Alternative drugs for mild infections could combat superbugs

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Washington: Developing alternatives to antibiotics for small infections could prevent bacteria from developing drug-resistance and help humans win the battle against superbugs, scientists say.

It has been widely reported that bacteria will evolve to render antibiotics mostly ineffective by mid-century, and current strategies to make up for the projected shortfalls have not worked.

Doctors are often quick to prescribe strong antibiotics for mild infections, helping bacteria evolve resistance to even the most potent drugs.

One possible problem is that drug development strategies have focused on replacing antibiotics in extreme infections, such as sepsis, where every minute without an effective drug increases the risk of death.

However, the evolutionary process that brings forth antibiotic resistance does not happen nearly as often in those big infections as it does in the multitude of small ones like sinusitis, tonsillitis, bronchitis, and bladder infections, according to researchers from the Georgia Institute of Technology in the US.

"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," said Sam Brown, an associate professor at Georgia Tech.

Bacteria that survive these many small battles against antibiotics grow in strength and numbers to become formidable armies in big infections, like those that strike after surgery.

For example, E coli is widespread in the human gut. While some strains secrete enzymes that thwart antibiotics, others do not.

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

Often, superbugs have made their way into hospitals in someone's intestines, where they had evolved high resistance through years of occasional treatment with antibiotics for small infections.

Then those bacteria have infected patients with weak immune systems.

Furious infections have ensued, essentially invulnerable to antibiotics, followed by sepsis and death.

Drug developers facing dwindling antibiotic effectiveness against evolved bacteria have looked for multiple alternate treatments.

The focus has often been to find some new class of drug that works as well as or better than antibiotics, but so far, nothing has, Brown said.

The researchers proposed a different approach. Developing non-antibiotic therapies for strep throat, bladder infections, and bronchitis could prove easier, thus encouraging pharmaceutical investment and research.

If doctors had enough alternatives to antibiotics for the multitude of small infections they treat, they could help preserve antibiotic effectiveness longer for the far less common but much more deadly infections, for which they are most needed.