LECTURE - Yersinia sp.

Question 1

bipolar staining sometimes referred to as safety pins for yesinia

Answer 1

wayson stain

Question 2

two cycles that are potential sources of Y. pestis during modern times

Answer 2

sylvatic and domestic

Question 3

T or F. Y. pestis is never motile

Answer 3

T

Question 4

These are only motile at room temperature

Answer 4

Y. pseudotuberculosis and enterocolitica

Question 5

T or F. Plasmid pYV is shared by all three species of Yersinia

Answer 5

T

Question 6

yadA

Answer 6

adherence

Question 7

yops

Answer 7

yersinia outer proteins

Question 8

Inv

Answer 8

• invasin
• expressed preferentially at 25C
• mediates cellular invasion
• room temp - fleas?

Question 9

Ali

Answer 9

accessory invasion locus

• not needed in mouse infection
• helps protect organisms from complement

Question 10

Yersiniabactin

Answer 10

iron-binding siderophore encoded on a PI

Question 11

chrosomally-mediated virulence in Yersnia

Answer 11

• Inv
• Ali
• Yersiniabactin
• other iron-sequestering mechanisms

Question 12

These were first identified in Yersini

Answer 12

T3SS

Question 13

most genes for T3SS r injectisomes are found on this plasmid

Answer 13

pYV

Question 14

assembles into long pilus-like fimbrial structure

Answer 14

F1 antigen (caf1) found on the pMT1 (pFra) plasmid

Question 15

This helps dissolve clots and allow spread

Answer 15

Plasminogen activator (Pa); encoded by pPla (Ppst)

Question 16

Yersinia motile

Answer 16

Yersinia enterocolitica and Yersina pseudotuberculosis can be motile at 25°C

Question 17

The prime sylvatic cycle in North America occurs in …

Answer 17

the four corners area of the U.S. southwest (where Arizona, Utah, Colorado and New Mexico meet)

Question 18

The three main genetic changes that resulted in the evolution of the three Yersinia species we have today.

Answer 18

1. Plasmids and lateral gene transfer of pathogenicity islands with characteristically different G+C ratios..
2. Insertion sequences (ISs) that caused rearrangements and deletions.
3. Mutation or insertional inactivation of ancestral genes resulting in what appear as pseudogenes in genome sequences.

Question 19

what is encoded by pYV:

Answer 19

adherence, T3SS and LcrV

T3SS proteins = YadA, Yops, Yscs, LcrV

Question 20

Chromosomally-mediated virulence in Yersinia

Answer 20

• Inv (invasin) expressed preferentially at 25°C
• Ail (accessory invasion locus) not needed in mouse infection. Helps protect organisms from complement.
• Yersiniabactin (iron-binding siderophore) encoded on a pathogenicity island
• other iron-sequestering mechanisms

Question 21

This is a list of the unique features produced only by Yersinia pestis:

Answer 21

• Flea blocking protein Ymt (yersinia murine toxin) phopholipase D.
• F1 antigen (caf1), capsular antigen fraction 1, found on the pMT1 (pFra) plasmid. The caf1 gene encodes a protein that assembles into a long (pilus-like) fibrillar structure. It has a role in human vs. mouse disease.
• Plasminogen activator (Pla) helps dissolve clots and allow spread. Encoded by pPla (pPst) plasmid.
• Other adherence and invasion genes encoded by the pPla (pPst) plasmid.