Differentiate enteric gram-negative bacilli based on dextrose and lactose fermentation and hydrogen sulfide (H₂S) production using Thermo Scientific™ Remel™ Kligler Iron Agar (KIA). In 1918, Klingler described a medium for detection of H₂S and differentiation of Salmonella spp.¹ Edwards and Ewing recommended KIA for determination of H₂S production by enteric gram-negative bacilli². KIA is also recommended by Gilardi for detection of H₂S produced by some strains of Pseudomonas³.

Bailey and Lacey modified the medium by substituting Phenol red indicator for Adrade indicator⁴. Fermentation reactions are read on the slant and in the butt. Phenol red is an indicator of carbohydrate fermentation whereas, Ferric ammonium citrate is an indicator of H₂S production.

• Ready to use – Solid media
• Recommended for determination of H₂S production by enteric gram-negative bacilli² and for detection of H₂S produced by some strains of Pseudomonas³
• Easy to interpret
  1. Carbohydrate Fermentation
     • Positive test for Slant/Butt Reaction – Yellow (acid)
     • Negative test for Slant/Butt Reaction – Red (alkaline)
  2. KIA Color Reactions
     • Red slat/yellow butt – dextrose (+), lactose (-)
     • Yellow slant/yellow butt – dextrose (+), lactose (+)
     • Red slant/red butt – dextrose (-), lactose (-)
  3. Hydrogen Sulphide Production
     • Positive test – Black color throughout medium, a black ring at the juncture of the slant and butt, or a black precipitate in the butt
     • Negative test – No black color development
  4. Gas Production
     • Positive test – Bubbles in the medium, cracking and displacement of medium, from side and bottom of tube
     • Negative test – No bubbles and no separation or displacement of the medium

This medium contains casein and meat peptones that supply nitrogenous compounds, amino acids and vitamins required for bacterial growth. Sodium chloride provides essential electrolytes and maintains osmotic equilibrium. The carbohydrate sources present in the medium are lactose and dextrose. Phenol red is an indicator of carbohydrate fermentation whereas ferric ammonium citrate is an indicator of H₂S production.