Pathogenic microorganisms at concentrations of 1-10 CFU/mL in the bloodstream can trigger sepsis, thus symptoms consistent with the presence of these microorganisms warrant treatment with antibiotics. There are no tests currently available that can characterize these microorganisms in a timely manner — the only available method for this is based on blood culture, which is too slow to influence initial therapy (it takes 12-48 hours for a culture positive flag and 120 hours for a culture negative flag). At 10 CFU/mL, the pathogen’s net weight is about 108 less than the cumulative weight of other plasma proteins, thus any detection mechanism requires significant amplification. Historically, this amplification has been provided by a culture method whereby the pathogenic microorganisms are given the time to replicate to > 106 CFU/mL. For most samples, it takes 24-72 hours for significant cell growth, and the absence of growth at 120 hours results in a “culture negative” diagnosis.
We sense and characterize pathogenic microorganisms at clinically relevant concentrations with a rapid (<20 minutes) test. Our methods have a demonstrated ability of detecting over 30 different microorganisms (covering most reported cases of bloodstream infection), with a limit of detection below 10 CFU/mL. Our methods have also been shown (in multiple clinical studies, described below) to be applicable to patient samples, and have a good concordance with standard blood culture results.
A Qsub to the FDA for this tool was submitted in January 2018.
We have validated this tool with a number of pilot studies around the world, with performance parameters described below
|Site 1||2011||1(0.86-1)||0.83 (0.66-0.93)|
|Site 1||2012||1 (0.7-1)||1 (0.93-1)|
|Site 2||2015||1(0.85-1)||1 (0.80-1)|
|Site 2||2016||0.46(0.2-0.74)||1 (0.87-1)|
|Site 3||2016||1 (0.52-1)||0.82 (0.65-1)|
|Site 3||2017||1 (0.2-1)||0.94 (0.78-0.99)|