Mycoplasma, chlamydia, rickettsia, spirochetes, and curved rods (complete) Flashcards Preview

DMD 5245 > Mycoplasma, chlamydia, rickettsia, spirochetes, and curved rods (complete) > Flashcards

Flashcards in Mycoplasma, chlamydia, rickettsia, spirochetes, and curved rods (complete) Deck (73):
1

What are the smallest free living microbes

Mycoplasmas

2

What are three significant structures that most bacterial organisms have, but mycoplasmas do not

cytochromes
enzymes of the krebs cycle
cell walls

3

What is necessary for the groth of mycoplasmas

cholesterol (sterols)

4

Where do you usually find colonized mycoplasmas in the human body

the mucus membranes or respiratory and urinary tracts

5

What is the mycoplasma that causes walking pneumonia

mycoplasma pneumonia

6

what is another name for walking pneumonia

primary atypical pneumonia

7

Where does mycoplasma pneumonia attach

to receptors at the bases of cilia on respiratory epithelial cells

8

What is different about walking pneumonia (primary atypical pneumonia) caused by mycoplasma pneumoniae

it causes a fever, headache, and sore throat those aren't typically pneumonia symptoms

9

how is walking pneumonia spread

by nasal secretions among people in close contact

10

how serious is walking pneumonia

it is usually not severe enough to require hospitalization and death

11

Why is diagnosis difficult for mycoplasma pneumoniae

because they are small and slow growing

12

why is treatment of walking pneumonia difficult

because patients can be infected for a long time without signs or symptoms

13

how big is rickettsias

Extremely small

14

what is the cell wall of rickettsias like

it has such a small amount of peptidoglycan that it appears almost wall less

15

Rickettsias are OBLIGATE INTRACELLULAR PARASITES, what is unusual about them?

it is unusual that an obligate intracellular parasite has functional genes for:
protein synthesis
ATP production
and reproduction

16

What are the four genera of rickettsia that cause disease in humans

Rickettsia
Orienta
Ehrlichia
Anaplasma

17

What causes rocky mountain spotted fever

Rickettsia Rickettsii

18

How is Rocky mountain spotted fever (Rickettsia Rickettsii) transmitted

it is transmitted by infected wood ticks (hard ticks)

19

What causes epidemic typhus

Rickettsia Prowazekii

20

What is the primary host of rickettsia prowazekii

humans

21

how is Rickettsia Prowazekii transmitted

by infected lice (when their feces is rubbed into a bite)

22

what is the mortality rate of epidemic typhus without treatments

70%

23

What is it called when epidemic typhus occurs many years later

Brill-Zinsser disease

24

What is the structure of chlamydial cell walls

Two membranes without any peptidoglycan between them

25

Chlamydias are obligate intracellular parasites, but where inside the cell do chlamydias grow

only within the vesicles of host cells

26

What is unique about Chlamydia's developmental cycle

it involves two forms Elementary Bodies (EB) and Reticulate Bodies (RB).
1. EBs enter the cell via endocytosis
2. EB converts into RB
3. RB rapidly divides
4. Most RBs convert back into EBs
5. EBs are released from the host cell

27

how is chlamydia diagnosed

with a direct fluorescent Ab test

28

What is the bacteria that causes a sexually Transmitted disease and Trachoma

Chlamydia Trachomatis

29

What is the problem associated with the chlamydia STD

Lymphogranuloma veneruem

30

what strain of chlamydia trachomatis causes lymphogranuloma veneruem

the LGV strand of chlamydia trachomatis

31

how is the infection of men and women with the LGV strain of C. trachomatis different

it is mostly in women, but most are asymptomatic (85%)
most of the men who are infected have symptoms (75%)

32

What is Trachoma

the leading cause of non-traumatic blindness in humans in which the bacteria multiplying in conjuctival cells results in scarring, this causes the eyelashes to turn inward and abrade the eye.

33

How is the trachoma transmitted

either to children at birth, or from genital C. Trachomatis bacteria infecting the eye

34

What are spirochetes

thin, tightly coiled, helically shaped bacteria

35

what must you do to see spirochetes

you must use dark-field to see them

36

What are the cell walls of spirochetes like

they are gram negative walls, but they have flagella located in the periplasmic space

37

What are the spirochete flagella called

endoflagella or axial filaments

38

how do spirochetes move

in a corkscrew fashion, the pathogenic ones can burrow through their hosts tissues

39

what are the three genera of spirochetes that are pathogenic to humans, in order of most tightly coiled to most loosely coiled

Leptospira (tight coils)
Treponema (8-20 coils)
Borrelia (3-10 coils)

40

Where is the only place that treponema palliidum pallidum lives naturally

in humans (obligate parasite)

41

What causes syphilis

treponema pallidum pallidum

42

what is almost the only way that syphilis is transmitted

via sexual contact, but it can be spread from infected mother to fetus

43

what occurs when a fetus is infected with syphilis

death, mental retardation, or malformations

44

What are the three stages of a syphilis infection

Primary: Chancre at contact site (3-6 weeks)
Secondary: Rash and chondyloma lata (grey, flat, wart-like lesions(6 weeks))
Tertiary: Gummas and neurologic symptoms (years later)

45

What are the two diseases caused by borrelia

lyme disease and relapsing fever

46

What is the bacteria that causes Lyme disease

borrelia borgdorferi

47

how is lyme disease spread

by ticks (deer tick) (and potentially sexually)

48

How is lyme disease treated

with penicillin or tetracycline

49

What are the three phases of lymes disease in untreated patients

1. An expanding bulls-eye rash
2. neurological symptoms and cardiac dysfunction
3. severe arthritis that can last for years

50

Are cases of lyme's disease increasing or decreasing

increasing due to living proximity between humans and deer ticks

51

how successful are treatments of lymes disease

they are pretty sucessful if done in the first stage of lyme disease, they are less successful after because at that point the damage is mostly done by the immune system

52

how is lyme's disease prevented

avoiding ticks

53

Where is leptospira interrogans normally found

in wild and domestic animals (causes leptospirosis)

54

how is leptospira interrogans transmitted to humans

via direct contact with infected animal's urine, or via contact of contaminated streams, lakes, or moist soil

55

how does leptospira interrogans enter the body

via invisible cuts and abraisions in the skin and mucus membranes

56

once leptospira interrogans enters the body how does it move

via the bloodstream

57

What typically happens with a leptospira interrogans infection

the bacteremia resolves itself and the bacteria are only found in the kidneys and in excreted urine

58

what is the most widespread zoonotic disease

leptospirosis

59

What causes cholera

vibrio cholerae, but there must be a large inoculum because the acidity in the stomach can kill them

60

what is the most important virulence factor of vibrio cholerae

cholera toxin

61

what does cholera cause

firehose diarrhea

62

What is the mechanism of cholera causing diarrhea

1. cholera binds to the epithelial cells
2. portion of toxin (A1) enters the cell
3. A1 stimulates adenylate cyclase
4. cAMP is synthesized
5. cAMP stimulates the cell to release Cl-, Na+ and other electrolytes
6. this draws water into the lumen = firehose diarrhea

63

Are all cholera infections severe

no, some are asymptomatic, others only cause slight diarrhea

64

What are the symptoms of a severe cholera infection

1. watery diarrhea (rice-water stool)
2. vomiting
3. severe dehydration and electrolyte loss
4. dramatic weight loss

65

How is cholera treated

fluid and electrolyte replacement

66

What is likely the most common cause of gastroenteritis in the US

campylobacter jejuni

67

how do humans become infected with campylobacter jejuni

consumption of contaminated food, milk, water, and poultry (poultry is the most common)

68

how is campylobacter jejuni prevented

proper food handling and preparation

69

what are the symptoms of a campylobacter jejuni infection

self-limiting bloody and frequent diarrhea

70

What is the bacteria that is implicated with 90% of stomach and duodenal ulcers

helicobacter pylori

71

What leads to a higher incidence of uclers

type O blood, the helicobacter pylori uses the O antigen on gastric cells as a receptor

72

what does helicobacter pylori do that allows it to live in the stomach

it produces a potent urease the produces ammonia and bicarbonate

73

how does helicobacter pylori cause ulcers

by causing the mucus layer in the stomach to become thin and go away. This allows the stomach acid to destroy tissue