the maxwell lab

Bacterial Diagnostics


     Rapidly increasing rates of antibiotic resistance are putting pressure on physicians to only prescribe antibiotics when absolutely required. Most current bacterial detection methods take several hours for diagnosis and require specialized laboratory space and equipment. In a hospital setting, an immediate, definitive diagnosis of the bacterial etiology and its antibiotic susceptibility could be life saving in cases of meningitis or sepsis. In water treatment facilities and food production plants, the ability to detect bacterial contamination quickly and inexpensively could prevent tragedies like the Maple Leaf Foods listeriosis outbreak in 2008 or the Walkerton, Ontario E. coli O157:H7 outbreak in 2000. For these reasons we are developing a biosensor that provides a rapid, inexpensive, culture-free test that can identify a broad range of bacterial pathogens and antibiotic susceptibilities in collaboration with University of Toronto researchers Glenn Gulak (Electrical Engineering) and William Navarre (Molecular Genetics).


     Our technology combines the specificity of phages or other agents that can lyse bacterial cells with the sensitivity of integrated electronic circuits. This bacterial biosensor, RapID™, is able to detect the infection of a bacterial cell by a specific phage using ion-sensitive field-effect transistors. We have shown that we can accurately detect E. coli, P. aeruginosa, and S. aureus for the diagnosis of urinary tract infections in under ten minutes. With an estimated cost of 10¢ per microchip and the ability to test on site in medical offices and food production facilities, this technology has the potential to revolutionize bacterial diagnostics. The range of bacterial pathogens that could be detected by this device is limitless and the applications encompass all fields in which the rapid detection of bacteria is critical, including medical diagnostics, water quality testing, food safety monitoring, and pharmaceutical production.