(1/29/15) Gram-Negative Pathogens of Mucosal Surfaces [2] (Bailey) Flashcards Preview

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Flashcards in (1/29/15) Gram-Negative Pathogens of Mucosal Surfaces [2] (Bailey) Deck (69):
1

what are the two types of toxin-producing bacterial pathogens?

-vibrio spp (primarily V. choloerae)
-entertoxigenic E. coli (ETEC)

2

what are the two types of "hybrid" misfit bacterial pathogens

-enterohemorrhagic E. coli (EHEC)
-enteropathogenic E. coli (EPEC)

3

what are the 5 characteristics of TOXIN-PRODUCING bacterial pathogens?

-occur in small intestine
-copious amounts of watery stool
-no blood in the stool
-no leukocytes in stool
-no tissue damage

4

what are the 4 types of vibrio?

-V. cholerae
-V. parahaemolyticus
-V. vulnificus
-V. alginolyticus

5

what two types of vibrio are involved with diarrhea?

-V. cholerae
-V. parahaemolyticus

6

what two types of vibrio are involved with tissues and blood?

-V. vulnificus
-V. alginolyticus

7

what are the two main cholera types?

-El Tor
-classical (thought to be the only one to cause disease till 1960's)

8

the new El Tor strand of cholera causes disease because of what?

-a mutated O1 antigen (changed the lipopolysaccharide)
-encapsulated

9

what age groups were affected by the new El Tor outbreak in the 1960's?

all age groups

10

in the 1960's outbreak, about 1 in _____ people developed cholera

20

11

what is V. cholera primarily transferred by?

shellfish

12

what are the three virulence factors used by V. cholera?

-flagella
-pili (to adhere to mucosal tissue)
-cholera toxin (phage encoded)

13

for V. cholera, a shift from saltwater to reduced ion levels found in the body leads to expression of _____ and to the _____

-pili
-toxin

14

two types of E. coli that are used for secretory diarrhea

-ETEC
-EPEC

15

type of E. coli that is dysentery-like (causes blood in the stool)

EHEC

16

type of E. coli that is associated with urinary tract infections

UPEC

17

what are the 4 steps to the identification of secretory diarrhea agents?

-rule out Vibrio cholera (want to rule out bc dangerous)
-inoculate plates with diluted stool samples
-not very rich medium, so fastidious G- won't grow
-aerobic incubation kills the anaerobes

18

what is the ideal treatment for secretory diarrhea?

oral rehydration (NOT IV)

(mix of sugar and salt)

19

what antibiotic is used to shorten the duration or reduce the severity of vibrio infections?

tetracyclines

20

what antibiotic is used to shorten the duration or reduce the severity of ETEC infections

2nd generation flouroquinolones (ex. ciprofloxacin)

21

what type of E. coli is prevalent in new borns?

EPEC

22

what type of E. coli has an absence of traditional exotoxins?

EPEC

23

what type of E. coli has a characteristic intimate adherence pattern (aka attaching and effacing lesion)

EPEC

24

what type of E. coli has a large infectious dose and colonizes the DISTAL SMALL intestine

EPEC

25

what are the three stages to intimate adherence (attaching and effacing lesion) by EPEC and EHEC?

-bundle-forming pili (Bfp) assist in adherence from relative long distance
-syringe-like secretion system injects Tir into host cell
-Tir binds to intimin on E. coli resulting in pedestral formation (actin polymeriszation) [PUTS BACTERIA ON A PEDESTAL]

26

what two factors cause the diarrhea for EPEC?

-malabsorption due to microvilli disruptions
-disruption of epithelial tight junctions

27

type of E. coli that has a set of EPEC genes so it produces an attaching effacing lesion but also produces toxin that can lead to hemolytic uremic syndrome (bleed form the kidneys)

EHEC

28

what type of E. coli is the most common, comes from cattle, causes an attaching effacing lesion and produces a shiva-like toxin?

EHEC

29

what do shiva-like toxins of EHEC attack?

small blood vessels of the large intestines

30

the shiva-like toxins of EHEC can be intensified when ____ _____ are present

inflammatory cytokines

31

a good way to test for the presence of EHEC is to test for _____ bc it is unable to ferment it

sorbitol

32

why is the treatment of EHEC with antibiotics controversial?

bc antibiotics are only used in the most severe cases so it is unsure whether the disease is due to the antibiotics of the severity of the disease itself

33

most common form of bacterial infection of an organ system (not including the mouth) and the most frequent cause of doctor's visits by adults (not including trips to the dentist)

urinary tract infections

34

inflammation of the bladder

cystitis

35

why do more women tend to get UTI's than men?

bc women have shorter urethras so the bacteria can move up them easier

36

why do men have UTI's more frequently later in life?

bc the prostate fails to keep working at normal levels

37

3 characteristics of an uncomplicated UTI

-normal defense mechanisms intact
-no recent hospital visits
-disease limited to lower urinary tract

38

3 characteristics of a complicated UTI

-some structural abnormality in urinary tract
-recently admitted to the hospital
-disease spread to the kidneys

39

what are the 6 natural defenses found in the urinary tract?

-complete voidance of bladder
-peristalsis (pushes urine down ureters)
-ureterovesicle valves
-mucous layer
-normal microbiota
-pH

40

UTI's can spread to the kidneys and cause _______

pyelonephritis

41

retrograde flow of urine from bladder to the kidneys can be caused by what three things?

-neurological disorders
-incomplete closing of ureterovesical valves in children
-dialation and decreased peristalsis in pregnant women

42

some bacteria, like proteus spa., neutralize pH of urine and cause the formation of "struvite" calculi or ____ ____ ____

urinary tract stones

43

type of E. coli that can adhere to uroepithelial cells through fimbriae, cause a production of aerobactin and hemolysin, and have a genetic link to recurrent disease

UPEC (uropathogenic E. Coli)

44

Proteus mirabilis is an additional cause of an _____ _____

uncomplicated UTI

45

causes a more abnormal urinary tract structure and is often more severe of a UTI than those caused by E. coli

P mirabilis

46

what are the 5 virulence factors for Proteus mirabilis?

-flagella
-fimbriae (special adhesion for urinary epithelium)
-hemolysins
-IgA protease (avoids immune system by degrading IgA on host cell surfaces)
-Urease (increases pH of urine, allows bacteria to grow)

47

it is surprisingly difficult to positively ID the causative agent of a UTI, but you could count the bacteria in the ______

urine

48

proteus can be diagnosed by what two things?

-consistently alkaline urine
-production of urease

49

the treatment of proteus UTI's are a variety of antimicrobials but ___/_____ is the first choice

TMP/SMX

50

for treatment of proteus UTI's in acute cystitis, how many days should treatment be done?

3

51

for treatment of proteus UTI's in polynephritis, how many days should treatment be done?

10-14

52

for treatment of proteus UTI's in pregnant females, what should be used?

asymptomatic bacteriuria

53

completely non-motile forms of bacteria that form large, mucoid colonies due to large capsule

klebsiella

54

type of klebsiella pili that are important for adherence to urinary tract epithelial cells

type 1

55

type of klebsiella pili that are important for respiratory tract epithelial cells

type 3

56

klebsiella have ______ that is an iron sequestering protein

aerobactin

57

what is the primary virulence factor for klebsiella?

antipagocytic capsule (bc if defends against the phagocytic microphages)

58

among the most prevalent Gm- GI bugs

Heliobacter pylori

59

unlike the other GI bugs we've studied, heliobacter pylori is transmitted through what two types of contact?

-oral to oral
-fecal to oral

60

______ _____ is a "slow" bacterium that takes weeks or years to cause symptoms

helicobacter pylori

61

what always precedes the major symptoms of H. Pylori infection?

chronic superficial gastritis

62

H. pylori is readily killed by ____ ____, and is an efficient producer of _____

-gastric acid
-urease

63

H. pylori is readily killed by gastric acid so it embeds itself in border epithelial cells that have their pH neutralized by _____

urease

64

regarding H. pylori, the inflammatory effector molecules cause epithelial cells to produce _____ which recruit neutrophils into the site of infection

IL-8

65

regarding H. pylori, ______ is associated with peptic ulcer disease (induces vascuolation and apoptosis of epithelial cells)

cytotoxin

66

H. pylori downregulates _____ which increases ____ and ____ ____ which over time can lead to ulcers

-somatostatin
-gastrin
-gastric acid

67

treatment of ______ is intense with many side effects

H. Pylori

68

what are the two stages of the first line of treatment of H. pylori

-proton pump inhibitor
-antibiotic cocktail

69

what are the two stages of the second line of treatment of H. pylori?

-proton pump inhibitor (same as first)
-numerous pills taken multiple times daily for 2 weeks