Media overview Flashcards
TSA
-complex media
-non-selective and non differential
-growth
MSA
-Gram positive high salt;mannitol fermentation
-Mannitol fermenter should have growth with yellow medium
-mannitol non fermenter should have grwoth with red medium
-salt intolerance shoul dhave no growth
Selective and differential
BAP
-Gram positive (blood hemolysis)
-beta hemolytic - clearing
-alpha hemolytic - greening
-gamma hemolytic - no clearing
EMB
-gram negative lactose fermentation
-rapid lactose fermenter: metallic green/black
-slow lactose fermenter - fish eye/pink/brown
-non fermenter - pale and colourless
MAC
-selective and differential
gram negative lactose fermentation, selects for enteric
-strong lactose fermenter - matte pink with halo
-weake lactose fermenter - gelatinous pink no halo
-non - ferementer - pale
MRS
-selective for lactobacillus
-lactobacillus growth - white to yellow
BSM
-differential
-growth can take up to three days
-selective for bifidobacterium
-bifidobacterium growth - light to dark pink/brown
starch agar
-gram positive (starch hydrolysis)
-growth - non selective,
-differential
PCA
-complex media
-growth
-non selective
-non differential
KF
-fecal streptococci
-e. faecalis growth
-fermentation (of sugars causes acids to change bromocresol purple to turn yellow
-selective
-pH indicator bromocresol purple
-contains azide to inhibit aerobic organisms
complex medium
-large amount of variety of nutrients to accomodate the growth of numerous typles of bacteria regardles of nutritional requirements
-not chemically defines - had unknown composition of some ingredients
-TSA and PCA
-non specific
defined medium
-is chemically defined with a known composition of all components required to allow bacteria to grow
-non specific
non selective
-do not select for certain organisms
non differential
-do not use biochemical properties for differentiating bacterial growth
minimal media
-only a few chemically defined ingredients and does not promote a wide attay of microbes
Purpose of CV in MAC agar
Inhibits growth of most gram positives
Purpose of neutral red in MAC agar
Permits different enfeteric bacteria based on ability to ferment lactose and produce acid
-decrease in pH from acid production changes colour of neutral red
Purpose of blood in BAP
-test for presence of hemolysis in gram positive
Hemolysis lyse RBC
Purpose of eosin and methylene blue dyes in EMB agar
Inhibitors growth of most gram positive bacteria and differentiate lactose fermenters and non fermenters
High salt concentration purpose in MSA
High salt concentration is inhibitory to bacteria other than gram positive streptococci
