New Antibiotics Prevents Hearing Loss


By: Ayanna Flegler, PreScouter Global Scholar
Bacterial infections remain a constant threat to human health. As treatment for such infections, antibiotics are used to either kill or prevent growth of bacteria. Aminoglycosides represent a widely used class of antibiotics that are effective, but can have a detrimental side effect of hearing loss. This reduction in hearing occurs when hair cells within the ear are lost as a result of aminoglycosides entering ear compartments. Although attempts have been made to develop new antibiotics preventing hearing loss, a difficulty has been that newly developed antibiotics are less potent as antimicrobial agents.
Researchers at Stanford University, directed by senior author Anthony Ricci, have developed a new class of aminoglycosides reducing the incidence of hearing loss. They modified regions of Sisomicin, a commercially available antibiotic, leading to nine new forms. The goal was to produce novel antibiotics that would reduce loss of hair cells, and ultimately, prevent hearing loss. “We targeted sites on the drug molecule that were not involved in the antimicrobial activity that kills off infection. This allowed us to reduce toxicity to the ear while retaining antimicrobial action,” says Ricci.
All nine of the structurally modified aminoglycosides exhibited a reduction in hair cell loss. One of the novel compounds, N1MS, shows great promise by demonstrating a different mechanism of interaction with hair cells than typical antibiotics. N1MS treatment resulted in more hair cells in comparison to normal antibiotics and prevented hearing loss in mice. Most importantly, N1MS remained as effective against various strains of bacteria as unaltered antibiotics.
The modified antibiotics represent a newly beneficial class of aminoglycosides that remain effective as antibiotics and minimizes hearing loss. “Our goal is to replace the existing aminoglycosides with ones that aren’t toxic,” says Ricci.
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Ayanna Flegler

About Ayanna Flegler
Ayanna has ten years of experience conducting biomedical research spanning multiple areas of the life sciences. She received her PhD in Cell and Molecular Biology from Northwestern University and B.S. in Biochemistry and Molecular Biology from the University of Maryland, Baltimore County. For her graduate work, she studied the distribution and abundance of the antigenic variants of the primary HIV-1 coreceptor, CCR5. Ayanna's scientific expertise includes HIV biology, primarily with HIV entry, and the G protein-coupled receptors associated with HIV infection.