MYCOBACTERIUM TUBERCULOSIS COMPLEX Flashcards
Mycobacterium spp general characteristics
Acid-fast bacilli (with Mycolic acid), Aerobic, Agents of pulmonary and skin diseases
Tuberculosis high-risk groups
Poor, homeless, IV drug users, alcoholics, elderly
Pulmonary TB symptoms
Productive cough, hemoptysis, low-grade fever, night sweats, anorexia, weight loss
CXR findings for Pulmonary TB
Formation of Gohn lesion with granulomas/hard tubercles, giant cells (cellular fusion with multiple nuclei)
Spread of TB
Through lymphatic or blood causing Meningeal, Miliary, or Disseminated tuberculosis (common in immunocompromised)
Latent tuberculosis characteristics
No symptoms, no active disease, not transmissible
Pott’s disease
Tuberculosis spondylitis/skeletal tuberculosis (bone TB)
Mycobacterium tuberculosis complex species
Mycobacterium tuberculosis, Mycobacterium bovis, Mycobacterium bovis BCG (Bacillus Calmette-Guerin), Mycobacterium africanum, Mycobacterium caprae, Mycobacterium microti, Mycobacterium mungi, Mycobacterium orygis, Mycobacterium canettii, Mycobacterium pinnipedii
Biosafety Level for Acid-fast smears and culture for NON-aerosolizing procedures
Biosafety Level 2
Biosafety Level for manipulation with aerosolizing procedures, opening centrifuge vial, adding reagents to biochemical tests, molecular tests, and sonication. After aerosolizing procedures, stand specimen for 15 minutes
Biosafety Level 3
Niacin Nitrate reduction Pyrazinamidase positive Mycobacteria
M. tuberculosis
Urease positive, T2H/TCH resistant Mycobacteria
M. tuberculosis
Urease positive, T2H/TCH sensitive Mycobacteria
M. bovis
Specimen for tuberculosis diagnosis DOH sputum
2 samples
Specimen for tuberculosis diagnosis according to Bailey
3 samples – each are 8 hours apart
Specimen of choice for mycobacterium for <12 years old
Gastric lavage
Specimen for immunocompromised individuals Mycobacteria
3 consecutive First-morning midstream clean catch urine, Stool (AIDS, M. avium complex = Immunocompromised patients)
Tissue samples (incubated at 35°C and 30°C) anticoagulants for M. tuberculosis
SPS, Heparin, or Citrate Blood culture, and CSF (tubercular meningitis - pellicle)
Digestion-Decontamination method 1 for Mycobacterium
NaOH method – 2-4% NaOH, both decontaminant and digestant
Digestion-Decontamination method 2 for Mycobacterium
Zephiran-Trisodium phosphate method
Digestion-Decontamination method 3 for Mycobacterium
NALC-NaOH method – most commonly used for TB specimen processing; used in MGIT 960
Reagent for TB specimen shelf life
1% Cetylpyridinium chloride – prolongs shelf life of sputum sample for up to 8 days
Reagent for decontamination of thin samples like Urine
Sulfuric acid – Decontaminant for thin samples like Urine
Reagent used for cystic fibrosis patients
Chlorhexidine – used for patients with cystic fibrosis (M. abscessus)
Sterile specimen process
Centrifuge and use sediment for microscopy and culture
Nonsterile specimen process
Liquefaction (NaCl)→ Decontamination (NaOH) → Neutralization (PO4 buffer)→ Centrifugation → use sediment for microscopy and culture
Solid Media Egg-based/Opaque for Mycobacteria - source of energy
glycerol
Purpose of Malachite green in egg-based/opaque media for mycobacteria
inhibitor of normal flora (M. avium complex)
Examples of Egg-based/Opaque media
Lowenstein-Jensen (Inspissation for sterilization), American Thoracic Society (ATS) Medium, Petragnani medium (2x Malachite green heavy contam), Wallenstein medium
Serum-based/Transparent media for Mycobacteria
Middlebrook 7H10 and 7H11 and Mitchison 7H11
Component for protection of AFB against toxins
Albumin
Hydrolysate for Isoniazid-resistant MTB
Casein
Liquid Media for Mycobacteria
BACTEC 12B, Middlebrook 7H9
Used for Mycobacteria Growth Indicator Tube (MGIT 960) system
BACTEC 12B broth and Dubos Tween Albumin broth = Middlebrook 7H9
Biphasic Media for rapid identification of Mycobacteria
SeptiCheK AFB
Automated method for Mycobacteria using Middlebrook 7H12 and radioisotope
BACTEC 460 TB system
Mycobacteria Growth Indicator Tube (MGIT 960) system
Uses Middlebrook 7H9 with continuous monitoring system
Digestion-Decontamination method for Mycobacteria in MGIT 960
NALC-NaOH
Growth supplements for Mycobacteria in MGIT 960
OADC (oleic acid, albumin, dextrose, catalase)
Inhibitors for NTB in Mycobacteria culture
PANTA (polymyxin B, amphotericin B, nalidixic acid, trimethoprim, azlocillin)
Automated methods for Mycobacteria
BACTEC 460 TB System, Mycobacteria Growth Indicator Tube (MGIT 960) system, BacT/Alert MB, versaTREK culture
Immunologic Tests for Mycobacteria that uses skin hypersensitivity to induce erythema and induration; Poor sensitivity, & anergy on patients with HIV
Mantoux (cross reacts with BCG vaccine)/Tuberculin/PPD (Purified protein derivative) test
Test for mycobacteria that do not cross-react with BCG vaccine and nontuberculous Mycobacteria
QuantiFERON-TB Gold Plus
POCT test kit for detection of intrathoracic and latent tuberculosis
LAM (LipoArabinomannan) assay
Molecular assay for Mycobacteria
Gene Xpert MTB/RIF
First-line/Primary Anti-Tubercular drugs (RIPES)
Rifampicin, Isoniazid, Pyrazinamide, Ethambutol, Streptomycin
Resistant to at least two first-line anti-TB drugs classification
MDR-TB(Multidrug resistant - TB)
Resistant to Isoniazid, rifampicin, fluoroquinolones, and at least one of the 5 second-line TB drugs (Amikacin, Amithiozones, Bedaquiline, Ethionamide, or Capreomycin) classification
XDR-TB(Extensively drug-resistant tuberculosis)
