Scientists at the University of California, Irvine (UCI; CA, USA), have developed new technology that can rapidly and accurately detect bacteria in milliliters of blood. The new test, called Integrated Comprehensive Droplet Digital Detection (IC 3D), does not require a cell culture unlike some conventional methods.
Bloodstream infections continue to be a major worldwide health problem. The Centers for Disease Control & Prevention (GA, USA) estimated there are around 23,000 deaths a year due to antibiotic-resistant blood infections globally, with over 2 million people affected in total. The lack of rapid diagnoses for early stage blood infections is a contributing factor in this mortality rate.
Previous methods involving molecular diagnosis were often not sensitive enough to detect bacteria in blood at low concentrations. The IC 3D technology uses a completely novel method, directly converting blood samples into billions of tiny droplets. A fluorescent DNA sensor solution is infused into the droplets of blood, and any droplets with bacterial markers then light up with an intense fluorescent signal.
Weian Zhao, who led the research as assistant professor of pharmaceutical sciences at UCI, explained that by using so many small droplets, potential interference is minimized. This then allows bacteria to be directly targeted without a purification step, which is usually required in conventional assays. The new technology incorporates a three-dimensional particle counter developed at UCI that identifies fluorescent particles within several minutes.
Enrico Gratton, who led the development of the particle counter, commented on the research: “The IC 3D instrument is designed to read a large volume in each measurement, to speed up diagnosis. Importantly, using this technique, we can detect a positive hit with very high confidence.”
Zhao concluded: “We are extremely excited about this technology because it addresses a long-standing unmet medical need in the field. As a platform technology, it may have many applications in detecting extremely low-abundance biomarkers in other areas, such as cancers, HIV and, most notably, Ebola.”
The IC 3D technology is currently being further developed by Velox Biosystems, a UCI spinoff company.