The next penicillin? Warwick researchers discover potent new antibiotic

Alexander Fleming, who discovered penicillin, said the following in his 1945 Nobel Prize acceptance speech: “I would like to sound one note of warning… It is not difficult to make microbes resistant to penicillin in the laboratory by exposing them to concentrations not sufficient to kill them, and the same thing has occasionally happened in the body.” Since 1945, many new and varied types of antibiotics have been discovered, but the problem of antimicrobial resistance persists. However, a new study conducted by the University of Warwick and Monash University has found a promising new antibiotic, which may help combat antimicrobial resistance.  

Before examining the scientific study in detail, it is helpful to understand what exactly antibiotics are and how they work. Antibiotics are used to “treat or prevent” some types of bacterial infection. They enter the bloodstream and combat bacteria by interrupting their reproduction, effectively slowing them down – this involves processes such as DNA replication or protein synthesis (these antibiotics are called bacteriostatic). Additionally, they also work by destroying bacterial cell walls, which kills the bacteria (these antibiotics are called bactericidal). However, sometimes bacteria, fungi, and parasites no longer respond to antimicrobial medicines, rendering antibiotics practically useless when dealing with these organisms. This phenomenon is called antimicrobial resistance (AMR). 

It is estimated that bacterial AMR was directly responsible for 1.27 million global deaths in 2019, and this figure rose to 4.95 million deaths in 2023

Some antibiotics and other antimicrobial medicines have become somewhat futile due to drug resistance, making some infections difficult or almost impossible to treat. In turn, this increases the risk of spreading severe illnesses. AMR is said to be a natural process that happens over time through genetic altercations in pathogens. That said, human misuse, such as overuse, of antimicrobials severely accelerates the development of this resistance. AMR is one of the top global public health and development threats. It is estimated that bacterial AMR was directly responsible for 1.27 million global deaths in 2019, and this figure rose to 4.95 million deaths in 2023. 

However, owing to the gravity of the threat, there are many scientists currently researching AMR and new antimicrobial medicines. Furthermore, researchers from the Monash Warwick Alliance have made a promising discovery: a new antibiotic, pre-methylenomycin C lactone, was found “hiding in plain sight” as an intermediate chemical in the natural process that produces the well-known antibiotic methylenomycin A. This new antibiotic is proven to be 100 times more effective against a certain type of bacteria compared to the antibiotic that was previously used.  

“By identifying and testing intermediates in the pathways to diverse natural compounds, we may find potent new antibiotics with more resilience to resistance that will aid us in the fight against AMR” 

Professor Greg Challis, University of Warwick, Department of Chemistry

This finding is particularly remarkable as the bacterium that produces both antibiotics has been a model antibiotic-producing species since the 1950s. The model species has been studied extensively since then and so, according to Dr Lona Alkhalaf, Assistant Professor at the University of Warwick: “Finding a new antibiotic in such a familiar organism was a real surprise.” This discovery is crucial for AMR studies and scientists, because not only does it propose a new paradigm for antibiotic discovery; it also suggests that not every new finding has to be made via the examination of new organisms or species. Co-lead author Professor Greg Challis of the Department of Chemistry at the University of Warwick and the Biomedicine Discovery Institute at Monash University stated: “By identifying and testing intermediates in the pathways to diverse natural compounds, we may find potent new antibiotics with more resilience to resistance that will aid us in the fight against AMR.”  

With that said, reducing the risk and effect of AMR does not solely depend on new research or new antibiotics being developed. The World Health Organisation suggests that there are measures that can, and should, be taken against AMR. The foremost way this can be achieved is by supporting countries in reducing AMR through the strengthening of infection prevention and control (IPC) measures, such as effective sanitation and hygiene in all healthcare settings. IPC is crucial for fighting the development and spread of AMR since every infection prevented reduces the need for antimicrobials. In addition to IPC measures, people can get vaccinated, acquaint themselves on AMR, and use their antibiotics responsibly. This means that, while it is crucial to continue the ongoing research into AMR, it is not the only way to fight antimicrobial resistance.