Environmental samples
In the central laboratory of environmental microbiology, environmental samples are analyzed for the presence of microorganisms, usually bacteria. In particular, water from drinking water supply systems, swimming pool water treatment systems, evaporative cooling systems and cooling towers, air handling systems, sewage treatment plants, dental units, ear flushing systems, eye and emergency showers, and many others are analyzed microbiologically. Bacteria as well as molds and yeasts are also determined in samples from surfaces (contact cultures), swab or swab samples and material from equipment and apparatus.
NEW: Coronavirus wastewater monitoring as an early warning system
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The Hygiene Institute of the Ruhr Area offers from October 2022 as a new service the sampling as well as the analysis for SARS-CoV-2 in wastewater according to the recommendation of the European Commission required by March 17, 2021. With regular sampling and analysis, it is possible to follow an increasing or decreasing trend of SARS-CoV-2 viral load in wastewater. Therefore, wastewater provides the opportunity to test whether and how much virus is present in relation to a specific geographic region and its population in the catchment area, since infected individuals also excrete virus before the onset of disease.
For an effective testing and traceability strategy, testing of wastewater is an additional tool in combating the spread of SARS-CoV-2.
In addition to monitoring municipal wastewater treatment plants, targeted wastewater monitoring in public buildings (e.g., hospitals, nursing homes, collective housing, educational facilities) and large operational sites is also useful for early detection of an infectious event (see below for more).
If a determination of the virus variants present in samples is desired, we will gladly take care of it.
Methods and parameters
The determination of microorganisms is mainly carried out by cultural methods (e.g. surface method / direct plating, plate casting method, membrane filtration method, Most Probable Number/MPN method, microtiter method). Here, the target organisms are grown in or on a nutrient medium and subsequently quantified. Biochemical and microscopic methods are also used to differentiate and identify the cultivated microorganisms.
In accordance with the requirements of the applicable laws, regulations and recognized rules of technology as well as the Federal Environment Agency and LANUV NRW, the following target organisms are examined using standardized methods:
- Colony count at 22°C and colony count at 36°C
- Escherichia coli (E. coli)
- coliform bacteria
- intestinal enterococci
- Pseudomonas aeruginosa
- Legionella / Legionella spp.
- Salmonella
- Somatic coliphages
- Molds and yeasts
The associated different methods can be found in the accreditation certificate.
Special investigations
Depending on the problem, other target organisms can also be examined. Examples are total bacteria count, slime bacteria, iron bacteria and sulfate-reducing bacteria.
Depending on the microbiological problem and in agreement with the customer, other methods can also be used, such as obtaining cell suspensions from raw materials, from material and material surfaces or from equipment.
Also, through cooperation with the other departments, other methods, such as scanning electron microscopy, fluorescence and light microscopy, can be offered for the determination of microorganisms.
Recently, we offer the determination of the pathogen SARS-CoV-2 by molecular biological methods in contaminated water. Various gene regions of SARS-CoV-2 are detected by qRT-PCR analysis (quantitative reverse transcription-polymerase chain reaction test). Quantification of the amplified nucleic acids is performed by comparison with an internal specific standard. Results are available within 24 to 48 hours of sample arrival at the laboratory. Usually, this method is applied in the influent water (cooled 24 h composite sample) of wastewater treatment plants.
For more information on our wastewater monitoring for SARS-CoV-2, please contact us.
