A team of French researchers from the Inserm, Université de Rennes 1, and the Rennes Institute of Chemical Sciences (ISCR) have developed two new types of antibiotics which are effective against Gram-positive and negative multi-resistant bacteria, and appear to be mostly neutral in terms of the development of resistance when used in mice.
The study was published in the journal PLOS Biology on 9 July, 2019.
Given their potency and importance for human health, antibiotics have been considered to be among the key breakthroughs of contemporary medicine. And yet, thanks to overuse and other complicated reasons, these drugs are now much less effective than in the past.
If the trend continues unabated, many experts predict a public health catastrophe which could lead to the loss of millions of lives.
Despite the seriousness of the situation, however, most new antibiotics brought to the market are what researchers call “me-too-drugs”, which refers to them being derivations of already existing classes of antibiotics that have been gradually losing their effectiveness.
Back in 2011, the research team had realized “that a toxin produced by Staphylococcus aureus whose role is to facilitate infection is also capable of killing other bacteria present in our body,” said Brice Felden, Director of the Bacterial Regulatory RNAs and Medicine laboratory in Rennes.
Ever since that moment, the goal was to separate the molecule’s toxic properties from its antibiotic effects, thereby creating a new antibacterial drug with little to no harmful effects on the body.
Out of the twenty brand new peptomimetic molecules, two proved effective against resistant Staphylococcus aureus and Pseudomonas aeruginosa in mouse models, with no observed toxicity to other human and mouse cells and organs.
In addition, the molecules were also found to be safe even when administered in doses 10 to 50 times higher than necessary to achieve the desired effect.
As regards resistance, the research team tested the molecules both in vitro and in vivo, finding no signs of the development of antibiotic resistance. However, given the short times frames (up to 15 days) used in the study, further research is needed to make sure that no adverse events take place when the molecules are left in contact with bacteria for longer.
“We think these new molecules represent promising candidates for the development of new antibiotics that can provide alternative treatments to antimicrobial resistance,” concluded Felden.