- Lactose fermentation media

- contains bile salts/crystal violet to inhibit Gram+

- Neutral red for lactose fermenters

- Luc+ --> red/pink (acid)

- Luc- --> white/colorless (ammonia)

- E. coli, Klebsiella, Shigella, Salmonella, Proteus, Yersinia, Serratia

MacConkey agar

 - MacConkey agar w/ lactose replaced by sorbitol

- Isolates E. coli O157:H7

Sorbitol MacConkey Agar

- Agar that contains pH indicators to inhibit Gram+, sucrose/lactose (CEEKs)

- Fermenters = blue-black colonies, E. coli = green metalic sheen (rapid lactose ferment), slow/weak fermenters = pink

- For fecal coliforms

Eosin-methylene blue agar

- agar that isolates Salmonella and  Shigella

- high bile salts/dyes inhibit Gram+

- Black = Salmonella (due to H₂S), Green = Shigella

- Fermentation indicators - green agar --> yellow/orange

Hektoen enteric (HE) agar

- agar used for Legionella

- has L-cysteine and ferric iron, detoxifying charcoal

- use in conjunction with direct fluorescent antibody test

Buffered charcoal-yeast extract (BCYE) agar

- agar used for Haemophilus

- consists of lysed blood cells containing X/V factors for growth (protoporphyrin/NAD)

- also used with Neisseria

Chocolate agar

- agar used for Bordetella pertussis

- consists of nicotinic acid and charcoal/starch absorbents

- accompanied by direct immunofluorescence

Regan-Lowe agar

- agar used for Vibrio cholerae

- consists of thio-sulfate-citrate-bile salts-sucrose

- alkaline media

TCBS/alkaline agar medium

- endotoxin for Gram-

- mediates inflammation in tissues and septic shock in the bloodstream

- released upon cell death

Lipopolysaccharide (LPS) Lipid A component

- ADP-ribosylates and inactivates EF-2

- inhibits protein synthesis primarily in liver cells --> killing cells

- A-B toxin

Psuedomonas aeruginosa exotoxin A

- A component cleaves eukaryotic 60s ribosomal rRNA, stopping protein synthesis and killing cells

- Type 1 strains carry most severe toxin

- Has A-B component that damages intestinal epithelium and glomerular endothelium

Shigella dysenteriae Shiga toxin (ST)

- same as shiga toxin

- cleaves eukaryotic 60s ribosomal rRNA, stopping protein synthesis and killing cells

- most notable strain is O157:H7

- A-B toxin

- do NOT give antibiotics

- internalized A component of toxin ADP-ribosylates G_s which activates adenyl cyclase, increasing cAMP

- leads to massive efflux of ions and water (small intestine) and "rice-water stools"

Vibrio cholerae cholera toxin

- less severe cholera toxin

- A-B toxin that increases cAMP by ADP-ribosylation of G_s

- "traveler's diarrhea"

- stable version causes same effects with cGMP

ETEC labile toxin (LT)

- helps attachment to respiratory mucosa

- internalized by phagocytes and inhibits G_i through ADP-ribosylation --> cAMP increase

- activated by calmodulin

- lymphocytosis and hypoglycemia result

Brudetella pertussis pertussis toxin