Southampton experts to trial ‘instant’ test for eye infections
Electronic engineers in Southampton have co-developed a microchip that could detect sight-threatening eye infections within minutes and prevent misuse of antibiotics.
Conventional testing methods for corneal infections, or microbial keratitis, which include using microscopes, growing cultures in the laboratory or antibiotic sensitivity testing, can take anywhere between 48 hours and two weeks to provide results.
Experts from Electronics and Computer Science (ECS) have worked alongside ophthalmologists at University Hospital Southampton NHS Foundation Trust (UHS) and molecular microbiologists from the University to produce a chip that analysed bacteria extracted from laboratory-infected tissue samples.
They found measuring the electrical properties of single bacteria as they pass one by one between tiny electrodes at high speed can identify instantly that an infection is present and distinguish between different bacteria such as E. coli and pseudomonas – something not possible using existing techniques.
As a result of the findings, a prototype device has been approved by the Health Research Authority and Research Ethics Service for patients presenting with corneal infections at Southampton General Hospital's eye unit, with a pilot study involving 30 patients set to launch next month.
Corneal infections occur when the cornea is damaged by a foreign object and through the growth of bacteria and other micro-organisms – often due to contaminated contact lenses. There are around 6,000 cases of corneal infections diagnosed in the UK every year, with around a third related to contact lens wear.
Professor Hywel Morgan, a Professor of Bioelectronics in ECS and Deputy Director of the Institute for Life Sciences at the University of Southampton, said: “Our technique is relatively simple – we just measure the electrical signals from the cells flowing one by one through the chip and this information is enough to distinguish the different microorganisms.
“It could have widespread applications, particularly given the current challenges we face in tackling overuse of antibiotics.”
Dr Daniel Spencer added: “Our miniaturised Lab-on-a-Chip technology enables analysis of the micro volumes of sample typical of these patient samples.”
In a further development, the team also hope to trial the test in Africa and South Asia as part of the study through links developed with Southampton General Hospital’s eye unit through overseas programmes.
The device – developed with funding support from the Engineering and Physical Sciences Research Council, the Network for Anti-Microbial Resistance and Infection Prevention and the Royal College of Surgeons of Edinburgh – was recently awarded the prestigious Founders Cup prize for research innovation at the 101st Oxford Ophthalmological Congress.