Microscopic freshwater organisms pilfer antibiotics from bacteria for self-defense

Recent research conducted by a team from the University of Oxford, the University of Stirling, and the Marine Biological Laboratory (MBL) in Woods Hole has uncovered a fascinating discovery about a group of small freshwater animals known as bdelloid rotifers. These tiny creatures, despite being smaller than a hair’s breadth, possess typical animal features such as a head, mouth, gut, muscles, and nerves. What sets them apart is their unique ability to protect themselves from infections using antibiotic recipes „stolen“ from bacteria.

When exposed to fungal infections, the study found that bdelloid rotifers activate hundreds of genes acquired from bacteria and other microbes. Some of these genes are responsible for producing defense mechanisms, including antibiotics and other antimicrobial agents, within the rotifers. Lead study author Chris Wilson of the University of Oxford expressed surprise at the discovery, stating, „The main genes were instructions for chemicals that we didn’t think animals could make — they looked like recipes for antibiotics.“

Previous studies have shown that rotifers have been acquiring DNA from their environment for millions of years. However, this new research is the first to observe their utilization of these genes in combating diseases. No other creatures are known to acquire genes from microorganisms to the extent that bdelloid rotifers do. Study co-author David Mark Welch of the Marine Biological Laboratory noted, „These complex genes – some of which aren’t found in any other animals – were acquired from bacteria but have undergone evolution in rotifers. This raises the potential that rotifers are producing novel antimicrobials that may be less toxic to animals, including humans, than those we develop from bacteria and fungi.“

Antibiotics play a crucial role in modern healthcare, and many of these essential drugs are naturally produced by fungi and bacteria. The discovery of rotifers utilizing genes from microbes to produce antibiotics could provide valuable insights for developing new drugs to combat human infections caused by bacteria or fungi. With the increasing threat of antibiotic resistance, this research could lead to innovative solutions in the ongoing battle against resistant microbes.

The genes that the rotifers obtained from bacteria contain a unique type of enzymes that construct amino acids into non-ribosomal peptides. Study co-author Irina Arkhipova of the Marine Biological Laboratory emphasized the importance of identifying multiple non-ribosomally synthesized peptides produced by bdelloid rotifers and establishing the conditions for inducing the synthesis of these compounds.

One of the challenges in drug development is the toxicity of many antibiotic substances produced by bacteria and fungi. If rotifers are already producing similar substances in their cells, it could pave the way for the development of safer drugs for use in other animals, including humans.

Rotifers‘ unique ability to acquire and utilize genes from microbes at high rates may be linked to their asexual reproduction, which results in genetic copies without genetic recombination. This lack of genetic variation could make them more susceptible to health issues, as any disease affecting one individual could spread throughout the population. Unlike sexually reproducing animals, rotifers do not have the opportunity for their parental genes to recombine beneficially, leading to a direct passing on of the mother’s genome to her offspring without introducing new variation.

The study authors believe that there is much more to learn from rotifers and their stolen DNA. Reuben Nowell of the University of Stirling highlighted the significance of the findings, stating, „The antibiotic recipes are exciting, and some other genes even look like they’ve been taken from plants. The findings are part of a growing story about how and why genes get moved between different kinds of life.“

In conclusion, the research on bdelloid rotifers and their use of antibiotic recipes „stolen“ from bacteria opens up new possibilities for drug development and understanding the intricate mechanisms of microbial defense in these tiny creatures. This groundbreaking study sheds light on the potential for developing novel antimicrobials that could be less toxic and more effective in combating infections in animals, including humans.