DIAGONOSIS OF

MYCOBACTERIUM TUBERCULOSIS BY

MUHAMMAD ZADA

Introduction

Pathogenic bacteria of mycobacteraceae familyAerobic bacilli –non spore forming

non motileCell wall –rich in lipidsAcid-fast bacilliVery slow growingRoute of transmission- aerosole

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)

Diagnostic Testing

Culture is still the recommended method for diagnosing TB

Detection of AFB in respiratory secretionsChest X-rayTuberculin skin test (TST)Molecular diagnostic tests

procedure

Pulmonary or extra pulmonary samples are first decontaminated (NAL soln.)

Smear formation Inoculation to LJ and MGIT media.

Smear formation

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

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