When treating cases of blood poisoning, doctors
resort immediately to broad-spectrum antibiotics.
The problem is that in many cases the bacteria are
resistant to the medicine. Analyzing antibiotic
resistance is a time-consuming process, and for many
patients the results come too late. Now a new
technique that supplies results in just nine hours
is to be presented at the Biotechnica trade show in
Hanover from October 6-8 (Hall 9, booth C34).
A new technique for analyzing antibiotic resistance
© Volker Lannert, Fraunhofer FIT
“For patients with blood poisoning, also known as
septicemia, every second counts. Doctors who suspect
a patient has sepsis start them on broad-spectrum
antibiotics right away, but the antibiotics don’t
always have the desired effect – for instance if the
bacteria are resistant to the medicines used.
Identifying the pathogens in the lab and
investigating their potential resistance routinely
takes between 60 and 100 hours. This is time the
patient simply doesn’t have – most cases end fatally
within around 48 hours. Blood poisoning accounts for
60,000 deaths a year in Germany alone.
In future, this analysis could take much less time –
saving many patients’ lives.
Once doctors know whether the bacteria are resistant
to certain substances, they can treat the patient
with a targeted antibiotic that reliably kills off
the pathogen.
This is possible thanks to a technology developed by
the researchers at the Fraunhofer Institutes for
Applied Information Technology FIT and for Laser
Technology ILT in collaboration with the Uniklinikum
Aachen and numerous industry partners. “Our testing
method yields results in just nine hours,” says
Professor Harald Mathis, department head at
Fraunhofer FIT.
So how are researchers now able to analyze the
bacteria in a blood sample up to ten times faster
than before? “We’ve developed a miniaturized system
with a patented optical design,” reveals Mathis. The
first step is to mark the pathogens indicative of
septicemia, so that they glow when exposed to laser
light.
This then allows the researchers to assess the
amount of bacteria present in the blood.
In the next stage of the process, the bacteria are
separated from the blood and channeled into a series
of miniaturized dishes. Each contains a culture
medium that includes a specific antibiotic.
A second optical system complete with the necessary
analysis software observes and precisely documents
how the bacteria develop.
Then comes the key step: algorithms analyze the
pictures taken of the bacteria and extrapolate the
growth curve, meaning the researchers can see within
hours whether the respective medicine is working or
whether the bacteria are resistant to it and
spreading rapidly. Essentially, the growth monitor
software is able to calculate and predict how
bacteria will develop over time.
It does so by analyzing both the extent of the
bacterial growth – which provides a one-to-one
indication of the number of bacteria present – and
the ratio of living to dead bacteria.
In short: This tells researchers which antibiotic
will be most effective in killing off the bacteria –
and help the patient the most.
For more information
Fraunhofer-Gesellschaft
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