Lecture 5: Mucusal Infections Flashcards

1
Q

Merkel cells

A

one of the first transformative viruses identified (cancer causing)

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2
Q

Enteric Bacterial Pathogens

A

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

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3
Q

Enteric Bacterial Pathogens

A

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

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4
Q

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

A

Gram Negative

Bile salt resistant

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5
Q

Bile start and studying enteric bacteria

A

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

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6
Q

Shigella vs. the other species

A

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

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7
Q

special things about EHEC

A

T3SS
urea gene
lactose gene

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8
Q

Special things about Salmonella

A

two T3SSs

ability to H2S

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9
Q

STUDY TO CORE-PAN GENOME FIGURE

A

STUDY TO CORE-PAN GENOME FIGURE

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10
Q

How E. coli causes diarrhea

A

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

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11
Q

diarrhea

A

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

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12
Q

how cholera causes diarrhea

A

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

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13
Q

how cholera causes diarrhea

A

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

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14
Q

pathotypes

A

groups of bacteria that cause disease in a certain way

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15
Q

who has E. coli

A

most mammals, usually doesn’t cause disease

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16
Q

ETEC

A

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

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17
Q

EIEC

A
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
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18
Q

EPEC

A

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

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19
Q

EHEC

A
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
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20
Q

EHEC

A
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
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21
Q

more on EHEC

A

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

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22
Q

more on EHEC : US strain

A
O157 H7 (these are ANTIGENS) 
we have the strongest response to these 2 antigens 
HEMORRHAGIC diarrhea 
has shiga toxin 
fecal contamination of undercooked foods
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23
Q

EHEC: what does O157 mean

A

O=LPS

157=bloody diarrhea

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24
Q

EHEC: what does H7 mean?

A

FLAGELLA

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25
Q

EHEC secretion

A

LEE type 3 secretion system

CAUSES PEDESTAL FORMATION

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26
Q

what is HEmorrhagic diarrhea

A

bright red blood

EHEC

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27
Q

Pedestal formation

A

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

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28
Q

EHEC transmission

A

mostly foodborne

because it has a requires a high infectious dose

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29
Q

EPEC secretion

A

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

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30
Q

How EHEC differs from EPEC

A

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

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31
Q

shiga toxin: A-B toxin

A

B part of protein : sticks to cell sruface

A part of protein: has catalytic activity that kills the cell

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32
Q

How shiga toxin kills the cell

A

retrograde transport

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33
Q

retrograde transport

A

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

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34
Q

A and ribosome

A

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

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35
Q

shiga toxin: A-B toxin

A

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
Q

A and ribosome

A

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

37
Q

WATCH VIDEO ON SLIDE 26 IT WILL BE ON EXAM

A

WATCH VIDEO ON SLIDE 26 IT WILL BE ON EXAM

38
Q

importance of shiga toxin being on a phage

A

it can jump into other strains

39
Q

what B subunit binds to (EHEC)

A

GB3

40
Q

amount of GB3

A

decreases as you age

more in men/boys

41
Q

so who gets most sick from EHEC infection?

A

young boys

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

42
Q

what does shiga toxin effect

A

gut
kidneys
nervous system
(where GB3 is found)

43
Q

people who survive EHEC…

A

severe kidney and sometimes brain damage

44
Q

what does shiga toxin do to BODY

A

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

45
Q

what does T3SS do?

A

secretes proteins from gram neg bact to euks cells

DOES NOT secrete shiga toxin

46
Q

so why does EHEC cause bloody diarrhea

A

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

47
Q

why is EHEC an American disease

A

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
Q

Pedestal formation ???? LOOK INTO

A

adhesion to cells?

DECREASES SURFACE AREA of epithelial cells

49
Q

why is EHEC an American disease

A

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
Q

Shigella

A

dysentery
intracellular pathogen
very low infectious dose-waterborne

51
Q

why does Shigella have a low infectious dose

A

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
Q

how are Shigella nd E. coli different

A

Shigella CANNOT ferment lactose

53
Q

how are Shigella nd E. coli different

A

Shigella CANNOT ferment lactose

54
Q

Shigella is a ______pathogen

A

specialized

55
Q

evolution of shigella

A

evolved to be good at SPREADING, doesnt need host for long

so doesnt really care if it kills the host

56
Q

Characteristics of specialized pathogens

A

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
Q

Salomnellosis found in

A

chickens, eggs
birds
reptiles
oysters

58
Q

salmonellosis in chickens

A

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
Q

how to avoid salmonella in food

A

wash and cook chicken

use different utensils for food prep of chicken and produce

60
Q

salmonella and egs

A

bacteria can move across the shells

so dont eat raw eggs in cookie dough you make

61
Q

salmonella serovars

A

Typhumurium

Typhi

62
Q

Salmonella enterica Typhi

A
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
Q

Typoid mary

A

she was a carrier shedding infectious agents

first time we realized this is possible

64
Q

salmonella-containing vesicles

A

get out via normal endocytic pathway

65
Q

2 T3SSs of salmonella typhi

A

1) gets into epi cells

2) helps for survival in macrophages

66
Q

how Salmonella enterica Typhi is different from plague

A

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
Q

Salmonella enterica Typhi vaccine

A

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

vaccine gets into macrophage and then dies

68
Q

2 T3SSs of salmonella typhi

A

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

changes how the macrophage sees the bacteria.

69
Q

2 T3SSs of salmonella typhi

A

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
Q

Salmonella enterica Typhi vaccine

A

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

vaccine gets into macrophage and then dies

71
Q

typhoid in the world

A

tends to be endemic

control of human feces=less of a problem

72
Q

Salmonella enterica Typhimurium

A

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
Q

Typhimurium vs. Typhi: genes

A

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

74
Q

Typhimurium vs. Typhi: peudeogenes as a portion of genome

A

Typhimurium: 0.6%
Typhi: 5%

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

75
Q

Typhimurium vs. Typhi: getting nutrients

A

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
Q

are humans prototrophs or auxotrophs

A

auxotrophs,,, we need vitamins and minerals

77
Q

review graph on slide 24

A

review graph on slide 24

78
Q

1940s: decrease in Typhoid fever due to

A

sanitation in suburbs

typhoid used to be a city disease bc they were dirty

79
Q

rising slamonellosis due to

A

more processed foods

80
Q

outbreak then decrease in salmonellosis

A

huge outbreak
then sanitation in processing plants
the water bath thing

81
Q

Pedestal formation ???? LOOK INTO

A

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

82
Q

outbreak then decrease in salmonellosis

A

huge outbreak
then sanitation in processing plants
the water bath thing

83
Q

Pan-Core genome figure for exam

A

core genome lets bacteria survive in intestines of vertibrea

how we differentiate species

evolution

84
Q

shigella and typhi

A

reduction in genes

85
Q

salmonella

A

more genes

but severe disease because its not meant for humans

86
Q

E. coli

A

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