Powerpoint 7: Salmonella

Question 1

What is the optimum growth temperature?

Answer 1

35-37

But can grow at 5-54 (mesophilic)

Question 2

Are they killed by pasteurization?

Answer 2

yes

Question 3

Are they sensitive to low pH?

Answer 3

yes

Question 4

What pH do they grow in?

Answer 4

4.5 - 9.5

Question 5

What is the lowest aw they can tolerate?

Answer 5

0.94

Question 6

What happens to heat resistance as water activity decreases?

Answer 6

Heat resistance increases (logic : when its hot, the tolerable water it can grow in decreases because heat removes water)

Question 7

What can affect heat resistance?

Answer 7

Types of solute in food

Question 8

Can cells survive in frozen and dried states for a long time? (ex: chicken nuggest, breaded chicken strips, chocolate)

Answer 8

Yes

Question 9

What is the Aw like in chclate?

Answer 9

lw

Question 10

Why can’t yu inactivate salmnella using heat?

Answer 10

-gives it a burned taste

lw aw makes the heat resistance even greater

Question 11

Hw much time can salomonela survive in chcolaote?

Answer 11

years

Question 12

How many species des the geonus have?

Answer 12

2 species

Question 13

Salomnela enetrica is gruped int hw many subspecies?

Answer 13

six subspecies

Question 14

Which subspecies is the nly onoe that causes disease in humans?

Answer 14

Salmonella enterica enterica

Question 15

Hw many types fo serovars exist fr the subspecies s.enterica enterica

Answer 15

> 2000

Question 16

Which 2 ser0vars are m0st c0m0nloy ass0ciated t0 f00dbrn illness?

Answer 16

Thyphymurium and Entiriditis

Question 17

What is the meth0d to ser0type?

Answer 17

• reacti0ns with antisera

- wh0loe gen0me typing

Question 18

Wh0 carries the ser0var Typhymurium?

Answer 18

-many pets, f00d animals

Question 19

What can servara entiriditis infect?

Answer 19

-0varies 0f chicken -> infect the egg

meth0d t0 av0id sickness: highly c00king

Question 20

H0w many h0urs after infecti0n d0 sympt0ms 0ccur?

Answer 20

8-72 h0urs

Question 21

Is it self-limiting?

Answer 21

yes

Question 22

D0es it have blo0dy diarhea?

Answer 22

n0

Question 23

In h0w many days d0 sympt0ms res0lve?

Answer 23

5 days

Question 24

What c0mplicati0n can happen in imun0c0mpr0mised individuals with n0n-typh0idal salm0nella?

Answer 24

• invasive disease
• bacteremia
• high m0rtality rate

Question 25

Where d0es salom0nella remain lo0caloized?

Answer 25

intestinal tissue

Question 26

What is resp0nsible f0r the sympt0ms 0f gastr0-entiritis?

Answer 26

h0st inflammat0ry resp0nse t0 invading pathgens | -> the number is n0t many th0ugh

Question 27

Where d0 m0st salm0nella bacteria remain after infecti0n?

Answer 27

gastr0-intestinal lumen

Question 28

Despite it being able t0 invade the cellos wh0 will clear s.typhymurium?

Answer 28

neutr0phils

Question 29

where are the virulence fact0rs lo0cated?

Answer 29

SPAI

Question 30

H0w d0es salom0nella survive the acidic pH 0f the st0mach?

Answer 30

-activates acid t0lerance resp0nse t0 maintain intracellular pH

Question 31

what is enc0ded in SPAI 3 and 4 that all0ws adherence t0 epithelium?

Answer 31

adhesins

Question 32

What are the 2 things enc0ded by SPAI 3?

Answer 32

1) MisL : binds fibr0nectin 0n epithelial cells | 2) Mgt CB: intramacr0phage survival

Question 33

Which things are enc0ded by SPAI 4?

Answer 33

c0ntains 0nly 6 ORF enc0ded in 0ne 0per0n.o 1)SiiE : mediates attachment t0 epithelial cells

Question 34

What d0es SPI 1 enc0de?

Answer 34

A T3 SS : delivers a c0h0rt 0f virulence effect0r pr0teins int0 the h0st cell

Question 35

What d0 the effect0rs secreted by SPI 1 d0?

Answer 35

``` #1 drive f0rce uptake 0f bacteria by n0n-phag0cytic cells -induce actin cytoskelet0n rearrangement in h0st, creating large pr0trusi0ns 0n membrane called ruffles ``` #2 manipulate h0st cell signalling pathway (i.e. inflammat0ry resp0nse)

Question 36

What are membrane ruffles?

Answer 36

result due t0 h0st cell rearanging actin cyt0skelet0n (due t0 effect0rs secreted by T3 SS)

Question 37

What d0 ruffles d0?

Answer 37

engulf the path0gen int0 large vesicles called Salm0nella c0ntaining vesicles

Question 38

What d0 salom0nella c0ntaining vesicles d0?

Answer 38

hoang 0ut near g0lgi apparatus t0 intercept vesicles and 0btain nutrients

Question 39

What causes diarrhea?

Answer 39

H0st resp0nse and inflammati0n due t0 bacterial invasi0n 0f the intestinal cells

Question 40

T/F in healthy individuals salom0nela c0ntaining vesicles can migrate t0 the bas0lateral side enter the bl00d and cause systemic infecti0n

Answer 40

F: this happens in immu0c0mpr0mised individuals

Question 41

what is a type 3 secreti0n system?

Answer 41

- pr0tein appendage - f0und in gram - bacteria - needle like structure is used as a sens0ry pr0be t0 detect eukarytic cells - can inject effect0r pr0teins (help survive + escape immune system)

Question 42

What is pry0pt0sis?

Answer 42

highly inflamat0ry f0rm 0f pre-pr0grammed cell death | -in intracellular path0gens

Question 43

Functi0n 0f SPI 1 genes ?

Answer 43

1) inhibiti0n 0f ap0pt0sis and macr0phage pry0pt0sis 2) stabilizati0n / lo0caloizati0n 0f actin filaments during invasi0n 3) adhesin 0f epithelialo cells 4) disrupti0n 0f actin cyt0skelet0n

Question 44

Functi0n 0f SPI 2?

Answer 44

intrace//u/ar rep/icati0n

Question 45

Functi0n 0f SPI 5?

Answer 45

cytskelet0n rem0de//ing + inducti0n 0f inflammat0ry resp0nse - rendundant - enc0des S0pE, S0p E2, Sig D

Question 46

What causes gastr0intestina/ dysbi0sis?

Answer 46

inflammati0n

Question 47

H0w d0es inflammati0n fav0r salom0nella gr0wth?

Answer 47

since respirat0ry electr0n accept0rs are 0ver pr0duced pr0vides an energetic gr0wth advantage t0 facultative anaer0bes loike salom0ne//a

Question 48

What 0per0n d0es Spi2 enc0de, and what is its functi0n?

Answer 48

enc0des ttr 0per0n: a//0ws sa/m0ne//a t0 use tetrathi0nate as TEA, 0utgr0w anaer0bic c0mpetit0rs

Question 49

Wh0 disrupts the tight juncti0ns?

Answer 49

intra and extra cellular path0gens

Question 50

H0w are ruffling re/ated t0 tight juncti0ns?

Answer 50

pr0teins f0r ruff/ing are essential t0 alter tight juncti0ns

Question 51

What 4 effect0rs are used t0 disrupt the tight juncti0ns?

Answer 51

Sip A, S0p B, S0p E and S0p E2 (research still 0ng0ing)

Question 52

Are antibi0tics administered?

Answer 52

Yes if bl00d b0rn infecti0n

Question 53

Why are strains resistant t0 antibi0tics?

Answer 53

Rutinely used in feed and godo animals and birds

Question 54

T/F : Genes for virulence factrs and antibi0tic resistance can 0ccur 0n the same ploasmid

Answer 54

True

Question 55

What is the difference bewteen thyph0id and n0n-typh0id?

Answer 55

Typhi / paratyphi : human restricted ; causes human fever N0n tyhph0id (typhimuirum, entiriditis): br0ad range; causes gastr0-entiritis (abdminalo pain, inflammat0ry diarrhea, vmiting)

Question 56

Gr0uped acc0rding t0 ser0var l00king at what?

Answer 56

- 0 antigen 0n LPS | - H antigen (flagellar)

Question 57

T/F It is a leading cause 0f f00db0rn illness in humans?

Answer 57

True

Question 58

What 2 0ther meth0ds can be used t0 gr0up it?

Answer 58

- wh0le gen0me sequencing | - pulsed field gel electr0ph0resis

Question 59

Which ser0type can cause systemic inflammati0n in immun0cmpr0mised individuals?

Answer 59

typhi and parathyphi

Question 60

Is antimicr0bial resistance a pr0blem?

Answer 60

yes!!