Carbon source utilization test

The carbon source utilization test is an identification test of the use of bacteria for a single source of carbon source. In the citrate medium, the bacteria only use citrate as a carbon source, and decompose to form sodium carbonate to make the medium alkaline, and the pH indicator bromothymol blue changes from pale green to dark blue. Commonly used test methods are citrate utilization test and malonate utilization test. Basic Information Specialist classification: Digestive examination classification: other examinations Applicable gender: whether men and women apply fasting: fasting Tips: pay attention to normal eating habits, pay attention to the normal value of personal hygiene The type and proportion of the flora in the body are normal, and the human body is in a state of dynamic balance and health. Clinical significance 1. The citrate utilization test is used for the identification of the genus of the genus Enterobacteriaceae. In Enterobacteriaceae, Escherichia, Shigella, Edwards and Yersinia are negative, and Salmonella and Klebsiella are usually positive. 2. Malonate utilization test Identification of intergeneric and species in Enterobacteriaceae. Klebsiella is positive, and some species in the genus Citrobacter, Enterobacter, and Hafnia are also positive, and other genus are negative. Abnormal results: Tissues or organs outside the gut, such as the urethra, biliary tract, prostate, lungs, bones, and other parts of the abdominal cavity, can cause extraintestinal infections. Extraintestinal infections are most common with urinary and purulent infections. Shigella causes bacterial dysentery. Human Salmonella infection: 1. Enteric fever 2. Gastroenteritis (food poisoning) 3. Sepsis 4. Asymptomatic carriers. Various abnormal symptoms caused by Klebsiella, Citrobacter, Hafnia, and the like. The people who need to be examined are: urinary tract infection, suppurative infection, extraintestinal infection, typhoid fever, gastroenteritis, sepsis and other symptoms. Precautions Forbidden before examination: Pay attention to normal eating habits and pay attention to personal hygiene. Requirements for inspection: Actively cooperate with the doctor. Inspection process Citrate utilization test (1) Principle: Some bacteria can use ammonium salt as the sole nitrogen source, and use citrate as the sole carbon source to grow on citrate medium, decompose citrate, and make the medium alkaline. Sex. (2) Medium: citrate medium. (3) Method: The test bacteria were inoculated into a citrate medium, and cultured at 35 ° C for 1 to 4 days, and the results were observed daily. (4) Results: The bromothymol blue indicator in the medium is positive from light green to dark blue; bacteria that cannot use citrate as a carbon source cannot grow on this medium, but the medium does not. Discoloration, negative. 2. Malonate utilization test (1) Principle: Some bacteria can use malonate as the sole carbon source, and decompose the malonate to form sodium carbonate to make the medium alkaline. (2) Medium: Malonate medium. (3) Method: The test bacteria were inoculated into the above medium, and the results were observed after incubation at 35 ° C for 24 to 48 hours. (4) Results: The medium was changed from light green to dark blue, and no change in color was negative. Not suitable for the crowd Inappropriate crowd: No. Adverse reactions and risks No related complications or hazards.

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