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D Bac Exam 2
| Question | Answer |
|---|---|
| Enterobacteriaceae | gram postive rods, non spore forming, grow on peptone media, grow on macconkey agar, usually faculatative anaerobes, ferment glucose with gas production, catalase +, oxidase -, reduce nitrate. |
| Friedlander's Bacillus ("brick red" sputum) | K. pneumoniae |
| endotoxin shock (symptoms) | fever, leucopenia, capilary hemorrhage, hypotension, circulatory collapse |
| limulus lysate assay | reagent prepared from the ameboctytes of the horseshoe crab (Limulus polyphemus). Tests for endotoxin shock |
| lipid A | toxic portion of lipopolysaccharide of gram negative cell wall that produces endotoxin |
| Flagellar antigen | H antigen |
| Capsular antigen | K antigen |
| Somatic antigen | O antigen |
| Ewig | developed the concept of tribes with Enterobacteriaceae |
| tribe I | Eschericheae |
| tribe II | Edwardsielleae |
| tribe III | Salmonelleae |
| tribe IV | Citrobactereae |
| tribe V | Klebsielleae |
| tribe VI | Proteeae |
| tribe VII | Yersinieae |
| Methyl Red Test | tests for mixed acid fermentation (red below pH 4.4 and yellow above pH 6.2) |
| Voges Proskauer Test | tests for butanediol fermentation |
| Embden-Meyerhof pathway | series of glycolytic cleavages that result in the production of pyruvic acid from glucose |
| ONPG-galactose test | tests for beta galactosidase and beta galactoside permease, (+ = yellow, - = colorless) |
| enzyme needed for fermentation of lactose | beta galactoside permease and beta galactosidase |
| Kligler Iron Agar (KIA) | contains lactose and glucose (10:1), ferrous sulfate, and phenol red |
| KIA: alkaline slant (red)/ alkaline butt(red) | no carbohydrate fermentation |
| KIA: alkaline slant (red)/ acid butt (yellow) | glucose fermented but lactose not (ex. Shigella) |
| KIA: alkaline slant (red)/ acid butt (black) | glucose fermented but lactose not, production of hydrogen sulfide (Salmonella, Citrobacter, and Proteus) |
| KIA: acid slant (yellow)/ acid butt (yellow) | glucose and lactose fermented (ex. E. coli, Klebsiella, and Enterobactor) |
| MacConkey Agar | differential media for selection and recovery of Enterobacteriaceae |
| MacConkey Agar: red colonies | strong lactose fermenters (ex. Escherichia, Klebsiella, Enterobactor) |
| MacConkey Agar: pink colonies | weak lactose fermenters (ex. Citrobactor, Providencia, Serratia, and Hafnia) |
| MacConkey Agar: colorless colonies | Non lactose fermenters (ex. Proteus, Edwardsiella, Salmonella, Shigella) |
| Eosin Methylene Blue Agar | differentiates between lactose and non lactose fermenters (similar to MacConkey Agar in the detection and differentiation of Enterobacteriaceae) |
| Eosin Methylene Blue Agar: green black colonies with metallic sheen | Strong lactose fermenters (E. coli) |
| Eosin Methylene Blue Agar: purple colonies | weak lactose fermenters |
| eosin methylene Blue Agar: purple to black colonies | sucrose fermenters and non lactose fermenters (ex. Yersinia enterocolitica) |
| Hektoen Agar | highly selective for recovery for Enterocacteriaceae (green media). Good for enhanced recovery of Salmonella and Shigella from material with heavy numbers of normal flora. |
| Hektoen Agar: bright orange, pink | rapid lactose fermenters (E. coli) |
| Hektoen Agar: blue green colonies with black centers | Salmonella |
| Hektoen Agar: more green colonies | Shigella |
| Xylose lysine deoxycholate agar | highly selective media for isolation of enterics, less inhibitory than HE agar (low conc. of bile salts), designed to detect shigellae in feces after enrichment in gram-negative broth. |
| Selenite Broth | used for recovery of Salmonella and Shigella from feces or sewage. maintain predominant E. coli in lag phase |
| ingredient in Selenite broth that inhibits E. coli | sodium selenite |
| indole | produced by the breakdown of trptophan, also produce is pyruvate and ammonia |
| tryptophanase | enzyme that breaksdown tryptophan |
| Kovac's reagent | p-dimethylaminobenxaldehyde, used in the detection of indole (red = +) |
| Citrate utiliatization | tests ability of strain to utilize citrate as a sole carbon and energy source |
| Citrate utilization: positive result | blue color |
| E. coli | indole +, methyl red +, VP -, Citrate - |
| Enterobacter aerogenes | indole -, methyl red -, VP +, citrate + |