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

Question 1

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

Answer 1

mucosal surfaces

Question 2

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

Answer 2

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

Question 3

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

Answer 3

• innate immunity
• adaptive immunity
• nonspecific barrier defenses

Question 4

what is the annual cost on GI tract diseases?

Answer 4

10 billion dollars

Question 5

what are the “seven F’s” that describe the possible modes of transmission for gram negative mucosal pathogens?

Answer 5

• feces
• food
• fluids
• fingers
• flies
• fomites
• fornication

Question 6

the inoculum size of shigella is as little as ______ organisms

Answer 6

50-100

Question 7

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

Answer 7

inoculum

Question 8

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

Answer 8

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

Question 9

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

Answer 9

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

Question 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

Answer 10

acidity

Question 11

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

Answer 11

motility

Question 12

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

Answer 12

mucus layer & underlying glycocalyx

Question 13

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

Answer 13

tight junctions

Question 14

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

Answer 14

bc there is much less oxygen in the colon

Question 15

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

Answer 15

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

Question 16

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

Answer 16

lysozyme

Question 17

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

Answer 17

gram +

Question 18

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

Answer 18

lactoferrin

Question 19

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

Answer 19

cathelicidin

Question 20

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

Answer 20

defensins

Question 21

where are the alpha defensins derived from?

Answer 21

neutrophils and paneth cell (in intestine)

Question 22

where are the beta defensins derived from?

Answer 22

epithelial cells

Question 23

microbes with low infectious doses tend to be ____ ____

Answer 23

acid resistant

shigella and enteroinvasive E. Coli

Question 24

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

Answer 24

fimbriae/pili

Question 25

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

Answer 25

membranes

Question 26

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

Answer 26

cationic amino acids

Question 27

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

Answer 27

sideophores

Question 28

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

Answer 28

pattern recognition receptors

Question 29

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

Answer 29

inflammatory

Question 30

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

Answer 30

TLR 4

Question 31

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

Answer 31

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

Question 32

what do bacteria develop to resist phagocytosis

Answer 32

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

Question 33

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

Answer 33

lymph nodes

Question 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?

Answer 34

invasive bacterial pathogens

Question 35

what are the two examples of invasive bacterial pathogens?

Answer 35

- salmonella spp. | - shigella spp.

Question 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

Answer 36

toxin-producing bacterial pathogens

Question 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

Answer 37

"hybrid" misfit pathogens

Question 38

what distinguishes the four different types of shigella species?

Answer 38

the O antigen

Question 39

for shigella, the inoculum size is _____

Answer 39

small

Question 40

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

Answer 40

stationary phase

Question 41

shigella will usually multiply and colonize the _____

Answer 41

colon

Question 42

simply put, how do shigella cells invade?

Answer 42

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

Question 43

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

Answer 43

ulcer

Question 44

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

Answer 44

leukocytes

Question 45

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

Answer 45

shigella dyseteriae type 1

Question 46

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

Answer 46

- gastroenteritis | - typhoid fever

Question 47

the inoculum for salmonella is ______

Answer 47

large (10-100 million)

Question 48

salmonella is more _____ _____ than shigella

Answer 48

acid sensitive

Question 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)

Answer 49

pathogenicity islands

Question 50

simply put, how does salmonella spa invade?

Answer 50

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

Question 51

simply put, how does salmonella typhi invade?

Answer 51

-enters LYMPHATIC SYSTEM then replicates within microphages throughout the body

Question 52

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

Answer 52

- shigella | - salmonella

Question 53

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

Answer 53

typhi

Question 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

Answer 54

asymptomatic carriers (typhoid mary)

Question 55

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

Answer 55

gall bladder (spread through the feces)

Question 56

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

Answer 56

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

Question 57

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

Answer 57

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

Question 58

what is a possible treatment of all enteric diseases?

Answer 58

oral rehydration

Question 59

what is a possible treatment of shigella?

Answer 59

antibiotics

Question 60

what is a possible treatment of salmonella?

Answer 60

2nd generation fluoroquinolones

Question 61

what is a possible treatment of typhoid fever?

Answer 61

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