Sepsis is a common and frequently fatal condition with a mortality rate that ranges from 20% to 50% for severely affected patients. It is the second leading cause of death in the U.S. among patients in non-coronary intensive care units and the 10th leading cause of death overall. It is a rapidly increasing health concern, especially for elderly, immune-compromised, or critically ill patients. Blood culturing with automated liquid culture systems is the standard test for identifying the pathogenic bacteria involved in sepsis, but it is slow and insufficiently sensitive for slow- growing bacteria or in patients pretreated wih antibiotics. iSense, LLC has a novel sensor technology that can simultaneously detect and identify the causative bacteria by sensing metabolic volatiles, and do so after only four hours of blood culture incubation: a substantial improvement in time to diagnosis. In collaboration with the Stanford School of Medicine, iSense has evaluated the new nanoporous pigment-based colorimetric sensor array's ability to detect and identify 33 different microorganisms cultured in Petri dishes and drawn from reference strains and clinical isolates from 14 clinically relevant pathogen species. Over 400 experiments were performed on solid media in Petri dish, yielding 99% accuracy for species identification. We propose to adapt this sensor matrix to develop a prototype system that can be used to detect and identify causative bacteria in blood culture bottles. If successful, iSense technology could revolutionize the sepsis diagnostic method, dramatically improving the quality of health care while reducing its cost.
The proposed research effort will develop and test a novel high-dimensional colorimetric sensor array technology for the detection and identification of bacteria responsible for sepsis. The proposed effort, if successful, will yield a rapid diagnostic tool for sepsis, allowing prompt delivery of appropriate antibiotic treatment and reduced health care costs.