TSI (Triple Sugar Iron) Test 32 Questions with Verified Answers,100% CORRECT

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TSI (Triple Sugar Iron) Test 32 Questions with Verified Answers List the tests that are involved with TSI. - CORRECT ANSWER H2S Gas and Carbohydrate Fermentation What is the media for H2S Gas? - ... CORRECT ANSWER TSI agar What method do you use to place content on the media? - CORRECT ANSWER stab and drag motion what is the substrate for H2S gas? - CORRECT ANSWER cystein What is the product for H2S gas? - CORRECT ANSWER H2S What is the reagent for H2S gas? - CORRECT ANSWER iron in media What is the pH indicator for H2S gas? - CORRECT ANSWER none What is the + appearance of H2S gas? - CORRECT ANSWER Black ppt. when H2S reacts with iron to form iron sulfied What is the positive organisms for H2S gas? - CORRECT ANSWER S. typhimurium and P. vulgaris What is the media for Carbohydrate fermentation? - CORRECT ANSWER TSI agar what is the substrate for the carbohydrate fermentation? - CORRECT ANSWER glucose, sucrose, and lactose whats it the product of carbohydrate fermentation? - CORRECT ANSWER organic acids what is the reagent for carbohydrate fermentation? - CORRECT ANSWER none What is the pH indicator for carbohydrate fermentation? - CORRECT ANSWER phenol red in agar What is the + appearance of carbohydrate fermentaiton? - CORRECT ANSWER media is yellow (acidic) or red (alkaline) How should you record the reaction of carbohydrate fermentaiton - CORRECT ANSWER slant or butt What does K/A mean? - CORRECT ANSWER glucose only What does A/A mean? - CORRECT ANSWER sucrose & lactose (+/- glucose) What does K/K mean? - CORRECT ANSWER none fermented What does a black "butt" mean? - CORRECT ANSWER acidic What is the TSI test used for? What are the two ways bacteria are inoculated - CORRECT ANSWER used to distinguish between enteric bacteria List the ingredients in the agar and explain their relevance to the test. - CORRECT ANSWER Peptone: source of amino acids, including cysteine Phenol red: pH indicator Glucose: carbon source Sucrose: carbon source Lactose: carbon source FeSO4 (ferrous sulfate): reacts with H2S gas to form ferrous sulfide (FeS) Explain why there is a lower concentration of glucose in the agar than lactose and sucrose. - CORRECT ANSWER because the glucose gets used up first since it is a cell's main source of energy H2S is produced from the breakdown of which sulfur-containing amino acid? - CORRECT ANSWER cysteine If the bacteria cannot ferment any of the sugars, what happens? - CORRECT ANSWER no acid is produced so pH not reduced -aerobic respiration of peptone in the slant produces alkaline products **no fermentation of sugars-pink slant/red butt If the bacteria can only ferment glucose, what happens? - CORRECT ANSWER acid produced by fermentation will turn the agar yellow at first -glucose runs out->catabolize peptone aerobically in slant **only glucose fermented -pink slant/yellow butt (butt stays yellow) If the bacteria can ferment glucose and lactose or sucrose, what happens? - CORRECT ANSWER glucose used up first -bacteria will synthesize certain enzymes to use other sugars for energy -fermenting lactose or sucrose produces acid -whole slant turns yellow **yellow slant/yellow butt If the bacteria can metabolize cysteine, what happens? - CORRECT ANSWER cysteine contains sulfer so surfer is released as H2S if cysteine is metabolized -agar contains FeSO4 which reacts with H2S to form ferrous sulfide (FeS) **black precipitate in butt How can you tell that acid is produced in the bottom of the tube if its black? How would you record a black bottom? - CORRECT ANSWER assume there is acid bc H2S formation requires acidic conditions -Y+ What do TSI results mean about bacterial metabolism? - CORRECT ANSWER Can tell us: -obligate aerobe vs. facultative (which enteric are supposed to be) -ability to ferment glucose only or lactose/sucrose as well -if fermentation produces gas or not -if the bacteria are able to metabolize cysteine, producing H2S gas How do you record TSI results? - CORRECT ANSWER Write slant color 1st: R for red/pink or Y for yellow (R=no acid so not enteric bacteria bc obligate aerobe, Y=acid) Write b u t t color 2nd (R, Y, Y+) 3rd: gas (yes/no) G FOR EXAM BE ABLE TO INTERPRET DRAWING/PICTURE OF TSI TUBE AND GIVE CODE (EX. R/R), WHAT SUGARS ARE USED, IS GAS PRESENT, IS CYSTEINE BROKEN DOWN :) - CORRECT ANSWER [Show More]

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