Yersinia

Question 1

Characteristics of yersinia

Answer 1

Enterobacteriaceae
Lactose negative
Growth <4C to 45C
Motile at 30C but no motile at 37C
4-10pH survival

Question 2

What are the 2 groups of enterocolitica?

Answer 2

Biovars and serovars

Question 3

What is the difference between biovars and serovars?

Answer 3

Biovars use substrate and serovars have LPS O-antigens

Question 4

What is the most common serotype of enterocolitica?

Answer 4

Bioserotype 4:O3

Question 5

Where can 4:O3 be found?

Answer 5

Pigs, salad and milk

Question 6

Symptoms of enterocolitica

Answer 6

Diarrhoea
Mild fever
Abdominal pain
Inflammation of lymph nodes

Question 7

How long do symptoms of enterocolitica last?

Answer 7

5-14 days

Question 8

How does enterocolitica cause infection?

Answer 8

Penetrates intestinal walls and produces heat-stable enterotoxins, controlled by plasmid and chromosomal genes

Question 9

How does enterocolitica cause inflammation of epithelial cells?

Answer 9

Stomach acid attach to epithelial cells of ileum
Cells multiply and spread to lymph nodes
Disseminate into deeper tissue and organs

Question 10

What are the adhesins used by yersinia?

Answer 10

myfA (fimbrial antigen and putative adhesin)
inv invasin (outer membrane protein required for translocation)

Question 11

What is the use of adhesins?

Answer 11

Colonisation and invasion

Question 12

What is the use of pYV plasmid in yersinia?

Answer 12

Allows replication in lymphoid tissue

Question 13

What are the enterotoxins of yersinia?

Answer 13

Yst A, B and C

Question 14

What is the use of enterotoxins by yersinia?

Answer 14

Acts on guanylate cyclase and iron utilisation

Question 15

When are yersinia enterotoxins expressed?

Answer 15

<30C

Question 16

What is Y. pseudotuberculosis?

Answer 16

Strain of yersinia found in rodents, carrots, lettuce and chocolate milk

Question 17

What does pseudotuberculosis cause?

Answer 17

Gastroenteritis
Lymphadenitis
Immune diseases