New review reveals how microbial communities accelerate the global spread of antibiotic resistance

Biochar Editorial Office, Shenyang Agricultural University

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Antimicrobial resistance in complex microbiomes: ecological evolution and public health risks

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Credit: Zhigang Yu, Michael Gillings, Nicholas J. Ashbolt & Jianhua Guo

A new scientific review has uncovered how complex microbial communities, including those in the human gut and the natural environment, act as powerful engines that drive the evolution and spread of antimicrobial resistance. The findings highlight urgent risks to global health and call for coordinated action across human, animal, and environmental sectors.

The research team synthesized evidence from microbiology, ecology, and environmental science to explain why antimicrobial resistance evolves differently in diverse microbial ecosystems compared with individual bacterial species. These ecosystems include the gut microbiome, wastewater networks, soils, and natural water bodies, all of which contain thousands of interacting species.

“Microbial communities are far more than random collections of bacteria,” said corresponding author Jianhua Guo. “They are dynamic ecosystems with constant competition, cooperation, and genetic exchange. These interactions create ideal conditions for antimicrobial resistance to emerge and spread.”

Antimicrobial resistance causes millions of deaths every year and continues to rise as bacteria acquire new resistance genes. The review describes how five major pathways of horizontal gene transfer enable bacteria to exchange resistance genes within communities. These pathways include plasmid mediated conjugation, transformation of free DNA, bacteriophage mediated transduction, extracellular vesicles that carry genetic material, and protozoan predation that concentrates bacteria inside protective vacuoles.

The authors explain that microbial communities amplify the efficiency of these processes. High population density creates more opportunities for cell to cell contact. Biofilms protect bacteria from antibiotics, allowing resistant strains to thrive. Cooperative behaviours such as antibiotic detoxification by neighbouring species can shield sensitive bacteria, enabling them to survive drug treatment and later acquire resistance genes.

The review also highlights the surprising role of protozoa in natural environments. These microbial predators can engulf bacteria and create enclosed spaces that promote genetic exchange. Some protozoa even expel packages of undigested bacteria that remain protected from antibiotics, which helps resistance spread further.

“Microbial predators and their prey have a long evolutionary history,” Guo said. “Our review shows that these interactions unintentionally create safe zones where bacteria can share resistance genes and become harder to kill. This makes antimicrobial resistance a true ecological problem that extends beyond hospitals.”

The authors frame these findings within the One Health perspective. Resistant bacteria and genes move freely among humans, animals, and environmental reservoirs. Wastewater discharge releases resistance genes into rivers and soils. Agricultural antibiotic use enriches livestock microbiomes and increases spillover into the food chain. Global travel accelerates the international spread of resistant strains.

Clinical settings remain major hotspots for antimicrobial resistance evolution. Patients on intensive antibiotics often carry mixed microbial populations that exchange genetic material. Biofilms on medical devices and drainage systems act as long term reservoirs. According to the review, these factors contribute to the rise of resistant pathogens that cause pneumonia, bloodstream infections, urinary tract infections, and other life threatening illnesses.

The authors conclude that understanding antimicrobial resistance within microbial communities is essential for predicting future risks and designing effective interventions. They recommend integrated surveillance, reduction of unnecessary antibiotic use, and improved management of waste and water systems.

“Microbial communities shape the future of antimicrobial resistance,” Guo said. “If we want to protect public health, we must consider the entire ecosystem rather than individual pathogens.”

 

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Journal reference: Yu Z, Gillings M, Ashbolt NJ, Guo J. 2025. Antimicrobial resistance in complex microbiomes: ecological evolution and public health risks. Biocontaminant 1: e011  

https://www.maxapress.com/article/doi/10.48130/biocontam-0025-0008 

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About Biocontaminant:
Biocontaminant is a multidisciplinary platform dedicated to advancing fundamental and applied research on biological contaminants across diverse environments and systems. The journal serves as an innovative, efficient, and professional forum for global researchers to disseminate findings in this rapidly evolving field.

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DOI

10.48130/biocontam-0025-0008 

Method of Research

Literature review

Subject of Research

Not applicable

Article Title

Antimicrobial resistance in complex microbiomes: ecological evolution and public health risks

 

Nearly 1 in 5 UK emergency department patients cared for in corridors/waiting rooms

Almost all emergency departments routinely deploying this approach

BMJ Group

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At any one time, nearly 1 in 5 emergency department patients in the UK is being cared for in corridors, waiting rooms, and other non-standard ‘overflow’ spaces—an approach known as escalation area care—suggest the results of a large observational study, published online in Emergency Medicine Journal.

 

Almost all emergency departments in the UK are routinely deploying this approach, which contravenes national guidance, the findings indicate.

 

Amid the high prevalence of emergency department overcrowding in the UK, escalation area care is reported to be widespread, but there is no high quality evidence describing its prevalence, say the researchers.

 

This is especially important as escalation area care is known to compromise patient safety, generate substandard and undignified experiences for the patient, and is thought to be a factor in the heightened risk of death among patients enduring long waits in emergency departments, they add.

 

To gauge its true prevalence, the researchers studied clinical activity in 165 out of 228 type 1 emergency departments—those providing consultant-led, 24-hour services with full resuscitation facilities—at 5 different time points across 10 days in March 2025.

 

Local reporting teams relied on electronic health records, department management systems, and real-time observations to record the number of patients in escalation areas.

 

They also recorded the number of patients awaiting an inpatient bed; the number of cubicles or chair spaces in each emergency department (stratified by resuscitation room and non- resuscitation room status); whether there were children and patients with a presenting mental health issue in escalation areas; and the availability of resuscitation cubicles.

 

An escalation area was defined as ‘any area not routinely used unless the capacity of the usual emergency department geographical footprint is exceeded’ and they included: an ambulance queueing to offload for more than 15 minutes; a repurposed clinical area; a non-clinical area, such as a hospital corridor or waiting room; and a doubled-up cubicle.

 

The data showed that the treatment of emergency department patients in escalation area spaces was a regular and common occurrence.

 

The total number of patients in escalation areas across all 5 time points totalled 10,042, or 18% of all 56,881 patients in the participating emergency departments. And the proportion of sites reporting patients in escalation areas ranged from 70% to 90%.

 

A break-down of the total proportion of patients treated in the various types of escalation area in use showed that repurposed clinical spaces (31.5% to 39%) and non-clinical spaces, such as waiting rooms and corridors (53% to 58%), made up the lion’s share.

 

Overall, the time point with the highest number of patients in emergency departments (15, 933) was Monday at 7pm. The highest proportion of patients in escalation areas was Thursday at 7 am (the end of the clinical night shift), when more than 1 in 5 (21%) of all UK emergency department patients were being cared for in these locations, despite this being the period with the lowest total number of patients (7056).

 

Both children and patients with a mental health presentation were being cared for in these spaces across all 5 time points. Among the emergency departments seeing children, 5% to 23% reported treating them in escalation areas. And the proportion treating patients with a mental health presentation in these spaces ranged from 26% to 35.5%.

 

Regionally, the proportion of patients in escalation areas was consistently highest in Northern Ireland and lowest in the Southwest of England. And this proportion was highest in adult only emergency departments and smaller local emergency hospitals, and lowest in major trauma centres.

 

The number of patients waiting for an inpatient bed consistently exceeded the number of patients being cared for in escalation areas.

 

And the proportion of sites without any immediate resuscitation cubicle capacity ranged from 10.5% to 26%, “representing a significant patient safety issue,” note the researchers.

 

They conclude: “National guidance from NHS England states that escalation area use is not acceptable; this study demonstrates that it is widespread and routine. The same guidance states that children and those with mental health problems should never experience escalation area care; this study demonstrates that this is occurring regularly.

 

“Admitting patients awaiting an inpatient bed from the [emergency department] would largely solve the escalation area care problem… Healthcare policy makers must address this issue or openly accept escalation area care and its associated harms as a standard experience in UK emergency care.”

 

In a linked editorial, the immediate past and current presidents of the Royal College of Emergency Medicine, suggest that the findings are likely to be an underestimate.

 

“The authors of this paper have successfully quantified the extent to which crowding leads to patients being treated in inappropriate spaces. If anything, their findings will be an underestimate.”

 

They point out: “Most recently, the harm associated with crowding has been quantified, such that for every 72 patients who wait 8–12 hours before admission there is one excess death.”

 

The study provides further evidence on the cause of overcrowding in emergency departments, they highlight. It’s not the volume of patients coming in, but the flow out.

 

“Basically, if all the patients who required admission were taken out of the equation, the [emergency departments] in the study (remember that is most of the [emergency departments] in the UK) would not have been overcrowded. The issue is the exit block, and the policy focus needs to be on that,” they insist.

 

They add that the research didn’t measure the effects on patients and staff of escalation area spaces, but it stands to reason that this can’t be the best quality care.

 

“Despite NHS England’s guidance on ‘providing safe and good quality care in temporary escalation spaces’, it simply isn’t possible to offer proper care in corridors and cupboards. Patients describe loss of autonomy, unmet expectations, and feelings of increased vulnerability. Many of these patients are elderly, frail, and vulnerable. Many have visual or hearing impairment, or are confused. Many have extensive nursing needs,” they write.

 

“The disconnect between guidance from politically driven organisations, such as NHS England, and the real world is starkly exposed here,” they add.

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Journal

Emergency Medicine Journal

DOI

10.1136/emermed-2025-215301 

Method of Research

Observational study

Subject of Research

People

Article Title

Understanding corridor and escalation area care in 165 UK emergency departments: a multicentre cross- sectional snapshot study

Article Publication Date

9-Dec-2025

 

Heavy energy drink intake may pose serious stroke risk, doctors warn

Fit man in his 50s who drank 8 cans daily developed extremely high blood pressure; Tighter regulation of sales and advertising of these drinks needed, urge report authors

BMJ Group

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Downing several strong energy drinks every day may pose a serious stroke risk, doctors have warned in the journal BMJ Case Reports, after treating an otherwise fit and healthy man in his 50s with a daily 8-can habit and exceedingly high blood pressure.

 

The findings prompt the authors to call for tighter regulation of the sales and advertising of these drinks, particularly given their popularity among young people.

 

The man in question had a stroke in his thalamus—the part of the brain involved in sensory perception and movement. His symptoms included left-sided weakness, numbness, as well as difficulties with balance, walking, swallowing and speech—collectively known as ataxia.

 

On admission to hospital his blood pressure was 254/150 mm Hg, which is regarded as extremely high.

 

He was started on drugs to lower his blood pressure, and his systolic blood pressure—reflecting arterial pressure during the heart’s pump action—fell to 170 mm Hg.

 

But once back home, his blood pressure rose again and remained persistently high despite the ramping up of his drug treatment.

 

On further questioning, he revealed that he drank an average of 8 energy drinks every day, each of which contained 160 mg of caffeine, adding up to a daily intake of 1200-1300 mg of caffeine: the recommended maximum daily intake is 400 mg.

 

He was asked to give up this daily habit, after which his blood pressure returned to normal and blood pressure lowering drugs were no longer needed.

 

But he didn’t regain full feeling on his left side. Commenting on the experience, he said: “I obviously wasn’t aware of the dangers drinking energy drinks were causing to myself. (I) have been left with numbness (in my) left hand side hand and fingers, foot and toes even after 8 years.”

 

The report authors point out that the man’s lack of awareness about the potential cardiovascular risks associated with heavy energy drink consumption is probably not surprising as they aren’t generally thought of as a potential cardiovascular disease risk.

 

“The year 2018 saw major UK supermarkets implement a voluntary ban on sales of [these drinks] to under 16s in a drive to tackle obesity, diabetes, and tooth decay, but less explored are the possible increased risks of [energy drinks] for cardiovascular disease, including ischaemic [restricted blood supply or blood clot] and haemorrhagic [bleed in the brain] strokes, particularly in younger demographics otherwise expected to have lower stroke risk,” they emphasise.

 

Energy drinks contain more than 150 mg of caffeine per litre and typically have a very high glucose-based sugar content and varying quantities of other chemicals, they highlight.

 

“This declared amount is the ‘pure caffeine’, but other ingredients contain ‘hidden caffeine’— for example, guarana is thought to contain caffeine at twice the concentration of a coffee bean.

 

“The hypothesis is that the interaction of these other ingredients, including taurine, guarana, ginseng and glucuronolactone, potentiates the effects of caffeine heightening stroke [cardiovascular disease] risk through numerous mechanisms,” they explain.

 

“The average [energy drink] is said to contain around 80 mg of caffeine per 250 ml serving, compared with 30 mg in tea and 90 mg in coffee, but in some cases can contain up to 500 mg in a single serving,” they point out.

 

This report represents just one case, but the authors nevertheless conclude: “While the current evidence is not conclusive, given the accumulating literature, the high morbidity and mortality associated with stroke and [cardiovascular disease] and the well-documented adverse health effects of high-sugar drinks, we propose that increased regulation of [energy drink] sales and advertising campaigns (which are often targeted at younger ages) could be beneficial to the future cerebrovascular and cardiovascular health of our society.”

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Journal

BMJ Case Reports

DOI

10.1136/bcr-2025-267441 

Method of Research

Case study

Subject of Research

People

Article Title

Energy drinks, hypertension and stroke

Article Publication Date

9-Dec-2025