Microbiology Media

Description:	Media selection
Category:	Laboratory Science
Created by:	Robert Walker on 2009-09-07

Question	Answer
5% Sheep Blood Agar is non-selective but differential for what?	Differentiates alpha, beta and nonhemolytic bacteria.
Blood Agar is composed of what nutrient?	5% sheep blood
What types of organisms are supported by the blood agar?	All but the most fastidious organisms. Most gram pos and gram neg bacteria
What is Brilliant Green differential for?	Lactose pos and Lactose neg bacteria.
Lactose pos on Brilliant Green decreases pH and is what color?	yellow green
on Brilliant Green what colors will be seen on Lactose neg?	pink colony with red zone in medium
What type of bacteria will Brilliant Green inhibit?	most enteric bacteria
What kind of agar is the Chocolate Agar?	Enriched
How is a Chocolate Agar enriched?	It is a Blood agar base with hemoglobin, hemin and co enzyme nicotine adenine dinucleotide(NAD)
what factor is hemin in a chocolate agar?	V Factor
What factor is NAD in a chocolate agar?	X Factor
The chocolate auger is enriched with X factor and V factor to support the growth of what?	H. influenzae and N. gonorrhaeae, plus most other gram pos and gram neg bacteria.
How is Columbia CNA agar differential?	it will demonstrate alpha /beta/no hemolysis
Columbia CNA agar is selective for what?	Gram pos bacteria.
The Columbia CNA agar has the ability to grow what?	Staph and Strep.
On the Columbia CNA agar what inhibits gram neg bacteria from growing?	Colistan and nalidix acid
The EMB ager contains what two dyes?	Eosin Y and Methylene Blue
The dyes in the EMB agar cause it to be selective by what?	The dyes inhibit gram pos rods.
The EMB agar is differential how?	Gram neg lactose fermentation
On the EMB agar what color will a lactose pos be.	Dark purple center, Lactose neg will not have a dark purple center.
Hektoen Enteric Agar inhibits wh
Hektoen Enteric agar is differential for what?	Lactose pos and neg bacteria
On the HE agar how do you differentiate between lactose pos and neg?	decreased pH will cause yellow colonies for L+ and green blue for L-.
What type of bacteria will the HE agar inhibit?	most normal enteric bacteria.
Selenite F broth is used to enrich what bacteria	Salmonella and other patogenic enteric bacteria
In Selenite F broth what is used to inhibit normal flora?	sodium selenite
The Thayer Martin Agar is selective for what?	N. gonorrrhoeae and some other Neisseria species.
What is the TM agar made of	colistan to inhibit other gram neg Vancomycin to inhibit gram pos nystatin to inhibit yeast
Modified TM contains what?	trimethoprim to inhibit Proteus.
Thioglycollate Broth is used for what?	enrichment for most all bacteria
Mac Conkey is selective for what?	enteric gram neg
Mac Conkey differentiate Lactose fermenters how?	Lactose + is red while Lactose- is clear
in the Mac Conkey agar what causes inhibition of gram + bacteria?	crystal violet dye and protein.
What species is Mannitol salt selective for?	Staph
In Mannitol Salt Agar what is used to inhibit gram- and other gram pos bacteria besides staph?	NaCl
Mannitol fermenters and be differentiated from non fermenters be?	fermenters are yellow and non-fermenters are pink.
PEA agar is used for?	same as CNA
What does SXT stand for?	Strep Selective Agar.
What kind of culture is most likely used with a SXT agar?	throat cultures
What is the SXT agar composed of?	Sheep blood agar with trimethoprim-sulfa an antibiotic used to inhibit most bacteria besides GpA and GpB strep.
What kind of hemolysis is caused my S.pyogenes and agalactiae?	beta hemolysis.