The gathering cloud of antimicrobial resistance in wound care and the nanocrystalline silver lining.

Join us twice a month for our insightful podcasts with leading expert guests, who will look at the latest 'hot topics' in wound care to update and inspire you.

Right patient, Right Product, Right time. This podcast discusses the challenges of wound infection, antibiotic resistance and why is this becoming such a problem. There is also an overview of the evidence for using nanocrystalline silver, and decision making tools to support antimicrobial stewardship in clinical practice.


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Welcome to Smith and Nephews Closer to Zero podcast, a bi-monthly podcast with leading experts in wound care hosted by Smith and Nephew. Helping health care professionals in reducing the human and economic cost of wounds.

Hello, I'm Ruth Timmins from Smith and Nephew. I'd like to welcome our listeners today to this podcast entitled 'The gathering cloud of antimicrobial resistance in wound care and the nanocrystalline silver lining'. We have a special guest with us today to discuss this hot topic, scientist Emma Woodmansey from Smith and Nephew based in the UK. So welcome Emma. Thanks for joining us today. Why don't you start off by telling us a little bit about yourself and what you do?

Hi Ruth, thanks very much. So as you've heard my name's Emma Woodmansey. I'm a clinical scientist as part of the global clinical strategy team for advance wound management at Smith and Nephew. I have a PhD in microbiology, and I've been at Smith and Nephew for over 17 years - a long time. I'm a microbiologist by background and I focus on developing and communicating the clinical and scientific evidence around wound care, particularly around antimicrobial resistance, antimicrobial treatments and also biofilms in wound care and the challenges all of these pose to delayed wound healing and issues and challenges with wound healing. I love educating people about bacteria. I know that sounds mad but it's a really interesting area and we can use our knowledge to make sure that we manage infections more appropriately, ensuring the best outcomes for our patients and infected wounds.

Yeah, well it's a fascinating title for this podcast. So firstly, can you help us understand perhaps some of the challenges of wound infection?

Definitely, Ruth. As you mentioned, infection is a massive challenge across wound care and the presence of bacteria not only acts as a barrier to wound healing, it also causes a vicious cycle of inflammation and tissue damage in the wound. (1)Furthermore, local infection, if not managed, can quickly progress to a spreading or a systemic infection. And a recent global survey of health care professionals reported that over 50% of clinicians highlighted a rapid deterioration of infected wounds are the key challenge*. Almost a third of patients with a venous leg ulcer (VLU) are estimated to have a wound at risk of infection or clinically infected upon presentation and over 23% of VLUs progressed to systemic infection. So more serious infection requires an extensive treatment and that has a massive impact on the patient. (2)

Similarly, local wound infection and diabetic foot ulcers, as we all know, can progress really rapidly which sadly in 17% of cases can lead to amputation in those patients. So It's no surprise that the average management costs for diabetic foot ulcers that are infected are over three times higher than a non-infected wound.(3) In addition, in burn wounds, infection is a major cause of morbidity and mortality, with over 75% of deaths linked to infection. (4) And the longer the time since the burn injury, the more chance that patient has of developing a multi drug resistant infection. (5) And obviously when you develop an infection with an antibiotic-resistant bacteria, it causes additional problems on top of the infection due to the fact that it requires a more intensive treatment. The antibiotics needed to kill those resistant bacteria using more toxic, and therefore the patient needs a lot more monitoring. And they need a lot longer in hospital which again adds to issues with higher costs and treatment costs for those patients.

*Megginson, S. Analysis of Survey Data conducted by Wounds International to Health Care Professionals on Infection and Biofilm. Smith+Nephew Statistical Results Sheet #ST1092. (2020).

So you mentioned antibiotic resistance there. So why is this becoming such a problem?

So antimicrobial resistance or AMR is a rapidly growing issue across all of health care actually, with a recent document from the UK government highlighting that over 10 million deaths were expected to be linked to antimicrobial resistance by 2050.(6) So only in the next 30 years which is quite scary actually. Wound infections are no exception to that. Antimicrobial resistance is increasing due to a number of factors and one of the main ones is the fact that antibiotics are being overused.(7) So the more antibiotics are being used, the more chances there are for bacteria to become resistant to those antibiotics. And that especially happens when a lower level than needed is used. 

So if we use a dose of antibiotic or any antimicrobial where a lower level than is needed to kill the bacteria is used, then the more likely you are to develop resistance to that antimicrobial. So when we're thinking about low levels of antimicrobials, this may be, for example, an antibiotic may not reach the site of injury or to site of infection due to poor perfusion, for example, in a chronic patient or in a burn, for example, we know that those patients have altered biomolecular dynamics of any drug following that massive burn injury.(8,9). So all of these things might lead to the fact that the antibiotic that you give might then be at a lower level at the sites of infection, again, can lead to resistance. But we also need to think about other antimicrobials that we're using like dressings, for example, antimicrobial dressing. If we use an antimicrobial dressing with a level of antimicrobial which is too low to kill the bacteria, then we have an increased risk of developing resistance to those antimicrobials too.(10) In addition, we know that many skin and soft tissue infections, the incorrect antibiotic was used. So, for example, you may use an antibiotic that hits a gram positive and you needed to hit a gram negative, for example, bacteria. And also, we know from various audits that antimicrobials can be used inappropriately i.e. when the wound isn't infected.(12) And again, that just exposes bacteria to more antimicrobial happening.

Yeah, wow. This is a growing issue, isn't it? So, how can we help to support this from a wound care perspective, in reality?

Good question, Ruth. There's two key things we can help with to address the challenge of antibiotic resistant bacteria in wound care.(13) The first one is to control the spread of antibiotic-resistant organisms. And obviously, I'm sure everybody listening knows that, you know, if a patient develops a resistant organism or resistant infection, that that patient will be isolated and there'll be barrier nursing and cleaning procedures in place. But we also need to think about the wound and preventing the spread of those organisms from the wound. And you can do that with an antimicrobial barrier dressing if the dressing kills bacteria quickly enough. 

So the barrier dressing will protect the wound - protect the people caring for that. The doctors, the other patients. It will prevent the spread of bacteria from that wound. And we have clinical evidence of that with nanocrystalline silver dressing which showed a reduction of transfer of MRSA from an infected wound, in 95% of cases using Acticoat dressing. The second thing we also need to think about is how we use our antimicrobials and to use them more appropriately. And this is called antimicrobial stewardship. It's sometimes defined as the right product, at the right time, at the right dose, for the right duration. And this is something we need to think about not only for antibiotics but also for our antimicrobial dressings. 

Recent silver guidelines highlight that the early intervention with an effective silver dressing can manage bioburden** and resolve the clinical signs of infection quickly, reserving antibiotics for when you need them for a spreading systemic infection. And as I mentioned earlier, that then reduces the exposure to antibiotics therefore reducing the antibiotic resistance likelihood. And this has been shown in action actually, in four different clinical studies in burn patients who were treated with Acticoat as part of an infection management protocol. The overall conclusions for these studies highlighted a significant reduction in antibiotic use and that was in combination with a reduce length of stay and reduce treatment costs for all of those patients. So in addition to that, one of the more recent studies highlighted a reduction in sepsis cases following the introduction of this protocol that occurred. And also, the reduction in antibiotic resistance to emerging bacteria which again highlights the massive impact that you can have if you intervene early with an effective antimicrobial dressing.

So you mentioned effective antimicrobial dressings. What exactly does that mean and how can you tell what is effective and what isn't, when choosing an appropriate intervention?

There are a few rules, Ruth, that we should all follow in when deciding if an antimicrobial dressing is effective.(13)  Ideally, the antimicrobials used in the dressing need to attack multiple targets on the bacterial cell. This helps to reduce the chance of developing resistance. In addition, it needs to have antimicrobial activity against a broad spectrum of wound pathogens, not only bacteria but also yeast and fungi which are really important when patients are immunocompromised or they've been on antibiotics for a long time. They're more likely to have these yeast and fungal infections as well. 

It should also kill microorganisms and that means if you're looking at microbiology tests, above 4 log reduction in the numbers of bacteria that you see in those tests. So it shouldn't only just slow the growth of those bacteria, it absolutely needs to kill them and the faster it does that, the better. As we all know, a dead bacteria can't become a resistant bacteria, so that's really key. The effect that we're talking about, also needs to be sustained for the wear time of a dressing. There's no point in having a large amount of an antimicrobial initially for the first few hours but then being exhausted over time and bacteria are allowed to regrow and cause problems again. And finally, the intervention needs to be supported by both laboratory and clinical evidence. There's no point just having lots of lab tests if we - the product doesn't work in the clinics. It's really important to show how the product will give you better clinical outcomes.

So are all silver dressings the same then, Emma?

Well, the short answer is, no, I'm afraid. Silver is a fantastic antimicrobial but it needs to be available at the right level to have an effect as we've heard in this discussion. Just as you'd give an antibiotic like penicillin, there's a known level that you need to give a patient to be able to kill the bacteria. The same applies to silver or any other antimicrobial. Different silver dressings not only have different levels of silver, some which are way below the amount that you need to be effective, by the way. They may also have many different ways of presenting that silver and this is really important, as the wound is a really complex environment with lots of proteins and fluid, as well as bacteria. And the silver will bind to these proteins in slough and exudate. (14) You need to have enough silver to overcome this protein barrier and still have plenty of silver available to rapidly kill those bacteria. 

The unique structure that we have with nanocrystalline silver in the Acticoat antimicrobial barrier dressings, provides a really large surface area of silver that's available to provide silver ions that can rapidly kill pathogens. (13) If we think about an analogy with coffee beans, for example, or coffee granules. Which one will release the most coffee? For coffee beans to work they need to be ground up to increase the surface area and create the perfect cup of coffee. The same applies to silver. Even if there is enough silver in the dressing, it may not be rapidly available due to its structure. And it's that availability that gives us that rapid antimicrobial action. So you can see all silver the dressings are not the same.

So what does this mean in the practical reality of the clinic setting?

Well, we've already mentioned how early intervention with Acticoat antimicrobial dressings as part of a burn infection protocol can rapidly reduce bioburden which in turn reduces both antibiotic use and progression to systemic infections for sepsis. In addition, in burn wounds, there was a recent meta-analysis published that compared the clinical outcomes of three different silver dressings. So they were Acticoat antimicrobial dressings, Mepilex Ag and Aquacel Ag silver dressings. From this analysis of those clinical outcomes, not only did Acticoat show a reduction in infections and a reduced length of stay and faster healing compared to these silver dressings. Further analysis of that data then demonstrated a significant reduction in the treatment costs with Acticoat as well because of the whole package and the clinical outcomes, the superior clinical outcomes that we have.(15,16) Similar impacts are being reported in chronic wounds also, with a comparison of Acticoat, Aquacel Ag and Biatain Ag dressings which showed the clinical signs and symptoms of infection were resolved significantly faster in the Acticoat group. In fact, 60% of patients treated with Acticoat had no clinical signs of infection following only two weeks of treatment. Comparably, this value is only 4 and 8% for Biatain Ag and Aquacel Ag respectively. So much less. This faster impact resulted, in that study, with faster healing times and less dressings needed for the Acticoat group compared to the other silver dressings. And then again further analysis of that data highlighted that, that would result in a 50% cost saving using Acticoat to manage the and reduce the infection in those chronic wounds. (17,18) So the clinical impact of using an effective silver dressing is obvious both on the superior clinical outcomes and also, as you're dealing with those issues more promptly, it will reduce the treatment costs for those patients as well.

That's really important these days, isn't it, to have, you know, cost-effective wound care as well as having those excellent outcomes for the patients. So what tools can clinicians use to support the appropriate use of antimicrobial dressings?

It's a really interesting question, Ruth and as we mentioned earlier, in some cases there may be a problem of overuse of antimicrobials when they're not really needed, and also, using antimicrobial for too long without evaluating whether that treatment's actually working. And we know that clinical decision tools or pathways can help guide healthcare professionals, particularly those maybe not specialising in wound care all the time, can help give consistent ways to support maybe the diagnosis and the treatment of infection, and really bring together a lot of the literature and evidence and guidelines that we have around managing infection and simplifying those in a pathway. 

This has been recognised by a global panel of wound experts who have been supported by Smith and Nephew and Wounds International. And they've developed a simple one-page infection pathway. Basically, this group have recognised the challenges of diagnosing wound infection and also highlighted how using the evidence surrounding effective antimicrobials, such as Acticoat for managing local infection and Iodosorb for managing biofilm, they can help guide clinicians as to how we should be using antimicrobials appropriately for different infections. Finally, it clarifies when to stop using antimicrobial dressings and therefore, is supporting antimicrobial stewardship and more appropriate use of those antimicrobials. This pathway will be published. So hopefully, this will be a great resource to guide and support consistent infection management across wound management.

OK, Emma. So what should we all remember in relation to antimicrobial stewardship or, you know, the appropriate use of antimicrobials?

So in essence Ruth, to ensure that we're using our antimicrobials properly, we should try and remember the following. (13) We should basically think about the right patient. So we should only use antimicrobial dressings when we see the clinical signs of infection or prophylactically in high risk patients such as burn wounds, immunocompromised patients or high risk DFU patients, for example. We need to think about the right product. The treatment needs to be effective and it needs to manage bioburden. And as we've seen quickly, an infection quickly, to prevent the progression of that infection. And we also need to think about the right time. We only need to use antimicrobial dressings for as long as, as long as they are needed and then we should stop. We should follow the principles of the two-week challenge in terms of when you see an improvement and the infections have resolved, then you should stop using that antimicrobial or if you don't see any improvement, you should re-evaluate and change your antimicrobial treatment. It's really key to think about all of those three things. This should help to provide the best outcomes for the patients while minimising antibiotic resistance and also ensure that our antimicrobial remain effective for the future.

OK. Well, thank you Emma for taking us through this topic of antimicrobial stewardship in relation to wound management and how we can be more aware of this issue in practice. And, you know, thank you to our listeners. Please join us for our next podcast and if you need any more information, particularly perhaps about the infection management pathway, please contact us at Thank you, Emma.

Thanks, Ruth.

Act on infection with Acticoat dressings and the power of nanocrystalline silver. Find out how they can help infection protocols and antimicrobial stewardship. The right product, at the right time, for the right patient. For more information, contact the local Smith and Nephew representative or email us at 

The information presented in this podcast is for educational purposes only. It is not intended to serve as medical advice. Products listed and outline of care are examples only. Product selection and management should always be based on comprehensive clinical assessment. The detailed product information, including indications for use, contraindications, precautions and warnings, please consult the products applicable instructions for use prior to use. 


Helping you get closer to zero complications from wound infection.


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13. Woodmansey, E. J. & Roberts, C. D. Appropriate use of dressings containing nanocrystalline silver to support antimicrobial stewardship in wounds. Int. Wound J. 15, 1025–1032 (2018).

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16. Nherera, L., Trueman, P., Roberts, C. & Berg, L. Cost-effectiveness Analysis of Silver Delivery Approaches in the Management of Partial-thickness Burns. Wounds  a Compend. Clin. Res. Pract. 1–8 (2018).

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 *Megginson, S. Analysis of Survey Data conducted by Wounds International to Health Care Professionals on Infection and Biofilm. Smith+Nephew Statistical Results Sheet #ST1092. (2020).

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Emma Woodmansey


Clinical Science Director Infection,

Clinical Affairs,  Smith+Nephew

Emma Woodmansey  is a clinical scientist, part of the Global clinical strategy team for AWM at Smith+Nephew.

Emma has a PhD in Microbiology and has been at S+N for over 17 years.

A microbiologist by background, Emma is focused  on developing and communicating clinical and scientific evidence around infection; particularly around antimicrobial resistance, antimicrobial treatments and biofilms in wound care.

Emma loves educating people about bacteria and infection and how we can use our knowledge to make sure we manage them appropriately ultimately ensuring the best outcomes for our patients with infected wounds.

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