AFB Rapid culture by MGIT - Tissue/Biopsy

Biopsy

Report in 1176Hrs

At Home

No Fasting Required

Details

Gold-standard method for detecting tuberculosis (TB) and nontuberculous mycobacteria (NTM) from sterile or deep tissue specimens

₹2,350₹3,000

22% OFF

AFB Rapid Culture by MGIT - Tissue/Biopsy

Why is it done?
- Detects and identifies Mycobacterium tuberculosis and other acid-fast bacilli (AFB) in tissue or biopsy samples using the MGIT (Mycobacterial Growth Indicator Tube) rapid culture system
- Diagnoses tuberculosis (TB) infection when tissue samples show suspicion for mycobacterial disease
- Ordered when patients present with clinical findings suggestive of extrapulmonary TB (lymph nodes, bone, skin, pleura, pericardium, meninges, or other tissues)
- Performed when histology or clinical suspicion indicates possible mycobacterial infection in tissue specimens
- Used to confirm TB diagnosis rapidly, providing results within 2-3 weeks compared to traditional culture methods (8+ weeks)
- Enables timely initiation of anti-tuberculous therapy based on confirmed diagnosis
Normal Range
- Normal (Negative) Result: No growth of acid-fast bacilli detected in the culture media; reported as 'No AFB growth' or 'Negative for Mycobacterium tuberculosis'
- Abnormal (Positive) Result: Growth detected in MGIT bottles with positive fluorescence detected by automated instrumentation; reported as 'AFB growth detected' with species identification (typically M. tuberculosis)
- Units of Measurement: Qualitative result reported as positive or negative; no quantitative values
- Time to Result: Typically 2-3 weeks for positive results; negative cultures are reported after 6-8 weeks of incubation
Interpretation
- Positive Result: Confirms active mycobacterial infection, most commonly tuberculosis; indicates patient has culture-confirmed TB which is the gold standard for diagnosis; results are typically accompanied by species identification and drug susceptibility testing recommendations
- Negative Result: No AFB growth detected; suggests absence of mycobacterial infection in the tissue sample, though does not completely rule out TB if clinical suspicion remains high or if specimen quality was compromised
- Factors Affecting Results: Specimen quality (inadequate tissue sample); improper specimen collection or handling; contamination of sample; previous TB treatment or current anti-TB therapy may reduce culture positivity; timing of biopsy relative to disease progression; site of biopsy (different tissues have varying bacterial load)
- Clinical Significance: Positive culture is essential for TB diagnosis confirmation and allows drug susceptibility testing to guide treatment; enables differentiation of TB from other granulomatous diseases; critical for epidemiological purposes and contact tracing; positive result indicates infectious disease requiring isolation and treatment protocols
- Species Identification: Results specify which mycobacterial species was isolated; M. tuberculosis indicates tuberculosis; non-tuberculous mycobacteria (NTM) require different treatment approaches
Associated Organs
- Primary Organs Involved: Lungs (pulmonary TB); lymph nodes (lymphadenitis TB); bones and joints (skeletal TB, Pott's disease of spine); pleura (pleural TB); pericardium (pericardial TB); central nervous system (TB meningitis); skin (cutaneous TB); liver and spleen (hepatic and splenic TB)
- Extrapulmonary TB Manifestations: Tuberculous lymphadenitis; Pott's disease (spinal TB) with potential for spinal cord compression and paralysis; TB meningitis causing severe neurological complications; pericardial TB leading to cardiac tamponade; peritoneal TB causing ascites; genitourinary TB affecting kidneys and reproductive organs
- Associated Diseases and Complications: Tuberculosis (confirmed diagnosis); granulomatous inflammation; immunosuppression (HIV/AIDS); malnutrition; chronic kidney disease; diabetes mellitus; TNF-alpha inhibitor use; spinal instability and neurological deficits; constitutional symptoms (fever, weight loss, night sweats)
- Potential Complications of Untreated Disease: Progressive tissue destruction; disseminated/miliary TB; multi-organ involvement; permanent disability; mortality if untreated; drug-resistant TB development if inadequately treated
Follow-up Tests
- Drug Susceptibility Testing (DST): Essential follow-up test performed on positive cultures to determine resistance to first-line TB drugs (isoniazid, rifampicin); results guide targeted therapy to prevent treatment failure
- AFB Smear Microscopy: Ziehl-Neelsen or auramine-rhodamine staining of the original tissue specimen; provides rapid preliminary diagnosis independent of culture results
- Tuberculin Skin Test (TST) or Interferon-Gamma Release Assay (IGRA): Detects TB infection immune response; used for risk stratification and contact investigation
- Chest X-ray or Imaging Studies: CT imaging for extrapulmonary TB to assess extent of disease; MRI for spinal TB, CNS TB, or soft tissue TB evaluation
- Histopathology: Microscopic examination of tissue biopsy showing caseating granulomas suggestive of TB; supportive but not diagnostic alone
- Molecular Testing/PCR for M. tuberculosis: Rapid detection of TB DNA; provides quick results complementary to culture methods
- HIV Testing: Recommended for all TB patients to assess immunosuppression and guide treatment strategy
- Monitoring During Treatment: Repeat cultures at 2 months of therapy to assess treatment response; liver and kidney function tests to monitor for drug toxicity; clinical assessment of treatment efficacy
Fasting Required?
- Fasting Requirement: No - This is a tissue/biopsy specimen culture test, not a blood test; fasting is not applicable
- Specimen Collection Requirements: Adequate tissue sample (minimum typically 0.5-1 gram) obtained by biopsy procedure from suspected TB site; specimen must be sterile and collected in appropriate sterile container without formalin fixative (formalin destroys mycobacteria and makes culture impossible)
- Pre-Biopsy Preparation: Standard pre-procedural assessment and consent required; NPO status may be required depending on biopsy procedure type and anesthesia use; baseline imaging often performed before biopsy; anticoagulant medications may need adjustment based on procedure risk
- Specimen Handling and Storage: Specimen should be transported to laboratory promptly (within 2-4 hours preferred); maintain at room temperature; do not refrigerate or freeze; use sterile container with no preservatives; arrange transport with laboratory to ensure timely processing to maximize culture positivity
- Medications: Continue regular medications unless specifically instructed otherwise by physician; anticoagulants may need temporary discontinuation depending on biopsy site and bleeding risk; do not stop anti-TB medications if already initiated, as this may affect culture results interpretation
- Additional Patient Instructions: Inform healthcare provider of immunosuppression or HIV status; disclose if currently on TB treatment; report allergies to anesthetics; arrange transportation as sedation may be used during biopsy; plan for rest period post-procedure; follow post-biopsy wound care instructions; contact laboratory before biopsy to confirm specimen handling protocols

How our test process works!