1 / 9

Api 20E

Api 20E. principle. The API 20E System is a standardized, miniaturized microtube system consisting of 21 conventional “basic” and 6 supplementary biochemical tests used for the identification of Enterobacteriaceae and other non-fastidious Gram-negative bacteria.

kieve
Télécharger la présentation

Api 20E

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Api 20E

  2. principle • The API 20E System is a standardized, miniaturized microtube system consisting of 21 conventional “basic” and 6 supplementary biochemical tests used for the identification of Enterobacteriaceae and other non-fastidious Gram-negative bacteria. • The API 20E System consists of microtubes containing dehydrated substrates. The substrates are reconstituted by adding a bacterial suspension. • They are then incubated so the organisms react with the contents of the tubes. Finally, they are then read when the various indicator systems are affected by the metabolites or added reagents, generally after 18 to 24 hours incubation at 35 - 37°C. Refer to API 20E package insert for the principles involved in each of the reactions, reactive ingredients and quantity of ingredients in each tube. Cupule tube

  3. Biochemistry • ONPG : ortho-nitrophenyl b-D-galactopyranoside. • ONPG is a substrate that have B-galactosidic bond “like lactose” but didn’t need permease to enter bacterial cell. • ONPG “colourless” galactose + ortho-nitrophenol “yellow/pale yellow” B-galactosidase + + + -

  4. Biochemistry • ADH : arginineDihydrolase • argeninecitrullin + NH3 • citrullin + phosphate ion carbamoil phosphate + ornithine • carbamoil phosphate ATP + CO2 + NH3 • This microtube contains phenole red indicator • orange color consider +ve only in first 24h ADH Catabolic argininecarbomolytransferase Carbamoilkinase 6.8 8.4 + -

  5. Biochemistry • LDC : lysine decarboxylase. “as LIA” Lysinecadaverine(pH ) +CO2 • ODC : ornithinedecarboxylase. “as MIO” ornithineputriscine(pH ) +CO2 LDC Phenol red + - ODC Phenol red + -

  6. Biochemistry • CIT : testing the ability of bacteria to utilize citrate as a carbon source sodium citrate acetic acid + oxaloacetic acid Na +CO2+H2ONa2CO3CO2+pyruvate ammonium saltNH3+NH4OH bromothymol blue : yellow (6) > green (6.9) > blue (7.6) Citrate layase OAA decarboxylase + -

  7. Biochemistry • H2S : H2S production test. sodium thiosulfate H2S (g) H2S ferrous sulfide “black ppt” • URE : urease utilization test. urea 2 CO2 + NH3 • urease works at both aerobic and anaerobic conditions, but it prefers the second. Reduction “H+” Ferrous sulfate + - urease Phenol red + -

  8. Biochemistry • TDA : tryptophan deaminase. tryptophan indole-pyruvic acid “form within 24 h” + NH3 indole-pyruvic acid +10%FeCl3+ HCl + hydrazine ferric hydrazon HCl added to TDA reagent to break dow the product of the reaction between FeCl3 and tryptophan to prevent false positive rasults. TDA “” Reddish brown ppt ”” + -

  9. Biochemistry • IND : tryptophan utilization test. tryptophan indole + pyruvic acid + NH3 indole pink or red “with or without ring” • VP : vogousproscauer test tryptophanase Kovac’s reagent Isoamyl alcohol + HCl + para-nitrophenylaminobenzaldehyde + - + -

More Related