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Flashcards in Innate defenses of mucosal surfaces Deck (21):
1

what are the 3 main defenses of mucosal surfaces

1 - innate immunity
2 - adaptive immunity
3 - nonspecific barrier defenses

2

how are gram-negative mucosal pathogens transmited ?

SEVEN F's
feces, food, fluids, fingers, flies, fomites, fornication

3

what gram negative bacteria can cause disease at small innoculum size ?

Shigella dysenteriae

4

what gram negative group needs a larger inoculum size to cause disease

salmonella

5

what are some of the natural barrier defenses (anatomical and physiological) of the GI tract

acidity changes (stomach vs. intestine)
motility of fluids (peristalsis)
mucous layer and glycocalyx
tight junctions

6

why are there more bacteria found in the large intestine compared to the small intestine

the motility of fluids is slower in large intestine, thus easier for bacteria to attach to

7

why are humans not ALWAYS infected with gram negative bacteria

Cuz there are many good gram negative bacteria in body, and those microbes take up potential attachment sites before bad bacteria

8

what is a lysozyme and how does it work ?

secretory antimicrobial compound that cleave beta 1,4 bonds
-kills murein (which makes peptidoglycan) so essentially kills gram positive bacteria

9

what is a lactoferrin and what does it do

secretory antimicrobial compound that sequesters iron (so bacteria cant use to make virulence factors)

10

what is cathelicidin and what does it do

secretory antimicrobial compound that disrupts both gram + and - bacterial membranes and then lyses them

11

what are defensins and what are the 2 types

secretory antimicrobial compounds that target microbe immune systems
-alpha-made by immune cells
-beta - made by epithelial cells

12

what are the 3 strategies that pathogenic bacteria use to overcome innate barrier defenses

-acid resistance (to get them through stomach)
-fimbriae/pili (allow for attachment and not washed off)
-bacterial structures to combat antimicrobial compounds

13

once a pathogenic bacteria gets across the hosts mucous membrane, what is the next and most important line of defense

macrophages which recognize, engulf, and kill

14

how do macrophages detect when foreign pathogenic bacteria have entered the cell

have pathogen recognize receptors that recognize PAMP's

15

what are PAMP's

pathogen associated molecular patterns (on bacteria)

16

what specific pathogen recognition receptor recognizes LPS (type of PAMP's) in gram negative bacteria, and is the main receptor for defense vs. gram negative bacteria

TLR4

17

once macrophages are activated, what else do they signal

signal cytokines which signal other immune cells

18

what is the negative side of macrophages signalling the cytokine inflammatory response

cytokines can disrupt tight junctions of epithelial cells making it easier for microbes to penetrate mucosal layer

19

what are siderophores and who do they help

they sequester iron for the bacteria in low iron environments
-combats lactoferrin antimicrobial compound

20

some bacteria develop capsules once they are inside the cell, what would this help avoid ?

phagocytosis

21

the adaptive immune response of the human body is generated where ?

in the lymph nodes
-densest clusters of lymph nodes are located near mucosal membranes