Citrate Utilization Test

The citrate utilization test is based on sodium citrate as the sole carbon source and a pH of 7.0. The aerobic bacterium decomposes sodium citrate to produce carbonate, which changes the medium from neutral to alkaline. The base indicator bromothymol blue (BTB) changed from light green to dark blue, which was positive for the citrate utilization test. E. coli was unable to utilize citrate, and this test was a negative reaction. Basic Information Specialist classification: Digestive examination classification: pathogenic microbiological examination Applicable gender: whether men and women apply fasting: not fasting Analysis results: Below normal: Normal value: no Above normal: negative: E. coli was unable to utilize citrate, and this test was a negative reaction. Positive: Aerobacteria. Tips: Maintain normal work and healthy eating habits. Normal value The digestive system and absorption system are in a healthy state. Clinical significance Abnormal results Some aerogens decompose sodium citrate to produce carbonate, which causes discomfort in the human body. The people in need of examination have various symptoms caused by suspected various gas-producing bacterial infections, such as abdominal fullness, discomfort or pain, often accompanied by other adverse symptoms such as heating, bloating and loss of appetite. Precautions Inappropriate crowd: No. Taboo before check: Maintain normal work and healthy eating habits. 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. . 2. Medium: citrate medium. 3. Method: The test bacteria obtained at a certain site to be inspected 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 changed from light green to dark blue; bacteria that cannot use citrate as a carbon source cannot grow on this medium, and the medium does not change color. , is negative. 5. Application: It is used for the identification of the genus of Enterobacteriaceae. In the Enterobacteriaceae, Escherichia, Shigella, Edwards and Yersinia are negative, and Salmonella and Klebsiella are usually positive. Not suitable for the crowd No. Adverse reactions and risks no.