New instruments for Johne’s disease and tuberculosis
Two prototype instruments to diagnose Johne’s disease in cattle and tuberculosis in humans and cattle have been successfully developed by Epigem.
The news follows the completion of two Innovate UK-funded projects, MilkEd and MIMIC. The micro-engineering company says that it is now focussed on preparing the instruments for extensive operational trials.
“We have made great strides technically in manufacturing devices to detect Johne’s disease in cattle and TB in humans,” said Epigem’s managing director Tim Ryan. “Complex problems require excellent multi-disciplinary teamwork, and these projects confirm that.”
The MilkEd project aimed to develop an instrument that could identify Johne’s disease in under 45 minutes. It was crucial that the instrument could work both on-farm and in the laboratory.
The prototype uses surface acoustic waves to control an assay that is packaged into a disposable cassette. The cassette is fully automated and interconnects in a ‘plug and play’ manner within a boxed data reader.
The portable reader consists of integrated miniature sub-assemblies that perform electro-opticals microfluidic and microelectronic functions. Operated by a microcomputer, the test is based on a polymerase chain reaction (PCR) in a miniaturised environment. The 45 minutes includes extraction time.
The MIMIC project aimed to diagnose tuberculosis (TB) in humans within minutes based on a sample of blood taken from a pinprick. Like the MilkEd prototype, the MIMIC prototype also contains a disposable cassette which, this time, can perform serology.
Epigem says that the assay can be used to identify human TB from a drop of blood in less than 20 minutes. More than 900 people were tested as part of the project, using a library of over 40 different antigens to identify TB-specific antibodies.
Final data analysis is still in progress, but an interim analysis shows that the instrument can achieve sensitivity and specificity values in excess of 80 per cent. Researchers say that, because of the speed of the device, it has the potential for use as a triage test in areas with high TB incidence.
The results of the project are also relevant to TB in cattle and similar diseases in other animals.
"The two projects are clear beacons of excellence in innovation - showing how teams of engineers, scientists and clinicians from industry, the NHS and academia can work together to deliver new products,” said Professor Jon Cooper from the University of Glasgow, whose research team was involved in the technical delivery of the project.
“The sensors potentially have significant impact in both the veterinary and clinical markets, here in the UK and globally."
Clinical lead Dr Marc Tebruegge, of the University Hospital Southampto, added: “Existing diagnostic methods for TB have significant limitations, and are generally poorly suited for use in high TB incidence, low resource settings.
“The project has shown that multiplexed, antibody-based tests for TB are potentially feasible. The advantage of antibody-based tests is that they are typically very robust, can produce results rapidly and can be produced at relatively low cost. All those characteristics would make them ideal tools to tackle the ongoing global TB pandemic.”