Surfing & antibiotic resistance: what's the connection?

Antimicrobial resistance is often in the news, and some articles report that surfers may be at a bigger risk of from this, compared to non-surfers, as seen in the example articles below. But what does this mean?! In fact, what exactly is antimicrobial resistance? Why does it matter? To answer these questions, we’ve got a microbiologist on board to write this week’s blog.  This means it might be a little more nerdy than usual, and quite a long one, but we hope you like it.

Well hello fellow surfers- most of the time people can’t run away fast enough when I say I’m a microbiologist, so this is a welcome change! So to try and answer these questions I’m going to start waaaaay at the beginning to try and answer these questions:

  • What are antibiotics actually?
  • How do bacteria become resistant to them?
  • Why aren’t all bacteria antibiotic/antimicrobial resistant?
  • Why is antibiotic resistance suddenly a problem now although antibiotics have been around for decades?

And finally we’ll talk about the research referred to in the news articles pictured below about surfers and antimicrobial resistance. It’s going to be a bit of a long read, so grab yourself a cuppa and get comfy.




What are antibiotics actually?

So microbes (bacteria, fungi and viruses) are everywhere – in the air, in the soil, in the sea, in the food we eat, in the water we drink and all over ourselves. In fact, we have more microbial DNA on and in us than we have of our own DNA. We are glorified, walking microbial incubators – but wait! Before you cover yourself in alcohol gel and get out the bleach…it’s a good thing. The microbes that live on and in us help to break down our food, to keep our immune system tip top and very importantly by competition, they help to keep out some of the bad bugs. They have even been shown to affect our mood! But with millions of them existing in the same spaces competing for food etc, microbial life is a very competitive one and they have some pretty cool tricks up their sleeve to make sure they ‘win’. This includes making and secreting substances that kill other microbes. Some very clever people figured out that we can actually use these substances to kill the bacteria that cause illnesses in humans. For example, a certain fungus makes ones of these substances for the purpose of killing the bacteria living near it and so it has more food for itself – and that substance is what we call penicillin, the first discovered antibiotic.  Substances like this only kill bacteria. Not viruses or fungi, which is why we don’t take antibiotics for a cold as it’s caused by a virus. Penicillin and other antibiotics were game changers for the medical world, open surgery became an almost guaranteed success (whereas before, many simple surgeries resulted in death from bacterial infections) and diseases such as pneumonia, scarlet fever and tuberculosis went from life threatening to virtually unheard of. So, while the majority of bacteria do us no harm, some are a bit nasty, causing us illness and infection and antibiotics are essential to getting rid of or preventing these infections.


How do bacteria become resistant to antibiotics?

Microbes have been living around each other for millennia, and so they have had plenty of time to evolve a few sneaky abilities to help them survive the toxic substances (aka antibiotics) made by their competitor microbes. For example, some bacteria have little ‘pump’ type systems that allow them to pump the antibiotic out of their cell as soon as it comes in. This ability to escape the effects of antibiotics is what leads to antimicrobial/antibiotic resistance. What is even more sneaky, bacteria can transfer the genes that give them this antimicrobial resistance ability to other bacteria, even bacteria that are not the same type (species) as themselves! As an analogy, this would be like zebras sharing their gene to be stripy with humans and enabling us to become stripy – mind blowingly cool. How some bacteria end up with the genes for antimicrobial resistance in the first place is simply down to chance – genes change little by little with time, often due to random mistakes made when genes are copied to create new ‘daughter’ bacteria. But there are millions and millions of bacteria, some of which take just 20 seconds to create a ‘daughter’ cell so by pure chance some of them end up with genes that give them the ability to resist antibiotics. This leads to the obvious question: So why do antibiotics work at all...



Why aren’t all bacteria just antibiotic/antimicrobial resistant?

Well, this ability to resist antibiotics is actually quite a demanding ability to have, the bacteria have to use a lot of their ‘fuel’ in order to do it.  Let’s compare the antimicrobial resistance ability to having a surfboard for HUGE waves…they are expensive, big, heavy surfboards which are a pain to carry around and 95% of the time the waves aren’t big enough to need it.  So only 1 in 50 people bother to buy them. Whereas short boards are cheaper, lighter, easy to carry around, and the right board for the conditions most of the time. So most people own a short board (longboarders are excluded from this analogy for simplicity! ). But, if a 15 foot swell arrives, those 1 out of 50 people lugging around their heavy big-wave board will suddenly be laughing. So, for bacteria it is the same: in normal situations where antibiotics are not around – bacteria don’t need to have this ability to survive the antibiotics as it is too ‘big and heavy’. They grow slower when they have this ability and so are actually at a disadvantage compared to bacteria without antimicrobial resistance. But if there are lots of antibiotics around (like a three month long 15 foot swell in our analogy) the ones best equipped to survive the conditions are the ones with antimicrobial resistance. And these bacteria then transfer this ability to their bacterial buddies, like making carbon copies of their big-wave board and handing them out…soon many more than 1 in 50 people have one of those big boards!  In other words, if there are antibiotics around then there is a huge gain (positive selection) for any bacteria that just happen to have antibiotic resistance genes. If there are no antibiotics around, there is no gain (or negative selection) for these bacteria as they need more energy to ‘carry around’ equipment they don’t need. So why would there be lots of antibiotics around?  This leads us to our next part:

Why is antibiotic resistance suddenly a problem now although antibiotics have been around for decades?

Well, as us humans are experts at messing things up – so we have done with antibiotics. We have used them by the kilo – prescribing them to people with the common cold just so they’ll stop complaining; feeding them to healthy animals so they put on weight faster and we can make more money, to name a few. Many of the antibiotics we take are excreted in our urine, and that of animals. And so our sewers, rivers and even soils are regularly dosed with left over antibiotics2 meaning we have been creating the perfect environment to select for bacteria which have the ability to resist antibiotics. Additionally, when antibiotics aren’t taken correctly this can lead to the same conditions. Then from a combination of environmental exposure, or taking antibiotics incorrectly, some of us end up carrying resistant bacteria which live harmlessly in our gut for example, as part of our good bacteria. But when we are then infected with a bacteria that causes illness, these good bacteria can potentially transfer their antibiotic resistance ability to the baddies, meaning antibiotics will no longer make us better.  Or if we visit a sick relative in hospital and don’t wash our hands, we can transfer a drug resistant bacteria that was causing us no harm to our sick relative, with devastating consequence

This means, when someone gets an infection from bacteria with antimicrobial resistance, the majority of antibiotics, like penicillin no longer work and we remain sick. We still have a few antibiotics in our arsenal that not many bacteria are resistant to, but time is running out, and the consequences are unimaginable. For instance, open surgery for something as routine as a caesarean will carry a far higher risk of mortality due to infection.



So what does this have to do with surfers? 

Well, we often hear about beaches being closed after large storms of heavy rain – and many of us have had the unfortunate experience of getting…let’s just say ‘sick’…after surfing in nasty water. This is because of sewage or animal waste flowing into the rivers and then the sea, carrying with it leftover antibiotics as well as all the microbes that come along with poo, and some of these bacteria will be those tricksters that are resistant to antibiotics1.  These bacteria in the water can then get swallowed when we go and play in the sea, and so end up in our guts where, even if they don’t make us sick, they can find a nice warm, food-filled home where they just hang out, eating and multiplying like happy bacteria do. Well, what’s the problem then? Firstly, we could transmit these bugs to someone already sick or with a weak immune system. Or, we could suddenly get a bacterial infection, or have to go to hospital for a routine operation like getting an appendix taken out, and are given a nice dose of antibiotics to take. Then, the antibiotic resistant bacteria will have the upper hand, they will survive, multiply and transfer their antibiotic resistance genes around to other bacteria, as we already talked about. And if there happens to be a really nasty bacteria in your gut too, if he gets transferred this ability to resist antibiotics then we’re in for it. The doctors will have to keep prescribing different antibiotics in the hope that the bacteria won’t be resistant to one of them and will save our bacon.


A number of research projects have looked into whether certain groups of people are at higher risk of harbouring these antibiotic resistant bacteria in their gut. From the different groups of people who recreate in the ocean, surfers are often at higher risk of getting infections as we swallow a lot more water than the average beach-goer 3. We are also more at risk of harbouring bacteria with antimicrobial resistance genes for this same reason – we are exposed to them more than most other water users and much more than non-water users  4. But it’s not all doom and gloom! Using good hand hygiene (which we’re all experts at by this stage!) can help reduce the chance of us transmitting any nasty bugs to our communities. Also, by exercising regularly (ie surfing!!) we hugely decrease our chances of infection because of the positive effects on our immune system5 and on our gut health6.  Surfing has also been shown to enhance well-being7 which in turn can help our immune system thereby keeping us healthy8. So by surfing we’re increasing our risks from one side, but we’re decreasing them from another, and having a lot of fun while doing it!


Furthermore, we are slowly changing our ways – both in antibiotic use and better sewage management. For example organisations like Surfers Against Sewage in the UK and Irish Surfers Against Pollution in Ireland, fight tirelessly in an effort to clean up our oceans.


Lastly, what can we do to make it better?

  1. ALWAYS take a full course of antibiotics. Even if we feel better, there will still be few of the bacteria that made us sick surviving. Not enough of them to make us sick, but still there. If we stop your pills before they are killed we are providing the perfect conditions for them to pick up resistance to the antibiotic we've have just been taking.
  2. Don't throw any un-used antibiotics down the drain. Take any old antibiotics in the house to a chemist or your GP to dispose of them. 
  3. Listen to our doctors when they tell us it’s a cold and antibiotics won’t help.
  4. Keep surfing and wash our hands!

Further information about antibiotic resistance can be found here:


Articles mentioned in this blog:

All scientific articles referenced in this article are open access.

1 Hatosy, S.M. and Martiny, A.C., 2015. The ocean as a global reservoir of antibiotic resistance genes. Applied and environmental microbiology, pp.AEM-00736. Available at:

3 Sanborn, M. and Takaro, T., 2013. Recreational water–related illness: Office management and prevention. Canadian Family Physician59(5), pp.491-495. Available at:

4 Leonard, A.F., Zhang, L., Balfour, A.J., Garside, R., Hawkey, P.M., Murray, A.K., Ukoumunne, O.C. and Gaze, W.H., 2018. Exposure to and colonisation by antibiotic-resistant E. coli in UK coastal water users: Environmental surveillance, exposure assessment, and epidemiological study (Beach Bum Survey). Environment international114, pp.326-333. Available at:

Pedersen, B. K and Hoffman-Goetz, L., 2000. Exercise and the Immune System: Regulation, Integration, and Adaptation. Physiological Reviews. 80:3, 1055-108 Available at:

Campbell, S.C. and Wisniewski, P.J., 2017. Exercise is a novel promoter of intestinal health and microbial diversity. Exercise and sport sciences reviews45(1), pp.41-47. Available at:


Caddick, N., Smith, B. and Phoenix, C., 2015. The effects of surfing and the natural environment on the well-being of combat veterans. Qualitative health research, 25(1), pp.76-86.


8  Lasselin, J., Alvarez-Salas, E. and Grigoleit, J.S., 2016. Well-being and immune response: a multi-system perspective. Current opinion in pharmacology, 29, pp.34-41. Available at:


7 Desmond, M., O'Brien, P. and McGovern, F., 2017. A summary of the state of knowledge on climate change impacts for Ireland. EPA. Available at:


Blog post written by Camilla Thorn, a post-doctoral microbiologist specialising in reducing greenhouse gas emissions from agriculture and interested in all things microbiology. 

All photographic images are from

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