Research scientists in Professor M. Cynthia Goh's lab in the Department of Chemistry have sent their prototype of a new diagnostic device for testing to a hospital in the Philippines.
“The instrument’s underlying science is based on optical diffraction,” explains Reece Lawrence, a research scientist in the Goh lab. “The instrument monitors a diffraction signal which changes in intensity as bacteria grow.”
The initial proof-of-concept experiments were conducted by fellow Goh lab research scientist Nick Kotoulas as part of his doctoral research, where he showed that diffraction could detect bacteria growth with high sensitivity. This technology is based on a previous patented invention in the Goh lab. As an extension of this research, the lab developed a prototype device dubbed “Bactiscan,” which can be used as a standalone instrument to detect bacteria growth.
“One potential use for the instrument would be to determine the susceptibility of a given bacteria to various antibiotics,” said Kotoulas. “This would enable the proper choice of medication for infection management."
Existing disk diffusion tests can test for bacterial resistance to antibiotics, he explained, but Bactiscan will significantly lower the growth time required to make a determination. The benefit? Patients receiving appropriate medications sooner.
As part of an ongoing development of this technology, the Bactiscan prototype instrument was sent to Philippine General Hospital to be tested on real world samples of pathogenic bacteria. Researchers at the University of the Philippines at Manila will oversee the trial, gathering data and working with U of T chemists to optimize uses for the instrument.
“The initial goal of Bactiscan was to develop a cheap and reliable instrument that would be suitable for use in low resource settings,” said Lawrence.
These specifications meant finding inexpensive hardware components, as well as designing cheap consumables. The resulting device utilizes a Raspberry Pi computer and Pi Camera, with the consumable being an agar molded Petri dish which can be made on site with a provided molding tool. The rest of the components are 3D-printed in the lab.
Bactiscan was developed from scratch in the Goh lab. The multidisciplinary work included hardware — the box, sample holders, and alignment mechanism — and software written and developed by the lab members.
Chemistry PhD student Tomoyuki Sen said he was delighted to be part of a uniquely multidisciplinary endeavor, explaining that Bactiscan incorporates biological, engineering, and physical chemistry concepts into one instrument.
“The project helped me understand the challenge of taking a scientific instrument from a laboratory prototype into a format that meets all the requirements set by the different disciplines it draws from. Fabricating something as seemingly simple as the Bactiscan’s outer box meant accounting for the biological assay, electrical components, and optical elements. It had to be strong enough to ship overseas, easy to troubleshoot and remain cost effective.”
The innovative approach was equally necessary in coding the device, agreed another PhD student, Jiaqi Wong. “The software needed to be user-friendly, reliable, and efficient, capable of handling complex data processing and analysis."
He added: "I am delighted that the Goh lab, with its diverse range of multidisciplinary members, was able to unite and contribute our unique talents. Bactiscan combines biological, engineering, and physical chemistry concepts into a single instrument, and I believe it has the potential to make a significant impact on the world!”
The long term goal of the project is effective and affordable management of infection, by proper use of antibiotics. In addition to improving medical efficiencies, the Bactiscan approach will reduce overuse of antibiotics, a problem that leads to increased prevalence of antibiotic-resistant microbes. With such exciting prospects in view, it is no surprise that everyone involved at the Goh lab is excited to contribute to this important global issue.