A team of scientists at The University of Texas has made a groundbreaking discovery that certain bacteria, notably E. coli, use iron levels to encode and retrieve information relevant to collective behaviors such as forming biofilms and swarming. This mechanism, which resembles a memory system, could be pivotal in developing innovative strategies to fight bacterial infections and the growing issue of antibiotic resistance.
The research reveals that bacteria are capable of developing memory-like systems that inform tactics leading to serious human infections. These tactics involve the formation of bacterial swarms and the development of resistance to antibiotics.
This finding is crucial for the future prevention and treatment of bacterial infections, especially those caused by antibiotic-resistant strains. The process hinges on a ubiquitous chemical element used by bacterial cells to form and relay these “memories” across generations.
Investigations at The University of Texas at Austin
The University of Texas at Austin researchers discovered that E. coli bacteria rely on iron levels to store behavioral information, which is then triggered in response to specific environmental cues.
Their research is detailed in the Proceedings of the National Academy of Sciences.
It was already known that bacteria with previous swarming experience displayed enhanced swarming capabilities. The team from UT Austin sought to understand the underlying reasons for this.
Image of bacterial swarm in a lab. Courtesy of The University of Texas at Austin
Decoding Bacterial “Memories”
Unlike humans, bacteria lack neurons, synapses, or nervous systems. Their form of memory is analogous to data storage on a computer.
“Bacteria don’t possess brains, yet they can absorb environmental information. If they frequently encounter a specific environment, they’re able to store this data for future advantage,” explained Souvik Bhattacharyya, the study’s lead author and a provost early career fellow at UT’s Department of Molecular Biosciences.
Iron’s Influence on Bacterial Actions
Iron, a prevalent earthly element, plays a key role. Individual bacteria exhibit varying iron levels. Those with lower iron levels were observed to be more proficient at swarming, whereas biofilm-forming bacteria had higher iron levels. Bacteria with antibiotic tolerance also displayed balanced iron levels. These iron-based memories can last up to four generations and fade by the seventh.
Bhattacharyya noted, “Iron was a critical component in early cellular life on Earth, and it remains essential in the evolution of life. It’s logical that cells would use it in this manner.”
Video of a bacterial swarm under a microscope. Credit: The University of Texas at Austin
The researchers hypothesize that low iron levels activate bacterial memories, prompting a swift swarm migration to seek iron. Conversely, high iron levels signal a conducive environment for biofilm formation.
“Iron levels are a key focus for therapeutic development, given their role in bacterial virulence,” Bhattacharyya stated. “The deeper our understanding of bacterial behavior, the better we can counteract them.”
The study, titled “A heritable iron memory enables decision-making in Escherichia coli” by Souvik Bhattacharyya and colleagues, was published on 21 November 2023 in the Proceedings of the National Academy of Sciences (DOI: 10.1073/pnas.2309082120).
Funded by the National Institutes of Health, the research also included contributions from Rasika Harshey, Nabin Bhattarai, Dylan M. Pfannenstiel, Brady Wilkins, and Abhyudai Singh from the University of Delaware. Rasika Harshey, a professor of molecular biosciences and Mary M. Betzner Morrow Centennial Chair in Microbiology, is the senior corresponding author of the paper.
Frequently Asked Questions (FAQs) about Bacterial Memory Research
What is the Key Discovery in the Bacteria Research by The University of Texas?
Researchers at The University of Texas found that E. coli bacteria use iron levels as a kind of memory system, influencing behaviors like swarming and forming biofilms.
How Does Iron Influence Bacterial Behavior?
Bacteria with lower levels of iron show enhanced swarming ability, while those with higher iron levels are more likely to form biofilms. This relationship plays a crucial role in bacterial responses and memory-like mechanisms.
What are the Implications of this Bacterial Memory Discovery?
This discovery opens up new avenues for treating and preventing bacterial infections, especially those involving antibiotic-resistant strains, by targeting their iron-based memory systems.
What Does This Research Suggest About Bacteria and Memory?
While bacteria do not have brains or nervous systems, they can store and recall environmental information using iron levels, which acts as a memory-like mechanism.
Who Led the Research on Bacterial Memory and Where Was it Published?
The research was led by Souvik Bhattacharyya and colleagues at The University of Texas at Austin and published in the Proceedings of the National Academy of Sciences.
More about Bacterial Memory Research
- University of Texas Bacterial Memory Study
- Proceedings of the National Academy of Sciences
- E. coli Behavioral Research
- Antibiotic Resistance and Biofilm Formation
- Iron’s Role in Bacterial Behavior