Pseudomonas
(Pseudomonas aeruginosa, Pseudomonas SSP.)
Stansted Laboratories offer 3 tests for Pseudomonas across many different environments -
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Presumptive Pseudomonas species
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Exact Pseudomonas species identification (by API 20NE)
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Pseudomonas aeruginosa
We use approved in-house membrane filtration methods, MoDW Part 8 (2015) For all Drinking water samples and MREW Part 7 (2015) For Recreational Waters as well as UKAS approved and certified test methods.
Pseudomonas spp. is an environmental bacteria commonly found in soil and on plants.
The organisms are able to grow in water containing very low levels of nutrient.
Although frequently present in small numbers in the intestinal tract of animals and humans,
it is desirable that the water should be free from this organism.
This is especially important in manufacturing of food, drink and pharmaceutical products and in hospitals, swimming pools and spa waters.
Pseudomonas aeruginosa are the microorganisms that grow on selective media containing cetrimide, they belongs to the family Pseudomonadaceae. The family include Xanthomonas which together with Pseudomonas comprise an informal group of bacteria called Pseudomonads. Of the 200 species that were originally present in the genus Pseudomonas, Pseudomonas aeruginosa has got an immense medical importance and is renowned for its resistance to antibiotics which is due to their cellular structure (permeability barrier in the lipopolysaccharide). It is a virulent ocular pathogen due to the copious amounts of enzymes it produces. These cause tissue damage and via the action of β-lactamase that render many antibiotics ineffective.
Where can we test for Pseudomonas?
Stansted Laboratories can test for Pseudomonas spp. bacteria in the following environments:
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Process – Closed System
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Process- Cooling Tower*
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Drinking Tap Non Reg*
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Swabs*
We can test for Pseudomonas aeruginosa bacteria in:
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Drinking Tap Non-reg
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Drinking Bottled Water
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Drinking Bowser/ Tanker
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Recreational-Swimming Pool
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Recreational- Hydrotherapy
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Recreational-Spa
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Drinking Tap Non-Reg Hospital Water
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Swabs*
* are in-house non UKAS methods
Samples for testing are collected from source in sterilized bottles, this can be done by the clients own staff with bottles provided by Stansted Laboratories or by one of Stansted's own technicians.
For chlorinated potable waters the sample bottles are sterilized and pre-dosed with 1.8% sodium thiosulphate solution, however, for borehole, bottled, potable waters and non-chlorinated water samples, sterilised but without sodium thiosulphate dosed bottles are used.
During transit and when in storage, samples should be kept cool (2-8°C). In exceptional circumstances, if there is a delay, storage under the above conditions should not exceed 24 hours before the commencement of analysis.
References
1)HTM 04-01 – Safe water in Healthcare Permisis- Part B Operation and Management- appendix F 2016 .
2) The Microbiology of Drinking Water (2015)-Part 8- The isolation and enumeration of Aeromonas and Pseudomonas aeruginosa by membrane filtration, Environment Agency, Methods for the Examination of Waters and associated materials
3) NHS - Water Sources and Potential for Pseudomonas aeruginosa Infection from taps and water systems; Advice for augmented care units, page 20-22, DH, March 2012.
4) The Microbiology of Recreational and Environmental Waters (2015) Part-7- Methods for the Isolation and enumeration of Aeromonas and Pseudomonas aeruginosa.
5) Pool water treatment advisory group (PWTAG): Swimming pool water(treatment and quality standard for pools + SPA, published Nov 2017
6) Oxoid Manual 9th Edition 2006
7) Handbook of Culture Media for Food Microbiology, Vol.34, Pg 123-127 By-Janet E. L., Corry, G. D. W. Curtis, Rosamund M. Baird.