Bonnie Bassler wins the 2023 Canada Gairdner International Award

The government of Canada announced today that Bonnie Bassler is being awarded the Canada Gairdner International Award 2023 alongside Michael Silverman and E. Peter Greenberg “for their discoveries of how bacteria communicate with each other and surrounding non-bacterial cells, providing a new paradigm for how microbes behave and yielding novel avenues for therapeutics against infectious diseases.” The Canada Gairdner Award is one of the most prestigious biomedical and global health awards in the world.

Bonnie Bassler

Bonnie Bassler

Bassler is Princeton’s Squibb Professor in Molecular Biology, Greenberg is a professor of microbiology and the molecular and cellular biology program at the University of Washington School of Medicine, and Silverman is an emeritus investigator with The Agouron Institute and an emeritus adjunct professor with the Scripps Institution of Oceanography.

The three scientists are being honored for discovering “quorum sensing,” the remarkable finding that bacteria talk to each other. “These discoveries revolutionized how we understand the microbial world and the relationship between bacteria, human health and disease,” the Gairdner Foundation said. “These scientists’ contributions paved the way for groundbreaking solutions to pressing problems in health and the environment.”

“I have followed the Gairdner Award for my entire career,” said Bassler. “Each year, I am awestruck by the pioneering scientists selected as winners. I never dared to imagine myself a member of that group, so winning the prize far exceeds my dreams. Also, it is most meaningful to me to receive the Gairdner Award together with my spectacular mentor Mike Silverman. Mike made the groundbreaking discoveries that launched the field of quorum sensing. As the field gained prominence soon after Mike’s early retirement, sadly, he was not recognized as the field’s founder. By selecting Mike as a Canada Gairdner Award recipient, the Gairdner Foundation has set the record straight. Thus, I am doubly happy about receiving the award.”

Bassler has spent her career investigating how bacteria talk to each other and orchestrate collective behaviors. Quorum sensing allows bacteria to coordinate their activities and, together, accomplish tasks that no single bacterium could accomplish if it acted alone. Alone, each bacterium is too small to make a difference. Quorum sensing relies on the production, detection and response to biochemical "words" (signal molecules).

The discovery of quorum sensing started with bioluminescence, the light emitted by organisms like fireflies and deep-sea fish. In the 1970s, scientists discovered that a bacterium called Vibrio fischeri released a chemical that stimulated bioluminescence when the cells were in a group, but not when alone.

A decade later, Silverman identified the first quorum sensing circuits. Silverman’s studies revealed the basic regulatory mechanisms controlling collective luminescence and, more broadly, provided the impetus for the discovery of thousands of related systems that underlie group behaviors in diverse bacteria. Greenberg was involved in showing that bacteria other than V. fischeri can communicate with each other, and he further fleshed out the mechanisms revealed by Silverman. Bassler, who had been a postdoc in Silverman’s lab, discovered that quorum sensing is not a rare phenomenon but is the norm throughout the bacterial world.

Since coming to Princeton, Bassler and her research team have demonstrated that bacteria use signal molecules to detect themselves (intra-species communication), related family members (intra-genera communication), others (inter-species communication), and non-bacteria (inter-domain communication). In every case, the chemical entities she discovered were new molecules to mankind.

Bassler’s group has demonstrated that interactions across all domains of life — eukaryotic, bacterial and viral — all depend on quorum sensing. For example, human intestinal cells use quorum-sensing molecules to communicate with bacteria of the gut microbiome, to help the body fight off disease. She also discovered that “eavesdropping viruses” can hijack the information encoded in quorum-sensing signal molecules to infect and kill quorum-sensing bacteria. Bassler’s team has invented quorum-sensing interference strategies for development into new medicines.

“Our view is that continuing to study bacterial quorum sensing will lead to new methods to combat infectious diseases,” she said. “Our focus is on antibiotic resistant infections. Because our anti-quorum-sensing compounds target bacterial signaling, not bacterial growth, we expect our therapies to be far less susceptible to antibiotic resistance than traditional antibiotics.”

She continued: “On a brighter note, we also now know that bacteria are higher organisms’ needed microbiome partners. For example, they supply us with biomolecules that our bodies can’t produce but are required for life. Quorum sensing is crucial for harmony among beneficial bacteria in the human microbiome and beyond. In addition to disrupting quorum sensing in pathogens, my group is developing pro-quorum-sensing compounds. Our goal is to safely and strategically deploy them to drive bacteria to make us healthier, to grow our food, to clean up our pollution, and to make ingenious bio-inspired products.

Bassler has received many awards and honors, including a MacArthur Foundation Fellowship, the Gruber Genetics Prize, the Wolf Prize in Chemistry, the Dickson Prize in Medicine, the UNESCO-L’Oreal Woman in Science Prize for North America, the Genetics Society of America Medal, and many others. She is a Howard Hughes Medical Institute Investigator and a member of the National Academy of Sciences, the National Academy of Medicine, the American Academy of Arts and Sciences, and the American Philosophical Society. President Barack Obama appointed her to the National Science Board, which prioritizes the nation’s research and educational activities in science, math and engineering.

The Gairdner Foundation, established in 1957, is dedicated to fulfilling James A. Gairdner’s vision to recognize major research contributions to the treatment of disease and alleviation of human suffering. Through annual prestigious Canada Gairdner Awards, the Gairdner Foundation celebrates the world’s most creative and accomplished researchers whose work is improving the health and wellbeing of people around the world. Since its inception, 410 awards have been bestowed on laureates from over 40 countries, and of those awardees, 96 have gone on to receive Nobel Prizes.