‘We can concentrate and purify the sample magnetically, without any cultivation or enrichment techniques,’ said Dr Daniel Schaffhauser, chief technology officer at Swiss-based rqmicro, the company that developed the platform as part of a project called CellCount.
Focused testing The sample is mixed with a cocktail of specific antibodies developed by rqmicro that are coupled with tiny magnetic beads, as well as fluorescent labels.
Once a target pathogen binds with the antibody, a magnetic field draws the beaded cell away from the rest of the sample.
The detection system has been developed to maintain its accuracy in the field, rather than the stable conditions of a research laboratory.
The system can be used for near-continuous monitoring of drinking water supplies and is already in use by water laboratories in Europe to detect legionella, with rapid results helping to locate sources of infection.
‘The technology is very general, so we see applications not only in drinking water, but also in broader microbial diagnostics,’ Dr Schaffhauser said.
Rather than doing one-off tests when a pathogen has already been discovered, however, another approach is to continuously monitor water to provide an early-warning system that a particular bacteria may be present.
‘We are particularly pleased with its effectiveness in helping to prevent people becoming sick, providing an early warning system for contamination of drinking water systems.’ Its first commercialised system, BactoSense, rapidly counts the total number of bacteria in a water sample, one of the crucial tests used by utilities to assess water quality.
coli is recognised worldwide as an indicator for faecal contamination and is a routine test for municipal water supply systems,’ said Dr Luigino Grasso, bNovate’s chief technology officer.
‘So the system does not need any human intervention for up to a couple of months, even if it is testing water several times a day.’ Through automation and monitoring from a distance, bNovate has reduced the amount of human intervention and eliminated the need for laboratory time, helping to shrink the price of BactoSense water tests to about €1 each – a fraction of the costs associated with older testing methods.