Final answer:
PNC has a narrow spectrum of activity against gram-positive and limited numbers of gram-negative bacteria, and is also active against Mycobacterium tuberculosis.
Step-by-step explanation:
PNC (Pyrazinamide Nicotinamide Cyclase) has a narrow spectrum of activity against gram-positive bacteria and a limited number of gram-negative bacteria. It is also active against Mycobacterium tuberculosis. This means that PNC is effective against a specific group of bacteria and may not be effective against others.