4.5: Eosin Methylene Blue Agar Flashcards
EMB is a complex ?? and ?? medium
-selective and differential
Is selective for gram-?? organisms and contain indicators to differentiate ?? fermenters from ?? non-fermenters
-negative
-lactose; how strong they use it
EMB agar is commonly used to test for the presence of ?? in environmental samples. The presence of ?? in the environment suggests??
-coliforms
-fecal contamination and possible presence of enteric pathogens
Composition of EMB agar:
-gelatin, lactose, and dyes eosin Y and methylene blue
Dyes react with vigorous lactose fermenters whose acid end products turn the growth ?? or ??, and sometimes accompanied by a ?? metallic sheen
-dark purple or black
-green
Green=
Purple=
Pink=
color of media=
-E.coli
-fast lactose fermentation
-normal lactose fermentation
-no lactose fermentation
You observe colonies growing on EMB agar that have a metallic green sheen. What species of bacteria is this likely to be?
-E.coli
The EMB Agar is commonly used to test
-coliforms
The eosin Y and methylene blue in the EMB Agar plate serves as
-a selective agent
TRUE OR FALSE:
Eosin methylene blue agar is used to isolate and differentiate members of the Enterobacteriaceae family based on the ability to ferment mannitol.
-false
If a Gram-negative organism does not fermenter of lactose, it will produce ____________ colonies on an Eosin Methylene Blue Agar plate.
-color of medium
Eosin methylene blue agar contains the dyes
-eosin Y
-methylene blue
The purpose of the dyes in eosin methylene blue agar are (Select all that apply)
-react vigorously with lactose fermenters
-to inhibit the growth of gram positive bacteria
Eosin Methylene Blue Agar is a selective and differential medium. It selects for ________________ while differentiating between those that can and cannot __________.
-gram negative
-ferment lactose
If a Gram-negative organism is a vigorous fermenter of lactose, it will produce ____________ colonies on an Eosin Methylene Blue Agar plate.
-purple
