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Microbial Techniques
1st and 2nd stage tests for identifying bacteria
Question | Answer |
---|---|
CAMP | Used to identify S. algalactiae because it can release a diffusible compound. In conjunction with s. aureus, this compound causes completes lysis on sheep blood agar plate. |
Coagulase | Coagulase is an enzyme express by certain pathogenic staphylococci which can coagulate blood plasma. Difinitive for S. aureus |
Mannitol Salt Agar | Used to identify staphylococci. Mannitol is sole carbon source. If organism can utilize mannitol the pH indicator change from red to yellow. |
Bile Esculin Agar | Used for Enterococci. Distinguishes from streptococci. HYDROLYSIS OF (SUGAR) ESCULIN TO ESCULATIN.The by-products of esculin hydrolysis react with iron in the media, turning it black. A postive result includes growth AND blackening. |
Superoxol | Definitive for N. gonorrheae Same as catalase test but higher concentration of Hydrogen Peroxide |
Lecithinase | Breaks down phospholipids into diglycerides. C. perfringens grows on this EYA. |
Lipase | Enzyme degrades triglycerides into glycerol and fatty acids. Uses tributyrin (lipase agar) |
Starch Hydrolysis | Measures the production of amylase. Amylase degrades the starches into glucose for use in metabolism. Iodine reacts with starch to turn black. If amylase is produced, there is no colored zone around colony |
Indole | Ability to use tryptophan. Indole-> pyruvic acid-> ammonia. Adding Kovac's reagent = red |