Scientists discover ‘potent’ breakthrough superbug killer drug

Harvard scientists have created a “potent” new antimicrobial compound that overcomes mechanisms used by superbugs to counter commonly used antibiotics, rendering them ineffective.

Researchers found that the new compound cresomycin can kill many strains of antibiotic-resistant bacteria such as Staphylococcus aureus and Pseudomonas aeruginosa.

However, it is yet to be determined how safe cresomycin and drugs like it are to humans, according to the new study.

But scientists say the compound has improved activity against a long list of disease-causing bacteria that kill over a million people every year.

“Antibiotics form the foundation on which modern medicine is built. Without antibiotics, many cutting-edge medical procedures like surgeries, cancer treatments, and organ transplants, cannot be done,” study co-author Kelvin Wu said.

Compared with clinically approved antibiotics, researchers say cresomycin has improved ability to bind to bacterial components called ribosomes that make proteins within cells.

While many antibiotics work by disrupting ribosomes, some bacteria have also adapted mechanisms that prevent this effect.

They do so by expressing genes that make enzymes called ribosomal RNA methyltransferases that box out and contain the drug components meant to latch onto the ribosome.

Some bacteria also show drug resistance by reducing the binding affinity of their ribosomes to antibiotic molecules.

“The bacterial ribosome is nature’s preferred target for antibacterial agents, and these agents are the source of inspiration for our program,” study co-author Ben Tresco said.

In the new research, scientists engineered their synthetic compound into a rigidified shape closely resembling its binding target, which gives it a stronger grip on the ribosome.

They found that cresomycin has “remarkably robust efficacy” against multiple forms of bacteria with antimicrobial resistance (AMR).

They found that cresomycin can inhibit the growth of the two main types of bacteria – Gram-positive and negative ones, including multi-drug resistant strains of Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa both lab culture tests as well as in a mouse model of bacterial infection.

“We do not suggest that cresomycin is fully optimised for inhibition of the bacterial ribosome,” scientists wrote, adding however that the “findings portend favorably for the future discovery of antibacterial agents broadly effective against antimicrobial resistance.”