A 27-year-old male presents with a 3-month history of cough, night sweats and weight loss of 5 kg. He was previously fit and well. He went on holiday with his family 4 months ago to Pakistan where his grandfather also had a cough. On examination:  Febrile 37.9; all other observations stable. CXR: bilateral hilar lymphadenopathy. Microbiology: on Ziehl-Neelsen staining of sputum, acid-fast bacilli seen.  He is diagnosed as having pulmonary tuberculosis. Which of the following are characteristics of Mycobacterium tuberculosis?