Acetamide Broth Base UNE-EN 12780, EN ISO 16266 Cat No: AG-1155
For confirmation of Pseudomonas aeruginosa by membrane filtration
Formula In g/l
Final pH 7.0 ± 0.5 at 25ºC
Suspend 3.4 grams of the medium in 900ml of distilled water .Adjust to pH 7.0 /- 0.5 at 25ºC add 1 ml of recently prepred solution B*.Whilst agitating add water to achieve a final volume of 1 Litre. Distribute into tubes in 5 ml aliquots, close and sterilize in autoclave at 121°C for 15 minutes. The prepared medium should be stored at 2-8ºC. Prepared tubes must be stored in a dark place. The color is colorless.
The dehydrated medium should be homogeneous, free-flowing and beige in color. If there are any physical changes, discard the medium.
|Iron Suphate heptahydrate FeSo4, 7H2O||0.05g|
Caution: This medium contains acetamide. It is toxic if swallowed, inhaled or comes into contact with skin. Wear gloves and eye/face protection.
Acetamide Broth contains acetamide which is the sole source of carbon. It is used for the confirmation and identification of Pseudomonas aeruginosa, as specified by the UNE-EN12780 and EN ISO 16266. It uses the ability of non-fermenting Gram-negative bacteria to deaminate the acetamide. The deamination of the acetamide produces ammonia which increases the pH of the medium, acetamide deamination is accomplished by P.aeruginosa, P. acidovorans, Group III (Achromobacter xylosoxidans), and Alcaligenes odorans.
Pseudomonas aeruginosa is an opportunist pathogen for humans, capable of growing in water with a low concentration of nutrients. This is why natural mineral water and spring water are Pseudomonas aeruginosa free at the time of their commercialization. This mircroorganism can also be found in swimming pool water.
Acetamide is the single carbon source. The Potassium salt has a high buffering capacity and Sodium chloride supplies essential electrolytes for transport and osmotic balance. Magnesium sulfate, sodium molybdate and iron sulfate allow the selective growth of Pseudomonas in the medium.
The colonies from Nutrient Agar (Cat. AG-1156) that need to be confirmed are inoculated in this medium and incubated for 22 ± 2 hours at 36 ± 2°C.
Add 1 or 2 drops of Nessler reagent and examine the production of Ammonia in the tubes, characterized by a color ranging between yellow and tile red, depending on the concentration.
It is prepared according to UNE-EN 12780 and EN ISO 16266.
The following results were obtained from type cultures in the performance of the medium, with the respective supplements added, at a temperature of 36 ± 2°C and observed after 22± 2 hours.
Pseudomonas aeruginosa ATCC 9027
Pseudomonas aeruginosa ATCC 10145
Pseudomonas aeruginosa ATCC 25783