Tuberculosis, Mycobacterium leprae Flashcards
(17 cards)
Mycobacterium Tuberculosis Complex
- M. Tuberculosis
- M. Bovis
- M. Africanum
= all cause TB in humans
M. Tuberculosis General info
- Spread by respiratory droplets
- M. Bovis spread by unpasteurized milk of infected cow
- Mostly in Africa & Asia
- Top 10 causes of Death
M. Tuberculosis Morphology
- Obligate Aerobe
- Non-motile Rods
- Slow growth
- Acid-Fast staining
M. Tuberculosis Culturing
Löwenstein Jensen Medium
- Salts, asparagine, glycerine, potato, egg, malachite green
- Malachite green supresses other bacteria, specific for Mycobacteria
- Irregular cream colonies with breadcrumb-like appearance
M. Tuberculosis Virulence factors
- Sulfatides
- Cord Factors
- Mycolic Acid (PM)
M. Tuberculosis Disease
Tuberclosis
- Primary: bacteria survive macrophage, Ghon focus, with lymphang/adenitis form Ranke-Ghon complex, hypersensitivity IV, granulomas
- Secondary: dormant reactivation, granuloma necrosis, dissemination (miliary TB), liver, spleen, brain
Symptoms of Tuberclosis
- Persistent cough >3 weeks
- Fatigue
- Night Sweats
- Hemoptysis
- Weight-loss
Cutaneous Symptoms of Tuberculosis
- Scrufoloderma: Infection of organs & tissues, inflammation of lymph vessels & nodes, pus appears on skin
- Lupus Vulgaris: disfiguring skin ulcer
- Abscesses on the Ribs
M. Tuberculosis Diagnosis
- Clinical Symptoms & X-ray
- Lab exam of Sputum (microscopy, cultivation, PCR)
- Immune response detection: Tuberculin skin test, IGRA (INF-y release factor)
M. Tuberculosis Treatment
RIPE
- Rifampicin (NA synth inh)
- Isoniazid (MA synth inh)
- Pyrazinamide (FA synth inh)
- Ethambutol (cell wall synth inh)
= 6-9 months
M. Tuberculosis Resistance
- MDR-TB: resistant to at least rifampicin & isoniazid
- XDR-TB: MDR resistance + fluoroquinolones + second-line injectables
- HIV Patients at risk (latent to secondary)
We needs DOT directly observed therapy to ensure long term med taking
M. Tuberculosis Prevention
- BCG Vaccine (live-attenuated)
- Prophylaxis with Rifampicin & Isoniazid
M. Leprae info
- Thrives in Low temp
- Acid-fast stain
- Armadillo Reservoir
- Long incubation time 10-15 years
2 Types of Leprosy
- Tuberculoid
- Lepromatous
Tuberculoid Leprosy
- Cell mediated response
- Th1 cells & Macrophages
- Lepromin Test +
- Hairless skin lesions
= Rifampicin + Dapsone (6 months)
Lepromatous Leprosy
- Very infectious, human to human
- Humoral response, Th2
- Lepromin Test -
- Many bacteria in lesions because unable to contain
- Poorly demarcated skin lesions (extensors)
- Neuropathy (extremities)
= Rifampicin + Dapsone + Clofazimine (>1 year)
M. Leprae Culturing
Unable to culture in Vitro
