Bacterial metabolism of carbohydrates

The only nitrogen source test is the ability to detect the use of different nitrogen sources (inorganic nitrogen) by bacteria. Nitrogen is an essential nutrient element for microbial synthesis of cellular material. Whether bacteria can use different inorganic nitrogen (nitrate nitrogen or ammonium nitrogen) for growth reflects the ability of bacteria to synthesize and can be used as an indicator for bacterial identification. Medium combination: The ammonium ammonia (ammonium sulfate) or nitrate nitrogen (potassium nitrate) to be measured is added to the basal medium at a concentration of 0.05% to 0.1%. If the test bacteria cannot use glucose as a carbon source, it can be replaced by other suitable carbon sources, such as citrate, acetate or mannitol, at a concentration of 0.2%-0.5%. Also make a blank control without nitrogen source (replaced with an equal volume of sterile water). Adjust the pH 7.0-7.2 and dispense the tubes, each tube is about 4-5cm high. Sterilization at 112 ° C for 20-30 min, the prepared medium requires no precipitation. Basic Information Specialist classification: Digestive examination classification: biochemical examination Applicable gender: whether men and women apply fasting: fasting Tips: Pay attention to normal eating habits and pay attention to personal hygiene. Normal value 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 There are many kinds of nitrogen-containing compounds in nature, and they are generally classified into organic nitrides, inorganic nitrides, and molecular nitrogen. Different bacteria have different ability to utilize nitrogen-containing substances. Some bacteria can use ammonium chloride instead of nitrate nitrogen. Some bacteria can use both ammonium and nitrate, which represents the genetic characteristics of different bacteria. Different nitrogen compounds are added to the nitrogen-free basic medium to observe whether the bacteria can grow, and the ability of the bacteria to utilize the nitrogen source can be judged to determine the genus of the tested bacteria, which is convenient for the symptomatic medicine. Abnormal results: Escherichia to the extra-intestinal tissues or organs, such as the urethra, biliary tract, prostate, lungs, bones and other parts of the abdominal cavity can cause intestinal infection. 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. Need to check the crowd: gastroenteritis, respiratory infections, glomerulonephritis, urinary tract infections, acute pharyngitis and other abnormal 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 experimental method: (1) Medium combination: Ammonium ammonia (ammonium sulfate) or nitrate nitrogen (potassium nitrate) to be measured is added to the basal medium at a concentration of 0.05% to 0.1%. If the test bacteria cannot use glucose as a carbon source, it can be replaced by other suitable carbon sources, such as citrate, acetate or mannitol, at a concentration of 0.2%-0.5%. Also make a blank control without nitrogen source (replaced with an equal volume of sterile water). Adjust the pH 7.0-7.2 and dispense the tubes, each tube is about 4-5cm high. Sterilization at 112 ° C for 20-30 min, the prepared medium requires no precipitation. (2) Inoculation and culture: The bacterial cells grown for 18-24 hours were inoculated with the inoculation loop or the inoculation needle in the above medium, and cultured for 3 days at a suitable temperature. (3) Observation of results: The turbidity of the inoculation tube was compared with the control tube, which was positive than the turbidity of the control tube. Not suitable for the crowd Inappropriate crowd: No. Adverse reactions and risks No related complications and hazards have been found.

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