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Flashcards in Bacteriology Lab Final Deck (63)
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1

Name the dye present in MacConkey Agar that is responsible for staining microbes that ferment lactose

neutral red

2

The catalase test detects the enzyme catalase, which is responsible for converting ____________ to _____________

The catalase test detects the enzyme catalase, which is responsible for converting hydrogen peroxide to water and oxygen

3

Is Staphylococcus aureus catalase positive or catalase negative

Staphylococcus aureus is catalase positive

4

Is Streptococcus equi catalase positive or catalase negative?

Streptococcus equi is catalase negative

5

The oxidase test depends on the presence of _____________ in a bacterial cell

Cytochrome C Oxidase

6

Are most Staphylococcus spp. oxidase positive or oxidase negative?

Most Staphylococcus spp. are oxidase negative

(the negative test is the cue-tip marked 'B')

7

In the motility test, tetrazolium salts are added to help detect motility. When the bacterium grows, the dye from the salts is incorporated into the bacterial cells, where it is reduced to an insoluble red pigment.

What is the name of that red pigment?

formazan

8

What is the pH indicator utilized in the urease test?

phenol red

9

What does the Methyl Red (MR) test test for?

Low MW acids like lactic, formic, & acetic acids

10

The citrate test tests for ________________________

What is the indicator used?

ability to use citrate as sole carbon source

Indicator used: Bromothymol blue

11

Does Proteus mirabilis produce a positive or negative motility test?

positive

12

What color will a positive urease test produce?

bright pink

13

Which amino acid is involved in the indole test?

Tryptophan

14

Is Pseudomonas aeruginosa oxidase positive or oxidase negative?

Pseudomonas aeruginosa is oxidase positive

15

Rappaport-Vassiliades Broth is used mainly for which bacterial species?

Salmonella spp.

16

Identify these Gram{+] cocci in clusters

Staphylococcus spp

17

Identify these Gram[+] cocci in chains

Streptococcus spp.

(just remember, "strepto" means chain in Greek)

18

Identify these Gram[+], gamma-hemolytic cocci in pairs or short chains

Enterococcus spp.

19

Identify these large aerobic or facultative anaerobic Gram[+] rods that form endospores

Bacillus spp.

20

True or False:

Candida spp. can all produce pseudohyphae

True

If you see pseudohyphae, it's more than likely Candida spp.

21

Identify these Gram[+] short rods:

Arcanobacterium spp.

22

T/F: MacConkey agar is designed to grow Gram-positive bacteria and differentiate lactose fermenters from non-fermenters

False.

MacConkey agar is designed to grow Gram-negative bacteria and differentiate lactose fermenters from non-fermenters

23

______________ is a differential, selective medium for the isolation of Shigella and Salmonella species from enteric pathological specimens. It contains lactose, sucrose and salicin.

Hektoen enteric agar

24

Between Microsporum spp. and Trichophyton spp., which one is known to have numerous microconidia?

Trichophyton spp.

25

Found in concentrated pigeon droppings due to their hig content of creatinine.

Identify.

Cryptococcus neoformans

26

Which one of these is Aspergillus spp?

That one.

27

Blood Agar is a general purpose enriched medium that is used to differentiate bacteria based on which properties?

hemolytic properties

28

Lactose-positive organisms display what color on MacConkey agar?

red/pink

lactose fermenters produce acid and lower the pH of the medium, producing red/pink colonies

29

Hektoen enteric agar contains indicators of lactose fermentation and H2S production. What are those indicators?

thiosulfate and ferric ammonium citrate

30

What are the components of Hektoen enteric agar that inhibit growth of Gram-positive organisms?

bile salts and bromothymol blue