mycobacterium

Question 1

genus mycobacterium

Answer 1

-gram pos irregular bacilli
-acid fast
-strict aerobes
-catalase +
-mycolic acid
-do not form capsules, flagella or spores
-slow growing

Question 2

mycobacterium tuberculosis

Answer 2

-tubercle bacillus
-no exotoxins or enzymes
-contain waxes & cord factor that prevent destruction by lysosomes or macros

Question 3

primary TB

Answer 3

-infectious dose = 10 cells
-phagocytosed by alveolar macros and intracellular multiplication
-3-4 weeks immune system attacks and forms tubercles
-center of tubercle breaks down into necrotic caseous lesions

Question 4

secondary TB

Answer 4

-if no recovery from primary, reactivation of bacilli can occur
-tubercles expand and drain into bronchial tubes and upper RT
-symptoms: coughing, bloody sputum, fever, weight loss, fatigue, night sweats
-60% mortality untreated

Question 5

extrapulmonary TB

Answer 5

bacilli disseminate into lymph nodes, kidneys, long bones, genital tract, brain & meninges
-deathly complications

Question 6

TB diagnosis

Answer 6

-mantoux testing: red bump skin test
-xrays
-direct acid fast ID
-culture & biochemical
-IGRA