Researchers at the Technical University of Munich have developed a rapid test that can confirm the source of an outbreak of Legionnaires’ disease in about 35 minutes.
In the clinic, rapid tests for detecting the Legionella pathogen identify compounds of Legionella in the urine of patients. “Unfortunately, this quick test serves only as a first indication and is not suitable for screening the water of technical systems,” says Michael Seidel, PD Dr rer nat habil, head of the research group and chair of analytical chemistry and water chemistry at the Technical University of Munich.
Legionella are rod-shaped bacteria that can cause life-threatening pneumonia in humans. They multiply in warm water and can be dispersed into the air via cooling towers, evaporative recooling systems, and hot water systems.
To meet the need for a test capable of detecting Legionella in such water systems, the team of scientists developed a measuring chip that not only detects the dangerous pathogen Legionella pneumophila,but also identifies which of the approximately 20 subtypes of Legionella is present. The chip was developed as part of the LegioTyper project funded by the German Federal Ministry of Education and Research.
The most dangerous among the almost 50 species of Legionella is Legionella pneumophila, which is responsible for 80% of all Legionella infections. When an outbreak occurs, the source of the bacteria must be identified as soon as possible to prevent further infections.
Similar to a paternity test, the origin of the outbreak is confirmed when the germs in the water of a technical system exactly match those identified in the patient. However, the process often requires testing of samples from numerous sites and systems, and the traditional bacterial cultivation required for the test takes around 10 days.
The foil-based measuring chip developed by the Munich researchers uses the MCR microarray analysis platform from GWK GmbH, Munich. Using 20 different antibodies, the system provides a complete analysis within 34 minutes.
The system can be deployed for environmental hygiene as well as clinical diagnostics. In combination with a second, DNA-based method, the system can even distinguish between dead and living Legionella pathogens.
REFERENCES
- Wunderlich A, Torggler C, Elsaesser D, et al. Rapid quantification method for Legionella pneumophilain surface water.Anal Bioanal Chem. 2016;408(9):2203–2213; doi: 10.1007/s00216-016-9362-x.
- Kober C, Niessner R, Seidel M. Quantification of viable and non-viable Legionella spp.by heterogeneous asymmetric recombinase polymerase amplification (haRPA) on a flow-based chemiluminescence microarray.Biosens Bioelectron. 2018;100:49 –55; doi: 1016/j.bios.2017.08.053.
