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ID & MIC at 6 hours

Current issues

Today, many pathogen ID tools can identify the pathogen from a culture positive vial.  Other tools can characterize the pathogen for it's response to a list of candidate antimicrobials, but they also require a culture positive sample.

Currently, it is not feasible to identify the pathogen from a blood draw itself because of two reasons:
  1. Cost.  The pathogen ID tools generally cost about $100/sample.  Given that most samples tested by the blood culture method are "culture negative", screening every sample for pathogen ID quickly becomes prohibitively expensive.
  2. Sampling limit.  The pathogen concentration in the blood draw is about 1-10 CFU/mL.  In a normal 10 mL blood draw, one can reasonably expect about 10-100 CFUs.  There are about 20 different pathogens that must be targeted individually (these 20 pathogens cover about 95% of all cases of infection), and most pathogen ID tools require at least 10 copies for reliable amplification for each pathogen being targeted.  Thus, one needs about 200 CFUs for reliable aliquoting into 20 parts.  This requires a period of incubation from the starting blood draw.
In addition, current methods are limited by the intermittent nature of bacteremia for all types of infection that are localized outside the vascular system (i.e., for most types of infection).  For such infections, the pathogen must travel from the source of infection to the bloodstream ~ this is not a continuous process.  Further, the vascular system has several filters that eliminates the pathogen once it is in the bloodstream.  Thus, the final nature of bacteremia is very much "intermittent" ~ depending on the source of infection, the likelihood of detecting pathogens in the bloodstream is about 30-60%.  This applies even when the infection is severe enough to trigger sepsis.

The tools that characterize the pathogen for it's response to a candidate antimicrobial also works from a culture positive sample.  Those tools do not work from the blood draw itself because they do not have the signal resolution; thus they need a pathogen concentration of 105 CFU/mL.

Spectral Platforms Solution

Our solution involves rapid screening of all blood draws (via InSpector-01), so as to quickly identify all the infected samples.  The infected samples would be incubated for an additional 3 hours, during which time the pathogen concentration would increase 500-fold.  Thus, the initial blood draw of 1-10 CFU/mL would become about 500-5000 CFU/mL.

At that point, commercially available pathogen ID tools would be deployed to identify the pathogen, and our InSpector-02 tool would be deployed to characterize it's response to candidate antimicrobials.

With regard to the intermittent nature of bacteremia, we propose a series of blood draws that are timed 30 minutes apart, and rapid analysis (via InSpector-01) on those samples.  For intermittent bacteremia, about 30-60% of those samples will be infected, and can be further analyzed for ID and MIC.




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