Swiss scientists have observed that a new class of antibiotics could be effective against a very dangerous and antibiotic-resistant family of bacteria.
- Acquired antibiotic resistance generally results from inappropriate use of antibiotics.
- A new class of antibiotics could in particular prevent the risk of bacterial resistance.
- After tests on mice, these new antibiotics have proven to be very effective, especially in treating lung infections.
Antibiotic resistance characterizes the ability of a bacterium to be insensitive to an antibiotic. Bacterial resistance can be natural, that is to say that the bacterium is naturally insensitive to certain antibiotics, or acquired, that is to say the bacterium was once sensitive to the antibiotic, but it has become resistant to it. Acquired antibiotic resistance is generally due to inappropriate use of antibiotics in humans as in animals.
A new class of antibiotics to fight resistant bacteria
The scientific community is therefore working to develop new antibiotics to fight against resistant bacteria. This is notably the case of researchers from the University of Zurich (Switzerland) and the company Spexix, who have modified the chemical structure of natural peptides, which are polymers of amino acids, to develop antimicrobial molecules that bind to new targets in bacterial metabolism.
In their study published in ScienceAdvance, researchers have worked on a class of highly effective antibiotics that fight Gram-negative bacteria, a very dangerous group of bacteria. Their resistance to antibiotics is very high due to their double cell membrane. This family of bacteria includes in particular carbapenem-resistant Enterobacteriaceae.
Further research ahead of first human tests
During the research, the scientists studied thanatin, a natural peptide, allowing insects to protect themselves and fight against infections. Thanatin disrupts an important lipopolysaccharide transport bridge between the outer membrane and the inner membrane of Gram-negative bacteria.
The team modified the chemical structure of thanatin to improve the characteristics of the peptide. “To do this, structural analyzes were essential”, said Oliver Zerbe, co-author of the study, chemist and head of nuclear magnetic resonance facilities at the University of Zurich. The scientists then synthetically assembled the various components of the bacterial transport bridge, and used nuclear magnetic resonance to visualize where and how thanatin binds to and disrupts the transport bridge. Grace To From this data, the researchers determined the chemical modifications needed to enhance the antibacterial effects of the peptide.
For the purposes of this research, the synthetic peptides were then tested on mice affected by bacterial infections. “The new antibiotics have proven to be very effective, especially in treating lung infections (…) They are also very effective against carbapenem-resistant enterobacteriaceae, where most other antibiotics fail. In addition, the newly developed peptides are not toxic or harmful to the kidneys, and they have also been shown to be stable in the blood over a long period of time”, noted Oliver Zerbe. However, preclinical studies will be necessary before starting the first tests on humans.
