Rapid Detection of Bacteriophage Susceptibility in Antibiotic-Resistant Pathogens using cellPhoresis®

Post-injury infection is a persistent problem among U.S. military service members in the field and in military hospitals. An increasing fraction of these infections are due to antibiotic-resistant bacteria such as Methicillin-resistant Staphylococcus aureus (MRSA). A key tool against these novel pathogens is bacteriophage therapy, in which phages (a form of virus that infect bacteria) are administered in lieu of antibiotics to halt bacterial reproduction. Bacteriophage therapy depends on determining the susceptibility of the specific strain of bacteria infecting a patient to a particular phage. This process typically takes hours to days and requires tissue culture facilities that are not feasible in many military field settings. cellPhoresis® is a mobile, cloud-enabled, microfluidics platform being developed by CBio for field-testing of biological samples. This technology is based on the ability to differentiate bacterial populations by their motility under an induced electric field and capture those populations for further analysis. Our academic collaborators at Arizona State University have shown that cellPhoresis® technology can reliably distinguish closely related strains of Salmonella or Listeria and can separate MRSA from Methicillin-susceptible strains. Key advantages of cellPhoresis® over other methods include speed (results in minutes instead of 16-18hr overnight culture), portability (tissue culture facilities typically require a dedicated sterile room, cellPhoresis® fits in a backpack), reliability (because cells are not cultured long-term there is less opportunity for contamination), and the fact that cellPhoresis® does not require any cold chain reagents for operation. We have recently demonstrated that the cellPhoresis® platform can identify dying bacteria based on their metabolic state. We propose to develop this technology to determine the susceptibility of antibiotic-resistant strains of bacteria to bacteriophage treatments. We will show that cellPhoresis® can rapidly report on whether a specific bacterial species is susceptible to a specific bacteriophage treatment. This will enable medical professionals in the field to make treatment decisions in real time.