Enterobacteriae

Question 1

Shigella, E. coli, and Salmonella are all gram _____, _____.

Answer 1

gram negative rods

* normal flora gone bad

Question 2

Which of these presents with bloody diarrhea: Shigella, E. coli, or Salmonella?

Answer 2

Shigella - starts watery and progresses to bloody, E. coli can cause it too

Question 3

How does E. coli present?

Answer 3

it can cause watery or bloody diarrhea. It can also cause meningitis or pneumonia

Question 4

What does it mean if the diarrhea is watery as opposed to bloody?

Answer 4

watery - non-invasive/ pre-invasive

bloody - destructive/ invasive

Question 5

Which of the following can cause HUS: Shigella, E. coli, or Salmonella?

Answer 5

Shigella, and O157:H7 E. coli

Question 6

Which of the following can cause Reiter’s syndrome ( Reactive arthritis): Shigella, E. coli, or Salmonella?

Answer 6

Shigella and Salmonella

Question 7

Virulence factors for Shigella

Answer 7

shiga toxin (Stx)
ShET1 and 2 
IcsA (actin based motility) 
Shu, Aerobactin (iron uptake) 
IcsP, Pic, SigA: proteases
T2SS, TTSS: secretion systems
IpaB induces macrophage apoptosis

Question 8

What is a unique virulence factor to the uropathogenic strains of E. coli?

Answer 8

P fimbriae for attachment

Question 9

What will you see on a blood smear in HUS?

Answer 9

schistocytes

Question 10

How do you minimize exposure to food-borne enterobacteriaceae?

Answer 10

sewage treatment, pasteurization, water chlorination, food processing, handwashing

Question 11

Who is at the highest risk for infection by food-borne enterobacteriaceae?

Answer 11

Highest risk of infection in children, highest risk of mortality in neonates and elderly

Question 12

Why is treatment of enterobacteriacaea (especially enterobacter) complicated?

Answer 12

extensively resistant to panresistant; bring in microbio consult

Question 13

Enterobacteriaceae are usually nosocomial but, when might we see community-acquired disease?

Answer 13

Klebsiella pneumonia, Serratia endocarditis in IV drug users

Question 14

Where are you most likely to see Klebsiella/ enterobacter/serratia infections?

Answer 14

All common causes of catheter-associated UTIs

All “ICU bugs”

Question 15

What traits are shared by all the Enterobacteriaceae?
 A  Gram(-) rods
 B  Not strictly anaerobic
 C  Problematic antibiotic resistances
 D  All of the above

Answer 15

D

Question 16

Which factor is discouraging for-profit drug companies from developing new antibiotics targeting Enterobacteriaceae?
A Lack of demand for new drugs
B Abundant supply of effective drugs
C Rapid development of antibiotic resistance
D Vaccines in the development pipeline

Answer 16

c

Question 17

Which enteric bacterial infection may lead to hemolytic-uremic syndrome (HUS)?
 A  Shigella
 B  Salmonella
 C  Yersinia
 D  Proteus

Answer 17

A

Question 18

Which of the following is an effective measure for reducing the spread of Enterobacteriaceae infections?
A  Prophylactic rifampin
B  Consistent use of condoms
C  Vaccination
D  Handwashing

Answer 18

D