Cigarette smoke has long been known to have harmful health effects and new research shows it also makes superbugs more aggressive.
Researchers at the University of California, San Diego found that when Methicillin-resistant Staphylococcus aureus (MRSA), an antibiotic-resistant bacteria, was exposed to cigarette smoke, it became even more resistant to killing by the immune system.
MRSA can cause potentially deadly skin and bloodstream and surgical site infections or pneumonia in patients at hospitals, nursing homes or dialysis centers.
“We already know that smoking cigarettes harms human respiratory and immune cells, and now we’ve shown that, on the flipside, smoke can also stress out invasive bacteria and make them more aggressive,” said senior author Dr. Laura E. Crotty Alexander, assistant clinical professor of medicine at UC San Diego and staff physician at the Veterans Affairs San Diego Healthcare System.
Crotty Alexander’s team infected macrophages, immune cells that attack infections, with MRSA. They grew some of the bacteria with cigarette smoke extract. The macrophages attacked both bacterial populations, but they had a harder time killing the MRSA that had been exposed to cigarette smoke extract, researchers found.
The study, published this week in the journal Infection and Immunity, also found that cigarette smoke strengthens MRSA bacteria by altering their cell walls so that they are better able to resist antimicrobial peptides and other charged particles.
“Cigarette smokers are known to be more susceptible to infectious diseases. Now we have evidence that cigarette smoke-induced resistance in MRSA may be an additional contributing factor,” Crotty Alexander said.
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The research was funded, in part, by the U.S. Department of Veterans Affairs.
Another recent study on MRSA found that an ancient concoction for eye infections, which contains garlic, onions and cow bile, kills MRSA, according to researchers at Britain's University of Nottingham.
They sent their findings to an expert at Texas Tech University who found the potion was more effective in battling MRSA than the currently-used antibiotic vancomycin.
Now researchers are trying to figure out what's in the salve that kills germs so effectively.
