Scientists have piloted silicon biosensor chips which can rapidly identify the best antibiotics for treating bacterial infections. The system can direct clinicians to the best antibiotic treatment in around 2 to 6 hours, rather than upwards of 2 days which is typical of conventional tests. The new technology, which is still in development, is being presented at the European Association of Urology congress in London.
The scale of the problem this test addresses is huge. Bacterial infections are still a major cause of death in the Western world, and because of over and mistreatment antibiotics resistant Bactria stains are increasing every day. In the UK, it is estimated that 300,000 patients a year acquire infections in hospital, with Over 9000 dying from bacterial infections1. In Europe generally, over 4 million people acquire a healthcare-associated infection every year2, and in the US3 around 100,000 die each year from hospital acquired infections. Up to 40% of these are Urinary Tract Infections (UTIs). It is vitally important for doctors to be able to identify which antibiotic works as rapidly as possible, but typically they need 24 hours to confirm the presence of bacteria, and at least another 24 to 36 hours to identify the correct antibiotic to use.
The team, led by Professor Ester Segal (Technion Israeli Institute of Technology, Haifa), has developed special silicon biosensor chips. Each chip contains thousands of nano wells, which are coated with a material which allows bacteria to stick to the chip. Once the bacteria have stuck to the well, technicians use reflected visual light to count the bacteria, and to see whether the colony is growing. They can then add a different antibiotic in various dilutions to each chip to see which best inhibits bacterial growth, giving results within 2 to 6 hours.
Professor Segal said “So far we have used the system to rapidly identify antibiotics for a range of bacteria, such as E. Coli, which causes many urinary tract infections (UTIs)”
Professor Sarel Halachmi (Bnai-Zion Medical centre, and the Faculty of Medicine, Haifa), said that “We are currently at initial testing stages using commercial bacteria solution and also human bacteria isolated from urine samples, however we are not yet at the stage where we can roll this out for routine clinical use. But the system is accurate, simple economical, and significantly shortens the time to accurate treatment recommendation and will save lives in the future.”
“Urinary Tract Infections (UTIs) for example, are a major health burden. Around half of all women in the West will have a UTI at some point. The major obstacle in the diagnosis and clinical management of UTI is the delay in our ability to isolate the bacteria causing the infection, and identify its susceptibility to certain antibiotics., We know that this silicon well system can significantly cut the time needed to identify the correct antibiotic, from a couple of days down to just a few hours. Using the best antibiotics will also help prevent the rise of antibiotic resistant bacteria which are one of the main problems in hospital acquired infections”.
“Of course, there is more work to do before the system is generally available. We envisage the costs of the system being pretty low, with each analysis costing between $5 and $25, but this will come down over time. If our system can save an extra day in hospital, that alone will save at least $300 in most countries”.
Commenting, Professor Florian Wagenlehner (University Clinic, Giessen, Chair of the European Section of Infections in Urology), said:
“This work addresses a really urgent medical requirement; how do we rapidly identify the best antibiotic? The current culture based techniques have a delay of several days in producing results, which leads on the one hand to inappropriate antibiotic treatment, and on the other hand to an overuse of broad spectrum, last resort antibiotics.
There are several labs working on this topic, and there are several alternative methodologies being presented at the EAU conference, including a new method from our own lab. Developing the right test will save resources and lives and slow down emergence of antibiotic resistance”.
(a) Photo of chip from the side
(b) Photo of chip from above, with bacteria
(c) Enlarged photo of chip from above, with bacteria