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SBA agar
- Sheep's Blood Agar
- Allows visualization of B hemolysis (some E. coli)
- Swarming of Proteus
- Mucoid colonies of Klebsiella pneumoniae
-
MAC agar
- MacConkey Agar
- Detection/isolation of gram- from clinical, dairy, food, water, etc
- Lactose and Neutral red: differential agents (fermentation)
- Bile salts and Crystal Violet: inhibit gram+
- **lactose fermentors (typical enteric) will grow pink, non-fermentors will grow clear
-
EMB agar
- Eosin-methylene Blue Agar
- For isolation of G- enteric bacteria (looking for coliforms)
- Eosin Y and Methylene Blue: selective age and differential pH indicator
- Lactose: differential agent (fermentation)
- **lactose negative = clear
- **lactose positive = pinkish/purple
- **E. coli = metallic green
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HE agar
- Hektoen Enteric Agar
- Isolation/cultivation of G- enteric ESPECIALLY Shigella
- Lactose, saccharose, salicin: differential agents
- Soldium thiosulfate and Ferric ammonium citrate: for H2S production (black colonies)
- **E. coli turns medium orange
- **Salmonella shows "bullseye colonies" w/ black center
- **Shigella shows no bullseye, agar remains blue
-
XLD agar
- Xylose Lysine Desoxycholate Agar
- Isolation/differentation of enterics esp. Shigella
- Lysine, lactose, succharose: fermentable carbs
- Sodiumthiosulfate and Ferric ammonium citrate: H2S production
- **Salmonella has bullseye colonies
- **Shigella appears clear w/ no bullseye, agar remains red
- **E. coli changes agar yellow
-
SS agar
- Salmonella-Shigella Agar
- isolation of pathogenic enteric bacilli, esp Salmonella and some Shigella
- Lactose and neutral red: differential agents
- sodium thiosulfate, and ferric citrate: H2S detection
- **Salmonella appears black (H2S)
- **Shigella appears clear
- **E. Coli grows pink (like MAC)
-
CIN agar
- Cefsulodin-Irgasan-Novobiocin agar
- AKA YSA (Yersinia selective agar)
- For isolation of Yersinia enterocolitica
- antibiotics inhibit most enterobacteria
- **Y. enterolytica shows bullseye morphology (red)
-
SMAC agar
- Sorbitol MacConkey Agar
- For detection of sorbitol-nonfermenting E. coli serotype O157:H7 (assoc w/ hemorrhagic colitis)
- same as MAC, but sorbitol replaces lactorse
- **this serotype cannot ferment sorbitol and WILL NOT have a pink color, find the clear colonies!
-
Broth cultures
- Gram neg broth isolates enterics
- mannitol: inhibits enterics by slowing growth
- selenite broth and tetrathionate broth: enrich recovery of Salmonella and Shigella (Selenite toxic to most enterics)
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