6. False-negative Mantoux test is observed in

A. early tuberculosis
B. Advanced tuberculosis
C. Severe malnutrition
D. All of these

7. Humans become infected with Mycobacterium tuberculosis most frequently by

A. inhalation
B. ingestion
C. contact
D. inoculation

8. Rough and buff colonies on LJ medium are characteristic of

A. M chelonae
B. M bovis
C. Mycobacterium tuberculosis
D. M fortuitum

9. Which of the following species of Mycobacterium is positive for nitrate reduction test?

A. M chelonae
B. M fortuitum
C. Mycobacterium tuberculosis
D. All of these

10. The bacteria which is microaerophilic on primary isolation is

A. M fortuitum
B. Mycobacterium tuberculosis
C. M bovis
D. none of these