Yet Another Reason Not to Smoke: It Gives Superbugs Superpowers

Antibiotic resistant bacteria even more resistant in the presence of cigarette smoke

Tabor Gus/Corbis

Cigarette smoke can make a person lightheaded in a pleasant, de-stressing way—or in a nauseous get-me-out of here way. It can incite long rants about the dangers of lung cancer and the evils of the tobacco industry. And it can also, according to a new study, pump up the powers of bacteria invading a person's body.

“Smoke can also stress out invasive bacteria and make them more aggressive," said Laura E. Crotty Alexander, an assistant clinical professor of medicine at UC San Diego, in a statement. In particular, she's talking about the antibiotic resistant superbug Staphylococcus aureus (MRSA)—which can cause fatal infections in the skin or blood stream and at surgical sites. In a recent study, Crotty Alexander showed how exposure to smoke may make them even more harmful.

Researchers grew MRSA in a lab, some with cigarette smoke extract and some in a "non-smoking section" of the lab bench. When they let the MRSA loose on immune cells, the cigarette-smoke bacteria were harder to kill: they were resistant both to chemical attacks and to the small pieces of protein that immune cells use to poke holes in invaders. When the researcher exposed human cells to the MRSA, the cigarette-smoke population was better at glomming onto and invading them. The researchers are not sure of the exact mechanism, but they think that smoke could alter the charge of the MRSA’s cell walls.

And be careful of touting the benefits of reaching for an e-cigarette instead: in work presented last year, Crotty Alexander found that exposure to e-cigarette vapor also made MRSA all the more powerful.

The connection between MRSA and smoke-exposure has been tested in mice but not yet humans. Future research will show if the connection holds up for smokers. But, interestingly, both MRSA infection rates and smoking rates are on the decline.

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