Group A Streptococci, colored yellow, are the most common culprits in bacterial upper respiratory infections. The Georgia Tech researchers suggest finding alternatives to broader spectrum antibiotics to take care of such ailments in order to preserve antibiotic effectiveness longer for more extreme infections. Credit: National Institute of Allergy and Infectious Diseases of the NIH

Prescribing antibiotics to treat minor illnesses like colds, coughs and strep throat may be leading to powerful drug-resistant superbugs.

New research shows that antibiotics used to treat minor illnesses including sinusitis, tonsillitis, bronchitis and bladder infections are contributing to the increasing strength and numbers of drug resistant bugs, which will then become formidable enough to cause damage in big infections in patients with weaker immune systems.

“Antibiotic prescriptions against those smaller ailments account for about 90 percent of antibiotic use, and so are likely to be the major driver of resistance evolution,” Sam Brown, an associate professor in Georgia Tech's School of Biological Sciences, said in a statement. “It might make more sense to give antibiotics less often and preserve their effectiveness for when they're really needed. And develop alternate treatments for the small infections.”

Some strains of E. coli, which is abundant in the human gut, secrete enzymes that thwart antibiotics, while other strains do not.

Drugs including amoxicillin are relatively broad-spectrum, meaning they kill not only the intended strep, but also many other bacteria in places like the digestive tract.

A broad-spectrum antibiotic kills off more of the vulnerable, less dangerous bacteria, while leaving the more dangerous and robust bacteria to propagate.

“You take an antibiotic to go after that thing in your throat, and you end up with gut bacteria that are super-resistant,” Brown said. “Then later, if you have to have surgery, you have a problem. Or you give that resistant E. coli to an elderly relative.”

In an effort to thwart the growing problem, drug developers have begun to look for alternate treatments, focusing on finding a new class of drugs that work as or better than antibiotics. The researchers have proposed only using antibiotics for the more serious ailments, while finding alternate treatments for the smaller illnesses.

“Take the easier tasks, like sore throats, off of antibiotics and reserve antibiotics for these really serious conditions,” Brown said.

Brown said less powerful drugs could be an answer to treat things like strep throat to push back against virulent bacteria until the body’s immune system can take care of it. Brown suggested that a spray-on treatment with bacteriophages that attack the bacteria might be effective.

The study was published in PLOS Biology