Lecture 12 10/19/23

Question 1

What are the general characteristics of gram neg. bacteria?

Answer 1

-outer membrane containing LPS
-majority are bacilli or coccobacilli

Question 2

What are the characteristics of endotoxin/lipid A?

Answer 2

-released when bacteria dies
-contained in LPS

Question 3

What test is used to detect endotoxin/lipid A?

Answer 3

limulus amebocyte lysate test

Question 4

What is the effect of endotoxin?

Answer 4

generalized endotoxic shock effect

Question 5

Where is endotoxin absorbed?

Answer 5

through damaged GI wall

Question 6

How can LPS be beneficial?

Answer 6

development of innate immunity

Question 7

What are the general characteristics of Enterobacteriaceae?

Answer 7

-facultative anaerobic rods
-reside in GI tract
-opportunistic

Question 8

What are the characteristics of E. coli?

Answer 8

-present in mammal GI tracts
-can cause enteritis and extra-intestinal infections

Question 9

What are the possible virulence factors of E. coli?

Answer 9

• capsule
  -fimbrial adhesins
  -enterotoxins
  -cytotoxins
  -siderophores

Question 10

What is a serotype/serovar?

Answer 10

serologically distinguishable microorganism within a bacterial species

Question 11

How are different strains of E. coli identified?

Answer 11

serotyping

Question 12

What are the main toxins of E. coli?

Answer 12

-heat labile LT
-heat stable Sta and Stb
-shiga-like

Question 13

What virulence factor is seen in attaching and effacing E. coli?

Answer 13

intimin

Question 14

What diseases are caused by enterotoxigenic E. coli in calves?

Answer 14

-colibacillosis
-colisepticemia

Question 15

Why are enterotoxigenic E. coli favored for attachment in newborns?

Answer 15

receptors for adhesins are expressed in the GI tract for the first week of life

Question 16

What type of mastitis is caused by E. coli in adult cows?

Answer 16

coliform mastitis

Question 17

What disease is caused by shigatoxigenic E. coli in weaned pigs?

Answer 17

edema disease

Question 18

What diseases are caused by E. coli in dogs?

Answer 18

-colisepticemia
-pyometra
-lower UTI

Question 19

What diseases are caused by E. coli in birds?

Answer 19

-septicemia
-omphalitis
-colispeticemia
-coligranuloma

Question 20

How can E. coli be diagnosed?

Answer 20

-aerobic culture
-fecal culture
-PCR
-serological techniques

Question 21

How should fecal samples be transported?

Answer 21

in screw cap containers while being refrigerated

Question 22

How can E. coli be treated?

Answer 22

-supportive therapy
-antimicrobials

Question 23

Why is it recommended to do AST with E. coli?

Answer 23

it has a lot of emerging antimicrobial resistance

Question 24

Which antimicrobials is E. coli resistant to?

Answer 24

-penicillin/beta lactams
-trimethoprim
-tetracycline
-aminoglycosides
-fluoroquinolones

Question 25

How can E. coli be controlled?

Answer 25

-management
-hygiene
-diet
-general health care
-bacterin and live attenuated vaccines

Question 26

What are the characteristics of zoonotic E. coli?

Answer 26

-food born infections
-mostly shiga-toxin-producing EHEC strain O157:H7
-causes hemorrhagic enteritis, hemolytic uremic syndrome, and kidney failure