Gram Neg Bacilli

Question 1

does klebsiella ferment lactose?

Answer 1

yes

Question 2

is klebsiella motile

Answer 2

no

Question 3

what antigens does klebsiella have?

Answer 3

O and K

Question 4

what infections are caused by klebsiella?

Answer 4

pneumonia, UTI, sepsis, meningitis, diarrhoea

Question 5

what are the majority of klebsiella infections caused by?

Answer 5

pneumonia, oxytoca

Question 6

what are two main species of salmonella?

Answer 6

enterica and bongori

Question 7

are salmonella; lactose fermenting, motile, spore forming?

Answer 7

non lactose fermenting
motile
non spore forming

Question 8

what antigens do salmonella have?

Answer 8

O and H antigens

Question 9

what is caused by salmonella enterica ?

Answer 9

typhoid fever

Question 10

what can typhoid fever lead to?

Answer 10

small intestine perforation

Question 11

what is salmonella incubated in for enrichment?

Answer 11

selenite broth

Question 12

what agar is used for salmonella identification?

Answer 12

MacConkey

Question 13

what tests are performed on salmonella

Answer 13

API20e and serovar testing

Question 14

what is one of the leading bacterial causes of diarrhea?

Answer 14

shigella

Question 15

is shigella lactose fermenting, motile, sporing?

Answer 15

non lactose fermenting,
non sporing
non motile

Question 16

what family is shigella from?

Answer 16

enterobacteriaceae

Question 17

how many shigella cells cause infection?

Answer 17

100

Question 18

what agar is used for shigella?

Answer 18

macconkey

Question 19

what test does not work for shigella

Answer 19

API20E

Question 20

what is XLD agar?

Answer 20

xylose - lysine - desoxycholate agar

Question 21

does shigella ferment xylose?

Answer 21

no

Question 22

what is the inhibitor in XLD agar?

Answer 22

sodium desoxycholate - inhibits coliforms

Question 23

what does salmonella do to lysine?

Answer 23

decarboxylates it making alkaline pH

Question 24

what does salmonella and shigella look like on XLD

Answer 24

shigella colourless

salmonella black - H2S

Question 25

what do red colonies on XLD indicate?

Answer 25

lactose fermenters that do not produce H2S

Question 26

is salmonella shigella agar differential or selective?

Answer 26

both

Question 27

what is SS agar a modification of?

Answer 27

DCA agar

Question 28

what ibhibits gpos and colifrosm in ss agar?

Answer 28

brilliant green. bile salts, thiosulphate and citrate

Question 29

what is an indicator of sulphide production?

Answer 29

thiosulfate turns black

Question 30

what carb is in SS agar?

Answer 30

lactose

Question 31

does proteus ferment lactose?

Answer 31

no

Question 32

what is a virulence factor of proteus?

Answer 32

urease, flagella - swarming

Question 33

what are the 4 pathotypes of e coli??

Answer 33

enteropathogenic enterotoxigenic enteroinvasive enterohemorrhagic

Question 34

what is EPEC associated with?

Answer 34

infant diarrhoea

Question 35

what is ETEC associated with?

Answer 35

travellers diarrhoea

Question 36

what plasmid encoded toxins are produced in ETEC?

Answer 36

a) heat labile adenyl cyclase activated | b) heat stable guanylate cyclase activated

Question 37

what does adenyl cyclase do

Answer 37

produce cAMP and increase water and ion secretion

Question 38

what does guanylate cyclase do

Answer 38

inhibits ionic uptake from gut

Question 39

what is EIEC associated with

Answer 39

dysentery

Question 40

what is EHEC associated with?

Answer 40

vertotoxins 1 and or 2 | haemorragic collitis and HUS

Question 41

what toxin does O157H7 produce?

Answer 41

shiga toxin

Question 42

how many e coli O157H7 cells cause infection

Answer 42

50

Question 43

how is O157H7 enriched and isolated?

Answer 43

dynabeads - enrichment broth and stomacher - immunomagnetic separation - magenti beads coated with o157 antibody - bound ecoli at bottom

Question 44

what issue does the dynabead system have

Answer 44

not completely specific - false positives

Question 45

what selective media is used for e coli o175h7 ?

Answer 45

macconkey agar with sorbitol, cefiximes and tellurite

Question 46

what is a key characteristic of e coli o157h7 from other e coli?

Answer 46

cannot ferment sorbitol

Question 47

what inhibitors are used in macconkey for ecoli ID?

Answer 47

cefixime (antibiotic) and tellurite inhibits other e coli strains

Question 48

how does e coli o157h7 appear on macconkey with sorbitol?

Answer 48

pale colonies

Question 49

example of chromogenic agar?

Answer 49

rainbow agar

Question 50

what chromogenic agar is used to ID e coli 157h7

Answer 50

rainbow agar

Question 51

what chromogenic substrates does rainbow agar have?

Answer 51

b galactosidase -blue black | b glucuronidase - red

Question 52

what colour colonies does o157h7 on rainbow agar

Answer 52

glucoronidase negative | black or grey

Question 53

what colour colonies non pathogenic e coli on rainbow agar

Answer 53

glucoronidase positive - pink purple blue

Question 54

what are the antigens

Answer 54

O - somatic - LPS H - flagellar K - capsular

Question 55

do ecoli ferment lactose, spores, motile?

Answer 55

lactose fermenters non spore forming motile

Question 56

e coli oxidase and catalase?

Answer 56

oxidase neg | catalase pos

Question 57

is macconkey agar selective or differential?

Answer 57

both

Question 58

what are the inhibitors in macconkey agar?

Answer 58

crystal violet and bile salts | inhibit gram pos

Question 59

what colour does lactose fermenters grow on macconkey agar

Answer 59

dark pink

Question 60

what are the agars used for differentiation of gram neg?

Answer 60

macconkey | eosin methylene blue

Question 61

what is an inhibitor in EMB agar

Answer 61

methylene blue gram pos

Question 62

how does e coli appear on EMB agar?

Answer 62

green metallic