2. Introduction
Pathogenic bacteria of mycobacteraceae family
Aerobic bacilli –non spore forming
non motile
Cell wall –rich in lipids
Acid-fast bacilli
Very slow growing
Route of transmission- aerosole
3. TB drug resistance: resistant to one or more of first
line drugs: isoniazid, rifampin, pyrazinamide and
ethambutol (~ 5% in Canada)
MDR-TB: resistance to at least INH and rifampin (~
0.7% in Canada)
XDR-TB: resistance to all first line therapeutic drugs
(rare)
4. Diagnostic Testing
Culture is still the recommended method for
diagnosing TB
Detection of AFB in respiratory secretions
Chest X-ray
Tuberculin skin test (TST)
Molecular diagnostic tests
5. procedure
Pulmonary or extra pulmonary samples are first
decontaminated (NAL soln.)
Smear formation
Inoculation to LJ and MGIT media.
7. After inoculation of specimen the MGIT are kept in
bactec for 42 days
If any tube appears positive,
It should be sub cultured, acid fast stained and
treated as presumptive positive