Section 6: Enterobacteriaceae

Question 1

what are the characteristics of enterobacteriaceae?

Answer 1

G- rods
acquire antibiotic resistance from conjugation
transmission is fecal-oral
facultative anaerobes
catalase positive
endotoxin

Question 2

Coliform

Answer 2

faculatitively anaerobic gram-, non endospore forming, rod shaped bacteria that ferments lactose with gas production
(specific definition so only few fit this criteria)

Question 3

What does the coliform group include?

Answer 3

escherichia coli
enterobacteria aerogenes
Klebsiella

Question 4

What are the characterisitics of escherichia coli?

Answer 4

opportunistic pathogen
DNA transfer via conjugation, transposons, lysogenic conversion, allows swapping of virulence factors and leads to serological variation
pili for adherence
flagella-motility, unipolar

Question 5

What is the pathogenesis of escherichia coli?

Answer 5

E. coli sepsis
UTIs
meningitis
gastroenteritis

Question 6

Enterotoxin producing E. coli-ETEC

Answer 6

traveler’s diarrhea
heat labile toxin similar to cholera
heat stable toxin stimulates fluid excretion
both toxins inhibit reabsorption of Na and Cl, water follows and lose electrolytes

Question 7

Enteroinvasive E. coli-EIEC

Answer 7

invades intestinal cells
virulence factor is encoded on plasma shared by Shigella
diarrhea with WBCs

Question 8

Enteropathogenic E. coli-EPEC

Answer 8

adheres to cells
adhesions cause loss of microvilli
cause non-bloody diarrhea particularly in bottle fed infants

Question 9

Enterohemorrhagic E. coli-EHEC

Answer 9

produce verotoxin which attacks the endothelium of blood vessels
specific target for the toxin is the vascular endothelium of the glomerulus

Question 10

E. coli 0157:H7

Answer 10

severe abdominal pain and diarrhea
hemolytic uremic syndrome (HUS) renal failure and lysis of RBCs
can lead to permanent kidney function loss