The Pheno system from Accelerated Diagnostics is ready to outperform all other methods in diagnosing sepsis infections. With the rise in antibiotic resistant “superbugs”, doctors are faced with more difficult diagnoses and treatment when it comes to infectious disease. In order to start treatment, they need to discover the cause of the infection-identification (ID), which antibiotic will be effective- Antimicrobial Susceptibility Testing (AST), and the sooner they know, the more effective they can be. Time is of the essence, and that is where Pheno blows away the competition.
The new Pheno system allows for all of the necessary diagnostic info in half the time. By combining several systems into one platform, it cuts down on labor and eliminates incubation times. Recent studies at multiple hospitals have compared the results to previous systems and the results promise improved outcomes for sepsis patients and hospitals alike.
Before Pheno, all ID/AST methods required an initial incubation period for the infectious agent in a patients blood to grow to testable levels prior- a process that takes at least a day. Pheno eliminates this by allowing for blood samples to be loaded directly into the machine.
Pheno also saves time (and increases precision) by automating the dilution step. For accurate AST results, a pathogen needs to be at a specific concentration. Anything higher or lower concentration could skew the results. Historically, this is performed by a technician adding the cultured pathogen to a saline solution. The concentration is then measure by analyzing the turbidity of the solution. The Pheno system employs a dynamic dilution method with direct cell counts, automatically followed by a final dilution to reach the testable range.
Once the sample has been loaded and the dilution is established, the Pheno machine is ready to move onto the testing phase. Using an electrical charge applied across two parallel plates, the negatively charged cells of the pathogen culture adhere to the positively charged plate. This will create a flat plane, allowing for digital microscopy to identify the species through Fluorescent In Situ Hybridization (FISH). The oligonucleotide probes used in this process are capable of testing for a wide array of organisms. Additionally, they are capable of detecting multiple species of microorganisms from one sample. In cases of polymicrobial infection, traditional methods of identification typically require an additional day or more to isolate and culture each species individually before ID/AST testing. The identification results with the Pheno system are ready within 90 minutes.
Finally, using Morphokinetic celular analysis, the Pheno system is able to provide AST results within 7 hours on average. This system of AST analysis relies on the microscopy capabilities of the machine to track cellular responses to panels of antimicrobial drugs. Historically, this step in the testing requires another day of incubation of the pathogen in drug dilution panels in order to observe growth/ no growth at various concentrations.
The pheno system is undoubtedly fast. It yields results in hours instead of days. But what does that mean in the context of and entire hospital system. And with that speed, is it still capable of maintaining the accuracy of a Hospital’s current system? Researchers have answered these questions in two different published studies, performed at three different hospital systems.
Joseph D. Lutgring et al. tested the Pheno system at both Emory University and University of Texas Southwestern hospitals. They found the Pheno gave ID results 41.5 hours faster and AST results 48.4 hours faster- both compared to the usual standard of care methods.
Angella Charnot-Katsikas, et al. performed testing on the Pheno system at the University of Chicago. The Pheno led to a decrease in time to ID of 23.47 hours. AST results were 41.86 hours faster. Charnot-Katisikas et al. further found that the Pheno system freed up 25.5 hours of hands on time by technicians.
Both of these studies, along with additional clinical testing has shown the Pheno to be highly accurate as well. The agreement with traditional, gold standard methods has exceeded FDA requirements and allowed the Pheno to be implemented for clinical use.
As the Pheno system moves into clinical laboratories it will allow for a new standard of care. Before physicians receive ID/AST results for an infection they use what is referred to as empiric therapy. Essentially, an educated guess that tends to rely on broad-spectrum antibiotics and general assumptions of resistance patterns.
After receiving the proper ID/AST results, the patient can then be moved to a more appropriate therapy. The physician can treat with a drug more targeted to the species of the pathogen and avoid using drugs that the pathogen may be resistant to.
The benefit provided by the Pheno system is in closing the gap between sample collection and treatment with targeted antibiotics. The time saved can save lives. It can decrease stays in the ICU, prevent further damage of the infection, shorten recoveries, and free up both physician and technician time. Accelerate Diagnostics has modeled the economic impact that the Pheno System can have on a typical hospital system. In the first year alone, their model shows a savings of $4,800 per patient, 1,700 fewer ICU days, and a total impact of $10.8 M.
The Pheno also allows for smarter antibiotic prescription. With the current rise in antibiotic resistance, antibiotic prescription and usage is critical. Proper antimicrobial stewardship relies on clearing infection faster with fewer and more targeted antibiotics. All of which the Pheno can help with. As the Pheno undergoes further development, Accelerated Diagnostics hopes to expand its menu of testable organisms and drugs allowing for further impact on the medical diagnostics industry.