All the following are true of Tuberculosis except ?
Ans. is 'c' i.e., Pathogenicity to rabbits differentiates M. tuberculosis and M. bovis . Culture is a very sensitive diagnostic technique for detection of tubercle bacilli, detecting as few as 10 to 100 bacilli/ml. . At least 10, 000 (109 acid fast bacilli should be present per mil of sputum for them to be readly demonstrable in direct smear. Differentiation between M. tuberculosis and M box is Type Nitrate reduction Niacin Oxygen preference Growth on TCH Pyrozinamide Growth culture . M. Tuberculosis . M. bovis (+)ve (-)ve +ve (-)ve Aerobic Microacrophilic + - Senstive resistant Luxuriant (eugonic) Sparse (dysgonic) . About option 'c' Pathogenecity to Rabbit is used to differentiate M bovis from BCG strain (attenuated strain of M. bovis, not from M. tuberculosis).
For sputum to be positive, (A194) bacilli should be > 1
Niacin test differentiates M. tuberculosis and M. bovis
Pathogenicity to rabbits differentiates M. tuberculosis and M. bovis
All