Mycobacterium genavense Infection in Patients With AIDS,” Lancet, 1992, 340(8811):76-80.
    22. Wayne LG and Sramek HA, “Agents of Newly Recognized or Infrequently Encountered Mycobacterial Diseases,” Clin Microbiol Rev, 1992, 5(1):1-25.
    23. René E, Marche C, Regnier B, et al, “Intestinal Infections in Patients With Acquired Immunodeficiency Syndrome: A Prospective Study in 132 Patients,” Dig Dis Sci, 1989, 34(5):773-80.
    24. Wolinsky E, “Mycobacterial Diseases Other Than Tuberculosis,” Clin Infect Dis, 1992, 15(1):1-10
    References

    Addison NV, “Abdominal Tuberculosis - A Disease Revived,” Ann R Coll Surg Engl, 1983, 65(2):105-11.

    Alvarez SZ and Carpio R, “Hepatobiliary Tuberculosis,” Dig Dis Sci, 1983, 28(3):193-200.

    Beck-Sague C, Dooley SW, Hutton MD, et al, “Hospital Outbreak of Multidrug-Resistant Mycobacterium tuberculosis Infections. Factors in Transmission to Staff and HIV-Infected Patients,” JAMA, 1992, 268(10):1280-6.

    Claydon EJ, Coker RJ, and Harris JRW, “Mycobacterium malmoense Infection in HIV Positive Patients,” J Infect, 1991, 23(2):191-4.

    Des Prez RM and Heim CR, “Mycobacterium Tuberculosis,” Principles and Practice of Infectious Diseases, 3rd ed, Chapter 229, Mandell GL, Douglas RG Jr, and Bennett JE, eds, New York, NY: Churchill Livingstone, 1990, 1877-906.

    Gradon JD, Timpone JG, and Schnittman SM, “Emergence of Unusual Opportunistic Pathogens in AIDS: A Review,” Clin Infect Dis, 1992, 15(1):134-57.

    Griffith DE, “Environmental Mycobacteria, An Increasing Problem,” Hosp Pract, 1988, 23(5):125-37.

    Mehta JB and Morris F, “Impact of HIV Infection on Mycobacterial Disease,” Am Fam Physician, 1992, 45(5):2203-11.

    Musial CE and Roberts GD, “Rapid Detection and Identification Procedures for Acid-Fast Organisms,” Clin Microbiol Newslet, 1987, 9:89-96.

    Pitchenik AE, “Tuberculosis Control and AIDS Epidemic in Developing Countries,” Ann Intern Med, 1990, 113(2):89-90.

    Woods GL and Washington JA II, “Mycobacteria Other Than Mycobacterium tuberculosis: Review of Microbiologic and Clinical Aspects,” Rev Infect Dis, 1987, 9(2):275-94 (review).

    Yajko DM, Nassos PS, Sanders CA, et al, “Comparison of Four Decontamination Methods for Recovery of Mycobacterium avium Complex From Stools,” J Clin Microbiol, 1993, 31(2):302-6.


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