Israeli researchers fight back against antibiotic resistant superbugs

Many bacteria have developed resistance to antibiotics due to overuse.

By JUDY SIEGEL-ITZKOVICH
Updated: JUNE 19, 2017 05:44
Dr. Zvi Hayouka. (photo credit: Courtesy)
Dr. Zvi Hayouka.
(photo credit: Courtesy)
A unique antibiotic that can kill bacteria that are resistant to conventional antibacterials without damaging the cells that store them has been developed by scientists at the Hebrew University of Jerusalem.
The pioneering study, published in the prestigious Angewandte Chemie of the German Chemical Society, was carried out by Dr. Zvi Hayouka and colleagues at the Hebrew University’s Institute of Biochemistry, Food Science and Nutrition at the Robert H. Smith Faculty of Agriculture, Food and Environment in Rehovot.
Reviewers called the study “a most important discovery” in the field of antibiotics and researchers said they believe findings of their research “will help develop new antibiotics and reduce mortality from future infectious disease.”
Many bacteria have developed resistance to conventional antibiotics due to overuse – including usage with viral infections against which they have no effect. This has become a major crisis for modern medicine in fighting infectious diseases.
Thus, the development of new antibiotics is a desperate need and a major challenge.
One of the first discoveries in understanding the ability of organisms to protect against bacteria was a peptide – chains of various amino acids that producer protein in humans – isolated from the skin of a frog and found to protect against infections. It is now known that humans, plants, fungi and others organisms naturally release various peptides with antimicrobial activity that enable them to deal with bacteria as if they were part of the immune system.
A new generation of peptide- based antibiotics has been developed In Hayouka’s lab.
Based on the properties of the naturally antimicrobial peptides, peptide mixtures made from random repetitions of two amino acids with the properties required for antibacterial activity have been prepared, varying in the order of the amino acid chains.
Researchers have shown that these agents kill many bacteria very efficiently, including those found to be highly resistant to various antibiotics. In collaboration with Dr. Maxim Ryadnov of England’s National Institute of Physics, the researchers were able to predict the peptides’ mechanism of antimicrobial activity. It was found that peptide mixtures perforate a cell membrane by means of an artificial bacterial substance that enters it and creates pores.
However, the substances also damages red blood cells, which is problematic because antibiotics should be safe for the cells that store them.
The researchers found that during a specific chemical change of these peptide mixtures, the antimicrobial activity was maintained and the toxicity to the host cells disappeared.
Thus, they were able to design materials that harm only bacterial membranes without damaging the storage cells.
The researchers believe not only that these peptide mixtures pose a challenge to the development of bacterial resistance, but also that their findings will lead to the development of additional new antibiotics and help reduce mortality from infectious diseases.
The researchers believe not only that these peptide mixtures pose a challenge to the development of bacterial resistance, but also that their findings will lead to the development of additional new antibiotics and help reduce mortality from infectious diseases.