CNA-blood agar
Colastin Naladixic Acid plus sheep's blood; selects for gram(+) bacteria, inhibits gram(-) bacterial growth
CNA-blood selective ingredient
Colastin Naladixic Acid
CNA differential ingredient
Sheep red blood cells
alpha hemolysis
partial hemolysis of the sheep red blood cells. produces andolive-green color in the blood
beta hemolysis
clearing of the media as the enzymes in the bacteria degrade the red blood cells.
gamma hemolysis
no hemolysis of the red blood cells
MacConkey media selective ingredient
Analine dyes such as crystal violet; bile salts
MacConkey differential ingredient
lactose
Maconkey media
selects for gram(-) organisms, inhibits gram(+) bacteria
MacConkey pH indicator
neutral red; produces fuschia bacteria if the bacteria can ferment the lactose
MSA
Manitol salt agar; selects for gram(+), salt tolerant bacteria. Inhibits bacteria that can not tolerate salt
MSA selective ingredient
salt
MSA differential ingredient
manitol
MSA pH indicator
Phenol red. This pH indicator turns yellow at low pH, fuschia at high pH, and is red at neutral pH
TSI media
Triple sugar iron media differentiates enterobacteria according to how they ferment different sugars, whether or not they produce gas and whether or not they produce a black percipitate
TSI media sugars
TSI media contains glucose, lactose and sucrose. A bacteria will utilize the glucose first, and the dissacharides second.
TSI pH indicator
phenol red
TSI sugar fermentation results (K/A)
Slant/butt can be red/yellow (K/A) indicating the bacteria can ferment glucose only, not the dissacharides
TSI sugar fermentation results (A/A)
Yellow slant and yellow butt indicate fermentation of the glucose and one or both of the dissacharides (lactose and sucrose)
TSI gas results
bubbles of carbon dioxide gas can show up next to the glass or as cracks in the media
TSI hydrogen sulfide production
A black color indicates hydrogen sulfide production. If it covers the butt of the tube, assume the butt is yellow
Citrate media
Citrate is the sole carbon source in this media. It is used to differentiate between the enterobacteria
Citrate pH indicator
bromothymol blue
Citrate results
A bright blue color indicates a positive result; the original media is blue-green and indicates a negative result
Carbohydrate fermentation tubes
This media contains a single carbohydrate per tube, plus a small, inverted test-tube called a Durham tube to catch any gas
Carbohydrate fermentation tube pH indicator
phenol red
Carbohydrate fermentation tube results
media must turn lemon-yellow to be positive, Durham tube must contain 25% gas to be positive.
MR-VP media
Methyl Red ,Voges-Proskauer tests for fermentation products, either acid or alcohol end products.
MR-VP pH indicator
methyl red; turns red at low pH
MR-VP results
MR positive indicates production of acid waste products. VP positive indicates production of an alcohol end product.
MR-VP reagents
After the bacteria has grown, methyl red pH indicator is added to the MR tube, and VP-A and VP-B are added to the VPtube.
SIM deep media
Used to differentiate enterobacteria according to motility, cysteine, and tryptophan digestion.
SIM inoculation
Use a sterile needle to pick up bacteria, stab straight down into media.
SIM results: motility
If the bacteria are flagellated, they will swim away from the stab line and produce cloudy media.
SIM results: S
If the bacteria can digest the cysteine, it will produce a black percipitate
SIM results: I
Production of Indole can be tested by adding Kovac's reagent to the top of the deep after incubation. A red ring is positive for indole production.
Urea slant
Contains urea
Urea slant pH indicator
Phenol red
Urea slant results
Bacteria that can digest the urea will grow, producing a fuschia color. If bacteria can not digest urea, the media stays the original color
Urea slant inoculation
Use a sterile loop to pick up a generous amount of bacteria. Inoculate with a fish-tail motion, bottom to top.
Phenylalanine slant
conatins the amino acid phenylalanine
Phenylalanine indicator
10 percent ferric chloride is added after incubation, a positive test will turn the slant a green color
Lysine or Ornithine broth
contain lysine or ornithine amino acids
Lysine or Ornithine broth pH indicator
bromocresol purple
Lysine or Ornithine inoculation
After steriley transferring bacteria, add 5 drops of oil to the top of the tubes.
Lysine or Ornithine results
A color change to purple is positve, yellow or the original color is negative