SBIR Phase II: Phage-amplified Identification and Antimicrobial Susceptibility Test

The broader impact of this Small Business Innovation Research (SBIR) Phase II project will be the expansion of a new diagnostic tool that was first developed in Phase I that allows rapid, direct-from-specimen bloodstream infection testing in clinical settings. This expansion may increase the method’s applicability from a single organism, E. coli, to a full suite of six highly virulent and antibiotic resistant bacterial pathogens (ESKAPE pathogens), as described below.

The new technological innovations proposed here may more quickly identify bacteria responsible for the vast majority of blood infections in patients and simultaneously provide phenotypic data to determine which antibiotics should be effective for treating these infections and at what doses. If successful, this will improve patient outcomes through faster diagnosis and more precise antibiotic selection while also helping to combat the growing incidence of multidrug resistant infections by reducing the indiscriminate prescription of these drugs, thereby preserving the effectiveness of existing antibiotics.

The proposed project will expand on the advancements achieved in Phase I to develop new tests for direct-from-specimen identification, antimicrobial susceptibility testing (AST) and minimum inhibitory drug concentration (MIC) determination against key ESKAPE bloodborne pathogens: Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa and Acinetobacter baumannii. A significant limitation with existing standards-of-care is time required for actionable results; current approaches require 18-72 hours.

Physicians must therefore make empiric treatment decisions that often lead to negative outcomes. Genotypic approaches are limited because of the varied mechanisms utilized by bacteria to evolve resistance, which can lead to false-negatives. Mass spectrometry requires colony isolation and provides ID only.

Other time-consuming tests are then required for AST and MIC. To solve these problems, the proposed approach utilizes bacteriophage mixtures that are highly specific and have demonstrated overlapping host ranges, produce a signal quickly, and are well-suited to automatable 96-well plate immunoassays. Project objectives are: 1) Develop regulatory pathway for FDA 510(k) or de novo clearance, 2) Develop/characterize antibodies to expand test and 3) Validate expanded tests against clinical specimens.

Side-by-side comparison to current standard-of-care strategies will also be performed. As demonstrated in Phase I feasibility work, results include ID, AST/MIC in less than 5 hours.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.