Chapter 1: Stains and Special culture requirements

Question 1

Which microbes can be stained using Wright-Giemsa? (5)

Answer 1

Certain Bugs Really Try my Patience

1) Chlamydia
2) Borrelia
3) Rickettsiae
4) Trypanosomes
5) Plasmodium

Question 2

What stain can be used to detect Chlamydia?

Answer 2

Wright-Giemsa

Question 3

What stain can be used to detect Borrelia?

Answer 3

Wright-Giemsa

Question 4

What stain can be used to detect Rickettsiae?

Answer 4

Wright-Giemsa

Question 5

What stain can be used to detect Trypanosomes?

Answer 5

Wright-Giemsa

Question 6

What stain can be used to detect Plasmodium?

Answer 6

Wright-Giemsa

Question 7

What does the periodic acid-Schiff (PAS) stain for?

Answer 7

PASs the SUGAR

Used to diagnose Whipple disease (tropheryma whipplei) by staining for glycogen and mucopolysaccharides.

Question 8

Which organisms stain with Ziehl-Neelson (carbol fuchsin)?

Answer 8

Acid fast organisms: Nocardia, Mycobacterium

Question 9

What stain can be used to detect acid fast organisms?

Answer 9

Ziehl-Neelson (carbol fuchsin)

Question 10

What does the India ink and mucicarmine stain for?

Answer 10

Cryptococcus neoformans (which has a thick polysaccharide capsule that stains red)

Question 11

What stain can be used to detect crytopcoccus neoformans?

Answer 11

India ink and mucicarmine

Question 12

What microbes does the silver stain identify?

Answer 12

1) Fungi (e.g. peneumocystis)
2) Legionella
3) Helicobacter pylori

Question 13

H. influenzae - special culture requirement?

Answer 13

chocolate agar with factors V (NAD+) and X (hematin)

Question 14

Which bug can be isolated with chocolate agar with factors V (NAD+) and X (hematin)?

Answer 14

H. influenzae

Question 15

N. gonorrhoeae, N. meningitidis - special culture requirement?

Answer 15

Thayer-Martin (or VPN) media
“to connect to Neisseria, please use your VPN client”
1) Vancomycin inhibits gram-positive organisms
2) Polymyxin inhibits gram-negative organisms except Neisseria
3) Nystatin inhibits fungi

Question 16

Which bug can be isolated with Thayer-Martin (or VPN) media?

Answer 16

N. gonorrhoeae

N. meningitidis

Question 17

B. pertussis - special culture requirement?

Answer 17

Bordet-Gengou (potato) agar

“Bordet for Bordetella”

Question 18

Which bug can be isolated with Bordet-Gengou (potato) agar?

Answer 18

B. pertussis

“Bordet for Bordetella”

Question 19

C. diphtheriae - special culture requirement? (2)

Answer 19

Tellurite (Hoyle’s) agar

Loffler medium

Question 20

Which bug can be isolated with tellurite (Hoye’s) agar?

Answer 20

C. diphtheriae

Question 21

Which bug can be isolated with Loffler medium?

Answer 21

C. diphtheriae

Question 22

M. tuberculosis - special culture requirement?

Answer 22

Lowenstein-Jensen agar

Question 23

which bug can be isolated with Lowenstein-Jensen agar?

Answer 23

M. tuberuculosis

Question 24

M. pneumoniae - special culture requirement?

Answer 24

Eaton agar, requires cholesterol

Question 25

Which bug can be isolated with Eaton agar and requires cholesterol?

Answer 25

M. pneumoniae

Question 26

Lactose-fermenting enterics - special culture requirement? (2)

Answer 26

1) MacConkey agar (lactose fermentation produces acid and turns colonies pink) 2) E.coli is grown on eosin-methylene blue (EMB) agar as colonies with green metallic sheen

Question 27

What is MacConkey agar used for?

Answer 27

Grows gram-negative bacteria (inhibits gram-positives) and turns lactose-fermenters pink

Question 28

What type of agar grows Gram-negative bacteria (inhibits the growth of Gram-positives), and turns lactose-fermenters pink?

Answer 28

MacConkey agar

Question 29

What is eosin-methylene blue (EMB) agar used for?

Answer 29

Grows gram-negative bacteria (inhibits Gram-positives). Lactose fermenters display nucleated colonies: colonies with dark centers. E.coli has a green metallic sheen

Question 30

How do Gram-negative lactose-fermenters appear on MacConkey agar?

Answer 30

pink colonies

Question 31

What type of agar grows Gram-negative bacteria (inhibits the growth of Gram-positives), and lactose-fermenters display nucleated colonies?

Answer 31

eosin-methylene blue (EMB) agar

Question 32

E.coli has a green metallic sheen when grown on what kind of agar?

Answer 32

eosin-methylene blue (EMB) agar

Question 33

How does E.coli appear when grown on EMB agar?

Answer 33

nucleated colonies with green metallic sheen

Question 34

How do Gram-negative lactose fermenters appear when grown on EMB agar?

Answer 34

nucleated centers

Question 35

What agars can be used to differentiate lactose from non-lactose fermenters? (2)

Answer 35

1) MacConkey agar | 2) EMB agar

Question 36

Legionella - special culture requirement?

Answer 36

Charcoal yeast extract agar buffered with cysteine and iron

Question 37

Which bug grows in charcoal yeast extract agar buffered with cysteine and iron?

Answer 37

Legionella

Question 38

Fungi - special culture requirement?

Answer 38

Sabourand agar | "Sab's a fun guy!"

Question 39

Which bug grows on Sabourand agar?

Answer 39

Fungi | "Sab's a fun guy!"