As The Guardian reports, scientists have discovered an entirely new class of antibiotics that appear to kill one of the three bacteria considered to be the biggest threat to human health due to their widespread drug resistance.

Zosurabalpin defeated highly carbapenem-resistant strains of Acinetobacter baumannii (Crab) in mouse models of pneumonia and sepsis and was tested in humans.

The World Health Organization classifies crab as a priority 1 critical pathogen, along with two other forms of drug-resistant bacteria, Pseudomonas aeruginosa and Enterobacteriaceae.

“Crab is a major cause of infection in hospitals, particularly among people on ventilators,” said Dr. Andrew Edwards, senior lecturer in molecular microbiology at Imperial College London, who was not involved in the study.

“Although it is not an aggressive pathogen, it is resistant to several different antibiotics, which makes it very difficult to treat.” Unfortunately, developing new treatments for this bacterium has been extremely difficult because it is very adept at preventing the release of antibiotics. its outer cell layer. So this work is very exciting and gives confidence that the approaches used to find new antibiotics can pay off,” he added.

Antibiotic-resistant bacteria are a major health problem

Antibiotic-resistant infections pose a threat to human health, especially those caused by a large group of bacteria known as gram-negative bacteria, which are protected by an outer shell containing a substance called lipopolysaccharide (LPS).

“LPS allows bacteria to live in challenging environments while also allowing them to evade attack by our immune system,” said Dr. Michael Lobritz, Global Head of Infectious Diseases at Roche Pharma Research and Early Development in Basel, Switzerland. , who developed a new drug.

In over 50 years, no new antibiotic has been approved for gram-negative bacteria.

Roche had previously determined that Zosurabalpin was able to block the growth of A baumannii, but it was unclear how it worked and whether it would be effective in animals with crab-related infections.

“Unique in composition and mechanism of action”

Through a series of experiments published in Nature, Professor Daniel Kahne from Harvard University in Cambridge, USA, and his colleagues showed that the drug prevents the transfer of LPS to the outer membrane of the bacterium, killing it. They also found that zosurabalpin significantly reduced bacterial levels in mice with crab-induced pneumonia and prevented death in those with crab-induced septicemia.

Lobritz said: “This is the first time we’ve found something that works this way, so it’s unique in terms of its chemistry and mechanism of action.”

While he stressed that the molecule alone will not solve the public health threat posed by antimicrobial-resistant infections, the discovery could lay the groundwork for future efforts to apply the same transport system in other bacteria.

Edwards said another type of antibiotic under development, known as murepavidin, similarly targets LPS transport – albeit through a different mechanism.

“It was shown to be active against a bacterium called Pseudomonas aeruginosa, suggesting the possibility of extending this work to other bacteria resistant to many antibiotics, such as Klebsiella and E. coli,” he said.

However, he cautioned that transferring new drugs from animal studies to humans can be extremely difficult.