Brainscape's Knowledge GenomeTM

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


See full index

Microbiology > E2- MTB and NTM > Flashcards

E2- MTB and NTM Flashcards

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

Are mycobacterium tuberculosis infections common?

A

Yes, many millions/billions infected but over 90% of healthy persons infected never become ill

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

What strains of mycobacterium tuberculosis are particularly difficult to tx?

A

MDR (multi-drug resistant) and XDR (extensively drug resistant) strains

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

What are the two main problems for pts with inadequate tx for a mycobacterium tuberculosis ?

A

Remain infectious

Opportunity for drug resistance

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

Who are the only reservoirs for MTB?

A

Humans

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

How is MTB transmitted?

A

Person-to-person via aerosol droplet nuclei

not as dangerous on surfaces

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

What populations have an especially difficult time with MTB and MAC?

A

AIDs`patients

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

What is an occupational hazard for people who do autopsy and anatomist from accidental exposure to MTB? How can you prevent these?

A

Prosector’s warts

Gloves

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

What age populations are most commonly affected by MTB?

A

Bimodal age distributions- infants and older adults

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

Who is at highest risk for MTB infection?

A

Infants and immunocompromised pts

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

What can result in meningitis?

A

Hematogenous dissemination of a MTB infection

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

What is a possible etiology of MTB in older pts?

A

Failure of the immune system

Possible reactivation of latent infection

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

What three things influence the probability of MTB infection?

A

Environment- crowded conditions
Duration of exposure
Virulence of strains

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

How do many children become infected by MTB?

A

Close contact with caregivers

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

What are some initial MTB infection risk factors?

A 
Close contact with TB case
Residence in long-term care facility
Low income/inner city housing
Alcohol or IV drug use
Malnutrition
DM
Silicosis- pneumoconiosis (coal minners)
Imunosupression
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What three species of MTB produce human TB?

A 
Mycobacterium tuberculosis
Mycobacterium bovis (cattle)
Mycobacterium africanum (Wast Africian)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How do we control Mycobacterium bovis?

A

Pasteurization and treatment of infected farm animals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How is Mycobacterium africanum spread?

A

Opportunist infection, especially in immunocompromised HIV pts
Spread by food, no animal reservoirs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What aerotolerance is M. tuberculosis? What shape?

A

Obligate aerobes

Bacillus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What vaccine can be used for MTB in high endemic regions?

A

BCG (Bacille Calmette-Guerin)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What can kill M. tuberculosis?

A

Heat sensitive- killed by pasturization

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Where does M. tuberculosis grow within a human?

A

Alveolar macrophages

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What two qualities does mycolic acid give M. tuberculosis?

A

Acid fast

Hydrophobic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What virulence factors and toxins do MTB have?

A

No classic virulence factors or toxins, the structural features create the issues

24
Q

What structural components makes MTB virulent?

A

Mycolic acids
Cord factor
Lipoarabinomannan (LAM)

25
Q

How does mycolic acid add virulence to MTB?

A

Prevent dehydration and resists H2O2

26
Q

What is a cord factor?

A

Mycoside- glycolipid mycolic acid + disaccharide

27
Q

How does Lipoarabinomannan (LAM) provide virulence to MTB?

A

Inhibits cell-mediated immunity

Scavenges ROI

28
Q

What are the five potential outcomes of MTB infection?

A
  1. Immediate resolution
  2. Primary disease
  3. Progressive primary (active) disease
  4. Latent infection
  5. Endogenous reaction/secondary infection
29
Q

If there is no active TB because the innate immune system is able to clear the bacteria, what is this called?

A

Immediate resolution

30
Q

Granuloma formation may progress to what?

A

Caseous lesions

31
Q

What are areas surrounded by macrophages, multi-nucleated giant cells, fibroblasts, and collagen fibers that harbor viable MTB cells?

A

Ganulomas

32
Q

Over time, what can form fibrotic tubercle and calcify, and can be seen on X-ray?

A

Granulomas

33
Q

What is MTB diagnosed?

A

X-ray
Skin test
Sputum strain culture
Rapid blood test based on IFN-y

34
Q

The USA depends on what for treatment of infection persons?

A

Recognition, isolation, and treatment of infected persons

35
Q

What kind of testing is used to ID latent TB?

A

Serial screening

36
Q

Is MAC gram positive/negative/acid fast? What shape?

A

Weakly gram positive bacilli

Acid fast

37
Q

Where is MAC found?

A

Water, soil, and plants

38
Q

How is MAC transmitted?

A

Ingestion of contaminated water or food

DISTINCT FROM TB- NO person to person transmission

39
Q

Is patient isolation required for MAC infection?

A

NO

no person to person transmission

40
Q

What is the leading cause of Nontuberculous mycobacteria (NTM) infection in HIV-positive pts in the US?

A

MAC

41
Q

What patient populations may get a disseminated MAC infection

A

AIDS patients

42
Q

How is Nontuberculous mycobacteria (NTM) dx?

A

Microscopy to reveal acid-fast bacteria and culture
Must exclude other etiologies (fungi, TB)
-Use PCR to determine 16s rRNA sequence pathogen

43
Q

What must you take into account when treating a MAC infection?

A

HIV infection status

44
Q

What is an epidemic infection among cystic fibrosis patients?

A

Mycobacterium abscesses (very difficult to treat in CF due to intrinsic abx resistance)

45
Q

Can latent TB be spread? Should these pts be treated?

A

Latent TB cannot be spread, but these pts should still be treated

46
Q

What results from lymphohematogenous spread of a primary infection or by a latent focus with subsequent spread?

A

Miliary tuberculosis

47
Q

What test can be used to detect MTB and Rifampin resistance?

A

GeneXpert Rapid Test

48
Q

What syndrome is found in elderly female non-smokers and is associated with MAC?

A

Lady Windermere’s syndrome

49
Q

What kind of stains are used for MTB?

A

Ziehl-Neelson or Kinyoun stains

50
Q

How would you treat a MAC infection in HIV negative patients?

A

Continue antibiotics until sputum cultures are negative for 1 year

51
Q

How do you prophylactically treat HIV positive patients without a MAC infection?

A

Chemoprophylaxis in patients with CD4< 50, and can discontinue after 3 months after CD4 >100

52
Q

How do you treat HIV positive patients with a MAC infection?

A

Lifelong therapy for patients without immune reconstitution

-or begin treatment for 2 weeks then anti-HIV HAART

53
Q

What can be used to treat HSV?

A

Acyclovir, valacyclovir, and Famciclovir

54
Q

What is the MOA of acyclovir/valacyclovir?

A

The viral enzyme thymidine kinase phosphorylates acyclovir and this will halt viral DNA replication

55
Q

What is the treatment for parvovirus?

A
  • Most patients make a rapid and full recovery.
  • NSAIDS
  • Immunoglobulin for anemic patients

Microbiology (23 decks)

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