Mycobacterium spp. Flashcards Preview

RUSVM BacT Exam 1 > Mycobacterium spp. > Flashcards

Flashcards in Mycobacterium spp. Deck (67)
Loading flashcards...
1
Q

Is corynebacterium gram positive or gram negative?

A

Gram Positive w/ Mycolic Acid

2
Q

Oxygen requirement?

A

Aerobic growth

3
Q

T/F: Mycobacterium survives well in the environment

A

True

4
Q

M. Avium is found in patients that are ____________

A

Immunocompromised and intracellular lay

5
Q

Mycobacterium avium subsp. paratuberculosis is the scientific name of _______

A

Johne’s Disease

6
Q

What type of pathogens are Mycobacterium?

A

Facultative intracellular pathogens (survive in macrophages)

7
Q

What type of immunity is assoc. with Mycobacterium?

A

Cellular - Th1 response

8
Q

What type of inflammation is assoc. with Mycobacterium?

A

Granulomatous inflammation (CHRONIC)

9
Q

What are the 2 virulence factors associated with Mycobacterium?

A
  1. Mycolic acid containing cell wall lipids

2. Cell protein antigens

10
Q

Mycolic acid in the cell wall allows for ________(3)

A

Survival in macrophages, stimulate cytokines production, enhance immunomodulating effects

11
Q

What protein is involved with Cell Protein Antigens (virulence factor)

A

Tuberculin

12
Q

Mycobacterium spp. stains Acid fast __________ bacteria, and the reaction is generally ___________

A

Positive, and weak

13
Q

M. tuberculosis, M. avium subsp. paratuberculosis, M. leprae, and M. lepraemurium are all considered ________________ pathogens

A

Obligate Pathogens

14
Q

Most spp. of Mycobacterium are soil and water ___________

A

Saprophytes - they can opportunistically infect hosts

15
Q

Important Diseases caused by Mycobacterium (5)

A

M. tuberculosis / M. bovis - mammalian tuberculosis

M. Avium subsp. avium - avian tuberculosis

M. Leprae (human) - leprosy

M. Lepraemurium (cat) - leprosy

M. avium subsp. paratuberculosis - Johne’s disease

16
Q

M. tuberculosis (human) is transmitted via

A

Inhalation

17
Q

M. bovis is transmitted via:

A

Ingestion

18
Q

What type of hypersensitivity is associated with Tuberculosis?

A

Type IV (Delayed) Hypersensitivity

19
Q

What type of necrosis is assoc. with Tuberculosis (think M. avian subsp. paratuberculosis)

A

Caseous necrosis

20
Q

What kind of lesions are assoc. with Tuberculosis?

A

Granulomas

21
Q

What types of tubercles can form from Granulomas? (2)

A
  1. “Hard” Tubercle - epithelioid macrophages

2. “Soft” Tubercle - caseous necrosis

22
Q

What type of epithelioid cells surround the Granuloma (tubercle)

A

Multinucleated giant cells (Langhan’s cells)

23
Q

What are the elements of a Granuloma (tubercle)?

A
  1. Activated macrophage/epithelioid cells
  2. Lymphocytes
  3. Fibrosis
  4. Mineralization
  5. Coagulative/ caseous/ liquefactive necrosis (sometimes seen)
24
Q

Who are the reservoirs for M. tuberculosis?

A

HUMANS

25
Q

Is M. tuberculosis zoonotic?

A

YES

26
Q

What is the transmitting route from Elephants-humans?

A

Through aerosol

27
Q

What are the 4 PRIMARY drugs to treat TB?

A

Isoniazid
Rifamycins
Ethambutol
Pyrazinamide

28
Q

What are the two secondary drug types to treat TB?

A

Aminoglycosides

Fluoroquinolones

29
Q

Can you use combination drug therapy with TB?

A

Yes, combination therapy is needed

30
Q

What drugs are associated with Multi-drug resistance TB (MDR-TB)?

A

Isoniazid and Rifampin

31
Q

Is M. Bovis zoonotic?

A

YES - zoonotic TB

32
Q

What is the main portal of entry for M. bovis?

A

The GI Tract

33
Q

What is the host range for M. bovis?

A

BROAD RANGE - primarily bovine but can infect opossum, badgers, deer, and several other wildlife spp.

34
Q

At what stage is M. bovis (Bovine TB) recognized?

A

Very advanced stages (earlier stages are generally unrecognizable); sometimes unrecognized until slaughter

35
Q

What is the most common mode of transmission for M. bovis?

A

Aerosol*** among cattle

36
Q

How do most humans acquire M. bovis?

A

In unpasteurized / contaminated milk

37
Q

Where does M. bovis enters the body for cattle? For badgers?

A

Cattle - at any site

badgers - through skin wounds

38
Q

What are the typical clinical signs assoc. with M. bovis?

A

Enlarged regional lymph nodes and generalized wasting

39
Q

How would you diagnose Bovine TB?

A
Tuberculin test
Acid-fast stain
Culture
PCR
*Tuberculin hypersensitivity skin tests*
40
Q

What vaccines are available (if any) for cattle and humans for M. bovis TB?

A

Cattle - no vaccines available

Humans - vaccine for high prevalent areas

41
Q

What are the primary hosts for Johne’s Disease?

A

Ruminants (CATTLE)

42
Q

What condition is associated with Johne’s Disease?

A

Chronic, progressive granulomatous enteritis

43
Q

Pathogenesis of M. avium subsp. paratuberculosis?

A

Granulomatous enteritis

44
Q

How do cattle develop M. avium subsp. paratuberculosis?

A

Infection via ingestion of contaminated milk OR in utero

45
Q

What disease is associated with having an “iceberg effect?

A

M. avium subsp. paratuberculosis ** - numerous asymptomatic shedders (in feces, and sometimes milk)

Infected herd: 35% immune, 60% asympt. shedders, 2-5% develop clinical disease

46
Q

What are the symptoms associated with M. avium subsp. paratuberculosis? (2)

A

Diarrhea and weight loss (due to disruption of ileo-cecal mucosa)

47
Q

How would you diagnosis Johne’s Disease?

A

SEROLOGY (ELISA - milk, serum)

48
Q

What mechanism can result in advanced stages of Johne’s Disease is left untreated?

A

A nervy

49
Q

What age group is most susceptible to infection of Johne’s Disease?

A

Young - incubation period can be up to 2 yrs.

50
Q

How to treat Johne’s Disease?

A
Culling sick
Detection/isolation
Separate calves at birth
Pasture rotation
Possible vaccination (usually restricted)
51
Q

M. Paratuberculosis may have a role in which disease?

A

Crohn’s Disease

52
Q

Mycobacterium avium complex (MAC) has 3 subsp. that are…?

A

Subsp. avium - Avian TB

Subsp. sylvaticum - Non-TB (atypical) mycobacteriosis

Subsp. hominisuis - pig and human

53
Q

What type of infections does MAC cause?

A

Opportunistic granulomatous infections in humans, animals, and birds

54
Q

Where is MAC typically found?

A

In soil and water (low pH, high temp tolerance)

55
Q

M. Ulcerans and Burundi ulcer is a frequent Mycobacterium disease in what host?

A

Humans - devastating disease

56
Q

In what region (topics / cold) would you find M. ulcerans?

A

Tropical wetlands

57
Q

M. Leprae is otherwise known as (common name)?

A

Leprosy or Hansen’s Disease

58
Q

Transmission of M. leprae is from shedding through _______

A

Nose

59
Q

What is the only known reservoir?

A

Nine-banded Armadillo

60
Q

Few acid fast positive bacilli in a lesion is associated with which type of leprosy?

A

Tuberculoid (paucibacillary)

61
Q

No cell mediated response, severe disease, with numerous acid fast positive bacilli, is assoc. with what type of leprosy?

A

Lepromatous (multibacillary)

62
Q

M. Lepraemurium is also called ____ (common name)?

A

Feline and Murine Leprosy

63
Q

What are the lesions associated with M. lepraemurium?

A

Solitary/multiple cutaneous nodules OR ulcerated lesions

64
Q

Pathogenesis assoc. with M. lepraemurium?

A

Granulomatous Dermatitis Panniculitis

65
Q

Diagnosis via:

A

Geimsa Stain

PCR

Acid Fast Stain

66
Q

What drugs are used for treatment?

A

Rifampin, Clarithromycin, Clofazimine

Doxycycline for dogs

67
Q

Saprophytic Mycobacterium spp. Have what type of host response? (What host pathogenesis?)

A

Granulomatous to pyogranulonatous

chronic non-healing cutaneous lesions with lack of anti-microbial treatment