BACTERIOLOGY 231PLATE MEDIA

MEDIA CARBOHYDRATE INHIBITOR pH INDICATOR RESULTBAPBlood agar

Outdated human blood or 5% defribinated sheep blood

(preferred)

Trypticase Soy Agar or Nutrient agar

{Nonselective Differential agar}

Alpha hemolysis Incomplete or partial lysis with greening

Beta hemolysis Complete lysis with colorless zone [diffusion of hemoglobin into the surrounding medium]

Gamma hemolysis Nonhemolytic

CAPChocolate agar

Lysed red blood cells

{Nonselective Differential agar}

Hemolytic

Trypticase Soy Agar or Nutrient agar

X factor (hemin)V factor or NAD ( nicotinamide

adenine dinucletide, coenzyme)

Nonhemolytic

PEA {Selective & Differential agar} {Selective agar} ✔ Staphylococcus sp.

Phenylethyl alcohol agar

Gram (-) inhibitor

Inhibits swarming of Proteus

MSAMannitol salt agar

{Selective & Differential agar}Inhibits Gram (+)

Mannitol 7.5% NaCl Phenol red

Yellow colonies ✔

[pH 6.8]Coagulase (+) Staph. sp.Some Micrococcus & Enterococcus

Beef extract

Small red colonies ✖

with red/purple zone [pH 8.4]

Most Gram (-)Coagulase (-) Staph. Sp.

EMBEosin methylene blue agar

{Selective & Differential agar}Inhibits Gram (+) Lactose

EosinMethylene blue

Green metallic ✔

sheen (LF)E. coli (lactose fermenter)

Green metallic ✔

sheen w/ fisheyeEnterobacter aerogenes (RLF)

Large purple ✔

mucoid (LF) Klebsiella pneumoniae

Yellow to colorless ✖

(pink) colonies (NLF)Salmonella typhiShigella sonneiProteus vulgarisPsedomonas aeroginosa

MACMacConkey agar

{Differential agar} Lactose Crystal violetBile salts

Neutral red Pink to red colonies✔ [pH <6.8]

Lactose fermenting Gram (-)

Yellow to colorless ✖

colonies [pH 6.8-8.0]Non-lactose fermenting Gram (-)

HEAHektoen enteric agar

{Selective & Differential agar}Inhibits normal flora coliform

of the lower GI tract

[Salmonella and Shigella species from other Gram (-)

enteric organisms]

LactoseSucroseSalicin

Bile saltsCitrate

Bromthymol blue

Blue to green w/ ✔

black centerProvidencia rettegriMorganella morganiiShigella dysenteriae

Blue to green w/o ✔

black centerSalmonella typhiProteus vulgarisProteus mirabilis

Yellow to orange ✖

w/ black centerCitrobacter freundiiSalmonella arizonae

Yellow to orange ✖

w/o black centerE. coliKlebsiella pneumoniaEnterobacter aerogenesShigella sonneiSerratia marcesens

XLDXylose-lysine deoxycholate

{Selective & Differential agar}Inhibits normal flora coliforms

[Partially E. coli & swarming of Proteus]

Xylose Deoxycholate

Phenol red[H2S: ferric ammonium

chitrate; sodium

thiosulfate]

Yellow colonies w/✔ black center

Citrobacter freundiiProteus vulgarisProteus mirabilis

Yellow colonies ✔

w/o black centerE. coliKlebsiella pneumoniaEnterobacter aerogenesProvidencia retteriSerratia marcesens

Red colonies w/ ✖

black centerSalmonella typhi

Red colonies w/o ✖

black centerShigella dysenteriae

SSASalmonella-Shigella agar {Selective & Differential agar}

Inhibition of normal flora coliforms

Inhibits Gram (+) & (-)Lactose

Bile saltsBrilliant green

Neutral red[H2S: ferric ammonium

chitrate; sodium

thiosulfate]

Pink to red colonies✔ w/o black center

Normal flora coliforms

Yellow to colorless ✖

w/o black centerShigella dysenteriaeShigella flexneriShigella boydii

Yellow to colorless ✖ w/ black center

Salmonella typhi

TCBSThiosulfate

{Selective & Differential agar}Isolate Vibrio sp.

Sucrose Sodium citrate

Bromthymol blue

Yellow colonies✔ V. choleraV. alginolyticus

Citrate Bile salt Sucrose agar Sodium

thiosulfateOxgall

[H2S: ferric ammonium

chitrate; sodium

thiosulfate]

Blue-green ✖

coloniesV. parahaemolyticusV. vulnificus

AeromonasPsuedomonas

BSABismuth sulfate agar

{Selective & Differential agar}Isolate Salmonella sp.

Inhibit Gram (+), lactose fermenter & shigellase

Bismuth sulfateBrilliant green

[H2S: ferric sulfide] soluble

Black colonies with✔ metallic cheen

Salmonella typhi

Light green ✔

coloniesS. gallinarumS. choleraesuisS. paratyphi

No growth✖ Other enterics

BACTERIOLOGY 231TUBE MEDIA

MEDIA FORMATION CARBOHYDRATE pH INDICATOR H2S INDICATOR RESULTTSITriple Sugar Iron agar

Butt Slant GlucoseLactoseSucrose

Phenol red Ferrous sulfate A/AG (4) E. coliEnterobacter aerogenesPantoea agglomeransKlebsiella pneumonia

A/AG+ or K/AG+ (5) Citobacter freundiiSalmonella arizonae

A/AG or K/AG (4a) Citrobacter koseriSerratia marcescensHafnia alvei

K/AG+ Proteus vulgarisProteus mirabilisSalmonella paratyphiSalmonella choleraesuisEdwardsiella tarda

A/A or K/A Yersinia entericoliticaShigella sonnei

K/A (2) Shigella dysenteriaeShigella flexneriShigella boydii

K/A+ (3) Salmonella typhiK/K (1) Pseudonmonas aeroginosa

Alcaligenes

MEDIA FORMATION AMINO ACID CARBOHYDRATE pH INDICATOR

H2S INDICATOR

RESULT

LIALysine Iron Agar[Lysine deamination]

Butt Slant Lysine Glucose Bromcresol purple

Ferric ammonium citrate

K/K E. coliEnterobacter aerogenesKlebsiella pneumoniaSerratia marcescensHafnia alvei

K/A Pantoea agglomeransCitobacter freundiiShigella dysenteriaeShigella flexneriShigella boydii

R/A ProteusProvidenciaMorganella

K/AG+ Salmonella typhimuriumSalmonella arizonaeSalmonella typhiSalmonella parayphiSalmonella choleraesuisEdwardsiella tarda

MEDIA PRINCIPLE FORMATION

MEDIUM REAGENT POSITIVE NEGATIVE

Indol Production

Test

The organism oxidized tryptophan

to indol by trytophanase.

Butt Tryptone broth

Ehrlich’s or Kovac’s (p-

aminobenzaldehyde)

Red Ring Yellow/Brown Ring

Methyl Red Test

The organism ferments glucose to

pyruvic acid resulting in mixed

acid products leading to decreased

pH (4.5-5.5) of the medium and takes

the color of the indicator

Butt MRVP (Methyl

Red Voges Proskauer)

medium

Methyl red indicator Red solution

Yellow solution

Voges Proskauer

Test

The organism ferments glucose

producing acetylmethylcarbinol

(acetoin) and converted to

diacetyl in the presence of oxygen

and KOH.

Butt MRVP VP Reagent A: Alpha napthol in absolute methyl

alcohol

VP Reagent B:KOH with creatine

Pink to Red color

Yellow or copper-like

Citrate Utilization

Test

The organism utilizes the citrate

producing ammonia and converted to

ammonium hydroxide. This

alkaline compound raises the pH of the medium and takes

the blue color.

Slant SCA (Simmon Citrate Agar)

Bromthymol blue (indicator)

Prussian blue color

Green color

Urease Test

Urease splits the urea molecules into ammonia, carbon dioxide and water. Ammonia reacts in

solution to form alkaline compound,

ammonium carbonate, which

results in an increased pH of the medium and a color

change in the indicator to pink-

red.

Butt (Broth) Urea broth

Phenol red(indicator)

Pink-red No color change

Sulfide indole

motility (SIM)

Butt (Semi-solid)

Motile (growth

pattern – away from inoculation

line)

Nonmotile(growth

pattern is confined)

H2S production (Blackening of the butt)

Indol production (red ring)