Technique combines light-based analytical methods with microfluidic sample processing for pathogen diagnosis

March 14, 2018, Leibniz-Institute of Photonic Technology
The microfluidic chip allows for optical determination of antibiotic resistance patterns. Credit: S. Döring/ Leibniz-IPHT

Scientists of the Leibniz-Institute of Photonic Technologies (Leibniz-IPHT), Center for Sepsis Control and Care at the University Hospital Jena and Friedrich Schiller University have developed a faster and cheaper alternative for pathogen diagnostics. Project manager Prof. Ute Neugebauer says, "We combine light-based analytical methods with microfluidic sample processing. With our Lab-on-a-Chip system, we are able to clearly identify bacterial strains and their resistances in less than three hours."

Standard practices for infectious diagnostics require up to 72 hours for a reliable result. This is due to the fact that the number of pathogens in a sample is generally too small to conduct tests. Analysis is therefore only possible after time-consuming cultivation. During clinical treatment of severe infections like sepsis, time is crucial. Intensive care physicians are confronted with an alarming dilemma: "Far too often, we have to administer broad-spectrum antibiotics blindly, because we can neither analyse pathogen nor potential resistances. Therefore, we use a sledgehammer to crack a nut. A vicious cycle that aides the development of new resistances," explains Prof. Michael Bauer, director of the Clinic of Anesthesiology and Intensive Care at the University Hospital Jena.

The new method out of Jena provides much faster diagnosis as a basis for choosing a reliable therapy. Ute Neugebauer, who works at Leibniz-IPHT and the University Hospital Jena points to tiny electrodes that are fixed on the surface of a stamp-sized chip: "Electric fields secure bacteria in a very small area." Jena's scientists then apply various antibiotics in different concentrations on the trapped bacteria and examine them with Raman spectroscopy. "This means that we irradiate the pathogens with laser light and evaluate the scattered light spectrum," describes Neugebauer the method.

Prof. Jürgen Popp of the Friedrich-Schiller University Jena, says, "After two hours, we can detect distinct changes in the Raman spectra. Out of these, we can derive whether the strain is resistant or sensible. At the same time, we get information on the desired concentration of the antibiotic to constrain bacterial growth. This is an important diagnostic parameter that influences the success of a treatment." The results were published in Analytical Chemistry in February 2018.

The combination of fast, light-based diagnostics and a high automation level reduces the time from sampling to result from 72 hours to only three and a half hours. "Such a fast procedure could revolutionise diagnostics of infectious diseases," says Prof. Bettina Löffler, director of the Institute of Medical Microbiology at the University Hospital Jena. Currently, the researchers are developing a platform for application in hospitals. A more far- reaching aim is to develop a cartridge-based rapid test system that will enable general practitioners to identify resistances quickly.

Explore further: Device may detect urinary tract infections faster

More information: Johanna Kirchhoff et al, Simple Ciprofloxacin Resistance Test and Determination of Minimal Inhibitory Concentration within 2 h Using Raman Spectroscopy, Analytical Chemistry (2017). DOI: 10.1021/acs.analchem.7b03800

Related Stories

Device may detect urinary tract infections faster

August 11, 2015

Urinary tract infections can quickly move from being a merely miserable experience to a life-threatening condition. Untreated cases may trigger sepsis, which occurs when the immune system, in an attempt to fight off the infection, ...

When proteins shake hands

February 21, 2018

Protein fibres are found virtually everywhere in nature, including in spider silk, wood, the spaces between tissue cells, in tendons, or as a natural sealant for small wounds. These protein nanofibres have outstanding properties ...

Nanoparticles as a possible solution to antibiotic resistance

December 15, 2017

Around one in 3,300 children in Germany is born with mucoviscidosis. A characteristic of this illness is that one channel albumen on the cell surface is disturbed by mutations. Thus, the amount of water of different secretions ...

Broadband light sources with liquid core

July 31, 2017

Research scientists from Jena have produced broadband laser light in the mid-infrared range with the help of liquid-filled optical fibers. The experiment produced proof of a new dynamics of hybrid solitons—temporally and ...

Chemists let fluorescent sugar sensors 'calculate'

June 19, 2014

In a chemistry lab at the Friedrich Schiller University Jena (Germany): Prof. Dr. Alexander Schiller works at a rectangular plastic board with 384 small wells. The chemist carefully pipets some drops of sugar solution into ...

Recommended for you

Coffee-based colloids for direct solar absorption

March 22, 2019

Solar energy is one of the most promising resources to help reduce fossil fuel consumption and mitigate greenhouse gas emissions to power a sustainable future. Devices presently in use to convert solar energy into thermal ...

EPA adviser is promoting harmful ideas, scientists say

March 22, 2019

The Trump administration's reliance on industry-funded environmental specialists is again coming under fire, this time by researchers who say that Louis Anthony "Tony" Cox Jr., who leads a key Environmental Protection Agency ...

The taming of the light screw

March 22, 2019

DESY and MPSD scientists have created high-order harmonics from solids with controlled polarization states, taking advantage of both crystal symmetry and attosecond electronic dynamics. The newly demonstrated technique might ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.