SPOTLIGHT
POSEIDON PROJECT–
NEW LIGHT SENSOR SPOTS DEADLY
LEGIONELLA BACTERIA IN MINUTES
O
utbreaks of Legionnaire’s Disease, a respiratory
infection that can cause pneumonia, and in
severe cases organ failure or septic shock, are
more common than we might think. With anyone being
susceptible, more than 100 cases are reported each week
both in America and in Europe, with a fatality rate of
around 10%.
Naturally occurring in freshwater lakes and rivers,
the Legionella bacterium is harmless in small enough
quantities, but problems start when it multiplies in
plumbing systems, air conditioning units, Jacuzzis,
decorative fountains or in a public water supply. Here it can
be transmitted to humans when it condenses into droplets
of fine mist which are inhaled and then settle in the lungs.
Roughly 5,000 cases are reported in the United States
every year, while 2013 saw 5,851 cases reported by 28 EU
Member States and Norway, according to the European
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HSE INTERNATIONAL
Centre for Disease Prevention & Control (ECDC).
The European group POSEIDON, (or ‘Plasmonic-based
automated lab-on-chip sensor for the rapid in-situ detection
of Legionella’) intends to change all this, having developed
their scanner to spot the deadly Legionella bacteria in
under one hour - a process that normally takes 10 days of
cultivation and analysis.
Equipped with tiny sensors, the device works by using
the photonics technique of Surface Plasmon Resonance
(SPR); a procedu re that reads information from a refracted
laser beam, allowing fast, highly sensitive, inexpensive
detection from a small sample without the need for
‘labelling’ - the process of binding to a protein in order to
be detected.
SPR occurs when polarized beams of light hit a metal
film at the interface of two media. A charge density
oscillation of free electrons (or “surface plasmons”) at the
metal film occurs, reducing the intensity of
reflected light. The scale of the reduction
depends on the substance on the metal at
the interface. Information then gathered
from the refracted can then be analysed,
and a pre-programmed pathogen
confirmed, resulting in an unambiguous
detection of the bacteria in situ.
“Detection and investigation of viruses,
bacteria and eukaryotic cells is a rapidly
growing field in SPR bio sensing, but
the detection has only been achieved
in laboratory settings. With our unique
innovative SPR sensing architecture,
POSEIDON provides reliable measurement
readouts of legionella bacterial cells that
are driven and entrapped on a custom
sensing surface specifically designed with
opportune positive and negative controls.”
Surviving and flourishing at
temperatures between 25° to 45°C,