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Flashcards in Skinny bacteria III Deck (81):
1

Drum stick appearing rods =?

Clostridium

2

What is the gram stain and morph of clostridium? Aerobic? Spores?

Gram positive, spore forming rods
Anaerobic

3

Where is clostridium found?

Soil, water, sewage

4

What are the three species and toxins of clostridium that cause disease?

C. perfringens (hemolysin)
C. difficile (enterotoxins)
C tetani (Neural toxins)

5

Growth of C perfringens produces a lot of what?

CO2 and H gas

6

What skin infection does C perfringens cause?

Gas Gangrene

7

What is the most important toxin associated with C perfringens? What is its function?

Alpha toxin

Phospholipase destroys cell membrane

8

Why will you not see leukocytes in the area surrounding C perfringins?

Alpha toxin kills them

9

What are the four skin diseases that C perfringens usually causes?

1. Cellulitis
2. Fasciitis
3. Suppurative myositis
4. Myonecrosis

10

What are the reservoirs of Clostridium?

Soil, or GI tract

11

Why is it called GAS (not group A strep) gangrene?

C. perfringens produces CO2, so there are crepitations of the wound

12

What are the symptoms of gas gangrene?

Cellulitis initially, later supprative myositis

13

Gas on x-ray = ?

Gas gangrene

14

How do you diagnose gas gangrene?

Microsopic deteaction of rods WITHOUT leukocytes

15

What is the treatment for gas gangrene?

Surgical debridment and high dose PCN

16

What is the MOA of C. tetani infection from a rusty nail?

Small local infection allow for anaerobic growth of C tetani, producing exotoxin

17

What is the MOA of tetanospasmin?

Inhibition of interneurons

18

Is tetanospasmin heat liable?

Yes

19

What are the symptoms of tetanus?

Spastic paralysis

20

True or false: Tetanospasmin is readily degraded by the GI tract?

yes

21

What is the most common site of infection for tetanus?

Umbilical stump of noenates

22

What is the risus sardonicus?

Tetanus infection smile

23

Why is it hard to culture tetanus?

Anaerobic bacteria

24

How do you diagnose tetanus?

Clinical presentation

25

What population is usually infected with tetanus in the U.S.?

Old people

26

What is the treatment for tetanus?

Debride the wound
Human IgG/antitoxin
Metronidazole

27

What is the gram stain and morphology of mycobacterium? Anaerobic? Spores?

Weakly gram positive
Acid fast
Aerobic
No spores

28

What is the lipid found in mycobacterium that allows them to be stained with the acid fast stain?

Mycolic acid
Lipoarabinomanan

29

True or false: mycobacterium are resistant to lots of stuffs

True

30

How fast do mycobacterium grow?

Super slow

31

What are the two major mycobacteria that cause disease?

Myobacterium TB
M. Leprae

32

Are there endotoxins or exotoxins with mycobacterium?

No

33

What is the agar needed to grow mycobacteria? (board question)

Lowenstein-Jensen

34

What is the primary infection associated with mycobacterium?

Pulmonary disease (mycobacterium TB)

35

What is Potts disease?

Skeletal TB (osteomyelitis) in the upper lumbar and lower thoracic vertebrae

36

What is the gibbus deformity?

Strange, painful lump in the back d/t Potts disease

37

How do you diagnose pott's disease?

PPD test
See in biopsy in macrophages

38

What cells do mycobacteria live in?

Macrophages

39

What is the host response to infection with mycobacteria? How?

Granulomas

**(T cells differentiate into Th1 and produce IFNgamma)**

40

What is the treatment for mycobacteria?

Isoniazid and rifampin for a **long time**

41

What cells does Mycobacterium Leprae target?

Macrophages and Schwann cells

42

What is the causative agent of Leprosy? How fast do symptoms present?

Mycobacterium leprae

Slow presentation

43

What are the antigens of Mycobacterium Leprae? (2)

Cell wall's phenolic glycolipid and phenolase

44

What are the two distinct stages of M. Leprae?

Tuberculoid
Lepromatous

45

What are the two different immune responses to M. Leprae?

Th1 = tuberculoid (cell mediated)
Th2 = lepromatous (immunoglobin mediated (not choose wisely)

46

What is Hansen's disease?

Lepromatous leprae

47

How do you diagnose leprosy? Can you culture?

Lepromin skin test (should be negative since no cell mediated rxn)

No culture

48

Does mycobacterium leprae have exo or endo toxin?

Neither

49

How is leprosy transmitted?

Nasal secretions

50

What are the symptoms of lepromatous leprosy?

Raised granulomas all over the skin

51

What are the symptoms of tuberculoid leprosy?

Single area infection that is flat

52

What is the gram stain and morphology of Nocardia? Aerobic? Acid fast? Aerobic?

Aerobic gram positive rod that forms

filamentous rods

Weakly acid fast

53

What are aerial hyphae?

Bacterial "hyphae" produced by Nocardia

54

What is mycetoma? Cause? Pain?

Chronic infections of the skin and underlying tissues caused by Nocardia

No pain

55

What is the most common site of mycetoma? How is it transmitted?

Foot, from walking around in the environment (gardening)

56

What are the two major infections associated with Nocardia?

1. Lymphocutaneous disease
2. Cellulits and cutaneous abscess

57

How do you diagnose Nocardia? Treat?

Culture
TMP=SMX

58

What is the gram stain and morphology of actinomyces israelii? Aerobic?

Filamentous rod that looks like fungi

Anaerobe

59

True or false: Actinomyces israelii is an opportunistic pathogen

True

60

What is Actinomyces israelii infxs associated with?

Abscesses from Dental work

61

What does Actinomyces israelii look like microscopically?

Sulfur granules

62

Sulfur granules = ?

Actinomyces israelii

63

How do you diagnose Actinomyces? What is the treatment for Actinomyces israelii?

Acid fast culture
PCN

64

What is the cause of cervicofacial actinomycosis?

Actinomyces israelii

65

How do you differentiate Actinomyces israelii from Norcardia?

Lack of staining with modified acid fast stains for Actinomyces israelii

66

What are the bacteria that causes acne vulgaris? Is it normal flora?

Propionibacterium acnes, which is normal flora

67

What is the gram stain and morphology of propionibacterium acnes?

Small, anaerobic gram positive rof

68

What is the treatment for propionibacterium acnes?

Topical benzoyl peroxide
oral Abx

69

What is peridontitis?

Chronic inflammatory disease which includes the gingiva along with loss of CT and bone support to the teeth

70

What is the cause of Gingivitis and periodontitis?

Bacteria in dental plaques (polymicrobial)

71

What is dental plaque?

bacterial biofilm

72

What is the dominant organism associated with dental caries?

Strep mutans

73

What is the the underlying cause of dental caries?

Acid products of Strep mutans in biofilm

74

Culture without any lymphocytes = ?

C. perfringens

75

What are the skin lesions present with tuberculoid leprosy? Lepromatous leprosy?

Tuberculoid leprosy= few plaques
Lepromatous leprosy= many red macules with nerve involvement

76

What is the histopathology with tuberculoid leprosy? Lepromatous leprosy?

Tuberculoid leprosy= few to no acid fast rods observed
Lepromatous leprosy= numerous acid fast rods in skin lesions

77

What is the infectivity of tuberculoid leprosy? Lepromatous leprosy?

Tuberculoid leprosy= Low
Lepromatous leprosy= High

78

What is the immune response to Tuberculoid leprosy? Lepromatous leprosy?

Tuberculoid leprosy= DTH rxn to lepromin
Lepromatous leprosy= no reactivity to lepromin

79

What is the clinical pattern seen with Actinomycosis? Nocardiosis?

Actinomycosis = lump with draining siinus
Nocardiosis = cellulitis

80

What is the site associated with Actinomycosis? Nocardiosis?

Actinomycosis = Face/neck
Nocardiosis = Extremities

81

What is the source of Actinomycosis? Nocardiosis?

Actinomycosis = endogenous flora
Nocardiosis = Environment