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Genetic mutation may help people fight off deadly MRSA infections

Genetic mutation could help people fight off life-threatening MRSA infections ‘by boosting their immune response’

  • Scientists from Duke University analysed 68 people for the research
  • Half had a persistent infection with the ‘superbug’ and half managed to clear it
  • DNA variation was in 62% who cleared the infection and just 9% who did not 

A genetic mutation may help people fight off life-threatening methicillin-resistant Staphylococcus aureus (MRSA) infections, research suggests.

Scientists from Duke University analysed 68 people, half of which were suffering from a persistent infection with the ‘superbug’.

The remaining 34 participants managed to clear the bacteria from their bloodstream within five days of treatment. 

Genetic sequencing revealed 62 per cent of the patients who cleared the infection had the DNMT3A mutation, compared to just nine per cent who suffered persistently.

This mutation is thought to boost levels of the anti-inflammatory substance IL-10, which keeps the immune system in check.

A genetic mutation may help people fight off life-threatening methicillin-resistant Staphylococcus aureus (MRSA) infections, research suggests (stock)

‘The increasing prevalence of antibiotic resistant staph infections has created an urgent need to better understand who is most susceptible to these difficult-to-treat S. aureus infections and why,’ study author Dr Vance Fowler said.

‘This study provides strong evidence of a genetic variant that appears to help people with MRSA to resolve their bloodstream infections.’ 

MRSA is a type of bacteria that is resistant to several widely-used antibiotics, making it harder to treat. 


Antibiotics have been doled out unnecessarily by GPs and hospital staff for decades, fueling once harmless bacteria to become superbugs. 

The World Health Organization (WHO) has previously warned if nothing is done the world is heading for a ‘post-antibiotic’ era.

It claimed common infections, such as chlamydia, will become killers without immediate solutions to the growing crisis.

Bacteria can become drug resistant when people take incorrect doses of antibiotics or if they are given out unnecessarily. 

Chief medical officer Dame Sally Davies claimed in 2016 that the threat of antibiotic resistance is as severe as terrorism.

Figures estimate that superbugs will kill 10 million people each year by 2050, with patients succumbing to once harmless bugs.

Around 700,000 people already die yearly due to drug-resistant infections including tuberculosis (TB), HIV and malaria across the world. 

Concerns have repeatedly been raised that medicine will be taken back to the ‘dark ages’ if antibiotics are rendered ineffective in the coming years.

In addition to existing drugs becoming less effective, there have only been one or two new antibiotics developed in the last 30 years.

In September, the WHO warned antibiotics are ‘running out’ as a report found a ‘serious lack’ of new drugs in the development pipeline.

Without antibiotics, C-sections, cancer treatments and hip replacements will become incredibly ‘risky’, it was said at the time.

It lives harmlessly on the skin of around one in 30 people, however, it can cause fever, chills and dizziness if it gets into the body. 

In severe cases, MRSA can cause bloodstream infections, pneumonia and sepsis.

Hospital patients are most at risk due to them often having a way for the bacteria to enter their body, such as a wound, feeding tube or urinary catheter.

They may also have other health concerns that make them more vulnerable.

MRSA can usually be treated by antibiotics that it has not developed resistance against. However, the resistance crisis means options are running out. 

Past research suggests genetic variations make people more or less vulnerable to the infection. 

The researchers analysed two sets of patients who were matched for age, sex, health status and MRSA risk. 

Persistent infection was defined as bacteria that was still in a patient’s bloodstream five days after treatment with supposedly effective antibiotics. 

Genetic analyses revealed a mutation in the ‘DNMT3A region of chromosome 2p’, the journal Proceedings of the National Academy of Sciences reported.

This was significantly more common among the participants who cleared the infection. 

The mutation is thought to help keep IL-10 at a healthy level, suggesting a better immune response against MRSA. 

Too little IL-10 dampens a person’s immune response, while too much has been linked to tissue damage and even death, past research suggests.

When the team blocked the DNMT3A mutation in mice, the animals showed increased susceptibility to MRSA.

‘Our study identifies a particular DNMT3A mutation that contributes to an increased ability to resolve MRSA infections,’ Dr Fowler said.