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Flashcards in Miscellaneous Bench (stools) Deck (38)
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1

What are the enteric pathogens that would be cultured on a routine stool work-up?

Salmonella
Shigella
Campylobacter
Escherichia coli 0157:H7

2

What enteric pathogens can be cultured but require special request by the physician?

Yersinia
Aeromonas
Plesiomonas
Vibrio
Listeria
Clostridium difficile

3

How should stool specimen be maintained (and how long) if they cannot be immediately processed?

room temp/ unpreserved -

4

What is the recommended transport medium as an alternative to fresh specimens?
- for routine specimen?
- for Vibrio?

Modified Carey-Blair
- buffered glycerol saline for salmonella and Shigella
- buffered glycerol saline enriched with CACl2 for Vibrio and Campylobacter

5

List 5 reasons for unacceptable stool specimens

1. contaminated with urine and/or water
2. contaminated with castor oil, bismuth, or barium
3. Multiple spemimens submitted on the same day
4. dry rectal swabs and stools sent in diapers or paper cups
5. unpreserved stool specimens greater than one hour old

6

Media used to culture routine stool pathogens (and temperatures)

1. BAP (35C ambient air for 24 hours)
2. Enteric agar media=MAC/HEK/MAC SORBITOL (35C in ambient air for 24 hours)
3. Campylobacter media (microaerophilic, capnophilic, 42C for 48 hours)

7

What are capnophilic conditions?

5% O2
10% CO2
85% N2

8

Media used and proper incubation for:
- Aeromonas species

BAP plate employing the cytochrome oxidase test. CIN or YSA may be used as a selective medium.

9

Media used and proper incubation for:
- Plesiomonas shigelloides

BAP plate employing the cytochrome oxidase test

10

Media used and proper incubation for:
- Vibrio species

Selective agar: TCBS incubated at 35C ambient air for 48 hours

11

Media used and proper incubation for:
- Yersinia species

YSA plate after 48 hours incubation at 25C
MAC plate after 48 hours incubation at 25C

12

Potenital pathogen colonial morphology on a BAP

Screen for Aeromonas and Plesiomonas by testing for cytochrome oxidase positive colonies

13

Potenital pathogen colonial morphology on a MAC

Clear or transparent colony

14

Potenital pathogen colonial morphology on a HEK

Green or black colony

15

Potenital pathogen colonial morphology on a MAC SORB

Clear or transparent colony

16

Potenital pathogen colonial morphology on a YSA

Any colony

17

Potenital pathogen colonial morphology on a Charcoal CAMPY

Non-hemolytic grey or colorless colonies can be flat with irregular edges or round and convex with entire edges. Colonies can be pin point or spreading along streak lines, some spread all over plate

18

Potenital pathogen colonial morphology on a TCBS

Yellow or green colony

19

Potenital pathogen colonial morphology on a PALCAM

Blackening around colony

20

How can a rapid urease help to rule out stool pathogens?

all positive urease isolates can be dismissed as normal flora

21

Campylobacter jejuni:
- typical gram stain

small, curved gram negative rods

22

Campylobacter jejuni:
- catalase? oxidase? hippurate test result?

Cat: pos
Ox: pos
Hip: pos

23

Report to the State Board of Health

Salmonella
E. coli 0157:H7
Shigella?
Campylobacter?

24

Shiga Toxin Producing E. coli methods:
- which methods screens for only O157

EHEC by EIA testing

25

Shiga Toxin Producing E. coli methods:
- purpose of broth

*

26

Shiga Toxin Producing E. coli methods:
-

Examine on MAC SORBITOL for colorless or clear colonies. Test with 0157:H7 Latex Kit

27

How do you identify
- Salmonella

*

28

How do you identify
- Shigella

*

29

How do you identify
- E. coli 0517

*

30

Organisms that cause food poisoning "infections"

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