Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Microbiology by Bonnie > Mycobacteria > Flashcards

Mycobacteria Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

Mycobacteria (stain)

A

Gram-positive structure but stains acid-fast (carbol fuchsin stain), mycolic acid in cell envelope, grow very slowly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

M. tuberculosis characteristics (where does it grow, metabolism)

A

Facultative intracellular, strictly aerobic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

M. tuberculosis pathogenesis

A

Exposure, infection (bacteria taken up by alveolar macrophages), disease (spreads to local lymph nodes -> dissemination)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How does host immune response control TB?

A

Cellular immune response (delayed type hypersensitivity)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What increase risk of reactivation in TB?

A

HIV infection, advanced age, alcoholism, malnutrition, immunosuppression

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

TB Histopathology

A

Macrophages undergo transformation as try to contain bacteria, lymphocytes surround macrophages, fibrous layer forms around macrophages (granuloma), necrosis of center of granuloma (caseating granuloma)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

M. tuberculosis bacterial factors

A

Mycolic acid and lipid, slow growth leads to antibiotic resistance (antibiotics work best against rapidly dividing bacteria)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Tuberculosis 2 types

A

Pulmonary TB: Chronic productive cough, cavitation in the apex of the lung (higher concentration of oxygen in upper lobes of lung)

Extrapulmonary TB: Particularly common in HIV-infected patients, referred to as Pott’s Disease when involve vertebrae of back

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

M. bovis

A

Infect cattle, acquired by drinking unpasteurized milk, causes tuberculosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Miliary TB

A

Widely disseminated TB not controlled by the immune system, systemic infections, organism in vasculature, not airways

“Snowstorm” pattern

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

TB Diagnostic Tests (Including active disease)

A

Tuberculin skin testing, Interferon-gamma release assays

Active disease: Acid-fast staining of sputum, Gold standard: Growth from clinical specimens, Nucleic acid amplification tests (NAAT)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

TB Treatment (Latent TB)

A

Small loads of organisms in body - Rifampin, isoniazid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

TB Treatment (Active TB)

A

High bacterial loads - risk of antibiotic resistance

Usually treated with multiple drugs (4 -> 2 drugs for 6 months)

Rifampin
Isoniazid
Pyrazinamide
Ethambutol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

MDR TB Definition

A

Multiple-drug-resistant

Resistance to rifampin and isoniazid, results from noncompliance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

XDR TB Definition

A

Extensively drug resistant

MDR-TB with additional resistance to quinolones and at least one 2nd line injectable agent (amikacin, capreomycin, kanamycin)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

TB Prevention

A

BCG vaccine derived from attenuated strain of M. bovis

Respiratory isolation for patients with AFB-positive sputum

17
Q

M. leprae (where does it grow, what does it cause)

A

Obligate intracellular pathogen, cause of leprosy (Hansen’s disease)

18
Q

M. tuberculosis versus M. laprae (where do they grow)

A

Facultative versus obligate intracellular

19
Q

M. laprae DP

A

Human-to-human transmission, directly kill Schwann cells

20
Q

2 extremes of leprosy

A

Tuberculoid (intense cell-mediated immune response, very few bacteria in tissues, Th1 response)

Lepromatous (no cellular immune response, many bacteria present, Th2 response)

21
Q

Leprosy CD

A

Hypopigmented skin lesions (cooler tissues, often raised along edges), affects peripheral nerves

Interesting manifestations - leonine facies, saddle-nose

22
Q

Leprosy DLT

A

Does not grow on artificial media or cell culture
Cultured in armadillos
Extremely slow grower
Diagnosis made by histologic examination of a biopsy of a skin lesion

23
Q

Leprosy treatment

A

Dapsone and rifampin +/- clofazimine for 6-12 months

24
Q

MAC (what does it cause)

A

M. avium-intracellulare complex

  • Disseminated and GI disease in immunocompromised patients
  • Pulmonary disease in elderly and individuals with cystic fibrosis
25
Q

M. kansasii (what does it cause)

A

Pulmonary infections similar to TB

26
Q

M. abscessus and M. fortuitum (what does it cause)

A

Rapid-growers

Pulmonary, skin, soft tissue infections

27
Q

M. marinum (what does it cause)

A

Soft tissue infections following contact with fish tanks, fish, salt-water, spread up lympathics

28
Q

Know for boards: Cuts finger while cleaning aquarium, develop soft tissue infection

A

M. marinum

29
Q

TB Signs and Symptoms

A

Fever and chills, night sweats, weight loss

30
Q

What medium does TB grow on

A

Lowenstein-Jensen medium

31
Q

M. tuberculosis virulence factors

A

Cord factor, sulfatides (prevent fusion with lysosome)

32
Q

TB Reactivation symptoms

A

Cough, night sweats, hemoptysis

33
Q

Reactivation can affect which systems

A

Skeletal system - Pott’s disease

Cavitary lesion - Tuberculoma

34
Q

What results after primary TB infection

A

Ghon complex

Microbiology by Bonnie (14 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions