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 plates consist of a special 50 mm diameter petri dish containing a detection specific nutrient pad.
The ready-to-use, chromogenic Compact Dry plates are suitable for in-process controls as well as the control of finished products. With the Promedia ST-25 swab tests (Art. No. Z0301, available from R-Biopharm) or the Compact Dry Swabs (Art. No. 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.
P. 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 pseudomonads 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).
|Art. No.||HS9491, HS9492|
|Test format||100 nutrient plates or 40 nutrient plates, respectively - packaged at four plates each in one aluminum bag|
|Incubation time||48 ± 3 hours at 35 ± 1 °C|