mycobacteria

Question 1

mycobacterium

Answer 1

intracellular slender rods with cell walls, acid-fast

Question 2

mycobacterium tuberculosis culture

Answer 2

colonies on Lowenstein-Jensen agar after 8 weeks of incubation
- strictly aerobic
- most species grow slowly

Question 3

mycobacterium tuberculosis pathogenesis

Answer 3

• inhalation of aerosols
• mycobacteria reach alveoli and multiply in pulmonary macrophages
• virulence depends on its ability to survive and grow within host cells

Question 4

primary tuberculosis

Answer 4

• TB skin test positive
• radiograph negative

Question 5

90% of primary tuberculosis turns into

Answer 5

latent-dormant tuberculosis

Question 6

latent-dormant tuberculosis

Answer 6

• TB skin test positive
• Radiograph negative for active disease

Question 7

10% of primary tuberculosis turns into

Answer 7

progressive primary (active) infection

Question 8

progressive primary (active) infection

Answer 8

• TB skin test positive
• radiograph positive
• sputum positive

Question 9

90% of latent-dormant tuberculosis turns into

Answer 9

no disease

Question 10

10% of latent-dormant tuberculosis turns into

Answer 10

secondary (reactivation) tuberculosis

Question 11

secondary (reactivation) tuberculosis

Answer 11

• TB skin test positive
• Radiograph positive
• sputum positive

Question 12

tuberculin test

Answer 12

injected into the dermis and it swells (if its big then its positive)

Question 13

tuberculosis treatment

Answer 13

multiple-drug regiment and prolonged treatment
- combination of INH and Rifampin for up to 9 months

Question 14

m. tuberculosis immunity

Answer 14

stimulates both humoral and a cell-mediated immune response
- delayed hypersensitivity

Question 15

mycobacterium tuberculosis in cattle

Answer 15

granuloma in the lymph nodes of the head, lungs, intestine and carcass

Question 16

mycobacterium paratuberculosis

Answer 16

chronic: causes Johne’s disease
- adult wild and domestic ruminants such as cattle, sheep, and goats
- thickening of the intestines

Question 17

johne’s disease transmission

Answer 17

• ingestion of an organism
• carrier animals, so called “fecal shedders” are the most important source of infection

Question 18

johne’s disease symptoms

Answer 18

gradual and chronic weight loss and emaciation
- rough hair coat and dry skin
- reduced milk production

Question 19

mycobacterium leprae

Answer 19

• leprosy (hansen’s disease)
• skin lesions and nerve damage
• cannot be cultured on artificial media
• armadillos are a natural reservoir of M. leprae in the US

Question 20

epidemiology of m. leprae

Answer 20

highly infectious
- person to person spread or through inhalation of infectious aerosols

Question 21

cell mediated response to leprosy

Answer 21

milder tuberculoid leprosy

Question 22

humoral (antibody) response to leprosy

Answer 22

more severe lepromatous leprosy

Question 23

tuberculoid leprosy

Answer 23

few skin lesions will small numbers of m. leprae at the site of the leison

Question 24

lepromatous leprosy

Answer 24

many skin lesions with large numbers of m. leprae at the site of the lesion

Question 25

which type of mycobacterium does not grow in culture?

Answer 25

leprae