Basic knowledge about MTB Mycobacterium tuberculosis, a small, aerobic, non-motile bacillus. "Gram-positive“ Tuberculosis typically spread through the air when people who have an active TB infection cough, sneeze etc. symptoms The classic symptoms of active TB infection are a chronic cough with blood-tinged sputum, fever, night sweats, and weight loss. Diagnosis Radiology (commonly chest X-rays) microbiological culture. tuberculin skin test (TST) etc