Episode 6: A Sweet Approach to Battling Bad Bacteria

Dr Sarah Fouch smiling wearing a scarf - life solved logo in left corner

With antibiotic resistance on the rise, Dr Fouch and her team have been looking at alternative solutions

  • 08 December 2020
  • 18 min listen

Your kitchen cupboard could hold the key to future-proofing our hospitals against infection.

With antibiotic resistance on the rise, Dr Sarah Fouch and her team have been looking at alternative solutions for the most pressing scenarios, such as hospitals. It's led to a sweet bit of research: Manuka honey, used in catheters, is proving effective in tackling infection. Could this be a solution for the future?

There is evidence that quite a high proportion of us are colonized with multi-resistant organisms in our gastrointestinal tract... Manuka Honey has been shown to have anti-microbial properties for a long time.

Dr Sarah Fouch, Senior Lecturer

Episode transcript:

Narrator: You're listening to Life Solved from the University of Portsmouth. Where we uncover world-changing work from our researchers and scientists. I'm John Worsey, a writer at Portsmouth and my colleagues and I have been catching time with these brilliant minds for some lunch break interviews.

Narrator: Earlier in this series, we heard about Anastasia Callaghan's research into how bacteria behave and how they develop antibiotic resistance. This time we're looking at how another team are working with the problem in hospitals.

Sarah Fouch: We will end up with quite a nice matrix of different components, plus multiple species of bacteria growing on the plastic. And actually, very often the patient hasn't got an infection. It's just because the bacteria form the biofilm up the plastic and then the patient's immune system is responding to that because it shouldn't be there.

Sarah Fouch: Bacteria are very promiscuous. So if they have an element of DNA that will help them to resist an antibiotic, then actually they're quite good at sharing those. Very problematic, particularly with patients that have got urinary catheters.

Narrator: We'll also hear about what happened when she took a health food and tested out its antimicrobial qualities for good. The results were pretty exciting.

Sarah Fouch: It's got wind healing, it's got anti-cancer properties, it's also got antimicrobial properties. Now, what we need to do is try and think about taking that a step forward and taking that into a clinical environment.

Narrator: I spoke to Sarah Fouch about how her research is battling bad bacteria with a sweet secret weapon. A kind of antimicrobial honey.

Narrator: Dr Sarah Fouch is from the School of Pharmacy and Biomedical Sciences.

Sarah Fouch: So I am a microbiologist. The area of research that I'm particularly interested in are multi-resistant organisms and how we can go about treating those, so antimicrobial resistance.

Narrator: Sarah came to her research after working in the NHS for 12 years. She'd originally studied her degrees and worked in labs. But for her, seeing the impact of this work in the real world is what drives her research. She's recently been part of the team looking at COVID-19 samples at Basingstoke Hospital, moving through hundreds of tests a day to help doctors and medical staff better understand the virus. Yet even before the Coronavirus pandemic, Sarah had witnessed the effects of rising antibiotic resistance in her work.

Sarah Fouch: When you work within the health care environment, particularly if you're on call at the weekend and evenings and you're dealing sort of almost one-to-one, you may not have the patient-facing role, but you're still dealing with that patient sample. And dealing one-to-one with a patient is, you know, and then you hear whether the patient's made it or they haven't. And having that sort of connection with that patient, you understand, do you know what, resistance is really increasing and this is going to be a problem.

Sarah Fouch: We've dealt with patients, sometimes very young patients with sepsis. And, you know, if the antibiotics, if the patient is late presenting or the antibiotics, the bacteria resistant to antibiotics, we've actually lost the patients in the past.

Sarah Fouch: Antibiotics can often be called antimicrobial resistance, antibacterial resistance, all those sorts of things. So when we talk about multi-resistant organisms, probably a really good example would be MRSA. And everybody's heard of MRSA.

John Worsey: Yes.

Sarah Fouch: Within the hospital environment. And that is just an organism that is resistant to multiple classes of antibiotics.

Narrator: It seems a race against time to find ways of tackling antibiotic resistance, to make sure modern medicine can continue to save lives around the world. But to face the problem, we first need to understand why bacteria, particularly bad bacteria, spread resistance to drugs in the first place.

Sarah Fouch: So these are bugs that are causing infections, but multiple antibiotics will not work against them. So we're finding that more and more bacteria are resisting antibiotics so the antibiotics aren't working. So they can produce virulence factors that help them either break down the antibiotic or pump the antibiotic out.

Sarah Fouch: Bacteria of a very promiscuous. So if they have an element of DNA that will help them to resist an antibiotic, then actually they're quite good at sharing those. So they're good at sharing them within species, but they're also good at sharing them with other species as well. So we start to see these resistances in certain species and then the sort of resistance gets worse between other species of bacteria. The sharing can occur in multiple ways. That we can have daughter cells, we can have replication of bacteria and daughter cells will share those resistances. But we can also have the sharing of resistance plasmids, so little areas of DNA that can be shared between different bacteria.

Sarah Fouch: Bacteria are very clever. If you have a sort of area where you have multiple different bacterial species, they can have what's called quorum sensing. So they will sense their environment. If there are too many bacteria there and nutrients are too low, they may move away or they may produce toxic substances to kill off other bacteria. So they're quite clever.

Narrator: We all have a host of good bacteria living in our bodies. This helps with all sorts of processes like digesting food and absorbing nutrients. It's estimated you have 10 times more bacterial cells in your body than human cells, and most of these are in the digestive system. Sarah began to look at how this plays a role in how an antibiotic tablet enters and behaves in our systems. Could this be contributing to the problem?

Sarah Fouch: When you take anything orally, it's going to be absorbed slightly differently. Different amounts are going to get to our gastrointestinal tract. And what I am interested in is are we increasing antimicrobial resistance within our normal gastrointestinal flora? Because the amount of antibiotic that's getting down to that area, is it removing bacteria? Or those bacteria that are still resident, is it helping them to overcome the effects of that antibiotic?

Sarah Fouch: There is evidence that quite a high proportion of us are colonised with multi-resistant organisms in our gastrointestinal tract. Are we consuming products where they're there? But surely if we've cooked those, they should be eradicated? Or is it the fact that we are taking antibiotics or other medications that are affecting our gastrointestinal flora, and is it making it more resistant?

Narrator: Sarah gave the example of female urinary tract infections. This common occurrence left untreated can lead to sepsis – something which Sarah has experienced firsthand.

Sarah Fouch: I have a particular love for a particular type of resistance, which is Extended Spectrum Beta Lactamase producing organisms because I suffered septicaemia from one in 2010. To have a look at the prevalence and to have a look at actually, are we promoting multi-resistant organisms within ourselves by the treatments that we have, really did resonate with me. They're completely harmless to us until they get to other areas of the body.

John Worsey: Right.

Sarah Fouch: So if you think about females are very, very prone to urinary tract infections because of our anatomy.

John Worsey: Yeah.

Sarah Fouch: But if we're colonised in our gastrointestinal tract with multi-resistant organisms, we are more likely to then contaminate other areas of our body with a multi-resistant organism, and then end up having an infection with that multi-resistant organism.

Narrator: In order to simulate a real environment for the bacteria she was studying, Sarah and her team had to build an artificial version in the lab.

Sarah Fouch: What I'm trying to do is almost build a gastrointestinal model so that actually we can treat this gastrointestinal model. We've carried out some primary research in the very crude model. But actually what we want to do is, is mimic that the gastrointestinal tract a lot more and then have a look to see the doses that actually reach the gastrointestinal tract. Are they having a detrimental effect on the bacteria that are resident? So that would basically be taking a faecal sample from a patient and then treating it as you would do if there was a pathology somewhere else. And then seeing what happens to the resistance in that normal flora.

Sarah Fouch: We will literally have the anaerobic cabinet. We will literally have vessels in there and it will be almost a gastrointestinal model bubbling away. So there'll be media pumped in and media pumped out and different pHs in the different areas of the gastrointestinal tract. Thinking about sort of mucin that's in there, thinking about different nutrients that need to be in there, all those sorts of things. We have quite a bit of mucus within our guts so that everything happily travels through. And some bacteria will quite happily sit in there and reside in there all the time.

Narrator: Manuka Honey is renowned for its healing powers, but Sarah explained that the antimicrobial properties could be really useful in everyday hospital contexts. In fact, it might even be a clue to how we tackle these multi-resistant infections going forward. The first step was to try it out in the lab.

Sarah Fouch: Manuka honey has been shown to have antimicrobial properties for a long time. It's got wind healing, it's got anti-cancer properties, it's also got antimicrobial properties. And we carried out some research a couple of years ago to have a look to see if it would actually penetrate a bacterial biofilm and if it would break the biofilm down or if it would actually stop the biofilm from forming.

John Worsey: Right, what's a biofilm, sorry?

Sarah Fouch: So a biofilm is if I put this in a clinical perspective, patients that have catheters, you know when you have catheters fitted, they often have problems because the bacteria like to grow on the plastic. So we will end up with quite a nice matrix of different components, plus multiple species of bacteria growing on the plastic. And actually, very often the patient hasn't got an infection, it's just because the bacteria from the biofilm up the plastic and then the patient's immune system is responding to that because it might be there. Very problematic, particularly with patients that have got urinary catheters.

Sarah Fouch: They'll form a biofilm on most surfaces. So in a laboratory environment, if you wanted to form a biofilm plastic, they'll form a biofilm on glass slides. In a clinical environment, plastic is used because it's very pliable so a patient can move about without sort of having that discomfort.

Sarah Fouch: Our research showed that actually the Manuka honey was able to break down a biofilm quite nicely and it was able to inhibit the biofilm quite nicely, which is all fine when you've got results that are in a small microtiter tray.

Narrator: So far, so good for the promising results shown in the lab. But how do you replicate this in an actual catheter without things getting sticky?

Sarah Fouch: Now, the annoying thing about Manuka honey is the fact that it has lots of different constituents that are thought to make up its antimicrobial properties. If you use those individually, they don't work as well. There is thoughts about incorporating it into the plastic but again, obviously, you would need to break those honey constituents down in order to be able to incorporate it into the plastic and then it's antimicrobial agents are lost a little bit. There's also thought about sort of lining the catheter bag, but then that's going to be pretty gloopy because Manuka honey is pretty thick.

John Worsey: Yes.

Sarah Fouch: So we're thinking about a couple of things. We're thinking about potentially looking to see if we could combine different constituents in order to see if we can still maintain that antimicrobial activity. We're also thinking about honey flushes to flush the catheter bag out once a day from the end of the catheter, that's obviously not in the patient because otherwise that's going to be quite difficult to get to. But literally just flushing a catheter bag out every day so that it's got a nice sort of honey coat that will try and reduce that biofilm from forming within the catheter bag.

Sarah Fouch: We're using the lab environment, we're using a 37 degree room and basically contaminating a catheter bag.

John Worsey: Right.

Sarah Fouch: And then using honey flushes either once a day or twice a day for a long period of time to see if we can actually see a reduction in A) the biofilm and B) the bacterial viable load within a control and within the different bags with the different types of honey flushes. We've noticed that 15+ and 20+ UMF factor Manuka honey actually are very good and they are showing quite a significant difference between the control and the bags that have been treated either once a day or twice daily.

Sarah Fouch: So, UMF factor is the unique Manuka factor. We're actually diluting it and we're still seeing antimicrobial properties with it diluted. So we're diluting, sort of, we're starting at 25% and then working down. So, you know, that's quite a nice because if we're thinking about a honey flush with a catheter bag, actually that's going to be quite tricky if you're trying to flush this gloopy agent into [laughing]. It's fully going to clog up the tap and everything else.

John Worsey: Yeah, yeah.

Sarah Fouch: So actually by making it quite liquid, then to have a honey flush would be quite nice. If we had perfect results, we could find a way to incorporate the honey into the plastic because that would actually, sort of, almost kill two birds with one stone. Because obviously, there's part of the catheter that's inserted inside of the patient, that also still has the potential to have biofilms in there and cause an infection. So if we can incorporate the honey into the plastic, that would be brilliant. At the moment, that bit's an area that we can't get to.

John Worsey: Yeah.

Sarah Fouch: But equally, a lot of catheter infections the bag becomes infected and then the bacteria ascend up and into the patient. So if we can actually reduce the chances of that bag becoming infected, then that will equally have impact for the patients.

Narrator: Sarah explained that there's a way to go before her honey flushes make it into hospitals. There's more to figure out and not just technically in the context of catheters.

Sarah Fouch: What we're trying to do is take it from the very primary research that we've had, literally one vessel stomach.

John Worsey: Yeah.

Sarah Fouch: Through to then a more enhanced gastrointestinal model. What we're hoping to do is get a student in the lab for a whole year, probably as in MRes, and really develop this model so that we're able then to perhaps think about maybe even a PhD for a further three years to look at the effects of different treatments.

Sarah Fouch: The implications could be the fact that actually what we need to do is look at our treatment regimes. So it may be the fact that we may need to hit with a higher dose of antibiotic for less time, or it may be the fact that we need to treat for longer. If our antibiotic regimes that we're using at the moment, are just tickling the bacteria in the gastrointestinal tract and allowing them to become more resistant, we need to do something about that. So it could inform prescribing.

John Worsey: Right.

Narrator: By bringing different ideas together, it sounds like there are opportunities to tackle some of the biggest problems facing medicine in the future. You can find out more about Sarah's work at port.ac.uk/research.

Narrator: Next time on Life Solved. How research taking place at Portsmouth is being used to change the way we talk about water safety. Drowning kills around 320,000 people worldwide per year. So is enough being done?

Mike Tipton: A really important thing is to try and get this preventative messaging into people before they enter into a high-risk group. There's more children dying in water than there are in fires or on bikes, and yet we will have bicycle proficiency in schools, we will have information on TV about fire protection – about having smoke detectors.

Narrator: Find out more next time. And if you have a curious mind and can't wait for the next episode, our new magazine, Solve, follows University of Portsmouth research when it's put into practice. It's full of news and stories on our world-leading advances and the changes these are making to lives and futures across the world. Get it at port.ac.uk/solve.

Narrator: Let us know what you think via social media using a hashtag Life Solved. Or maybe just share the big idea with a friend. Thanks for listening.

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