How Bacteria Evolve to Evade Antibiotics: The Role of Tagging in Resistance

Bacteria can change their ribosomes when exposed to common antibiotics, according to a new study in Nature Communications. This change may help them resist antibiotics.

Researchers studied Escherichia coli (E. coli), a bacterium that can cause serious infections. They tested how E. coli reacted to two antibiotics: streptomycin and kasugamycin. Streptomycin has been used since the 1940s for tuberculosis, while kasugamycin is mainly used in agriculture to protect crops from bacterial diseases.

Both antibiotics target the ribosomes in bacteria. Ribosomes are vital for protein production and are made of proteins and ribosomal RNA. This RNA often has chemical tags that can change how the ribosomes work. The study showed that E. coli changes its ribosomes when exposed to these drugs. The altered ribosomes lacked certain tags, particularly in the areas where the antibiotics try to bind.

Anna Delgado-Tejedor, the study’s first author, explained that these changes in ribosomes might prevent the antibiotics from working effectively. E. coli has developed antibiotic resistance through various means, such as DNA mutations or actively pumping antibiotics out of their cells. This new method of changing ribosome structure adds to the known strategies for antibiotic resistance.

Dr. Eva Novoa, the study’s corresponding author, highlighted the precision of E. coli’s adjustments. The researchers used advanced nanopore sequencing technology to observe these ribosomal changes directly. This method allowed the scientists to see the chemical modifications in their natural state.

The study does not yet explain why or how these chemical tags are lost. Future research could explore this question. Understanding these changes may lead to new ways to combat antibiotic resistance, a significant issue in global health. Since 1990, global antimicrobial resistance has caused over a million deaths each year. It could lead to 39 million more deaths by 2050.

Dr. Novoa emphasized the importance of this research. By understanding why bacteria alter their ribosomes, scientists may develop strategies to prevent these changes or create new drugs that can effectively bind to the new ribosomes.