Food Safety: Yersinia

Front 1

What are the 3 main strains of Yersinia?

Back 1

Y. pestis, Y. enterocolitica, Y. pseudotuberculosis

Front 2

Is Yersinia gram positive or negative?

Back 2

negative

Front 3

Is Yersinia aerobic or anaerobic?

Back 3

Facultative anaerobe

Front 4

Does Yersinia form spores?

Back 4

no

Front 5

What shape is Yersinia?

Back 5

rod

Front 6

`What temp does Yersinia like?

Back 6

Psychotrophic (0-44*C) optimim: 28*C

Front 7

How many members of Yersinia are known pathogens?

Back 7

4

Front 8

When did Yersinia emerge as a pathogen?

Back 8

1930

Front 9

How is Yersinia distinguished?

Back 9

Biochemical activity and O antigen

Front 10

What are the 6 biotypes of Yersinia?

Back 10

1A, 1B, 2, 3, 4, 5

Front 11

What bio and serotype is most common in humans and pigs?

Back 11

Biotype 4, Serotype: O:3

Front 12

What is the most pathogenic biotype of Yersinia?

Back 12

1B

Front 13

Which stains are avirulent?

Back 13

1A

Front 14

What are the 2 sub-species of Yersinia?

Back 14

Yersinia enterolcolitica subsp. enterocolitica and Yersinia enterocolitica subsp. palearctica

Front 15

What are the symptoms of Yersinia enterocolitica infection?

Back 15

diarrhea, low grade fever and abdominal, lymphadenitis, blood-transfussion-related septicemia and post infection reactive arthritis

Front 16

What age group is affected by Y. enterocolitica infection?

Back 16

<5 years

Front 17

How longer after ingestion does Y. enterocolitica infection become apparent?

Back 17

2-3 days

Front 18

How long does Y. enterocolitica infection last?

Back 18

1-3 weeks

Front 19

What determines pathogenicity of Y. enterocolitica?

Back 19

Presence of 63kbp

Front 20

What are the 3 biomarkers of Y. enterocolitica infection?

Back 20

yadA, inv and ail

Front 21

What is yadA responsible for?

Back 21

adhesion, invasion and resistance

Front 22

What encodes yadA?

Back 22

plasmid

Front 23

What is invasin responsible for?

Back 23

binding to host cell integrins

Front 24

What encode inv?

Back 24

chromosomes

Front 25

What is ail responsible for?

Back 25

attachment and protection

Front 26

What encodes ail?

Back 26

chromosomes

Front 27

What does Y. enterocolitica survive?

Back 27

freezing

Front 28

What pH does Y. enterocolitica like?

Back 28

4-10, optimum: 7.6

Front 29

How much salt can Y. enterocolitica grow in?

Back 29

5%

Front 30

How much is bacterial load reduced by hot water (80*C)?

Back 30

99% in 10-20secs

Front 31

What are the 6 sources of Y. enterocolitica?

Back 31

surface water, dairy, meat, livestock, companion animals and seafood

Front 32

What industry is Y. enterocolitica a problem for?

Back 32

blood transfussion

Front 33

What is the history of Y. enterocolitica in Ireland?

Back 33

not notifiable until 2004, small number of cases, reports increasing since 2000

Front 34

What European country has the highest prevalence of Yersinia in pigs?

Back 34

Finland

Front 35

What % of pigs tested positive for Y. enterocolitica in year 1?

Back 35

14%

Front 36

What biotype was found in pigs year 1?

Back 36

1A

Front 37

What % of pigs were found positive year 2?

Back 37

35%

Front 38

What biotype was found in pigs year 1?

Back 38

1A

Front 39

How many human cases of Y. enterocolitica were found?

Back 39

none

Front 40

Why were no human cases found?

Back 40

mild self-limiting forms of yersiniosis

Front 41

What percentage of blood donors were positive for IgG antibodies against Yersinia pYV encoded proteins?

Back 41

23%

Front 42

What is comparative phylogenomic analysis?

Back 42

investigation of gene inventory differences between Y. enterocolitica isolates selected to be representative of different pathogenicity groups by biotyping and DNA profiling

Front 43

What are the 4 stages of Phylogenomics?

Back 43

Hybridisation (65%) ---> scanning ---> analysis ---> phylogenetic tree

Front 44

What is a phylogenetic tree based on?

Back 44

whole genome comparison achieved with DNA-DNA microarray hybridisation

Front 45

What does optical mapping make?

Back 45

a comprehensive view of genomic architecture

Front 46

What are the stages of optical mapping?

Back 46

HMW DNA recovered from microbial cells, genomic DNA captured and immobilised as single molecules on a charged optical substrate, digested with restriction endonuclease, genomic DNA stained, scanned, measured and assembled into whole genome ordered restriction map

Front 47

What percentage of porcine tissue samples were positive for Y. enterocolitica?

Back 47

19%

Front 48

What bio/serotypes were found in porcine tissue?

Back 48

3/O:9 mostly, 4/O:3

Front 49

How many different MDR profiles were identified?

Back 49

11

Front 50

What were all isolates resistant of?

Back 50

caphalothin

Front 51

Why are RTE foods susceptible to re-contamination?

Back 51

minimally processed

Front 52

How are AAs involved in cold-adapted phenotypes?

Back 52

AA substitutions facilitate catalytic activity at low temp

Front 53

How are lipids involved in cold-adapted phenotypes?

Back 53

changes in the lipid composition of bacterial membrane to allow for maintainance of fluidity at low temps

Front 54

How is the freeing point of cytoplasm reduced and proteins stabilized?

Back 54

Accumulation of compatible solutes, cryoprotectants and/or anti-freeze proteins

Front 55

What are genes that respond to cold-shock stimulus different to?

Back 55

genes that are required to support growth at low temps

Front 56

What does a pnp-encoding gene produce?

Back 56

polynucleotide phosphorylase that functions to degrade mRNA at 5*C

Front 57

What does lysophosphatidic acid transferase do?

Back 57

modifies membrane lipid composition at low temp

Front 58

In what 4 ways does plsC change membrane lipid composition?

Back 58

change in FA profile, unaltered UFA/SFA, more susceptible to high pressure and growth at low pH, capable of growth at elevated salt conc