Reham Sabri HammadReham Sabri Hammad2005\00762005\0076

SupervisorSupervisor ::Dr. Dr. Abdelraouf A. ElmanamaAbdelraouf A. Elmanama

2007\20082007\2008

Islamic University_Gaza

Medical Technology Department

OutlinesOutlines

Introduction.Introduction. Principle Of Citrate Test.Principle Of Citrate Test. Significance Of Citrate Test.Significance Of Citrate Test. Materials and Method.Materials and Method. Result.Result. Summary.Summary.

IntroductionIntroduction

Tests for the ability of bacteria to Tests for the ability of bacteria to convert convert citratecitrate (an intermediate of (an intermediate of the Krebs cycle) into the Krebs cycle) into oxaloacetate oxaloacetate (another intermediate of the Krebs (another intermediate of the Krebs cycle). cycle).

In this media, citrate is the only In this media, citrate is the only carbon source available to the carbon source available to the bacteria. bacteria.

PrinciplePrinciple OfOf Citrate TestCitrate Test

To determine if an organism is capable of To determine if an organism is capable of utilizing citrate as sole carbon source for utilizing citrate as sole carbon source for metabolism with resulting alkalinity.metabolism with resulting alkalinity.

If organisms utilize If organisms utilize citratecitrate and and ammonium ammonium saltssalts, the medium becomes more basic and , the medium becomes more basic and the the bromthymol bluebromthymol blue changes from green changes from green to blue as a result of an to blue as a result of an increase in the pHincrease in the pH of the media. of the media.

If it can not use citrate then it will not grow. If it can not use citrate then it will not grow.

Significance Of Citrate Significance Of Citrate TestTest

A differential cultural test to identify A differential cultural test to identify genera within the bacterial family genera within the bacterial family EnterobacteriaceaeEnterobacteriaceae that are able to that are able to utilize sodium citrate as a sole source utilize sodium citrate as a sole source of carbon.of carbon.

MaterialsMaterials Simmons Citrate agarSimmons Citrate agar

which contains :which contains :

1.1. sodium citrate (sodium citrate (carbon carbon sourcesource) .) .

2.2. ammonium salts ammonium salts ((nitrogen sourcenitrogen source). ).

3.3. Bromthymol blue Bromthymol blue indicator.indicator.

Inoculating needle .Inoculating needle .

MethodMethod

1.1. Streak one Streak one organism over organism over the surface of the the surface of the agar slant, then agar slant, then stab the butt.stab the butt.

2.2. Incubate the tube Incubate the tube atat37°C37°C for for 4848 hourshours . .

ResultResult Examine for growth Examine for growth

(+) . (+) . Growth on the Growth on the

medium is medium is accompanied by a accompanied by a rise in pH to rise in pH to change the change the medium from its medium from its initial green color initial green color to deep blue. to deep blue.

ResultResult

Some intestinal bacteria are Some intestinal bacteria are (+)citrate as: (+)citrate as: KlebsiellaKlebsiella ..

CitrobacterCitrobacter..

EnterbacterEnterbacter aerogenesaerogenes ..

  while others is(-) citrate as: while others is(-) citrate as: E. coliE. coli

SummarySummary KlebsiellaKlebsiella Enterbacter Enterbacter

aerogenesaerogenesCitrobacterCitrobacter E. coliE. coli

(+)(+) (+)(+) (+)(+) (-)(-)

At last, I wish that you have enjoyed At last, I wish that you have enjoyed my presentation.my presentation.

Thank you, and have a nice day Thank you, and have a nice day please.please.

My best wishes My best wishes

ReferencesReferences

http://srv2.lycoming.edu/~diehl/321-f03/lecture2.htmhttp://srv2.lycoming.edu/~diehl/321-f03/lecture2.htm 20\11 20\11

http://whitewolf.newcastle.edu.au/techinfo/http://whitewolf.newcastle.edu.au/techinfo/proc_bacto_biochem.html 20\11proc_bacto_biochem.html 20\11

http://science.swu.edu/~wsinnamon/micrometabolism.htm http://science.swu.edu/~wsinnamon/micrometabolism.htm 20\11 20\11

http://web.fccj.edu/~lnorman/unknowns.htm?index=2 http://web.fccj.edu/~lnorman/unknowns.htm?index=2 21\11 21\11