03 - Microbe 36 - Mycobacterium tuberculosis LOTS OF INFO Flashcards

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1
Q

Acid-fast bacilli – large amounts of mycolic acids and lipids in cell wall impairs staining with aqueous stains

A

Mycobacterium tuberculosis and related mycobacteria

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2
Q

look at picture on page 28 of PDF for exterior of Mycobacterium tuberculosis

A

sweet & neat

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3
Q

Causes tuberculosis – world’s leading infectious disease (hundreds of millions of cases)

A

Mycobacterium tuberculosis

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4
Q

Mycobacteria other than M. tuberculosis are collectively referred to as

A

MOTT

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5
Q

(1) Pulmonary lesions

2) Disseminated (kidney, liver, testes, CNS

A

Description of tuberculosis caused by Mycobacterium tuberculosis

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6
Q

Transmission and epidemiology of Mycobacterium tuberculosis

A

(1) Highly communicable via aerosols or dust particles containing tubercle bacilli
(2) Prevalent in AIDS patients, crowded populations (e.g. prisons), and street people
(3) Transmission in American society has been greatly affected by changes in building codes (e.g. reduced fresh air circulation) and social mores (e.g. lack of quarantine, including HIV-infected persons).

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7
Q

(1) Highly communicable via aerosols or dust particles containing tubercle bacilli
(2) Prevalent in AIDS patients, crowded populations (e.g. prisons), and street people
(3) Transmission in American society has been greatly affected by changes in building codes (e.g. reduced fresh air circulation) and social mores (e.g. lack of quarantine, including HIV-infected persons).

A

Transmission and epidemiology of Mycobacterium tuberculosis

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8
Q

Study page 29 of PDF in detail about Mycobacterium tuberculosis

A

did you do it? …..

seriously don’t be a turd and put down the sweet treats

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9
Q

Pathogenesis of

(1) Primary tuberculosis

A

(a) Mild and often asymptomatic (flu-like symptoms possible)
(b) Bacteria are breathed into alveoli where they multiply
(c) Tubercle bacilli are ingested by resident macrophages in the pulmonary alveoli
(d) Bacteria multiply within the macrophages
(e) Macrophages containing the bacteria migrate to local lymph nodes where they encounter T-lymphocytes of the cell mediated immunity
(f) Cell Mediated Immunity slows the growth and causes inflammation – process takes about 30 days from initiation of infection
(g) Tuberculin skin test becomes positive
(h) Chest X-ray may reveal growing patches of density in the lung
(i) Bacteria are contained within tubercles – small granulomas consisting of epithelioid and giant cells. Granuloma formation is partly caused by cord factor.
(j) Spontaneous healing – calcified tubercles – occurs in about 75% to 90% of the cases

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10
Q

Which phase of tuberculosis is Cell Mediated Immunity effective?

A

Primary tuberculosis

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11
Q

in which phase of tuberculosis will the Mycobacterium tuberculosis be contained to TUBERCLES?

A

Primary tuberculosis

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12
Q

tubercles

A

– small granulomas consisting of epithelioid and giant cells. Granuloma formation is partly caused by cord factor

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13
Q

– small granulomas consisting of epithelioid and giant cells. Granuloma formation is partly caused by cord factor

A

tubercles

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14
Q

in which phase of Tb will we most likely see calcified tubercles?

A

Primary tuberculosis – occurs in about 75% to 90% of the cases

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15
Q

(a) No clinical symptoms
(b) No shedding of bacteria
(c) Skin test positive; chest xray probably negative
(d) No true medical disease, just potential presence of live bacteria within tubercules

A

Latent phase of Tb

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16
Q

clinical disease of Tb?

A

Secondary tuberculosis

17
Q

After some time (often years after infection begins), cell mediated immunity fails to contain the infection

A

Secondary tuberculosis

18
Q

The centers of the tubercles become necrotic and advance to form acellular masses of cheesy debris – caseous material. Ghon complex – combination of tubercles in the lung and caseation in lymph nodes

which phase?

A

Secondary tuberculosis

19
Q

Ghon complex

A

– combination of tubercles in the lung and caseation in lymph nodes

20
Q

(a) After some time (often years after infection begins), cell mediated immunity fails to contain the infection
(b) The centers of the tubercles become necrotic and advance to form acellular masses of cheesy debris – caseous material. Ghon complex – combination of tubercles in the lung and caseation in lymph nodes

(c) Macrophages become more activated
i. Interleukin-1 – mediator of fever
ii. Tumor necrosis factor (cathectin) – interferes with lipid metabolism (leads to weight loss)

(d) Ghon complex enlarges and tubercles rupture into airways and blood vessels – clinical tuberculosis (about 6% of cases)
i. Caseous material coughed up
ii. Major organ involvement

(e) Rapid failure of Cell Mediated Immunity may lead to disseminated miliary tuberculosis – rapidly progressive systemic disease and death (about 3% of cases)
i. Miliary – lesions resembles grains of millet (bird seed)
ii. Occurs in less than 5% of cases; primarily immunocompromised patients
iii. Disseminates to various organs, especially kidneys, brain, spleen, and liver
iv. Usually fatal generalized infection

A

Secondary tuberculosis

21
Q

i. Interleukin-1 – mediator of fever

ii. Tumor necrosis factor (cathectin) – interferes with lipid metabolism (leads to weight loss)

A

Macrophages become more activated in secondary tuberculosis

22
Q

Ghon complex enlarges and tubercles rupture into airways and blood vessels – clinical tuberculosis (about 6% of cases)

i. Caseous material coughed up
ii. Major organ involvement

A

secondary tuberculosis or clinical tuberculosis

23
Q

i. Miliary – lesions resembles grains of millet (bird seed)
ii. Occurs in less than 5% of cases; primarily immunocompromised patients
iii. Disseminates to various organs, especially kidneys, brain, spleen, and liver
iv. Usually fatal generalized infection

A

Rapid failure of Cell Mediated Immunity may lead to disseminated miliary tuberculosis – rapidly progressive systemic disease and death (about 3% of cases)

secondary tuberculosis or clinical tuberculosis

24
Q

Miliary think fatal and think

A

secondary tuberculosis or clinical tuberculosis

25
Q

vaccine for

A

BCG (Bacillus Calmetter-Guerin) is prepared from attenuated bovine TB
bacterium. Is administered in many countries with high TB rate, but not used inUSA.

26
Q

Tuberculin Skin Test

A

PPD or Purified Protein Derivative (looking for previous immune response) Remember that previously vaccinated person will produce a false-positive

27
Q

Antimicrobic Resistance and Treatment of

Mycobacterium tuberculosis

A

(a) Due to high frequency of resistance, infections are treated with two- to four-drug regimen of antituberculosis and traditional antimicrobics: Isoniazid (INH),
Rifampin, Ethambutol, Streptomycin, etc.

(b) MDR-TB (Multiply Drug Resistant) – resistant to 2 or more TB drugs

(c) XDR-TB (Extremely Drug Resistant) – resistant to 2 or more plus
fluroquinolones and one second-line anti-TB drugs

28
Q

Mycobacteria other than ____ are collectively referred to as MOTT

A

M. tuberculosis

29
Q

unrelated to this block, but if you have a quick response for salmonella or many other microbes (12 hrs or less) think this…

A

Toxin