DNA is the genetic material that makes species unique. The T2Bacteria Panel exploits this fact and uses cell-associated DNA to specifically identify bacterial pathogens. But a key difference compared to other diagnostic platforms is how the T2Bacteria Panel detects bacterial DNA. In particular, all other FDA cleared diagnostics for bacteremia require blood culture before species identification. Therefore, the T2Bacteria Panel identifies bacteria in several novel ways relative to all other FDA cleared bacteremia tests:
1. New FDA Product Code – Upon clearance of the T2Bacteria Panel, the FDA issued a new, unique product code (QBX, NSU for a “Direct Blood Bacterial Nucleic Acid Detection System”). This reflects that the mechanism of action for the T2Bacteria Panel is novel and new.
2. No cell growth – The T2Bacteria Panel is independent of biological growth rate and does not require waiting 1 to 5 days for sufficient cell doublings (9). The T2Bacteria Panel requires no growth and identifies species in 3 to 5 hours direct from blood.3. No interference from antibiotics – The T2Bacteria Panel detects cell-associated DNA regardless of whether or not the cells can grow in vitro. Antibiotics are a well-known interferent in blood culture dependent methods. For instance, a recent study of 1364 clinical blood cultures found a 60% lower odds of bacterial detection with prior antibiotic administration compared to no prior antibiotic administration (10). In contrast, the T2Bacteria Panel shows no interference from antibiotics and can still identify cell-associated DNA in the presence of antibiotics (11).4. No competitive growth – In blood culture bottles, one species can grow faster than other species and mask the true presence of a polymicrobial infection. For example, in a study of 687 positive blood cultures, compared to monomicrobial infection, polymicrobial infections showed 8.1% lower sensitivity (12). In addition, polymicrobial infections are difficult to treat. A study in the emergency department found that relative to monomicrobial infections, polymicrobial infections showed a 2.5-times higher rate of inappropriate therapy and a 2-times higher mortality rate (13). In contrast, the culture-independent T2Bacteria Panel shows no interference from polymicrobial species and can sensitively and specifically detect multiple species simultaneously (11).
5. Direct detection – The T2Bacteria Panel detects DNA from pathogens causing disease. In contrast, blood culture dependent methods detect DNA from progeny cells after many doublings. Similarly, other technologies depend on microbiological methods and require other hardware and consumables, often from third parties. The T2Bacteria Panel does not have these dependencies.
6. Detection Mechanism – T2MR uses magnetic resonance coupled with breakthroughs in nanotechnology to detect pathogens via DNA.
Taken together, while the T2Bacteria Panel does identify species with DNA, the differences from direct and independent detection, lack of growth, and lack of interference from antibiotics and competitive growth relative to all other FDA cleared diagnostics distinguishes the T2Bacteria Panel as a novel technology.