Plating Media for Routine Bacteriology

BEA (Bile esculin agar)

Nurtient agar base with ferric citrate. Hydrolysis of esculin by group D streptococci imparts a brown color to medium.

Differential & Selective group D streptococci and enterococci

Blood Agar

5% sheep blood

Nutritive & Differential

Brain heart infusion agar or broth

Dextrose pork brain and heart dehydrated infusions

Cultivation of fastidious organisms

BCYE Buffered Charcoal yeast extract agar

Yeast extract agar charcoal and salts supplemented with L-cysteine HCL, ferric pyrophosphate ACES buffer and alpha-ketoglutarate

Enrichment for Legionella spp

Supports the growth of Francisella and Nocardia spp.

Campy-blood agar

Contains vancomycin trimethoprim, polymyxin,amphotericin B, cephalothin in a Brucella agar base with sheep blood

Selective for Campylobacter spp.

Chocolate agar

Peptone base, enriched with solution of 2% hemoglobin or IsoVitaleX (BBL)

Enrichment for Haemophilus, Brucella, Neisseira spp.

CNA agar

(Columbia Colistin Nalidixic Acid)

Columbia agar base with 10mg colistin per liter, 15 mg nalidixic acid per liter and 5 % sheep blood

Selective for gram positive cocci

Cysteine-tellurite blood agar

infusion agar base with 5% sheep blood reduction of potassium tellurite by Corymebacterium diptheriae products block colonies

Selective & Differential

EMB

Eosin methylene blue agar (Levine)

Peptone base containing lactose eosin Y and methylene blue as indicators

Selective & Differential

GN

(Gram Negative) broth

Peptone base broth with glucose and mannitol

sodium citrate and sodium desoxycholate act as inhibitory agents

Selective & Enrichment

HE

(Hektoen enteric) agar

Peptone base agar with bile salts lactose sucrose salicin and ferric ammonium citrate. indicators include bromthymol blue and acid fuchsin

Selective & Differential for Salmonella spp and Shigella spp from other gram negative enteric bacilli

Loeffer's Medium

Animal tissue (heart muscle) dextrose eggs and beef serum and sodium chloride

Selective & Enrichment

MacConkey agar

Peptone base with lactose. Gram positive organisms inhibited by crystal violet and bile salts. neutral red as indicator

MacConkey sorbitol agar

A modification of MacConkey agar in which lactose has been replaced with D-sorbitol as the primary carbohydrates

Selective & Differential for E. Coli O157:H7

PEA

(Phenylethel alcohol) Agar

Nutrient agar base. Phenylmethanol inhibits growth of

gram-negative organisms

Selective

Regan Lowe

Charcoal agar supplemented with horse blood cephalexin and amphotericin B

Enrichment & Selective

Bordetella pertusis

Salmonella-Shigella Agar

Peptone base with lactose, ferric citrate, and sodium citrate. neutral red as indicator inhibition of coliforms by brilliant green and bile salts

Selective for Salmonella spp and Shigella spp.

Selenite broth

Peptone base broth. sodium selenite toxic for most Enterobacteriacese

Enrichment & Selective

SSA

(Streptococcal selective agar)

Contains crystal violet, colistin, and trimethoprimsulfamethoxazole in 5% sheep blood

Selective for Streptococcus pyogenes & Streptococcus agalactiae

Thayer-Martin agar

Blood agar base enriched with hemoglobin and supplement B. contaminating organisms inhibited by colism, nystatin,vancomycin, and trimethoprim

Selective for N.gonorrhoeae and N.meningitidis

Supports growth of Francisella and Brucella spp.

Thioglycollate broth

Pancreatic digest of casein, soy broth, and glucose enrich growth of most microorganisms. includes reducing agents thioglycolate,cysteine, and sodium sulfite.semisolid medium with a low concentration of agar reducing oxygen diffusion in the medium

Enrichment

TCBS Agar

(Thiosulfate citrate bile salts) Agar

Peptone base agar with yeast extract, bile salts, citrate,

sucrose, ferric citrate and sodium thiosulfate

bromthymol blue acts as indicator

Selective & Differential for Vibrio spp.

Todd-Hewitt broth

enrichment broth for streptococci

Enrichment & Selective