18 MIC 206 Differential Tests 1 Results S24 PDF

11/5/2024 Differential Tests 1 Results: Carbohydrate Fermentation Triple Sugar–Iron Agar Test...

11/5/2024 Differential Tests 1 Results: Carbohydrate Fermentation Triple Sugar–Iron Agar Test IMViC Test Hydrogen Sulfide Test Utilization of Malonate General Enzymatic Action Biochemistry I (PR) Phenol Red (Broth) (TSI) Triple Sugar Iron Agar (Slant) – (BASE) Base Broth Salmonella spp Escherichia coli Proteus vulgaris Enterococcus faecalis Escherichia coli Proteus vulgaris Orphan Pseudomonas aeruginosa (SC) Simmons Citrate (Slant) Orphan Enterobacter aerogenes Escherichia coli – (GLU) Glucose Broth – (LAC) Lactose Broth Orphan – (SUC) Sucrose Broth (MAL) Malonate (Broth) Enterobacter aerogenes (MRVP) Methyl Red/ Voges-Proskauer (MRVP Broth) Escherichia coli Enterobacter aerogenes Orphan Escherichia coli Orphan (SIM) (SIM Stab) Inoculation should be with a needle, straight down and up with a needle. Escherichia coli Proteus vulgaris Klebsiella pneumoniae Orphan 1  11/5/2024 For EACH assay, know the following: Name of the Assay: Example: Catalase Production 1. Input(s) & Output(s): Example : Input: Hydrogen Peroxide and Output: Oxygen + Water 2. Specific enzyme(s): Example : Catalase 3. Reagents/ pH Indicator: Example : Hydrogen Peroxide 4. Principle of the test: Example : Organisms with catalase can render hydrogen peroxide harmless 5. What does a positive and negative result look like: Example : + Bubble/ - No Bubbles (Sup) Malonate Test Malonate broth tests an organism’s ability to utilize malonate as a sole carbon source If the organism utilizes malonate, it will alkalinize the medium, and the pH indicator changes from green to blue. E. coli is the negative control E. aerogenes is the positive control Bromthymol blue is a pH indicator (detects changes in pH) If the pH of the media is: Less than pH of 6.9, the Malonate Malonate indicator is Green (-) Positive Negative Greater than pH of 7.6, the indicator is Blue (+) Phenol Red Basics Fermentation – Using carbohydrate (sugar) converting it to acids or gas (H 2 and CO2.) – The release of acid will lower the pH of the media – To perform fermentation Glycolysis is used (Multiple enzymes)in this process. Growth from Proteins – When bacteria use proteins for growth this will result in the release of ammonia (NH3). This will result in an increase in pH of the media. Phenol red is used to monitor the pH of the media (pH indicator) – Pink at alkaline (>7.4) pH – Red at neutral (6.9 – 7.3) pH – Yellow at acidic (7.4) pH – Red at neutral (6.9 – 7.3) pH – Yellow at acidic (