Electrical Biosensor for Rapid Point-of-Care Diagnosis of Urinary Tract Infections and Antibiotic Susceptibility Testing

Project Summary Every year over million people are diagnosed with urinary tract infections UTIandapos s in the United States alone UTIandapos s encompass bacterial infiltrations of the urinary tract and the most common bacterial infections worldwide Together with the increasing threat of antimicrobial resistance and the lengthy diagnosis time physicians are in need of technology that allows for rapid bacterial identification and their susceptibility to antibiotics at the point of care Todayandapos s gold standard for point of care UTI diagnosis is dipstick testing a calorimetric test strip that changes colors if bacterial and leukocyte metabolites are present in a urine sample However the sensitivity and specificity of dipsticks for those UTI markers are poor For accurate diagnosis and antibiotic susceptibility testing urine samples are sent for laboratory bacterial cultures a process that takes up to three days To bring rapid and accurate UTI diagnosis and antibiotic susceptibility testing to the point of care we are developing a device that uses a silicon nanowire field effect transistor SiNW ISFET to detect protons produced upon bacterial metabolism In the device bacteria from clinical urine samples are captured and concentrated on a filter that is in liquid contact with the sensor Exposing the captured bacteria to a carbon source containing media with low buffering capacity and incubating at C we are able to detect bacterial infections CFU ml by a significant pH change of the media and in as low as minutes discriminate Gram types by selective dye based inhibition of proton production by Gram positive bacteria and detect antibiotic susceptibility and resistance when bacteria were exposed to the drugs The three specific aims of this proposal address the optimization of the three assays and their validation in de identified clinical urine samples We will determine the accuracy of our technology by comparing our results with the laboratory gold standards including urine dipstick disk diffusion broth dilution and microscopic gram staining Project Narrative In the United States every year over million people are diagnosed with urinary tract infections UTIs the most common bacterial infections worldwide In addition bacterial resistance to antibiotics is an increasing health threat hence non targeted antibiotic treatments not only result in unknown therapy outcome for the patients but also promote further formation of antimicrobial resistance One major problem today is the long diagnosis times of an infection together with the identification of an antibiotic that will effectively treat the infection We have developed state of the art nanotechnology that has miniaturized a microbiology lab and hence enables bacterial detection and antibiotic resistance testing in the patientandapos s urine at the point of care Thus physicians can prescribe the right antibiotic right away In this way the therapy outcome for the patients will be dramatically improved and healthcare costs will be reduced