Bacteria including MRSA can become stronger, more invasive and persistent after exposure to tobacco fumes, a study has found
Cigarette smoke is making superbugs which live inside the human nose more resistant to antibiotics. The same bugs also become more hardy and invasive because cigarette smoke makes them mutate. Researchers at Bath University said they were “shocked” at their findings.
It is well understood how cigarette smoke changes the cell structure of the human bodycausing cancers. But the new findings show the impact of smoking on the cells of bacteria which live mainly in the nasal passages with serious potential health consequences.
Professor Hugh Pennington, a world renowned bacteriologist, said the findings were “another nail in the tobacco coffin”.
Another nail in the tobacco coffin
Researchers at Bath University’s Department of Biology and Biochemistry, led by Dr Maisem Laabei, found a strain of Staphylococcus aureus(MRSA) becomes stronger and more resistant to antibiotics after being exposed to cigarette smoke.
The team, who published the findings in the journal Scientific Reports, said the strains of MRSA used in the research were known to cause skin infections, pneumonia and endocarditis - an infection of the heart.
Tests revealed some strains of Staphylococcus aureus, estimated to be carried by up to 30 percent of people, became more invasive and persistent after smoke exposure. The smoke caused a hardy sub-population in the bugs - called small colony variants - to emerge.
These new variant bugs adapted better to the harsher smokey environment. Dr Laabei said: “We have a lot more work to do but I would hope our research is something that smokers will consider and conclude that it is one more reason to stop smoking.
“We were shocked by the findings but in retrospect we shouldn’t have been. We know that cigarette smoke can cause mutations in human cells so there is no reason it wouldn’t have the same effect on bacteria that inhabit the same environment - the nasal cavity and the respiratory tract. We know smokers are more predisposed to respiratory tract infections and pneumonia.
“In the majority of the human population Staphylococcus aureus is asymptomatic and doesn’t cause infections. But when you add in cigarette smoke - which is toxic to the bacteria - it responds by changing genetically and becoming more adhesive.
“There are many complicating factors we need to research but it appears this change helps the bacteria to become more antibiotic resistant and more invasive.
“It means antibiotics may not work as well on smokers as non-smokers. These small colony variants are highly adhesive, invasive and persistent. They can sit around for a long time, are difficult to kick out, and are linked to chronic infections.”
Antibiotics may not work as well on smokers
He said: “It is another nail in the tobacco coffin, although I consider that exposure to antibiotics remains by far the biggest thing in itself that drives the evolution of resistance.
“Smokers of course damage their airways and lungs which helps infection to become established.”
Antibiotic resistance or antimicrobial resistance (AMR) poses a global health threat and Britain’s outgoing Chief Medical Officer Professor Dame Sally Davies said routine treatments could cause harm or even kill if new antibiotics are not found.
Dame Sally, who will become the UK’s special envoy on antimicrobial resistance, later this year said: “I am tremendously worried. This is one of the biggest intergenerational threats of our time.
“If we don't find new antibiotics to replace those which are failing, procedures such as caesarean sections, hip replacements and cancer treatments will become potentially life threatening.”
A Department of Health and Social Care spokesperson added: “AMR is one of the most pressing global challenges we currently face this century.
“It already contributes to over 2,000 deaths in the UK each year and without action, it is predicted that globally 10 million people could die from resistant infections by 2050.
“As world-leaders in the fight against AMR, we will invest in cutting edge research both here and overseas, work with pharmaceutical companies to develop new drugs and help the NHS to reduce antibiotic prescribing to achieve our vision of a world where AMR is contained and controlled by 2040.”
Dr Laabei said he believes overuse of antibiotics in the food chain and over prescription are far bigger factors in antibiotic resistance than smoking.
But he said more research is needed to find out more including on how air pollution from diesel exhaust fumes and vaping and other sources, might affect the microbes in nasal passages. He added: “There are many different strains of S aureus we need to look at.
“Bacteria can become antibiotic resistant through a number of factors and with cigarette smoking it is difficult to say bacteria is becoming antibiotic resistant on the same kind of levels Dame Sally was talking about.
“It is definitely a factor but I don’t think it would be the main driving force.
“What I can say is more work needs to be done on a range of issues from diesel fumes to aerosols.”
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