Category: Antibiotics

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PCT Test Fails to Shorten IV Antibiotics for Hospitalised Children

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Photo by Marcelo Leal on Unsplash

A groundbreaking UK study led by the University of Liverpool has examined whether an additional procalcitonin (PCT) blood test could safely shorten the time children spend on intravenous (IV) antibiotics in hospitals. Despite promising previous analysis, the findings showed that using the PCT biomarker to guide treatment decisions did not reduce antibiotic duration when compared to usual care.

The study, published in the Lancet Child & Adolescent Health, is part of the ‘Biomarker-guided duration of Antibiotic Treatment in Children Hospitalised with confirmed or suspected bacterial infection’ (BATCH) trial. BATCH is a UK national research trial to tackle antibiotic overuse in hospitalised children and reduce the spread of antimicrobial resistance (AMR).

Antibiotic overuse is a key driver of AMR, one of the world’s greatest public health challenges. Infections caused by resistant bacteria lead to longer hospital stays, higher healthcare costs, and increased mortality. Children are especially vulnerable, and smarter use of antibiotics is essential to protect their future health.

This study, conducted across 15 hospitals, enrolled nearly 2000 children aged between 72 hours and 18 years with suspected bacterial infections.

The researchers found that adding the PCT test to routine care did not reduce the duration of IV antibiotic use. The test was safe but costlier than standard methods, and healthcare teams faced challenges integrating it into their decision-making processes.

The study comes after a systematic review and cost-effectiveness analysis conducted by NICE in 2015 evaluated PCT testing to guide antibiotic therapy for the treatment of sepsis, and recommended further studies to adequately assess the effectiveness of adding PCT algorithms to guide antibiotic treatment in hospitalised adults and children with suspected or confirmed serious bacterial infection.

The results highlight that introducing new tools like PCT tests alone isn’t enough. Effective use requires:

  • Robust Antimicrobial Stewardship (AMS) programmes: Many hospitals already use AMS programmes to ensure antibiotics are prescribed responsibly, reducing unnecessary use.
  • Training and education for Clinicians: Familiarity with new tests and confidence in interpreting results are crucial for success.
  • Implementation research: Future studies should identify barriers and facilitators to implementation to optimise fidelity of the intervention.
  • Behaviour change: Better understanding of the complex interactions influencing whether/how/why clinicians act on information from diagnostic tests to make antibiotic prescribing decisions will improve trial intervention fidelity and facilitate implementation and adoption of tests shown to be effective.

The findings emphasise the importance of continuing to invest in AMS programmes and public health campaigns to reduce antibiotic misuse. The researchers note that although PCT-guided treatment didn’t provide clear benefits in this trial, it could still play a role in specific situations with further refinement.

Chief investigator Professor Enitan Carrol, from the University of Liverpool, said: “The BATCH study was a pragmatic trial evaluating if the intervention works under real-world conditions where clinicians do not have to adhere to diagnostic algorithms about antibiotic discontinuation. Adherence to the algorithm was low in our study, and there were challenges in integrating the test into routine clinical workflows. The study highlights the importance of including behaviour change and implementation frameworks into pragmatic trial designs.”

Source: University of Liverpool

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The Spread of a Highly Drug-resistant Cholera Strain

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Scanning electron micrograph image of cholera bacteria.

Scientists from the National Reference Center for Vibrios and Cholera at the Institut Pasteur, in collaboration with the Centre hospitalier de Mayotte, have revealed the spread of a highly drug-resistant cholera strain from Yemen down through Africa. The study was published in the New England Journal of Medicine.

Cholera is caused by the bacteria Vibrio cholerae and in its most severe forms, it is one of the most rapidly fatal infectious diseases: in the absence of treatment, patients can die within hours. Treatment primarily involves replacing lost water and electrolytes, but antibiotics are also used in addition to rehydration therapy. They are essential in reducing the duration of infection and breaking chains of transmission as quickly as possible.

A strain resistant to ten antibiotics – including azithromycin and ciprofloxacin, two of the three recommended for treating cholera – was identified for the first time in Yemen during the cholera outbreak in 2018-2019[1].

Scientists have now been able to trace the spread of this strain by studying the bacterial genomes. After Yemen, it was identified again in Lebanon in 2022[2], then in Kenya in 2023, and finally in Tanzania and the Comoros Islands – including Mayotte, a French département off the south-east coast of Africa – in 2024. Between March and July 2024, the island of Mayotte was affected by an outbreak of 221 cases caused by this highly drug-resistant strain.

“This study demonstrates the need to strengthen global surveillance of the cholera agent, and especially to determine how it reacts to antibiotics in real time. If the new strain that is currently circulating acquires additional resistance to tetracycline, this would compromise all possible oral antibiotic treatment,” concludes Professor François-Xavier Weill, Head of the Vibrios CNR at the Institut Pasteur and lead author of the study.

[1] Press release 19/08/2023 – Genes fuelling antibiotic resistance in Yemen cholera outbreak uncovered

[2] https://www.nature.com/articles/s41467-024-51428-0

Source: Institut Pasteur

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Tuberculosis Strains Resistant to New Drug Regimen are Being Transmitted between Patients

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Mycobacterium tuberculosis drug susceptibility test. Photo by CDC on Unsplash

Multidrug-resistant tuberculosis (MDR-TB) poses a particular threat to global health. A study led by the Swiss Tropical and Public Health Institute (Swiss TPH) shows that resistance to the new MDR-TB treatment regimen recently recommended by the World Health Organization is already spreading between patients. The findings, published in NEJM, highlight the urgent need for better surveillance and infection control to counteract the rise in antimicrobial resistance.

The traditional treatment regimen for MDR-TB is lengthy, expensive, and comes with severe adverse event. In 2022, the World Health Organization (WHO) endorsed a new 6-month regimen, the BPaL(M), based on evidence of its improved safety and efficacy from numerous clinical studies, including TB-PRACTECAL.

Monitoring the implementation of a new treatment regimen

“While this new regimen is a game changer for patients suffering from MDR-TB, we knew that it will be difficult to outsmart Mycobacterium tuberculosis, the bacteria causing TB,” said Sébastien Gagneux, Head of the Department Medical Parasitology and Infection Biology at Swiss TPH and senior author of the study. “It was therefore crucial to study how the TB bacteria would react to the global roll-out of this new regimen.”

This new study led by Swiss TPH in collaboration with the National Centre for Tuberculosis and Lung Diseases in Tbilisi, Georgia, now examined in detail whether resistance to the drugs in the new regimen has already emerged since its introduction, and whether this resistance is transmitting between patients.

Over a quarter of resistant strains result from transmission between patients

The researchers analysed the genomes of close to 90 000 M. tuberculosis strains from Georgia and many other countries around the world. They identified a total of 514 strains that were resistant to TB drugs, including both the old and the new treatment regimens. These highly drug-resistant strains were found in 27 countries across four continents.

Alarmingly, 28% of these strains were transmitted directly from one patient to another. “We already had anecdotal evidence of resistance emerging to the new regimen, but we did not know to what extent transmission was responsible for the spread of these highly drug-resistant strains,” said Galo A. Goig, postdoctoral collaborator at Swiss TPH and first author of the study.

“The good news is that the total number of these cases is still low. However, the fact that more than a quarter of these highly drug-resistant cases are due to patient-to-patient transmission, only two years after WHO endorsed the new regimen, is worrying,” added Goig.

Call for better surveillance and infection control

These findings have important implications for public health policy and interventions. “These new drugs have taken many years to develop, and to prevent drug resistance from emerging, it is essential to combine the deployment of these new regimens with robust diagnostics and surveillance systems,” said Chloé Loiseau, postdoctoral collaborator at Swiss TPH and co-author of the paper.

The authors emphasise the need for improved diagnostic tools, better infection control and robust surveillance systems to curb the spread of these highly drug-resistant strains, and to safeguard the efficacy of the new treatment regimen.

Tackling antimicrobial resistance

While there are already new TB drugs in the pipeline, experts worry that M. tuberculosis will continue to find ways to evade new drugs. “The example of these highly drug-resistant TB strains further illustrates that antimicrobial resistance is one of the most critical threats to global health today,” said Gagneux. “We must stay ahead in this constant race between drug development and bacterial resistance, and take proactive steps to prevent a ‘post-antibiotic era’ for TB and other diseases.”

Source: Swiss Tropical and Public Health Institute

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Faulty ‘Fight or Flight’ Drives C. Diff Infections

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Clostridioides difficile. Credit: CDC

The portion of our nervous systems responsible for the “fight or flight” response can shape the severity of potentially deadly Clostridioides difficile infections, new research from the School of Medicine reveals in Cell Reports Medicine.

The findings suggest that doctors may be able to save patients from the infections – a plague for hospitals and nursing homes – by using drugs to quiet the hyperactive nervous system response, the researchers say.

“Compared to how much we know about immune system influences in C. difficile infections, the field is just scratching the surface in understanding neuronal contributions to disease,” said researcher William A. Petri Jr., MD, PhD, of UVA Health’s Division of Infectious Diseases and International Health. “Newly identifying components of the nervous system that worsen inflammation will allow us to determine potential therapeutic targets and biomarkers for patients at risk of severe disease.”

C. difficile, is a perpetual burden for healthcare facilities. Extensive antibiotic use, particularly among patients who are hospitalised or in nursing care, can allow it to establish dangerous infections. Further, patients who make it through the severe diarrhoea, nausea, fever and colitis C. difficile can cause are not necessarily in the clear: One in six will develop another C. diff infection within eight weeks, according to the federal Centers for Disease Control and Prevention.

The new UVA research reveals the critical role the nervous system plays in severe C. difficile infections. The researchers found that the “sympathetic” nervous system – the branch that responds to dangerous situations – can be a key driver of serious C. diff.

Normally, our “fight or flight” response is helpful for avoiding danger. It helps us respond quickly, improves our eyesight, boosts our strength. It also can stimulate our immune system and help us recover from injury. But in C. difficile cases, the nervous system can have a hyperactive response that becomes part of the problem, and UVA’s new research explains why.

“Neurons are the first responders that coordinate defences against toxic attacks. Sometimes those responders don’t recruit the right size and kind of artillery and that can make things worse,” said researcher David Tyus, a neuroscience graduate student at UVA. “Interestingly, the receptor we identified as important in C. difficile infection [the alpha 2 adrenergic receptor] has also been linked to irritable bowel syndrome. I’m curious to know if there could be a unifying underlying mechanism between the two disease contexts.”

Promisingly, the researchers found that targeting the receptor in lab mice reduced intestinal inflammation and decreased C. difficile severity and mortality. That suggests that, with further research, doctors may be able to take a similar tact to better treat severe C. diff infections in patients. For example, they may be able to surgically remove a portion of nerves in the gut, or they may be able to develop medicines to target the alpha 2 receptor – as Petri and Tyus are attempting to do.

“Our next step is to determine which cells with the alpha 2 receptor are receiving signals from the sympathetic nervous system and play a role in C. difficile-mediated disease,” Petri said. “We are very excited to think about how our findings translate to clinic and how the sympathetic nervous system might play a role in recurrent infection. I hope that this study sets the foundation for future findings of how neurons affect the course of C. difficile infection outcomes.”

Source: University of Virginia Health System

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Transperineal Prostate Biopsy is Safer than the Standard Technique

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Credit: Darryl Leja National Human Genome Research Institute National Institutes Of Health

A multi-institutional clinical trial led by Weill Cornell Medicine and NewYork-Presbyterian investigators showed that a newer technique for collecting prostate biopsy samples reduced the risk of infection compared with traditional biopsy approaches and removed the need for prophylactic antibiotics. The results of the study appear in JAMA Oncology.

The technique, called transperineal prostate biopsy, collects prostate tissue via a needle through the skin of the perineum, the area between the rectum and the scrotum. The procedure, which uses local anesthesia to numb the area, allows physicians to bypass the traditional and more infection-prone route of collecting prostate biopsy tissue with a needle through the rectum.

The PReclude infection EVEnts with No prophylaxis Transperineal (PREVENT) trial, funded by the National Cancer Institute, part of the National Institutes of Health, was conducted at multiple sites, including NewYork-Presbyterian/Weill Cornell Medical Center, NewYork-Presbyterian Queens and NewYork-Presbyterian Brooklyn Methodist Hospital. The study found no infections among 382 men randomised to undergo the transperineal procedure compared with six infections affecting 1.6% of the 370 men randomised to undergo the traditional transrectal biopsy procedure. The lower infection rate is particularly remarkable because the men in the transrectal biopsy group received a targeted course of antibiotics designed to help reduce their infection risk, and the men in the transperineal group received no antibiotics.

“Transperineal biopsy should be the new standard of care for prostate biopsy,” said Dr Jim Hu, Professor of Urologic Oncology at Weill Cornell Medicine. “It was as effective as the traditional transrectal biopsy approach at detecting cancer, but without the risk of infection or the need for antibiotics.”

Prostate biopsies are an essential tool for detecting prostate cancer, and about 3 million people worldwide undergo the procedure each year. Dr Hu noted that physicians collect about 90% of these biopsies in the United States via a transrectal procedure. Yet studies have found that 5% to 7% of patients develop infections after biopsy, and 1% to 3% require hospitalisation for these complications, he said. To help prevent infections, physicians typically prescribe a prophylactic course of antibiotics before the procedure.

Dr. Hu noted that the investigators used a personalised approach to prophylactic antibiotics in the patients undergoing the transrectal biopsy procedure. Rather than giving the men a broad-spectrum antibiotic or multiple antibiotics, they matched the antibiotics to cultures obtained from the patient’s rectum during prostate exams before the procedure. This targeted antibiotic approach reduced the infection rate in those undergoing the traditional transrectal procedure substantially compared with the national infection rate for the procedure. Yet, they achieved a statistically significant reduction in infections in the transperineal group by eliminating infections altogether.

 “Transperineal prostate biopsy makes a common diagnostic procedure safer for men,” said Dr Hu, who is also a member of the Sandra and Edward Meyer Cancer Center at Weill Cornell Medicine. “It also eliminates the use of antibiotics, helping to reduce the emergence of antibiotic-resistant infections, a growing public health concern.”

Despite the promise of the new procedure, Dr. Hu acknowledged a few hurdles to making it more widely available to men in the United States. He explained that few physicians in the country have been trained in the perineal procedure. Additionally, he noted that US insurers pay the same amount for either procedure but the transperineal biopsy costs more and takes longer to perform, creating a financial disincentive for physicians to make the switch.

However, there is reason to think the status quo will change, Dr Hu said, noting the switch to transperineal prostate biopsies in Norway after a man died after a routine transrectal prostate biopsy. The change virtually eliminated biopsy-related infections and deaths in that country with the nationwide switch to transperineal biopsy, he said.

“There is a strong case to make the switch,” he said. “It will take time. But as more patients request the new procedure, we think it will become more widely available.”

Source: Weill Cornell Medicine

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Antibiotic Usage can Damage the Intestine’s Protective Mucus Layer

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Source: CC0

Researchers at Umeå University and Tartu University have found that a history of repeated antibiotic use causes defects in the normally protective mucus barrier of the gut, due to antibiotic-driven alterations in the microbiota. In a further study in a different collaboration, the researchers found a bacteria-independent mechanism through which antibiotics can damage the mucus barrier directly.

The results have been published in the scientific journals Gut Microbes and Science Advances.

“Together, these two studies suggest that antibiotics can damage the mucus layer through at least two independent mechanisms, and that they may have long-lasting effects through an altered gut bacteria. This further supports the notion that antibiotics should be administered in a responsible manner,” says Björn Schröder, Docent in Infection Biology in the Department of Molecular Biology at Umeå University.

Previous research has shown the consequences of short-term antibiotic treatments on the intestinal environment, but it is less clear how repeated antibiotic use in past years can affect our guts.

To address this question, Björn Schröder and his group at Umeå University teamed up with a research group at Tartu University in Estonia, who have built a deeply characterised cohort of individuals that provided stool samples and health records.

The researchers selected individuals who had taken at least five courses of antibiotics in the past, but not within six months before the stool collection, and compared their microbiota composition to individuals who had not taken any antibiotics within the last 10 years.

“The analysis revealed changes to the gut bacteria composition, even though the antibiotics were taken a long time ago. These results indicate that repeated antibiotic use has a lasting effect on gut bacteria composition that can persist at least months after the last treatment,” says Kertu-Liis Krigul, PhD student at Tartu University.

After transplantation of the human microbiota into mice and using specialised methods to analyse the mucus function in the gut, the researchers found that the function of the mucus layer was disrupted in mice transplanted with bacteria from humans with a history of repeated antibiotic use. Expansion of the mucus was reduced, and the mucus layer became penetrable, allowing bacteria to move closer to the intestinal lining.

“Looking at the bacteria present in the gut in more detail, we could see that bacteria known to feed on the mucus layer were present at higher levels in these mice. This further supports a role for the gut bacteria in determining how well the mucus barrier can function,” says Rachel Feeney, PhD student at the Department of Molecular Biology at Umeå University.

A separate study carried out in another international collaboration, further showed that antibiotics can also directly disrupt the mucus barrier in a gut bacteria-independent manner.

By giving the antibiotic vancomycin to normal and ‘bacteria-free’ mice, the researchers were able to show that this antibiotic can act directly on the mucus barrier, independent of the gut bacteria. Complementary experiments on intestinal tissue were carried out at Umeå University and showed that the antibiotic could disrupt the mucus expansion within a few minutes of application.

Source: Umeå University

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Bacteria able to Overcome Cost of Vancomycin Resistance in Lab Setting

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Compensatory mutations enabled vancomycin resistance to persist through several generations

Methicillin resistant Staphylococcus aureus (MRSA) – Credit: CDC

Staphylococcus aureus has the potential to develop durable vancomycin resistance, according to a study published August 28, 2024, in the open-access journal PLOS Pathogens by Samuel Blechman and Erik Wright from the University of Pittsburgh, USA.

Despite decades of widespread treatment with the antibiotic vancomycin, vancomycin resistance among the bacterium S. aureus is extremely uncommon – only 16 such cases have reported in the US to date. Vancomycin resistance mutations enable bacteria to grow in the presence of vancomycin, but they do so at a cost. Vancomycin-resistant S. aureus (VRSA) strains grow more slowly and will often lose their resistance mutations if vancomycin is not present. The reason behind vancomycin’s durability and the potential for VRSA strains to further adapt have not been adequately explored.

In this study, researchers took four VRSA strains and grew them in the presence and absence of vancomycin to see how the strains would evolve. They found that strains grown in the presence of vancomycin developed additional mutations in the ddl gene, which has previously been associated with vancomycin dependence. These mutations enabled VRSA strains to grow faster when vancomycin was present. Unlike the original strains, which quickly lost vancomycin resistance, the evolved strains maintained resistance through several generations, even when vancomycin was no longer present.

The study shows that durability of vancomycin susceptibility to date should not be taken for granted. The trade-off that often comes with vancomycin resistance can be overcome if the bacteria is allowed to grow in the presence of vancomycin. As antibiotic resistance continues to grow as a public health threat, studies like this underscores the importance of developing new antibiotics.

The authors add: “The superbug MRSA has been held off by the antibiotic vancomycin for decades. A new study shows we will not be able to count on vancomycin forever.”

Provided by PLOS

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Treatment with a Mixture of Antimicrobial Peptides can Impede Antibiotic Resistance

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Pseudomonas exposed to mixtures instead of single peptides did not gain resistance

A common infection-causing bacteria was much less likely to evolve antibiotic resistance when treated with a mixture of antimicrobial peptides rather than a single peptide, making these mixtures a viable strategy for developing new antibiotic treatments. Jens Rolff of the Freie Universitat Berlin, Germany, and colleagues report these findings in a new study publishing July 2nd in the open-access journal PLOS Biology.

Antibiotic-resistant bacteria have become a major threat to public health. The World Health Organization estimates that 1.27 million people died directly from drug-resistant strains in 2019 and these strains contributed to 4.95 million deaths. While bacteria naturally evolve resistance to antibiotics, misuse and overuse of these drugs has accelerated the problem, rendering many antibiotics ineffective. One emerging strategy to combat antibiotic resistance is the use of antimicrobial peptides, which are chains of amino acids that function as broad-spectrum antimicrobial compounds and are key components of the innate immune system in animals, fungi and plants.

In the new study, researchers investigated whether antimicrobial peptide mixtures synthesised in the lab could reduce the risk of the pathogen Pseudomonas aeruginosa from evolving antimicrobial resistance, compared to exposure to a single antimicrobial peptide. They found that using antimicrobial peptide mixtures carried a much lower risk of the bacteria developing resistance. The mixtures also helped prevent the bacteria from developing cross-resistance to other antimicrobial drugs, while maintaining – or even improving – drug sensitivity.

Overall, the findings suggest that the use of antimicrobial peptide mixtures is a strategy worth pursuing in the search for new, longer-lasting treatments for bacteria. The researchers suspect that using a cocktail of multiple antimicrobial peptides creates a larger set of challenges for bacteria to overcome, which can potentially delay the evolution of resistance, compared to traditional antibiotics. Furthermore, these cocktails can be synthesized affordably, and previous studies have shown them to be non-toxic in mice.

Lead author Bernardo Antunes adds, “Even after four weeks of exposure, a usual treatment duration for Pseudomonas infections, we could not find resistance against our new random peptide, but against other antimicrobials.”

Provided by PLOS

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Which is Better? Prolonged vs Intermittent Infusion of β-Lactams in Sepsis

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Photo by Anna Shvets on Pexels

In adults with sepsis or septic shock, β-lactams are recommended by Surviving Sepsis Campaign guidelines, in a prolonged (after an initial bolus) rather than intermittent infusions – but owing to only moderate quality of evidence this is currently a weak recommendation. Now, a new systematic review and meta-analysis comparing the two approaches across multiple clinical trials has found a survival benefit for prolonged infusion The findings appear in JAMA.

To address whether prolonged infusions of β-lactams improve clinically important outcomes in critically ill adults with sepsis or septic shock, the study investigators searched medical databases for relevant randomised controlled trials comparing β-lactam infusion types in critically ill adults with sepsis or septic shock. The primary outcome was 90-day mortality, with secondary outcomes including intensive care unit (ICU) mortality and clinical cure.

In all, they found 18 eligible trials that included 9108 critically ill adults with sepsis or septic shock (median age, 54 years; 5961 men [65%]), 17 trials (9014 participants) contributed data to the primary outcome.

The pooled estimated risk ratio for all-cause 90-day mortality for prolonged infusions of β-lactam antibiotics compared with intermittent infusions was 0.86, with high certainty and a 99.1% posterior probability that prolonged infusions were associated with lower 90-day mortality. There was high certainty that prolonged infusion of β-lactam antibiotics was associated with a reduced risk of ICU mortality (risk ratio, 0.84) and moderate certainty of an increase in clinical cure (risk ratio, 1.16).

The findings were tempered with the authors’ understanding that, “Potential challenges associated with prolonged infusion administration, including drug instability and incompatibility with other intravenous medications, the need for a dedicated intravenous portal, and the potential effect on clinical workload, require some considerations before broad implementation. Future studies should determine the optimal duration of infusion when β-lactam antibiotics are administered as prolonged infusions.”

The authors concluded that, “Among adults in the intensive care unit who had sepsis or septic shock, the use of prolonged β-lactam antibiotic infusions was associated with a reduced risk of 90-day mortality compared with intermittent infusions. The current evidence presents a high degree of certainty for clinicians to consider prolonged infusions as a standard of care in the management of sepsis and septic shock.”

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Temperature may be a New Weapon in the Battle against Antibiotic Resistance

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Scientists from the University of Groningen in the Netherlands, together with colleagues from other European universities, have tested how a fever could affect the development of antimicrobial resistance. In laboratory experiments, they found that a small increase in temperature from 37 to 40 degrees Celsius drastically changed the mutation frequency in E. coli bacteria, which facilitates the development of resistance. If these results can be replicated in human patients, fever control could be a new way to mitigate the emergence of antibiotic resistance.

There are two ways to fight the threat of antimicrobial resistance: by developing new drugs, or by preventing the development of resistance. ‘We know that temperature affects the mutation rate in bacteria’, explains Timo van Eldijk, co-first author of the paper published in JAC-Antimicrobial Resistance. ‘What we wanted to find out was how the increase in temperature associated with fever influences the mutation rate towards antibiotic resistance.’

‘Most studies on resistance mutations were done by lowering the ambient temperature, and none, as far as we know, used a moderate increase above normal body temperature,’ Van Eldijk reports. Together with Master’s student Eleanor Sheridan, he cultured E. coli bacteria at 37 or 40 degrees Celsius, and subsequently exposed them to three different antibiotics to assess the effect. ‘Again, some previous human trials have looked at temperature and antibiotics, but in these studies, the type of drug was not controlled.’ In their laboratory study, the team used three different antibiotics with different modes of action: ciprofloxacin, rifampicin, and ampicillin.

The results showed that for two of the drugs, ciprofloxacin and rifampicin, increased temperature led to an increase in the mutation rate towards resistance. However, the third drug, ampicillin, caused a decrease in the mutation rate toward resistance at fever temperatures. ‘To be certain of this result, we replicated the study with ampicillin in two different labs, at the University of Groningen and the University of Montpellier, and got the same result,’ says Van Eldijk.

The researchers hypothesized that a temperature dependence of the efficacy of ampicillin could explain this result, and confirmed this in an experiment. This explains why ampicillin resistance is less likely to arise at 40 degrees Celsius. ‘Our study shows that a very mild change in temperature can drastically change the mutation rate towards resistance to antimicrobials,’ concludes Van Eldijk. ‘This is interesting, as other parameters such as the growth rate do not seem to change.’

If the results are replicated in humans, this could open the way to tackling antimicrobial resistance by lowering the temperature with fever-suppressing drugs, or by giving patients with a fever antimicrobial drugs with higher efficacy at higher temperatures. The team concludes in the paper: ‘An optimized combination of antibiotics and fever suppression strategies may be a new weapon in the battle against antibiotic resistance.’

Source: University of Groningen