Lecture 5: Mucusal Infections Flashcards Preview

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Flashcards in Lecture 5: Mucusal Infections Deck (86):
1

Merkel cells

one of the first transformative viruses identified (cancer causing)

2

Enteric Bacterial Pathogens

E. Coli (EPEC and EHEC (enteropathogenic and enterohemorrhagic)
Shigella (dysenteriae)
Salmonella (serovar typhi and serovar typhimurium)
Yersinia (enterocolitica)

3

Enteric Bacterial Pathogens

E. Coli (EPEC and EHEC (enteropathogenic and enterohemorrhagic)
Shigella (dysenteriae)
Salmonella (serovar typhi and serovar typhimurium)
Yersinia (enterocolitica)

4

Core and Pan Genome of Enteric Bacteria: Core of EHEC, Shigella, and Salmonella

Gram Negative
Bile salt resistant

5

Bile start and studying enteric bacteria

streak fecal matter on plate with bile salt
things that arent enteric will die
study whats left

6

Shigella vs. the other species

was though to be different until recently
BUT: found that shigella is an E. Coli that lost some genes and gained a few plasmids

"subspecies of E. coli" say som

7

special things about EHEC

T3SS
urea gene
lactose gene

8

Special things about Salmonella

two T3SSs
ability to H2S

9

STUDY TO CORE-PAN GENOME FIGURE

STUDY TO CORE-PAN GENOME FIGURE

10

How E. coli causes diarrhea

1) inhibits absorptive function of intestine
2) opens tight junctions between cells (bloody)
3) causes inflammation

11

diarrhea

caused by excess fluid in GI tract
intestines absorb water usually, in this case they dont
feces become thinner
Caused by inflammation OR an actual function of the bacteria

12

how cholera causes diarrhea

causes epithelial cells to pump salt into the lumen of the gut
water rushes into gut from body
rice water diarrhea
active function of toxin

13

how cholera causes diarrhea

causes epithelial cells to pump salt into the lumen of the gut
water rushes into gut from body
rice water diarrhea
active function of toxin

14

pathotypes

groups of bacteria that cause disease in a certain way

15

who has E. coli

most mammals, usually doesn't cause disease

16

ETEC

enterotoxin e.c.
most common
produces a toxin that produces a protein that degreulates water absoprtion of intestines
TRAVELER's diarrhea

17

EIEC

enteroinvasive e.c.
mild diarrhea
the one that evolved into shigella
can invade host cells-lives at epi layer
pretty self-limiting: goes away on its own
often get traveling

18

EPEC

enteropathogenic e.c.
major cause of infant dirrhea and death oitside US
ADHERES tightly to epi cells
serious inflammation

19

EHEC

enterohemorrhagic E.c.
bloody diarrhea
sometimes a problem in the US
its EPEC plus a toxin: SHIGA TOXIN
destroys epithelial cells, blood goes into lumen of the gut... pretty bad

20

EHEC

enterohemorrhagic E.c.
bloody diarrhea
sometimes a problem in the US
its EPEC plus a toxin: SHIGA TOXIN
destroys epithelial cells, blood goes into lumen of the gut... pretty bad

21

more on EHEC

lose some genes from EPEC
add a toxin
one of worst enteric infections you can get

22

more on EHEC : US strain

O157 H7 (these are ANTIGENS)
we have the strongest response to these 2 antigens
HEMORRHAGIC diarrhea
has shiga toxin
fecal contamination of undercooked foods

23

EHEC: what does O157 mean

O=LPS
157=bloody diarrhea

24

EHEC: what does H7 mean?

FLAGELLA

25

EHEC secretion

LEE type 3 secretion system
CAUSES PEDESTAL FORMATION

26

what is HEmorrhagic diarrhea

bright red blood
EHEC

27

Pedestal formation

cause actin to polymerize underneath the bacteria
this lets the bacteria move pretty well?
DECREASES SURFACE AREA of epithelial cells

28

EHEC transmission

mostly foodborne
because it has a requires a high infectious dose

29

EPEC secretion

secrete proteins into the host
bacteria stick to the bacterial protein
this causes actin to polymerize under the bacteria
other proteins secreted lead to death of host cell... bacteria eventually kills the host cell by apoptosis because thats the only way the bacteria can get off the surface

30

How EHEC differs from EPEC

because it also has a bacteria phage that contains the SHIGA TOXIN

31

shiga toxin: A-B toxin

B part of protein : sticks to cell sruface
A part of protein: has catalytic activity that kills the cell

32

How shiga toxin kills the cell

retrograde transport

33

retrograde transport

vesicle meant to go outside moves backwards
vesicle fueses with the Golig again, eventually the ER again
in the ER: the B portion forms a pore, A goes to cytosol, finds RIBOSOME

34

A and ribosome

a portion cleaves the ribsomal RNA
this stops protein synthesis
cell dies because it cant make proteins

35

shiga toxin: A-B toxin

B part of protein : sticks to cell sruface 5 of them
A part of protein: has catalytic activity that kills the cell 1 of them

36

A and ribosome

a portion cleaves the ribsomal RNA
this stops protein synthesis
cell dies because it cant make proteins

37

WATCH VIDEO ON SLIDE 26 IT WILL BE ON EXAM

WATCH VIDEO ON SLIDE 26 IT WILL BE ON EXAM

38

importance of shiga toxin being on a phage

it can jump into other strains

39

what B subunit binds to (EHEC)

GB3

40

amount of GB3

decreases as you age
more in men/boys

41

so who gets most sick from EHEC infection?

young boys
they have the most GB3, which the Shiga toxin can take advatage of

42

what does shiga toxin effect

gut
kidneys
nervous system
(where GB3 is found)

43

people who survive EHEC...

severe kidney and sometimes brain damage

44

what does shiga toxin do to BODY

causes clots to form in small blood vessles
RBCs damaged: ANMEIA
kidney filtration decline... HUS (hemulytic-uremic syndrome)

45

what does T3SS do?

secretes proteins from gram neg bact to euks cells
DOES NOT secrete shiga toxin

46

so why does EHEC cause bloody diarrhea

break down of tight junctions
shiga toxin causes clots in capplaiers... blood builds up in liamina propria
destroy surface and underlying tissues

47

why is EHEC an American disease

non-human reservoir is COWS
which we don't threat the best... and Indians cows dont have O157 H7
our cows eat feces of other cows... most of the get O157 H7
we get it in produce a lot bc its sprayed with cow feces

48

Pedestal formation ???? LOOK INTO

adhesion to cells?
DECREASES SURFACE AREA of epithelial cells

49

why is EHEC an American disease

non-human reservoir is COWS
which we don't threat the best... and Indians cows dont have O157 H7
our cows eat feces of other cows... most of the get O157 H7
we get it in produce a lot bc its sprayed with cow feces

50

Shigella

dysentery
intracellular pathogen
very low infectious dose-waterborne

51

why does Shigella have a low infectious dose

it lost the genes it didnt need for infection
also: it infects by entering the M cells of pyers patches...lyses M cells when it gets inside, then pushes to neighbors using actin polymerization and replicates and repeats
ALSO: avoids immune cells other than NK (whic mostly recognizes VIRUSES, not BACT) and CD8 cells

52

how are Shigella nd E. coli different

Shigella CANNOT ferment lactose

53

how are Shigella nd E. coli different

Shigella CANNOT ferment lactose

54

Shigella is a ______pathogen

specialized

55

evolution of shigella

evolved to be good at SPREADING, doesnt need host for long
so doesnt really care if it kills the host

56

Characteristics of specialized pathogens

don't care if they kill host
Shigella, Norovirus

wants you to produce a lot of feces so it can spread more, doesnt care if you die after a week

often waterborne diseases

57

Salomnellosis found in

chickens, eggs
birds
reptiles
oysters

58

salmonellosis in chickens

doesnt cause disease in chickens
but all chicken meat in oregon had it after processing due to the washing process to reduce pathogens

so why isnt everyone there dying: there isnt enough bacteria in the meat to make people sick

59

how to avoid salmonella in food

wash and cook chicken
use different utensils for food prep of chicken and produce

60

salmonella and egs

bacteria can move across the shells
so dont eat raw eggs in cookie dough you make

61

salmonella serovars

Typhumurium
Typhi

62

Salmonella enterica Typhi

Typoid fever
infects and lives off macrophages, goes from one to another... rides them to liver and spleen... fever and death
2 T3SSs
pilli
flagella

63

Typoid mary

she was a carrier shedding infectious agents
first time we realized this is possible

64

salmonella-containing vesicles

get out via normal endocytic pathway

65

2 T3SSs of salmonella typhi

1) gets into epi cells
2) helps for survival in macrophages

66

how Salmonella enterica Typhi is different from plague

typhi enters through M cells, less at a time, tends to be more self-limiting
plauge: lots of bacteria enter the body at once, quick death

67

Salmonella enterica Typhi vaccine

live bacteria with ONE T3SS and a plasmid for living in the macrophages removed

vaccine gets into macrophage and then dies

68

2 T3SSs of salmonella typhi

1) gets into epi cells
2) helps for survival in macrophages

changes how the macrophage sees the bacteria.

69

2 T3SSs of salmonella typhi

1) gets into epi cells
2) helps for survival in macrophages

changes how the infected macrophage sees the salmonella containing endosome so that it DOESNT fuse it with a lysosome, which would kill it

70

Salmonella enterica Typhi vaccine

live bacteria with ONE T3SS and a plasmid for living in the macrophages removed

vaccine gets into macrophage and then dies

71

typhoid in the world

tends to be endemic
control of human feces=less of a problem

72

Salmonella enterica Typhimurium

mouse typhi... also found in chickens a lot
only causes enteritis in humans... just bad diarrhea, doesnt go to spleen and liver like typhi
cold and warm blooded vertebrates

73

Typhimurium vs. Typhi: genes

Typhimurium: lots of genes, can live in birds, reptiles, amphibians
Typhi: lost many genes, specailized in infecting humans

74

Typhimurium vs. Typhi: peudeogenes as a portion of genome

Typhimurium: 0.6%
Typhi: 5%

pseudogenes are genes that have LOST function. (more in typhi=it doesnt need 5% of its genome)

75

Typhimurium vs. Typhi: getting nutrients

Typhimurium: prototroph: ability to synth all amino acids, nucleic acids, vitamins
Typhi: Auxotroph: needs supplementation for ceretain nutrients (tryptophan and cystine in this case)

76

are humans prototrophs or auxotrophs

auxotrophs,,, we need vitamins and minerals

77

review graph on slide 24

review graph on slide 24

78

1940s: decrease in Typhoid fever due to

sanitation in suburbs
typhoid used to be a city disease bc they were dirty

79

rising slamonellosis due to

more processed foods

80

outbreak then decrease in salmonellosis

huge outbreak
then sanitation in processing plants
the water bath thing

81

Pedestal formation ???? LOOK INTO

adhesion to cells?
see picture on slide 8
DECREASES SURFACE AREA of epithelial cells

82

outbreak then decrease in salmonellosis

huge outbreak
then sanitation in processing plants
the water bath thing

83

Pan-Core genome figure for exam

core genome lets bacteria survive in intestines of vertibrea

how we differentiate species

evolution

84

shigella and typhi

reduction in genes

85

salmonella

more genes
but severe disease because its not meant for humans

86

E. coli

normal flora, but can cause disease if genes move around (like the shiga toxin)