9. Family Enterobacteriaceae (II)

Question 1

Disease caused by Y. enterocolitica

Answer 1

Gastroenteritis (may resemble appendicitis)

Question 2

Temperature for Yersinia spp. to grow on media

Answer 2

25-30°C

Question 3

Appearance of Yersinia spp. on MAC agar

Answer 3

Small

Lactose-negative colonies

Question 4

Agar that may be used instead of MAC for Yersinia spp.

Answer 4

Cefsulodin-irgasan-novobiocin (CIN) agar

Question 5

Colony morphology of Yersinia spp. on CIN agar

Answer 5

Pink colonies

With red center

Question 6

TSI characteristics of Yersinia spp.

Answer 6

Acid/acid

No gas

Question 7

Hemolysis characteristics of Plesiomonas shigelloides on blood agar

Answer 7

No hemolysis

Question 8

Lactose fermentation of P. shigelloides

Answer 8

Non-lactose fermenter

Question 9

Oxidase reaction of P. shigelloides

Answer 9

Oxidase positive

Question 10

Indole reaction of P. shigelloides

Answer 10

Indole positive

Question 11

Lactose positive Enterobacteriaceae

Answer 11

Serratia
E. coli
Enterobacter
Citrobacter
Klebsiella

SEECK

Question 12

Lactose negative Enterobacteriaceae

Answer 12

Proteus
Hafnia
Edwardsiella
Morganella
Providencia

Question 13

Differentiate E. coli, C. jejuni and V. cholerae based on findings in stool specimen

Answer 13

E. coli: bloody stool, no WBCs
C. jejuni: bloody stool, high WBC count
V. cholerae: no blood, no WBCs (Rice water stools)

Question 14

Differentiate Vibrio, Aeromonas and Plesiomonas based on reservior

Answer 14

Vibrio: fresh, brackish, saltwater
Aeromonas: saltwater
Plesiomonas: freshwater

Question 15

Nonmotile Enterobacteriaceae

Answer 15

Shigella spp.
Klebsiella spp.
Yersinia enterocolitica

Question 16

Yersinia spp. that causes plague

Answer 16

Yersinia pestis