What is the purpose of citrate utilization?
Citrate testing is used to determine the ability of the bacteria to use sodium citrate as the only source of carbon and inorganic ammonium hydrogen phosphate (NH4H2PO4) as a source of nitrogen. The citrate utilization test is possible only if the organisms are capable of fermenting citrate.
What is a utilization test?
[Test utilization] means using your expertise to drive behavioral changes both within the laboratory and throughout the entire medical system. It can be as simple as designing a paper requisition that's easy to read and understand, making test ordering easier.
Which reagent is used in citrate Utilisation test?
The medium used is Simmons citrate agar slant. It contains mineral salts, sodium citrate for carbon, and ammonium phosphate for its nitrogen source. The pH indicator is brom thymol blue, which is green at neutral pH, yellow at acidic pH <6.0 and turns blue at alkaline (basic) pH >7.6.
What is the purpose of utilization?
Utilization is the action of using something, i.e., making practical and effective use of it. Put simply; the term refers to the use of something or the process of using it effectively.
What is utilization used for?
Utilization is defined as the amount of an employee's available time that's used for productive, billable work, expressed as a percentage. An employee's utilization rate is a critical metric for organizations to track.
What is the pH after citrate utilization?
Citrate utilization is a metabolic test used to determine an organism's ability to utilize citrate as its lone source of carbon. Simmons citrate agar is a synthetic medium containing citrate, ammonium ions, and the pH indicator bromthymol blue. This indicator is green below pH 7.6 and blue above pH 7.6.
What are products of citrate utilization?
The growth of the organism is indicative of the utilization of citrate as it is an intermediate metabolite in the Krebs cycle. The enzyme citrase breaks down citrate into oxaloacetate and acetate, where oxaloacetate is further broken down to form pyruvate and carbon dioxide.
What color is citrate utilization test?
When Simmons Citrate agar is inoculated with Salmonella typhimurium , the medium turns royal blue. This is a positive result for the citrate test. When Simmons Citrate agar is inoculated with Escherichia coli , the medium remains green. This is a negative result for the citrate test.
What are the 3 assessments for utilization management?
Utilization review contains three types of assessments: prospective, concurrent, and retrospective.
What is the utilization process?
A utilization review is a process in which a patient's care plan undergoes evaluation, typically for inpatient services on a case-by-case basis. The review determines the medical necessity of procedures and might make recommendations for alternative care or treatment.
What is a standard for utilization?
Utilization is defined as the amount of billable time can you pull out of the total available time of your employees. Industry standards suggest an overall successful agency staff utilization rate should fall between 85 and 90%.
What is utilization in medical billing?
Utilization Management (UM) Wikipedia Definition: “…the evaluation of the appropriateness and medical need of health care services and procedures and facilities according to evidence-based criteria or guidelines, and under the provisions of an applicable health benefits plan.
Principle of Citrate Utilization Test
Citrate agar is used to test an organism’s ability to utilize citrate as a source of energy. The medium contains citrate as the sole carbon source...
Media Used in Citrate Utilization Test
CompositionDeionized water = 1,000 mlFinal pH 6.9 +/- 0.2 at 25 degrees C.Preparation 1. Dissolve above salts in deionized water. 2. Adjust pH to 6...
Procedure of Citrate Utilization Test
1. Streak the slant back and forth with a light inoculum picked from the center of a well-isolated colony. 2. Incubate aerobically at 35 to 37C fo...
Quality Control of Citrate Utilization Test
Citrate Positive: Klebsiella pneumoniae ATCC 13883 (growth; blue color)Citrate Negative: Escherichia coli ATCC 25922 (no growth or trace of growth)
What is citrate agar used for?
Citrate agar is used to test an organism’s ability to utilize citrate as a source of energy. The medium contains citrate as the sole carbon source and inorganic ammonium salts (NH4H2PO4) as the sole source of nitrogen.
What happens when bacteria metabolize citrate?
When the bacteria metabolize citrate, the ammonium salts are broken down to ammonia, which increases alkalinity . The shift in pH turns the bromthymol blue indicator in the medium from green to blue above pH 7.6.
Can citrates change color?
Limitations of Citrate Utilization Test. Some organisms are capable of growth on citrate and do not produce a color change. Growth is considered a positive citrate utilization test, even in the absence of a color change. Tests with equivocal results should be repeated.
Can bacteria grow on citrate negative medium?
Christensen’s medium contains both peptone and cysteine. Thus citrate-negative bacteria can also grow on this medium.
What is Citrate Utilization Test ?
A citrate utilization test is a part of the IMViC Test, which stands for Indole, Methyl-Red, Vogues-Proskauer, and Citrate; a procedure that differentiates Gram negative bacilli in Enterobacteriaceae family. (1)
What happens if you use citrate?
If citrate is utilized, then expect that there will be a growth of an organism. It will then become an intermediate metabolite in the Krebs cycle. (1, 2, 3, and 4) Picture 3: A biochemical test wherein two test tubes represent two distinct results. Picture 4: A Simmon’s citrate agar medium is used for this procedure.
What bacteria are citrate positive?
Organisms that will test positive for citrate utilization test include the following:
What happens when citrate is metabolized?
Once the organism metabolizes citrate it would lead to the breakdown of ammonium salt to ammonia thereby increasing its alkalinity. From a neutral pH, it becomes alkaline making the bromthymol blue indicator present in the medium change its color from green to blue.
What is the enzyme that converts citrate to pyruvate?
An organism that grows on this medium produces an enzyme called citrate permease, which has the ability to convert citrate to pyruvate. The latter will enter the metabolic cycle of the organism so as to produce energy. If citrate is utilized, then expect that there will be a growth of an organism.
How long to autoclave bromothymol blue?
Put about 5 ml into a tube and autoclave at 121 degree Celsius for 15 minutes under 15 psi pressure. Allow to cool in a slanted position.
Can citrate be positive?
When it comes to result interpretation, we can say that the organism is citrate positive if the color of the slant changes from green to blue. The truth is that some organisms have the ability to grow on citrate but do not produce changes in the slant’s color at all. If this happens, the result is still read as positive.
What is Citrate Utilization Test?
The citrate utilization test is a part of the IMViC test ( Indole, Methyl Red, Vogues-Proskauer, and Citrate Test) that differentiates organisms on the basis of their ability to use citrate as a sole source of energy.
What is citrate test?
Citrate test is used to determine the ability of an organism to utilize citrate as a sole source of energy. A citrate test is performed as a part of the IMViC test to differentiate members of Enterobacteriaceae. The test is also used for the differentiation between fecal coli and members of the aerogenes group on the basis of citrate utilization.
What is the principle of citrate utilization?
Principle of Citrate Utilization Test. Citrate agar is used to test the ability of an organism to utilize citrate as a source of energy. The agar medium contains citrate as the sole carbon source and inorganic ammonium salts as the sole source of nitrogen. The growth of the organism is indicative of the utilization of citrate as it is an ...
What is the enzyme that breaks down citrate?
The growth of the organism is indicative of the utilization of citrate as it is an intermediate metabolite in the Krebs cycle. The enzyme citrase breaks down citrate into oxaloacetate and acetate, where oxaloacetate is further broken down to form pyruvate and carbon dioxide.
What is a positive citrate test?
A positive test is demonstrated by growth with a color change from green to intense blue along the slant. A negative test is demonstrated by no growth and no color change, and the color of the slant remains green. The following table demonstrates the result of Citrate utilization of important medical bacteria: 1.
What is the result of citrate metabolism?
The growth of the organism on the medium followed by the change in the color; as a result, of citrate metabolism gives a positive citrate test.
What is the test called for citrate?
The test is also called Simmon’s citrate test as it utilizes Simmon’s citrate agar that contains citrate as the major source of energy.
What is citrate utilization test?
The citrate utilization test is a part of the IMViC test procedure or a standard method for identifying and classifying Enteric bacteria based on their tendency to produce an enzyme citrase that splits sodium citrate into pyruvate.
What are the sources of citrate utilization?
The test organisms in the citrate utilization test exploit energy in the form of carbon and nitrogen from the sources like sodium citrate and inorganic ammonium salts , respectively.
What enzyme catalyzes the hydrolysis of sodium citrate?
The citrate metabolism involves subsequent chemical reactions. First, an enzyme “ Citrase lyase ” catalyzes the hydrolysis of sodium citrate into oxaloacetate and acetate. Then, the enzyme “ oxaloacetate decarboxylase ” causes decarboxylation of oxaloacetate into pyruvate and carbon dioxide.
Why does citrate turn blue?
As a result, the colour of the media turns blue from green due to the pH shift of the bromothymol indicator (from 6.9 to more than 7.5).
What is citrate agar?
Principle of Citrate Utilization Test. Citrate is an organic acid, which hydrolysis ultimately results in the production of alkaline carbonates or bicarbonates. Simmons citrate agar is a media used to detect whether the test organism can exploit citrate or not. The citrate metabolism involves subsequent chemical reactions.
What is the nitrogen used in the test organism?
The test organism makes use of nitrogen from the ammonium salts present within the media. The metabolism of ammonium salts by the microorganisms yields ammonia, which later combines with H 2 O to form ammonium hydroxide. Compounds like sodium carbonate and ammonium hydroxide cause alkalinity in the media.
How to take a test culture after solidification?
After solidification, take the test culture via a sterilized inoculating loop.
What is citrate testing?
Citrate testing is used to determine the ability of the bacteria to use sodium citrate as the only source of carbon and inorganic ammonium hydrogen phosphate (NH4H2PO4) as a source of nitrogen. The citrate utilization test is possible only if the organisms are capable of fermenting citrate. The process takes place via the enzymes is called citrase.
What is the product of sodium citrate?
Sodium from sodium citrate combines with CO 2 and water, to form an alkaline product (sodium carbonate).
What happens to citrate after it is absorbed?
Upon cell absorption of citrate, it is cleaved into oxaloacetate and acetate by the citrate lyase. Oxaloacetate is further metabolized to carbon dioxide and pyruvate. After the formation of pyruvic acid metabolic degradation depends on the pH of the solution. 1.
How long to incubate Simmons citrate agar?
In the citrate medium, organisms require more time to grow. Therefore, the solution must be incubated at 35°C to 37°C for 18 – 24 hours.
Is sodium citrate a carbon source?
Sodium citrate is considered as both a carbon source and an energy source. Nitrogen source is NH 4+. The presence of enzymes such as citrate permease (citrase) facilitates the citrate into the bacterium. Bromothymol blue is considered as a pH indicator.
What is the citrate utilization test?
In the citrate utilization test, the citrate medium most commonly used is the formula of Simmons. The medium is poured into a tube on a slant. The composition of Simmons citrate agar is as follows:
What color is a citrate positive medium?
Citrate positive: growth will be visible on the slant surface and the medium will be an intense Prussian blue . The alkaline carbonates and bicarbonates produced as by-products of citrate catabolism raise the pH of the medium to above 7.6, causing the bromothymol blue to change from the original green color to blue .
How long to incubate Simmons citrate agar?
Inoculate Simmons citrate agar lightly on the slant by touching the tip of a needle to a colony that is 18 to 24 hours old. Incubate at 35°C to 37°C for 18 to 24 hours. Some organisms may require up to 7 days of incubation due to their limited rate of growth on citrate medium.
Is E. coli citrate positive?
Although uncommon, natural E. coli variants that are citrate positive have been isolated. Citrate-negative strains of E. aerogenes have also been found.
Can citrate negative bacteria grow on Simmons?
No color change will occur; the medium will remain the deep forest green color of the uninoculated agar. Only bacteria that can utilize citrate as the sole carbon and energy source will be able to grow on the Simmons citrate medium, thus a citrate-negative test culture will be virtually indistinguishable from an uninoculated slant
What is the principle of citrate utilization test?
Principle of citrate utilization test. When citrate, an organic acid, is used as the only source of carbon, two things are produced like. Besides, when the ammonium salts are used as the sole nitrogen source , ammonium hydroxide is also produced in the medium. The organism that grows and develops on this medium produces an enzyme called citrate ...
What is the name of the test kit for citrate utilization medium?
Test kits are available such as the API-20E and Enterotube II that include citrate utilization medium as one of the diagnostic tests.
What is the IMVIC test?
It is one of the IMVic series groups of tests where IMViC stands for Indole, Methyl red, VP, and citrate test. A citrate utilization test helps detect the organism’s ability to produce citrase enzymes, i.e., citrate lyase. The bacteria which rely on citrate as the sole source of carbon for their energy needs are determined.
What is the enzyme that breaks citrate into oxaloacetate?
The organism that grows and develops on this medium produces an enzyme called citrate permease (citrate transport protein), which has the ability to break citrate to oxaloacetate and acetate by the enzyme citrate lyase. After that, oxaloacetate is metabolized into pyruvate and CO2.
How to inoculate a simmon's citrate agar?
Take the loopful of microorganisms and inoculate on Simmon’s citrate agar lightly on the slant. Do this by touching the tip of a needle to a colony which is 18 to 24 hours old.
What happens if you use sodium citrate?
If citrate is utilized, there would be profuse growth of the organism. This will then become an intermediate metabolite in the Krebs cycle. Production of Na2CO3 from the utilization of sodium citrate and NH3 from the utilization of ammonium salt results in alkaline pH. This results in a change in the color of the medium from green to blue.
Can bacteria grow on Simmons citrate?
Those bacteria which can utilize citrate as the sole carbon and energy source will be able to grow on the Simmons citrate medium.
