{"id":548448,"date":"2026-07-14T02:07:12","date_gmt":"2026-07-14T02:07:12","guid":{"rendered":"https:\/\/www.newsbeep.com\/ie\/548448\/"},"modified":"2026-07-14T02:07:12","modified_gmt":"2026-07-14T02:07:12","slug":"microplastics-could-accelerate-antibiotic-resistance-studies-find-news-eco-business","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/ie\/548448\/","title":{"rendered":"Microplastics could accelerate antibiotic resistance, studies find | News | Eco-Business"},"content":{"rendered":"

Plastic pollution is among the gravest environmental crises facing humanity. Plastic production since 1950 has exceeded\u00a08,300 million metric tons<\/a>, with most plastic waste ending up in the environment, affecting\u00a0wildlife<\/a>,\u00a0ecosystem<\/a>\u00a0functionality, and\u00a0human health<\/a>.<\/p>\n

Simultaneously, the ability of disease-causing bacteria to withstand one or more antibiotics (known as antimicrobial resistance, or AMR) has surged to become a public health emergency now accounting for around\u00a05 million deaths worldwide annually<\/a>.<\/p>\n

\u201cAMR is an existential human threat,\u201d says Tim Walsh, a professor at the\u00a0University of Oxford<\/a>\u00a0and director of biology at the UK\u2019s\u00a0Ineos Oxford Institute of Antimicrobial Research<\/a>, who spoke to Mongabay via video call. \u201cIt will kill more people [each year] than TB, HIV and malaria, and if unchallenged could eclipse cancer as the biggest killer.\u201d<\/p>\n

Until very recently, these two global crises, plastic pollution and antimicrobial resistance, were considered separately by scientists and policymakers. But a new line of research suggests they\u2019re inextricably linked:<\/p>\n

Plastic waste is quickly colonised by microorganisms, creating a new type of ecosystem dubbed the \u201cplastisphere<\/a>.\u201d And bacteria living in the plastisphere are developing greater resistance to antibiotics at an unprecedented rate.<\/p>\n

\u201c<\/p>\n

We know that microplastics are ingested at the base of the food chain by filter feeders, like mussels, if there\u2019s any harmful pathogens or microplastics in there, they could be making their way into the human food chain.<\/p>\n

Emily Stevenson, researcher,\u00a0University of Exeter<\/p>\n

How microplastics enhance antimicrobial resistance<\/p>\n

In 2025, researchers at\u00a0Boston University<\/a>\u00a0found that\u00a0Escherichia coli\u00a0bacteria exposed to microplastics developed\u00a0enhanced resistance<\/a>\u00a0to four common antibiotics when compared to bacteria not exposed to microplastics.<\/p>\n

After just 10 days of microplastic exposure, the bacteria\u2019s tolerance to antibiotics \u201cjust shot up,\u201d reaching 100 times the level it had started at, says Neila Gross, the doctoral researcher who led the study, in a video call with Mongabay. \u201cThis was very, very concerning.\u201d<\/p>\n

Researchers are still unravelling exactly how and why microplastics enhance antimicrobial resistance. A key piece of the puzzle is the way bacteria behave when colonising a surface. Although we usually think of bacteria as solitary, when they grow on a surface they stick together and form a complex community known as a biofilm.<\/p>\n

Biofilm bacteria secrete a protective gel-like material made of proteins, carbohydrates and DNA, which helps them stay attached to the surface they\u2019re on and provides protection against harmful substances, including antibiotics. \u201cIt\u2019s a physical barrier, sort of like armour, [and the bacteria] hang out in the middle of it,\u201d Gross says.<\/p>\n

Biofilm bacteria are\u00a0more likely to develop resistance to antibiotics<\/a>\u00a0than solitary bacteria, in part because the protective gel blocks most, but not all, of the antibiotics that are trying to break through. This means the bacteria are exposed to antibiotics at levels high enough to prompt a defensive response, but not high enough to kill them outright. Much like an incomplete course of antibiotics, this low-level exposure primes the bacteria to evolve resistance.<\/p>\n

Here\u2019s where microplastics enter the equation: They don\u2019t just provide a surface on which biofilms can form; they actively promote their formation. Gross\u2019s research has shown that bacteria form\u00a0denser, thicker biofilms on microplastic beads<\/a>\u00a0than on glass. The microplastics also appear to select for bacteria that are\u00a0better at forming biofilms<\/a>.<\/p>\n

By promoting the formation of stronger, more stable biofilms, microplastics create the perfect environment for drug resistance to develop.<\/p>\n

Separate studies conducted in\u00a0China<\/a>\u00a0and the\u00a0UK<\/a>\u00a0have found that, in river environments, microplastic waste can harbor more antibiotic-resistant bacteria and a higher abundance of some resistance genes, compared to naturally occurring surfaces like wood or rock.<\/p>\n

Microplastics encourage gene sharing<\/p>\n

Another reason drug resistance can spread so rapidly through biofilms is that the bacteria residing in such films readily exchange genetic material via a process known as horizontal gene transfer. Instead of every bacterium having to individually evolve resistance to every antibiotic from scratch through chance mutations, a resistance gene evolved by one bacterium can be shared with the whole community.<\/p>\n

\u201cBacteria are like these genetic sponges, and their DNA is very plastic,\u201d Walsh says. \u201cThey\u2019re able to grow together, communicate together, and exchange [genetic] information far more readily than human beings. They are a formidable foe in that regard.\u201d<\/p>\n

Walsh and colleagues discovered that\u00a0exposure to microplastics increases the rate of horizontal gene transfer<\/a>\u00a0by up to 200 times. This happens because bacteria respond to microplastics by expressing so-called \u201cS.O.S. genes,\u201d \u2014 a group of genes that help to repair damaged DNA and have\u00a0previously been shown to encourage gene swapping<\/a>. \u201cThe bacteria see the microplastics as a toxin and go into overload, stimulating the exchange of genetic material,\u201d Walsh says.<\/p>\n

Some plastic types are higher risk<\/p>\n

Scientists are now working to understand what specific plastic characteristics make them effective at promoting drug resistance. What we know so far is that certain types of plastics seem to be more problematic than others.<\/p>\n

For example, scientists have found that polyethylene, ubiquitous in plastic packaging, harbours\u00a0higher levels of AMR<\/a>\u00a0than polyvinyl chloride, used in hard plastics such as pipes. A separate study found\u00a0denser bacterial biofilms and more horizontal gene transfer<\/a>\u00a0on polyethylene compared with other plastics.<\/p>\n

Research also suggests that expanded polystyrene, the type used to make packing peanuts, may be at\u00a0higher risk of<\/a>\u00a0fostering drug-resistant bacteria<\/a>\u00a0than other plastic types. \u201cThe very nature of plastics makes them a risky substrate, but polystyrene is a very complex matrix,\u201d study lead author Emily Stevenson, a PhD researcher at the UK\u2019s\u00a0University of Exeter<\/a>, tells Mongabay in a video call. \u201cThat porous structure gives more surface area for colonisation of bacteria.\u201d<\/p>\n

A further complication: Plastic particles change over time as they\u2019re exposed to sunlight and water. This ageing process can make their exteriors rougher, creating a bigger surface area on which bacterial biofilms can stick. Ageing also causes toxic chemicals to leach out of plastics, which can trigger the bacteria\u2019s S.O.S response,\u00a0helping resistance genes spread<\/a>.<\/p>\n

Microplastics could carry resistant bacteria to new locations<\/p>\n

Once AMR has developed in an environment, humans can contract drug-resistant infections through contact with contaminated water, soil or food. Microplastics may play a role here too: Lightweight plastics, such as expanded polystyrene, can be carried in storm runoff, in streams or by ocean currents, potentially relocating antibiotic-resistant bacteria into new environments.<\/p>\n

Another potential route to infection, say experts: Microplastics harbouring drug-resistant biofilms could carry those harmful bacteria up the food chain to humans.<\/p>\n

\u201cWe know that microplastics are ingested at the base of the food chain by filter feeders, like mussels,\u201d Stevenson says. Her\u00a0PhD research<\/a>\u00a0suggests that microplastics could increase the amount of AMR genes in the mussels\u2019 guts. Since humans eat shellfish like mussels whole, \u201cif there\u2019s any harmful pathogens or microplastics in there, they could be making their way into the human food chain,\u201d she says. More research is needed to confirm and expand on these preliminary findings.<\/p>\n

Wastewater: A hotspot for drug-resistance<\/p>\n

Bacteria are ubiquitous in the global environment, as are microplastics. But there are locations where they come together in high concentrations, alongside antibiotics and other toxic substances, creating AMR hotspots.<\/p>\n

Advanced wastewater treatment plants (WWTPs) filter and treat raw sewage to remove bacteria, pharmaceutical residues and pollutants, including microplastics. Though this process can be very effective, it\u2019s not perfect.<\/p>\n

\u201cPlastics break down into smaller and smaller pieces, which are really difficult to filter or remove from the wastewater,\u201d Tam Tran, a senior researcher at the Norwegian research institute (NORCE<\/a>), says in a video call with Mongabay.<\/p>\n

Tran and colleagues analysed wastewater samples from Norway, Iceland and Finland, and found that\u00a0treatment reduced the levels of antibiotic residues, microplastics and drug-resistance genes<\/a>\u00a0in the water, but not completely. When treated wastewater carrying traces of antibiotics and microplastics is released into marine environments, \u201cIt potentially creates a new hotspot for AMR,\u201d Tran says.<\/p>\n

Wastewater, even after going through an advanced treatment facility, presents a risk for AMR development. But when sanitation facilities are limited, inadequate or missing entirely, for example, in disadvantaged communities, war zones or refugee camps, there is an even greater risk that drug-resistant bacteria will emerge.<\/p>\n

\u201cWhenever you have degradation of infrastructure \u2026 there is that direct link to the carriage of resistant bacteria,\u201d Walsh says.<\/p>\n

In high-income countries, drug-resistant infections are a big problem, but one that can often be overcome with medical care. In low- and middle-income countries, where sanitation facilities and water treatment plants are less available, multidrug-resistant infections are prevalent, and often fatal.<\/p>\n

In many African and Southeast Asian nations, \u201cwe\u2019ve already run out of antibiotics [to choose from], and of course, it affects the poorest population,\u201d Walsh says. \u201cIt\u2019s directly linked to poverty.\u201d<\/p>\n

Low- and middle-income countries also often have fewer recycling facilities, which means plastic waste is also more likely to end up in open-air dumps and streams, on beaches, and in the street, greately expanding the plastisphere colonised by bacteria.<\/p>\n

Multiple crises combine to promote drug resistance<\/p>\n

Plastics and antibiotics are both manufactured substances introduced by humans into the environment. They can both affect the functioning of Earth\u2019s life-support systems, for better or worse. For this reason, they are grouped together in the \u201cnovel entities<\/a>\u201d planetary boundary, one of nine boundaries that, if breached,\u00a0threaten to push Earth out of the habitable zone<\/a>. Scientists say that humanity has now\u00a0exceeded safe thresholds<\/a>\u00a0for six of the nine boundaries, including the novel entities boundary.<\/p>\n

Climate change is another planetary boundary whose safe zone has been exceeded by humanity. Its transgression may also be exacerbating AMR. That\u2019s because higher temperatures\u00a0speed up bacterial growth and promote horizontal gene transfer<\/a>, helping drug resistance spread.<\/p>\n

There may also be indirect climate effects: Extreme heat, humidity, flooding and drought brought by global warming can negatively impact water quality and food security, increasing the prevalence of infectious diseases and necessitating more use of antibiotics, which promotes AMR.<\/p>\n

\u201cHow we treat our environment, both in terms of environmental degradation, but also in terms of climate change, is directly linked to AMR,\u201d Walsh says.<\/p>\n

Climate change may also amplify the effect of plastic pollution on AMR. Higher temperatures cause plastics to\u00a0fragment into microplastics and leach harmful chemicals more rapidly<\/a>, providing more surfaces for biofilm formation and promoting the S.O.S. response that encourages bacterial gene swapping.<\/p>\n

Plastics influence AMR throughout their life cycles<\/p>\n

Although research into the link between microplastics and drug resistance has focused on plastic pollution in the environment, there is good reason to believe that\u00a0plastics are promoting AMR throughout their life cycles<\/a>.<\/p>\n

Most plastics are produced from fossil fuels, which need to be extracted and pumped via pipes to refineries. Biocides, chemical substances used to kill microorganisms such as bacteria, are used in those pipes to prevent the buildup of bacterial biofilm, which could clog the pipes. But because biocides rarely succeed in killing 100 per cent of bacteria, their systemic industrial use could, in fact,\u00a0encourage AMR development<\/a>. Chemical additives used in the plastic manufacturing process may also\u00a0promote drug resistance<\/a>. Again, more research is needed to fully understand these risks.<\/p>\n

Collecting and transporting plastic waste, whether moving it to landfills or recycling plants, could transport drug-resistant bacteria to new environments. Even recycling may promote AMR, because plastic waste is often treated with disinfectants before being processed, with any surviving bacteria potentially becoming resistant.<\/p>\n

\u201cPlastics and AMR are fundamentally linked,\u201d Stevenson says. \u201cAt every stage of the life cycle of plastics, from production to disposal, there [is] something that could influence antimicrobial resistance.\u201d<\/p>\n

However, plastic can also be a useful tool in the battle against AMR. \u201cOne of the really beneficial uses of plastics is that they keep things sterile,\u201d Stevenson says, which reduces the transmission of drug-resistant bacteria in hospitals and clinics. \u201cIt\u2019s sort of a double-edged sword.\u201d<\/p>\n

The uncertain path forward<\/p>\n

Scientists have now uncovered a deeply concerning link between microplastics and AMR, potentially exacerbated by other environmental crises such as climate change. But many question remain:<\/p>\n

How do biofilms on microplastics change and evolve over time? How do chemical additives \u2014\u00a0tens of thousands of which are routinely added to different types of plastic<\/a>\u00a0\u2014 influence AMR? What happens when other substances in the environment, ranging from heavy metals to plant secretions, interact with biofilm-laden microplastics? And how do microplastics in our digestive system influence drug resistance in the microbiome?<\/p>\n

While scientists work to answer these and many other questions regarding microplastics and AMR, public health experts\u00a0recognise<\/a>\u00a0that action is desperately needed to stop the spread of drug-resistant bacteria and to control the flood of plastic waste into the environment.<\/p>\n

A good place to start would be \u201creducing the amount of plastics and antibiotics going into the wastewater treatment plant \u2026 so using less plastics and having better antimicrobial stewardship,\u201d Stevenson says. \u201cWe really need to make sure we\u2019re not just regulating one of those contaminants. We need to look at them holistically.\u201d<\/p>\n

Slowing AMR spread is just another in a long list of reasons humanity needs to break free from the cycle of plastic manufacture and waste. But, with so much plastic already in the environment, it may be too little, too late.<\/p>\n

Limiting opportunities for the mixing of this dangerous bacterial, antibiotic and microplastic cocktail by utilising better wastewater management and ongoing AMR surveillance may be the best hope for global public health and safety.<\/p>\n

This story was published with permission from Mongabay.com<\/a>. <\/p>\n","protected":false},"excerpt":{"rendered":"Plastic pollution is among the gravest environmental crises facing humanity. Plastic production since 1950 has exceeded\u00a08,300 million metric…\n","protected":false},"author":2,"featured_media":548449,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[10],"tags":[103,61,60],"class_list":["post-548448","post","type-post","status-publish","format-standard","has-post-thumbnail","category-health","tag-health","tag-ie","tag-ireland"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts\/548448","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/comments?post=548448"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts\/548448\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/media\/548449"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/media?parent=548448"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/categories?post=548448"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/tags?post=548448"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}