Enteric Bac 2

Question 1

What is the gram stain for Salmonella?

Answer 1

Gram neg rod

Question 2

What causes the salmonella-shigella agar medium to turn black with salmonella?

Answer 2

Production of H2S by salmonella

Question 3

What things are caused by salmonella?

Answer 3

Enterocolitis
Enteric fever–typhoid fever
Septicemia
Risk of reactive arthritis–Reiter’s syndrome

Question 4

What strains of salmonella usually cause enterocolitis?

Answer 4

S. typhimurium
S. enteritidis
S. Heidelberg

Question 5

What increases the risk of developing enterocolitis caused by salmonella?

Answer 5

Use of antacids

Question 6

What cells do the salmonellae selectively attach to in order to enter the intestinal cells?

Answer 6

M cell of the Peyer patches –loads into macrophages

Question 7

What does the Ipf operon virulence factor of salmonella enhance?

Answer 7

Adhesion to M cells

Question 8

What virulence factor does salmonella have the enhances bacterial translocation?

Answer 8

type 3 secretion system

Question 9

What virulence factor is present in S. typhi that allows remodeling of phagosomes for systemic spread?

Answer 9

Spi2 type 3 system

Question 10

What virulence factor of S. typhi allows for immune invasion?

Answer 10

Vi antigen

The Vi capsule protects it from humoral immunity

Question 11

What predisposition allows septicemia from salmonella?

Answer 11

Sickle cell anemia

Causes osteomyelitis

Question 12

What abx are used for enteric fevers and septicemia caused by salmonella?

Answer 12

Ceftriaxone or cirofloxacin

Question 13

What is the gram stain for yersinia enterocolitica and pseudo tuberculosis?

Answer 13

Gram neg oval rods

Urease +

Question 14

Where does yersinia enterocolitica and pseudo tuberculosis grow?

Answer 14

Grows in cold–motile at 25c and nonmotile at 37c

Question 15

Where may yersinia enterocolitica spread causing “false appendicitis”?

Answer 15

Local lymph nodes–mesenteric lymphadenitis

Question 16

What virulence factors of yersinia enterocolitica enhance binding to M cells?

Answer 16

Pili and Inv

Question 17

What virulence factor of yersinia enterocolitica is a dermonecrotic toxin that destroys tissue?

Answer 17

CNF

Question 18

What virulence factor of yersinia enterocolitica injects proteins into macrophages–no phagocytosis–reduced inflammatory response?

Answer 18

Yop–type 3 secretion system

Question 19

Pt with yersinia enterocolitica or pseudo tuberculosis are at an increased risk of developing what?

Answer 19

Reactive arthritis–Reiter’s syndrome

Question 20

What is Y. pseudo tuberculosis associated with in children?

Answer 20

Izumi fever–generalized vasculitis with symptoms of fever, rash, conjunctival injection, cervical lymphadenitis, inflammation of the lips and oral cavity, and arrhythmia and edema of the hands and feet

Question 21

What is seen on exam of pt with Y. enterocolitica?

Answer 21

Diarrhea
Dehyrdation
False appendicitis

Question 22

What agar is used to grow Y. enterocolitica and pseudo tuberculosis?

Answer 22

Cefsulodin-irgasan-novobiocin (CIN)

Question 23

What is the gram stain of listeria?

Answer 23

Gram + rod

Question 24

What is the appearance of listeria on non-blood agar?

Answer 24

Blue-green sheen

Question 25

What type of motility is seen with listeria?

Answer 25

Tumbling motility

Question 26

What virulence factor is present in listeria that binds host E-cadherin and mediates invasion of cells in GI tract, placenta, meninges?

Answer 26

Internalin

Question 27

How does the listeria escape into the cytosol

Answer 27

Listeriolysin–opens phagosome

Question 28

What virulence does listeria have allowing it to spread cell-cell?

Answer 28

ActA