Novel E. coli treatment may prevent risk for hearing loss

A novel antibiotic designed to treat Escherichia coli infections could do so without the risk for hearing loss, according to a press release.

“So many approaches have failed,” Anthony Ricci, PhD, professor of otolaryngology at Stanford University Medical Center, said in the press release. “The main problem has been that if you succeeded in stopping the drug from killing hair cells [within the inner ear], then you also stopped its antimicrobial effect. The drug just doesn’t work anymore.

“If we can eventually prevent people from going deaf from taking these antibiotics, in my mind, we will have been successful. Our goal is to replace the existing aminoglycosides with ones that aren’t toxic.”

While using the newly developed antibiotic N1MS in mice, Ricci and colleagues were able to eliminate E. coli without causing hearing loss. The preclinical treatment reduced toxicity to nonregenerating hair cells without affecting the aminoglycoside’s ability to fight infection by targeting sites of the molecule not associated with antimicrobial activity.

Besides N1MS, researchers created eight other sisomicin-based compounds that were found to have less toxicity to hair cells than the parent compound in mice. While N1MS was the most effective, two other compounds had similar results compared with sisomicin in preventing the growth of and killing bacteria. N1MS also reduced toxicity to the kidneys, another adverse event caused by aminoglycosides.

According to the release, it is estimated that 20% to 60% of patients assigned aminoglycosides become partially or completely deaf. Aminoglycosides are commonly used to treat bacterial infections because they cost less, do not require refrigeration and have a stronger potency compared with other antibiotics.

“It is speculation at this point because unlike with the hair cell, we have not measured drug entry into the kidney cells, but it seems reasonable,” Ricci said.