Part of Thermo Fisher Scientific
Organisms this product works with:
Other products used in the isolation of Enterobacteriaceae :
KLIGLER IRON AGAR
Code: CM0033
A medium for the identification of Enterobacteriaceae, based on double sugar fermentation and hydrogen sulphide production.
Typical Formula* | gm/litre |
`Lab-Lemco’ powder | 3.0 |
Yeast extract | 3.0 |
Peptone | 20.0 |
Sodium chloride | 5.0 |
Lactose | 10.0 |
Glucose | 1.0 |
Ferric citrate | 0.3 |
Sodium thiosulphate | 0.3 |
Phenol red | 0.05 |
Agar | 12.0 |
pH 7.4 ± 0.2 @ 25°C |
Directions
Suspend 55g in 1 litre of distilled water. Bring to the boil to dissolve completely. Mix well and distribute into containers. Sterilise by autoclaving at 121°C for 15 minutes. Allow to set as slopes with 1 inch butts.
Description
A differential medium for the identification of Enterobacteriaceae on a basis of double sugar fermentation and hydrogen sulphide production.
Oxoid Kligler Iron Agar based on the original medium1,2,3 combines the principles of Russell 4, double sugar agar, with ferric citrate as an indicator to detect hydrogen sulphide production. The medium is recommended for the identification of colonies picked off from plating media such as MacConkey Agar, Bismuth Sulphite Agar, or Desoxycholate Citrate Agar, etc.
Technique
Smear the surface of a Kligler Iron Agar slope and stab the butt with a colony picked off one of the solid media.
There are three reactions to record when interpreting a KIA tube.
1Carbohydrate utilisation:
(i) slant reaction | (ii) butt reaction |
acidity: yellow colour | acidity: yellow colour |
alkalinity: red colour | alkalinity: red colour |
2 Gas production:
aerogenic | anaerogenic |
bubbles or splitting of agar | no gas production |
3 H2S production:
blackening in whole or part of butt:-
Record the slant reaction/the butt reaction/gas production/H2S production; in that order.
Red slant/yellow butt - glucose only fermented
Yellow slant/yellow butt - glucose + lactose fermented
Red slant/red butt - neither glucose nor lactose fermented
Reactions after 18 - 24 hours at 35°C
Organism | Slope | Butt | Gas | H2S |
Shigella sonnei | Red | Yellow | - | - |
Shigella dysenteriae | Red | Yellow | - | - |
Salmonella typhi | Red | Yellow | - | + |
Salmonella species | Red | Yellow | + | + |
Enterobacter species | Red | Yellow | + | - |
Klebsiella species | Yellow | Yellow | + | - |
Escherichia coli | Yellow | Yellow | + | - |
Proteus mirabilis | Red | Yellow | - | + |
Morganella species | Red | Yellow | V | - |
Citrobacter freundii | Yellow | Yellow | + | + |
Yersinia species | Red | Yellow | V | - |
V = variable, + = positive, - = negative.
Storage conditions and Shelf life
Store the dehydrated medium at 10-30°C and use before the expiry date on the label.
Store the prepared medium at 2-8°C.
Appearance
Dehydrated medium: Straw-orange coloured, free-flowing powder
Prepared medium: Red coloured gel
Quality control
Positive controls: | Expected results | |||
Slope | Butt | Gas | H2S | |
Citrobacter freundii ATCC® 8090* | Yellow | Yellow | + | + |
Shigella sonnei ATCC® 25931* | Red | Yellow | - | - |
Alcaligenes feacalis ATCC® 19018 | Red | Red | - | - |
Negative control: | ||||
Uninoculated medium. | No change |
Precautions
It is essential that Kligler Iron Agar is examined and reported at 18-24 hours. Early or late readings will give false results.
KIA will grow both oxidative and fermentative organisms. Confusion will result if care is not taken to distinguish between the two groups.
Always use a straight wire to inoculate the butt, to avoid splitting the agar with a loop.
Pure cultures are essential to avoid misinterpretation.
Do not use screw-capped tubes or bottles for KIA medium. It is essential that air is freely available to growth on the slant.
References
1. Kligler I. J. (1917) Am. J. Pub. Hlth 7. 1042-1044.
2. Kligler I. J. (1918) J. Exper. Med. 28. 319-322.
3. Bailey Sadie F. and Lacey G. R. (1927) J. Bact. 13. 182-189.
4. Russell F. F. (1911) J. Med. Res. 25. 217-229.