Lecture 8: Enteric Bactera

Question 1

Shigella, E coli, Salmonella, and Yersinia are fodborne member of which phylogenetic grouping?

Answer 1

Enterobacteriaceae

Question 2

Klebsiella, Enterobacter, Serrratia, Proteus, Providencia, and Morganella are opportunistic pathogens of which phylogenetic grouping?

Answer 2

Enterobacteriaceae

Question 3

Are enterobacteriaceae G+ or G-?

Answer 3

G-

Question 4

Are Enterobacteriaceae sporulating?

Answer 4

no - non-sporulating

Question 5

What shape are Enterobacteriaceae?

Answer 5

straight rods

Question 6

How are Enterobacteriaceae classified by their tolerance for oxygen?

Answer 6

Facultative aerobes

Question 7

Are Enterobacteriaceae:
Catalase +/-
Oxidase +/-
and can they ferment glucose?

Answer 7

Catalase+
Oxidase-
ferment glucose

Question 8

What does Enterobacteriaceae’s promiscuity for new DNA (plasmids) confer?

Answer 8

new virulence factors

antibiotic resistance

Question 9

Which phylogenetic group has widespread, extreme antibiotic resistance?

Answer 9

Enterobacteriaceae

Question 10

What are standards to look for in antimicrobial sensitivity testing?

Answer 10

Lawn of bacteria interrupted by zones of clearance

Zones of clearance must be compared to a table to determine which antibiotic is most effective

Question 11

What are two important virulence factors of Enterobacteriaceae in the gut?

Answer 11

Pili and T3SS

Question 12

What three functions does the T3SS serve Enterobacteriaceae in the gut?

Answer 12

adhesion
enterotoxins
subverting gut macrophage

Question 13

A tactic used by Enterobacteriaceae in the gut:
Encourage themselves to be sampled by 1_____ in the 2_____, then alter local macrophages for bacterial survival and spread to the 3_____ through use of 4_____.

Answer 13

1. M cells
2. Peyer’s Patches
3. exterior surface of the gut
4. T3SS

Question 14

Which species of Enterobacteriaceae use the trojan horse method to pass into local lymph nodes, causing false appendicitis?

Answer 14

Y. enterocolictia

Question 15

Which species of Enterobacteriaceae use the trojan horse method to pass into system-wide lymph nodes, causing typhoid fever?

Answer 15

S. typhi

Question 16

The foodborne Enterobacteriaceae infections are ________ a d best prevented by these four methods.

Answer 16

Fecal-Oral
Water treatment
Handwashing
Food Pasteurization
Cooking

Question 17

Shigella and EHEC infections carry a risk of which syndrome?

Answer 17

Hemolytic-Uremic Syndrome (HUS)

Question 18

What is Homolytic-Uremic Syndrome caused by? In whom does it usually present? What is the mortality rate?

Answer 18

Release of shiga toxin into the bloodstream
Pediatric
5-10% mortality

Question 19

Patients positive for Human Leukocyte Antigen-B27 (HLA-B27) may develop __________ after an infection by which 5 species of Enterobacteriaceae?

Answer 19

Reactive arthritis
Shigella
Salmonella
Yersinia
Campylobacter
Chlamydia

Question 20

What are ICU bugs?

List 6 Enterobacteriaceae in this category

Answer 20

major opportunistic nosocomial pathogens
Kelbsiella, 
Enterobacter, 
Serratia, 
Proteus, 
Providencia, 
Morganella