Clinical Procedures - Microbiology and Mycology

Question 1

Good sample collection technique?

Answer 1

Aseptic
Refrigerate samples immediately
Wait 1-2 wk post antibiotics for good results

Question 2

Gram Positive results appear?

Answer 2

Blue/Purple - easy to stain and hard to decolorize

Question 3

Gram Negative results appear?

Answer 3

Red - picks up counter stain after decolorizing alcohol

Question 4

Gram Variable results appear?

Answer 4

Red and blue mixed together. Can be due to over decolorization or old gram positive bacteria that dont take on stain

Question 5

Nutrient Media is used for?

Answer 5

Basic growth of many pathogens.

Question 6

Selective media is used for?

Answer 6

Facilitate the isolation of particular bacteria

Question 7

Bacteria turn brilliant agar green with the presence of?

Answer 7

Salmonella

Question 8

MacConkey agar does what?

Answer 8

Suppresses gram positive, thusly promotes gram negative

Question 9

Mannitol salt agar does what?

Answer 9

Not used often but highly selective for Staphylococcus

Question 10

Example of indicator media?

Answer 10

Blood agar

MacConkey Agar

Question 11

Beta-hemolytic indicates what?

Answer 11

Can utilize all RBC for energy causes clear zone

Question 12

Alpha-hemolytic indicates what?

Answer 12

Utilizes partial breakdown of RBC and greenish hazy appearance

Question 13

Gamma-hemolytic indicates what?

Answer 13

Bacteria used no RBC and just grows on top

Question 14

MacConkey indicates what?

Answer 14

pH indicator - turns pink as lactose is broken down
indicates E. Coli and Klebsiella
Bile salts - selective for enterobacter

Question 15

Muellar-Hinton Agar used for what technique?

Answer 15

Kirby-Bauer technique - antimicrobial susceptibility

Question 16

Incubation of culture technique?

Answer 16

37 degrees for bacteria that invade internal organs
incubate routine cultures for 48 hr, 56-72 hr for negatives
Examine 18-24 hr