Mycobacteria (complete)

Question 1

What are the structures of an acid fast cell wall

Answer 1

1. peptidoglycolipids
2. Arabinogalactan
3. PIM (phosphatidyl-inositol mannosides)

Question 2

What are the 3 main mycobacterial diseases in humans

Answer 2

Tuberculosis
Leprosy
Buruli Ulcer

Question 3

what is the estimate for the portion of the worlds population that is infected with TB

Answer 3

1/3 of the worlds population

Question 4

What bacteria causes TB

Answer 4

mycobacterium tuberculosis

Question 5

What is the cell wall component in the virulent strains of M. Tuberculosis that is necessary to cause disease

Answer 5

cord factor

Question 6

What are the three types of TB

Answer 6

1. Primary TB
2. Secondary TB
3. Disseminated TB

Question 7

What is primary TB

Answer 7

initial infection with M. Tuberculosis

Question 8

what is secondary TB

Answer 8

reestablishment of an active infection after a period of dormancy. a tubercle from primary TB ruptures and spreads again

Question 9

what is disseminated TB

Answer 9

This is when infection spreads throughout the body

Question 10

What two things reduced the incidence of TB in the US

Answer 10

pasteurization of milk and the isolation of patients in sanatoriums

Question 11

who is at high risk for TB

Answer 11

those in contact with infected patients and those with immunodeficiencies (HIV)

Question 12

How is TB diagnosed

Answer 12

by stethoscope, X-rays, skin tests using PPD, culturing

and an ACID FAST STAIN OF SPUTUM

Question 13

what does a TB skin test identify

Answer 13

individuals with previous exposure to M. Tuberculosis by the presence of a hard red, swelling at the test site

Question 14

What does a chest X-ray do for TB diagnosis

Answer 14

it identifies individuals with active TB

Question 15

What easy is TB treatment, and what is used

Answer 15

it is difficult with common antimicrobials because the bacteria grow slowely and live in macrophages, but months of combination therapy is used to treat the disease

Question 16

what are MDR TB strains

Answer 16

Multi drug resistant TB strains, are at least resistant to INH and rifampin

Question 17

how are MDR TB strains treated

Answer 17

with cipro and kanamycin for up to 2 years (100 x more expensive)

Question 18

What are XDR TB strains

Answer 18

Extensively drug resistant TB strains (INH, rifampin, fluoroquinone and one of the second line drugs)

Question 19

how is TB prevented

Answer 19

prophylactic use of antibacterial drugs for those who went from negative to positive on the skin test and those exposed to active TB
vaccine (BCG) more effective for kids, used in countries where TB is common

Question 20

What are MOTTs

Answer 20

mycobacterium other than tuberculosis

Question 21

What are common MOTTs

Answer 21

1. Mycobacterium avium complex (MAC)
2. Mycobacterium Kansasii
3. Mycobacterium fortuitum
4. Mycobacterium Marinum
5. Mycobacterium Scrofulaceum

Question 22

what happens with mycobacterial infections in AIDS patients

Answer 22

mycobacterium avium-intracellulare is the most common amongst AIDS patients, they affect almost every organ and cause massive organ failure.

Question 23

how easily are mycobacterial infections in AIDS patients to treat

Answer 23

very difficult do to the disseminated nature of the infection

Question 24

What is the bacteria that causes leprosy

Answer 24

mycobacterium leprae

Question 25

how easily in mycobacterium leprae grown

Answer 25

hard, it has never been grown in cell-free culture

Question 26

how is leprosy transmitted

Answer 26

person to person contact, or a break in the skin

Question 27

What are the two forms of leprosy

Answer 27

Tuberculoid leprosy

lepromatous leprosy

Question 28

What is tuberculoid leprosy

Answer 28

• high cell-mediated response
• Low antibody
• nonprogressive disease, loss of sensation in skin regions

Question 29

What is lepromatous leprosy

Answer 29

• low cell-mediated response
• High antibody
• gradual tissue destruction
• loss of facial features, digits, and other structures

Question 30

what are the only two places mycobacterium leprae can be cultivated

Answer 30

footpads of mice, bellies of 9-banded armadillos

Question 31

how is leprosy diagnosed

Answer 31

loss of sensation in skin lesions (tuberculous leprosy)

disfigurement (lepromatous leprosy)

Question 32

how is leprosy treated

Answer 32

dapsone and rifampin for 6 mo. (tuberculoid)

dapsone, rifampin, and clofazimine for 2 years dapsone for 10 years

Question 33

what is the mycobacterium that causes beruli ulcers

Answer 33

mycobacterium ulcerans

Question 34

where is mycobacterium ulcerans foudn

Answer 34

slow moving water

Question 35

how does mycobacterium ulcerans enter the body

Answer 35

through skin abraisions

Question 36

does mycobacterium ulcerans grow intracellularly or extracellularly

Answer 36

extracellularly

Question 37

what is the toxin make by mycobacterium ulcerans

Answer 37

mycolactone, a polyketide (lipid)

Question 38

what does mycolactone (beruli ulcer toxin) do

Answer 38

destroys subcutaneous tissue, and is a powerful immune suppressing agent

Question 39

what is the main visible symptom of a beruli ulcer

Answer 39

when the subcutaneous tissue has been destroyed by mycolactone, the skin on top dies and sloughs off producing a clean ulcer

Question 40

how is a beruli ulcer treated

Answer 40

there is no reliable drug therapy, the infected skin must be removed and replaced with a skin graft