Mycobacteria

Question 1

Characteristics - Mycobacteria

Answer 1

Rod/slight curve shape, strict aerobe, slow growing. main types, tuberculosis, leprae

Question 2

Diseases caused - Mycobacteria

Answer 2

Pulmonary tuberculosis, military tuberculosis, leprosy

Question 3

Virulence factors Invasion/replication - Mycobacteria

Answer 3

mycolic acid leads to granuloma formation

Question 4

Evasion virulence factors - mycobacteria

Answer 4

ESAT-6 and CFP-10 are responsible for immunomodulation. Lysocytrate lyase will metabolise fatty acid and catalyse/superoxide dismutase which will protect from H2O2 and O2. Cell wall components such as glycolipids interact with innate immune system. Granuloma formation caused by mycolic acid

Question 5

Pathogenesis TB - mycobacteria

Answer 5

transmitted through lungs via aerosol droplets. Will invade bronchus and spread throughout lung. Will survive and multiply by killing alveolar macrophages for first 7-21 days. After this the adaptive immune response will be induced causing 3 potential pathways

First pathway is that the adaptive immune system will kill the bacteria
Second pathway is that TB will be active and the patients will either die or be treated (5-10%)
Third pathway is that infection will stay in body and be asymptomatic (90%) forming granulomas, and in 10% of cases will reactivate.

Military TB is when blood vessels are invaded.

Question 6

Leprosy pathogenesis - Mycobacterium

Answer 6

entrance via skin and upper respiratory tract, will either cause strong t-cell response and weak Ab response with low bacterial load and few lesions or the opposite

Question 7

How are TB and leprosy detected?

Answer 7

TB: ziehl-neelsen staining
Leprosy: physical features

Question 8

How is TB and leprosy treated?

Answer 8

TB: vaccines are used but relatively ineffective. 6 month long usage of multiple antibiotics.

Leprosy: multidrug treatment 6-12 months