Enterobacteriaceae- II

Question 1

Shigella is an enterobacteriacea that is gram _____ with the shape of_____

Answer 1

gram negative rods

Question 2

Is shigella an anerobe or aerobe?

Answer 2

A facultative anaerobe.

Question 3

What is a faculatative aerobe?

Answer 3

A facultative anaerobe is an organism that makes ATP by aerobic respiration if oxygen is present, but is capable of switching to fermentation or anaerobic respiration if oxygen is absent.

Question 4

There are four species of Shigella what are the three main species?

Answer 4

Shigella sonnei
Shigella flexneri
Shigella dysenteriae

Question 5

What is dysentery?

Answer 5

stool containing blood and mucus

Question 6

Shigella is the major cause of what?

Answer 6

dysentery

Question 7

What is the most infection Shigella species in developed countries?

Answer 7

Shigella sonnei

Question 8

What species of shigella is known for presence in developing countries?

Answer 8

Shigella flexneri

Question 9

Where is the shigella strain shigella dysentriae most commonly found?

Answer 9

Africa and central America

Question 10

What age group of people are more frequently infected with Shigella?

Answer 10

children

Question 11

What is required for transport of shigella? why?

Answer 11

transport media because shigella is acid sensitive.

Question 12

How is Shigella transported?

Answer 12

spread person to person (fecal - oral route) but it is also in the reservoir of humans.

Question 13

What is the infectious dosage of Shigella?

Answer 13

low dosage; 10-200 organisms

Question 14

What are the symptoma of shigella?

Answer 14

• lower abdominal cramps
• tenesmus (straining to defecate)
• pus and blood in stool
• fever

Question 15

what is tenesmus?

Answer 15

straining to defecate

Question 16

What is the major virulence in shigella?

Answer 16

shiga toxin

Question 17

What is the shigella toxin similar to?

Answer 17

EHEC AB5 toxin

Question 18

The shigella toxin does what?

Answer 18

Binds to Gb3. THe A subunit cleaves the 28 rRNA and inhibit protein synthesis.

Question 19

Does Shigella contain LPS?

Answer 19

yes

Question 20

Type 3 secretion Survive where and how?

Answer 20

1) survives in cytoplasm and propelled in to the neighboring cells
2) Survives phagocytosis by inducing apopotosis.

Question 21

What is one treatment for shigella?

Answer 21

oral rehydration

Question 22

How is shigella diagnosed?

Answer 22

• stool samples to detect toxin or bacteria

- Media with bile salt.

Question 23

What are the different Salmonella infections?

Answer 23

1) S. enterica var Typhimurium (S. typhimurium)
2) S. bongori
3) S. enterica var Typhi (s. typhi)

Question 24

What type of salmonella infection causes the most infections?

Answer 24

S. enterica var Tymphimurium (S. typhimurium)

Question 25

What type of Salmonella infection is mostly in cold-blooded animals?

Answer 25

Salmonella bongori

Question 26

What salmonella infection is currently having a food-borne outbreak?

Answer 26

S. enterica var Typhimurium (S. typhimurium).

Question 27

What salmonella infection is associated with Enteric fever?

Answer 27

Salmonella enterica var typhi (Salmonella typhi)

Question 28

Which salmonella strain is known to have a reservoir in humans?

Answer 28

Salmonella enterica var Typhi (Salmonella typhi)

Question 29

What is the infectious dose of S. enterica var Typhi (S. typhi)

Answer 29

Large infectious dose 10^5- 10^9

Question 30

Salmonella typhimurium has what type of secretion as a virulence factor? which does what?

Answer 30

Type 3 secretion;; injects protein effectors into host cell- actin rearrangement- invasion.

Question 31

How does the host response play a role in the virulence of Salmonella typhimurium?

Answer 31

Causes inflammation from PAMP recognition by TLRs. It usually causes symptoms but usually clearance of disease.

Question 32

Some products from the inflammatory response like tetrathionite and ethanolamine do what?

Answer 32

promote Salmonella typhimurium competition against normal flora.

Question 33

What strains of Salmonella can kill macrophages?

Answer 33

S. typhimurium and S. typhi

Question 34

Some patients with typoid exhibit what? which causes what?

Answer 34

exhibit genetic changes in immune response possibly promoting carrier state or potential for reinfection

Question 35

How do salmonella macrophages survive?

Answer 35

T3 secretion and effectors used to promote macrophage uptake, dissemination (spread, carry)

Question 36

Biofilms of Salmonella promote survival where in the body?

Answer 36

gall bladder

Question 37

Salmonella typhimurium has normal flora in what animals?

Answer 37

birds and many reptiles.

Question 38

Klebsiella pneumoniae primary and secondary as well as UTI wound infections are all examples of what?

Answer 38

Enterics; bacteria of the gut or intestines.

Question 39

Enterobacter occasionally cause what?

Answer 39

UTI as well as sepsis

Question 40

Serratia, chromobacterium occassionally causes what?

Answer 40

UTI, wound infections and sepsis