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(3002) Clinical Micro > Enterobacteriaceae > Flashcards

Flashcards in Enterobacteriaceae Deck (14)
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1

Define fermentation

use glucose under anaerobic cond.

2

Fermentative vs oxidatiive

F: breakdown of glucose anaerobically & aerobically
O: breakdown of glucose aerobically via Krebs cycle

3

Overt pathogens of enterobacteriaceae

- salmonella
- SHigella
- YErsina

4

2 non-motile enterobacteriaceae genera

- Klebsiella
- SHigella

5

major antigens

H: flagellar protein
K: capsular polysaccaride
O somatic: cell wall LPS
F: fimbrae> adherance

6

List properties/charact. of gram pos*. exotoxins. (5)

- heat labile
- Extremely potent toxins
- Antigenic

7

Diarrhoea producing strains of E.coli

EHEC: Enterohaemorrhagic E.coli
EPEC: ...pathogenic
ETEC: ...toxigenic
EIEC: ...invasive
EAEC: ...aggregative

8

Features of E.coli

- Magenta pink on MAC
- Bright yellow on CLED
- motile
- indole pos.
- sensitive to everything
- GNB

9

Features of Klebsiella sp

- pale pink on MAC
- pale yellow on CLED
- non-motile
- Mucoid capsules = stringy like cheese
- Idole +ve = K. oxytoca
- Indole -ve= K. pneumonia
- GNB
- catalase pos.
- lactose fermenter

10

What primary test results would you expect for a member of the enterobacteriaceae?

- Oxidase test: neg
- Catalase test: +ve
- O-F test: fermentative
- Shape: 5mm, grey colonies on BA w/ opaque centers
- Glucose acid: +ve
- non-haemolytic
- motility: peritrichous flagella
- facultative anaerobes: Grow w/ or w/out O2

11

List properties/charact. of gram neg. endotoxins. (5)

- Lipid A (Gneg. cell wall)
- Heat stable
- no antigen ≠ IR ≠ anitbody made
- activate coagulation, fibrinolysis, complement
- less potent than exotoxins (not strong in effects)

12

features of Enterobacter sp.

- motile
- Indole Neg
- GNB
- Pale pink on MAC

13

Differentiate Proteus vulgaris, P. mirabilis, P. penneri

1. Indole positive: P. vulgaris
2. Maltose positive: P vulgaris & P. penneri

14

Differentiate Serratia marcescens, S. rubidaea, S. plymuthica

Ominthine decarboxylase (ODC on API) pos: S. marcescens