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Flashcards in Mycobacteria (complete) Deck (40):
1

What are the structures of an acid fast cell wall

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

2

What are the 3 main mycobacterial diseases in humans

Tuberculosis
Leprosy
Buruli Ulcer

3

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

1/3 of the worlds population

4

What bacteria causes TB

mycobacterium tuberculosis

5

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

cord factor

6

What are the three types of TB

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

7

What is primary TB

initial infection with M. Tuberculosis

8

what is secondary TB

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

9

what is disseminated TB

This is when infection spreads throughout the body

10

What two things reduced the incidence of TB in the US

pasteurization of milk and the isolation of patients in sanatoriums

11

who is at high risk for TB

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

12

How is TB diagnosed

by stethoscope, X-rays, skin tests using PPD, culturing
and an ACID FAST STAIN OF SPUTUM

13

what does a TB skin test identify

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

14

What does a chest X-ray do for TB diagnosis

it identifies individuals with active TB

15

What easy is TB treatment, and what is used

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

16

what are MDR TB strains

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

17

how are MDR TB strains treated

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

18

What are XDR TB strains

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

19

how is TB prevented

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

20

What are MOTTs

mycobacterium other than tuberculosis

21

What are common MOTTs

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

22

what happens with mycobacterial infections in AIDS patients

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

23

how easily are mycobacterial infections in AIDS patients to treat

very difficult do to the disseminated nature of the infection

24

What is the bacteria that causes leprosy

mycobacterium leprae

25

how easily in mycobacterium leprae grown

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

26

how is leprosy transmitted

person to person contact, or a break in the skin

27

What are the two forms of leprosy

Tuberculoid leprosy
lepromatous leprosy

28

What is tuberculoid leprosy

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

29

What is lepromatous leprosy

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

30

what are the only two places mycobacterium leprae can be cultivated

footpads of mice, bellies of 9-banded armadillos

31

how is leprosy diagnosed

loss of sensation in skin lesions (tuberculous leprosy)
disfigurement (lepromatous leprosy)

32

how is leprosy treated

dapsone and rifampin for 6 mo. (tuberculoid)
dapsone, rifampin, and clofazimine for 2 years dapsone for 10 years

33

what is the mycobacterium that causes beruli ulcers

mycobacterium ulcerans

34

where is mycobacterium ulcerans foudn

slow moving water

35

how does mycobacterium ulcerans enter the body

through skin abraisions

36

does mycobacterium ulcerans grow intracellularly or extracellularly

extracellularly

37

what is the toxin make by mycobacterium ulcerans

mycolactone, a polyketide (lipid)

38

what does mycolactone (beruli ulcer toxin) do

destroys subcutaneous tissue, and is a powerful immune suppressing agent

39

what is the main visible symptom of a beruli ulcer

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

40

how is a beruli ulcer treated

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