Urinary tract infections, or UTIs, are extremely common in the UK, accounting for 3% of all GP consultations and over 200,000 emergency hospital admissions annually. Part of the challenge is that it also takes a relatively long time for the bacterial cause of a urine infection to be identified, and an appropriate, narrow spectrum antibiotic specific for that bug to be selected. As a result, doctors tend to play it safe and over-treat UTIs, often with broader spectrum, more expensive agents, which drives up costs and rates of antimicrobial resistance. Now a new technology is hoping to change this. Astratus, a spin-out company from the University of Reading, has a microfluidic system that grows bacteria from patient samples in tiny volumes, watching how the microbes respond to different antibiotics. It can produce a diagnosis – and an antibiotic sensitivity – in under 6 hours. Better still, it should be ready to roll within the next couple of years. Speaking with Chris Smith, Oliver Hancox is their CEO…
Oliver – If we start with antimicrobial resistance as a top level problem, this is when we give an antibiotic to treat a bacterial infection and the drugs are no longer effective. In this case, we’re dealing with one of the most prevalent bacterial illnesses going, so urinary tract infections. It affects more than 30% of our population and currently it takes up to three days to return a clinical result. So how do we make that faster? And what we’ve got here is a platform and a mechanism to take that test that takes three plus days and give a same day actionable results. And we can link that right drug with the right bug, importantly, at the right time.
Chris – Tell us how it works. What have you done to do that?
Oliver – We call ourselves pragmatic microfluidics. So we’re looking at a very small amount of liquid, so one microlitre in this case, so a thousandth of a mil. And we’re looking at bacterial growth within that physical growth. We’re also able to look at it in response to some metabolic indicators that then tell us whether there’s been bacterial growth in response to those drugs that we’re exposing them to.
Chris – So, in practical terms then, you would, say, have a urine specimen; you’d need a tiny volume and you’re able to watch the microbes that are causing what we think is potentially an infection there in real time growing and you can expose them to a host of different drugs and see which ones do and don’t work.
Oliver – Yeah, exactly. So we take a panel of these antibiotic drugs, and as you say, monitor that bacterial growth in real time in response to those drugs, and then out of that map their growth or no growth and then give an accurate result out of that.
Chris – How do you actually monitor the growth though? How do you see these microbes are growing, these ones are not?
Oliver – The bacterial growth will then cause, in this case, an optical change. And we can then monitor that optical change and give a curve to then say there’s either been bacterial growth here, we see an optical change or a colour change, or in this case, we don’t see it if there’s no colour change. And then we also look at physical bacterial growth itself.
Chris – Is that because the microbes just change the characteristics of the light you’re looking at them with, or are they actually eating something that you’ve put there that produces a colour that enables you to see them?
Oliver – A little bit of both actually. We do some metabolic indicators, in which case the bacteria, through physical bacterial growth and activity, cause a colour change in some metabolic indicators, and that gives us a colour change that we’re able to see. And when we also look at their physical mass, so the more bacteria grow, the more we’re able to see them, because we’re looking for them in a very small area, we’re able to monitor that growth and categorise that as growth or no growth and the amount of growth that goes along with that.
Chris – Does it work for all different kinds of bacteria? Because although there are some that are really common causes of UTIs, urine infections, there are still nevertheless a number of different bacterial species that can do it, and they are quite different, some of them. So will this work to detect all of them and their sensitivities?
Oliver – Most urinary tract infections are caused by either E. coli or Klebsiella, but we also monitor the whole range of microorganisms to ensure this platform is accurate across not just one disease type, one just infection type, but multiple.
Chris – One of the things that the microbiology team in a lab will do is that they’ll not just say which antibiotic works or not, they’ll also give some indication of how sensitive the bugs are to it, so that doctors can make an informed choice. I’ll go for the super sensitive one, or I’ll go for one that’s a bit more of a risk, but it’s a lot cheaper. Can you do that too? Can you say we know how sensitive they are relative to each?
Oliver – Absolutely. So at the moment, for example, most of these tests are done by a method called disk diffusion. That requires you to measure with a ruler or a template the ring of growth or no growth around that little disc of antibiotic. We’re able to simplify that all the way down and say for this given concentration of antibiotic, we see this growth from this, we see this amount of growth, and then categorise that and bring that back to a meaningful dose that the clinician can then take forward into their prescription.
Chris – And why stop with just urine? Could you do this for other things? Because micro labs are growing blood cultures, they’re taking swabs from people’s noses and throats and wounds and so on. Can the same thing not equally speed up those diagnostics?
Oliver – Absolutely. So we’ve chosen to start with urine. It’s the most prevalent bacterial infection that’s tested globally as a starting sample. Antibiotics are almost always given out for a urinary tract infection. And there’s also up to a 60% rate of reinfection within UTI within six months. So how do we make a big impact on antimicrobial resistance as a whole antimicrobial usage? It starts there. But there’s no reason why this technology can’t be deployed and in the future will be deployed in things like blood swabs and joint fluids.
Chris – And the cost? Because at the end of the day, that is the thing that the accountants are going to look at. If it’s saving them time, as well as saving money, it’s a win-win.
Oliver – Yeah. So for us, this was really important from the get-go. And I said earlier that we called our platform Pragmatic Microfluidics. We’ve always wanted to make a platform that fitted directly within the workflow and was price competitive with that of a Petri dish. And so what we’re really trying to do is to rapidise the routine here. So we bring rapid technology down to routine sample analysis. And when it makes it to market, it will be price competitive with the current workflow and what microbiologists already use.
Chris – And how far away is that?
Oliver – We spun Astratus out at the end of 2024 and we’re moving down that regulatory roadmap. Unfortunately, with these technologies, or fortunately for these technologies, you can’t just sell them. They have to go through a rigorous trial and regulatory procedure. And for us, that looks like 2028 by the time this will make it to market. And it will be deployed prior to that as a research use only tool and trying to build as much pilot traction and traction with laboratories up to that point, but it will be for sale by the start of 2028.