(1/27/15) Gram-negative Pathogens of Mucosal Surfaces [1] (Bailey) Flashcards Preview

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Flashcards in (1/27/15) Gram-negative Pathogens of Mucosal Surfaces [1] (Bailey) Deck (61):
1

surface that interacts with air that has associated glands for secreting mucus

mucosal surfaces

2

what are the 4 main mucosal surfaces for gram-negative pathogens

-oral cavity
-respiratory tract
-reproductive/urinary tract
-GI tract

3

what are the three types of defenses of mucosal surfaces that the body has against pathogens

-innate immunity
-adaptive immunity
-nonspecific barrier defenses

4

what is the annual cost on GI tract diseases?

10 billion dollars

5

what are the "seven F's" that describe the possible modes of transmission for gram negative mucosal pathogens?

-feces
-food
-fluids
-fingers
-flies
-fomites
-fornication

6

the inoculum size of shigella is as little as ______ organisms

50-100

7

size of the colony of bacteria that is required to cause disease

inoculum

8

what are the three types of natural barrier defenses that are used by our bodies?

-secretory substances
-anatomical and physiological barriers (acidity, motility, tight junctions, etc)
-indigenous bacteria

9

what are the 4 types of anatomical and physiological properties that assist with creating a physical barrier?

-acidity (ranges from 1-9)(both acid and base)
-motility (fluid rushes bacteria away)
-mucus layer & underlying glycocalyx
-tight junctions

10

type of anatomical barrier that ranges from 1-9 making it so that bacteria must be able to survive in acidic and alkaline environments

acidity

11

type of anatomical barrier that is a movement of fluid that can wash away unwanted bacteria

motility

12

type of anatomical barrier that is used to trap the bacteria and kill it

mucus layer & underlying glycocalyx

13

type of anatomical barrier that makes it hard for bacteria to diffuse into the body

tight junctions

14

why are there more functional anaerobes in the colon than in the stomach?

bc there is much less oxygen in the colon

15

what do our body's normal bacteria do in order to make is so we are not constantly infected with pathogens?

creates a blanket on the GI walls that outocmpetes the incoming pathogens

16

enzyme used by immune system to cleave the beta 1,4-glycosidic linkages between N-acetylnuramic acid and N-acetylglucosamine

lysozyme

17

because of its function, what is the only type of bacteria that lysozyme can effectively degrade?

gram +

18

used by the body to sequester iron so that it cannot be used by the bacteria

lactoferrin

19

used by the body to disrupt bacterial membranes of Gm- and Gm+ (as well as fungi)

cathelicidin

20

used by the body to create pores in microbes. composed of alpha and beta subunits

defensins

21

where are the alpha defensins derived from?

neutrophils and paneth cell (in intestine)

22

where are the beta defensins derived from?

epithelial cells

23

microbes with low infectious doses tend to be ____ ____

acid resistant
(shigella and enteroinvasive E. Coli)

24

used by the pathogens to adhere to tissue to resist being shed

fimbriae/pili

25

for both Gm- and Gm+, the cell _____ have sensitivities to bactericidal compounds

membranes

26

bacteria often initiate _____ ____ _____ into their cell membrane to reduce effects of cationic antimicrobial peptides (interaction of charges)

cationic amino acids

27

bacteria use _____ to sequester iron in low iron environments (or to get it away from the lactoferins used by the body)

sideophores

28

macrophages recognize microbes via ____ _____ receptors leading to the activation of the macrophages and the ability to kill many microbes

pattern recognition receptors

29

in macrophages, the activation of the pattern response receptors also initiates the ______ response

inflammatory

30

which TLR receptor is the most important for this class and recognizing lipopolysaccharides?

TLR 4

31

what is the negative aspect of initiating the inflammatory response at mucosal surfaces?

inflammatory cytokines, such as TNF-alpha can disrupt the tight junctions between the epithelial cells

32

what do bacteria develop to resist phagocytosis

capsule
(they also develop a mechanism that can neutralize the phagocytic compartment of macrophages)

33

most of our immune response is at mucosal surfaces bc the _____ _____ are also at most of the mucosal surfaces

lymph nodes

34

type of pathogens that are usually found in the large intestine, have SMALL volume of stool, bloody stool, leukocytes in the stool, and have tissue ulcerations?

invasive bacterial pathogens

35

what are the two examples of invasive bacterial pathogens?

-salmonella spp.
-shigella spp.

36

type of pathogens that are usually found in the small intestine, have copious amounts of watery stool, NO blood in stool, NO leukocytes in stool, and cause NO tissue damage

toxin-producing bacterial pathogens

37

type of pathogens that are found in lower small intestine and upper large intestine. their colonization causes attaching and effacing lesions, and they cause blood to be in the stool

"hybrid" misfit pathogens

38

what distinguishes the four different types of shigella species?

the O antigen

39

for shigella, the inoculum size is _____

small

40

for shigella, the acid resistance is controlled by a global regulatory system of genes under the control of RpoS made in the _____ _____

stationary phase

41

shigella will usually multiply and colonize the _____

colon

42

simply put, how do shigella cells invade?

they enter M cells lining the mucosal surface and spread throughout the adjacent epithelial cells, staying away from the immune system, via IcsA and ATPase

43

during shigella, what develops when invaded cells die and slough off?

ulcer

44

all species of shigella will induce an inflammatory diarrhea with ____ in the stool

leukocytes

45

only shigella type that produces shiga toxin and disrupts the Na absorption

shigella dyseteriae type 1

46

what are the two types of salmonella that we need to know about in this class

-gastroenteritis
-typhoid fever

47

the inoculum for salmonella is ______

large (10-100 million)

48

salmonella is more _____ _____ than shigella

acid sensitive

49

in salmonella, the low pH of the stomach induces the expression of at least 40 proteins found on _____ ______ on large virulence plasmids (triggered by the acid)

pathogenicity islands

50

simply put, how does salmonella spa invade?

inc. cellua Ca+ levels that inc the uptake of the salmonella, remain in the cells for many hours (unlike shigella), induces NaCl loss from host cell

51

simply put, how does salmonella typhi invade?

-enters LYMPHATIC SYSTEM then replicates within microphages throughout the body

52

_______ is a localized infection, whereas _____ occurs all over the body

-shigella
-salmonella

53

salmonella _______ is strictly a human pathogen (no animal reservoir)

typhi

54

salmonella typhi is known to have _______ ______ that show no symptoms of the disease but have it colonized in their gall bladders and the organisms can be cultured from their feces

asymptomatic carriers (typhoid mary)

55

for asymtomatic carriers of salmonella typhi, where are the organisms colonized?

gall bladder (spread through the feces)

56

what are the two similarities between the two invasive enteric pathogens? (salmonella and shigella)

-both invasive so more in large intestine than small intestine (induce diharrea)
-both are able to respond to environmental changes

57

what are the 3 differences between the two invasive enteric pathogens? (salmonella and shigella)

-inoculum size (shigella=small || salmonella=large)
-bacteremia (shigella contained in intestines || salmonella is widespread)
-species that cause severe disease are very dissimilar

58

what is a possible treatment of all enteric diseases?

oral rehydration

59

what is a possible treatment of shigella?

antibiotics

60

what is a possible treatment of salmonella?

2nd generation fluoroquinolones

61

what is a possible treatment of typhoid fever?

-fluoroquinolones or surgical removal of gall bladder
-vaccine to the capsule of S. Typhi