Compact Dry PA is a simple and safe test procedure for the determination and quantification of Pseudomonas aeruginosa counts in foods, cosmetics, water samples or pharmaceutical materials. The ready-to-use plates consist of a special 50 mm diameter petri dish containing a detection specific nutrient pad.
Pseudomonas aeruginosa is a rod shaped, gram-negative, aerobic bacterium which is motile by unipolar flagella. Under anoxic conditions it is able to reduce nitrate for energy generation. It has been identified as an opportunistic pathogen of both humans and plants and can cause a variety of diseases especially in people with weakened immune systems. P. aeruginosa and other members of the genus (e.g. P. putida) are also known to occur as a cause of spoilage in food products.
During incubation of the Compact Dry PA plate, the growing colonies will develop a red coloration which is due to the integrated redox indicator die Tetrazolium salt. The differentiation to other pseudomonas is the formation of a greenish-yellow halo surrounding the colony (see image). Some other bacterial genera or Pseudomonas species are able to grow in some cases, but will form colorless or red colonies without the greenish-yellow halo (colonies marked with black circles in the image).
The ready-to-use, chromogenic Compact Dry plates are suitable for in-process controls as well as the control of finished products. With the optional additional product Promedia ST-25 swab test (Z0302) or Compact Dry Swab (ZCS1002953) Compact Dry plates may also be used for surface sampling and therefore applied for quantitative hygiene monitoring even on surfaces which are difficult to reach.
- Compact Dry PA is therefore an extremely easy-to-use method and also convincing due to the high time saving; a confirmation test is also not necessary.
|Article Numbers||HS9491 / HS9492|
|Test format||HS9491: 100 nutrient plates, |
HS9492: 40 nutrient plates,
four plates are packed in one aluminum bag.
|Sample preparation||Viable count in water or liquid foodstuff, in solid foodstuff or in swab tests.|
|Incubation time||45 - 51 hours at 34 - 36 °C|
|Detected analyte||Pseudomonas aeruginosa = red colonies with greenish-yellow halo|