Acinetobacter Millichrome^™ plus Agar is a selective and differential chromogenic culture medium, intended for use in the Acinetobacter and MDR Acinetobacter spp. The components of the medium are peptone and yeast extract, salts, chromogenic mix, and agar. Peptone and yeast extract provide nutrients for growth, salts help with osmotic balance and provide essential ions, the chromogenic mix contains substrates for color differentiation based on enzymatic activity, and agar is the solidifying agent. The medium is designed to selectively and differentially detect Acinetobacter, including multi-drug resistant strains (by supplementing with MDR Acinetobacter Millichrome^™ plus Supplement ), and aid in the prevention and control of Acinetobacter in healthcare and pharma settings.

Acinetobacter Millichrome^™ plus Agar Base is used for the qualitative direct detection of colonization with Acinetobacter spp. to aid in the prevention and control of Acinetobacter, drug-susceptible or multi-drug resistant (MDR), in healthcare settings and pharma production. It can also be used in hygiene monitoring in the clinical and pharma environment with surface sampling.

Step 1: Disperse slowly 32.8 g of powder base in 1 L of purified water. Add 4.0 mL of the liquid Acinetobacter Chromocult^® plus Supplement into slurry. Stir until agar is well thickened. Heat and bring to boil (100 °C) while swirling or stirring regularly. DO NOT HEAT TO MORE THAN 100 °C. DO NOT AUTOCLAVE AT 121 °C. Warning: If using an autoclave, do so without pressure. Advice: in case of product samples containing a high load of Pseudomonas and/or Aeromonas, Cefsulodin can be added at 5 mg/L. Cool in a water bath to 45-50 °C, swirling or stirring gently. Step 2: (optional, If screening is focused on MDR Acinetobacter, add the MDR Selective supplement as following:): Rehydrate one vial with 5 mL of purified water. Add 5 mL of this solution to 1 L of the melted mix (step 1) at 45-50 °C. Stir well for homogenization Step 3: Pour into sterile Petri dishes. Let it solidify and dry. Warning: Slight variation of the media coloration after solidification can be observed, from yellowish to light orange without any impact on the media performance. Add 5 mL of this solution to the melted mix (step 1) at 45-50 °C. Stir well for homogenization.

Characteristic red color colonies indicate the Acinetobacter after 24 h at an optimal growth temperature of 37°C. At the same time, most other Gram-negative bacteria form blue or inhibited after incubation at the same temperature.

CHROMOCULT is a registered trademark of Merck KGaA, Darmstadt, Germany

MilliChrome is a trademark of Merck KGaA, Darmstadt, Germany