Dr. Dao Nguyen: Fighting Pseudomonas Aeruginosa in the Trikafta Era  

When the cystic fibrosis (CF) community talks about what they want most from research, eliminating infections from the bacteria Pseudomonas aeruginosa (PA) emerges as one of their top priorities. For decades, PA has been a constant threat to people with CF, requiring intensive antibiotic treatment and affecting their daily quality of life. Even in the era of highly effective modulator therapy (HEMT) like Trikafta,  Pseudomonas aeruginosa is still sticking around and Dr. Dao Nguyen’s lab wants to know why.   

Dr. Dao Nguyen is a Clinician-Scientist at McGill University, who has spent a large part of her career studying why Pseudomonas aeruginosa infections are chronic and difficult to treat. With the support of funding from Cystic Fibrosis Canada, she is turning her attention to CF patients on Trikafta as new questions emerge as to why this stubborn bacteria still infiltrates the airways of many.   

“Although patients on Trikafta are feeling a lot better and their infections are improving, Pseudomonas isn’t always completely cleared” says Dr. Nguyen. “This begs the question: why is that?” 

The Nguyen lab in the Meakins-Christie Laboratories at the Research Institute of the McGill University Heath Centre is exploring whether certain strains of Pseudomonas aeruginosa, often found in the lungs and airways, have developed ways to hide from the body’s defenses. In particular, they are looking at neutrophils, which are immune cells responsible for detecting and destroying bacteria in the body.  

“Neutrophils are very important in fighting Pseudomonas” she explains. “But we’ve seen in the past that some strains can resist or evade them, especially in patients with CF. Now, we want to know if that is still true in patients on Trikafta.” 

Immunotherapy for Infections? 

Dr. Nguyen’s team is interested in the potential of monoclonal antibodies to fight PA, which are lab-produced clones of natural proteins that help the immune system recognize and attack threats. In collaboration with an industry partner, her lab is testing whether a Pseudomonas-specific antibody could help neutrophils do their job better.  

As Director of the McGill Antimicrobial Resistance Centre, Dr. Nguyen brings a broad perspective on chronic infections and resistance. People with CF often require long-term antibiotic treatment, and a big concern is that the bacteria can stop responding to the medicine and become harder to get rid of.   

“If our findings support the use of these antibodies, we hope it opens the door for further therapy development by industry.” she says. “It’s exciting to work with something that could truly help people in clinical practice”.  

The Impact of HEMT 

HEMT has changed the landscape of CF care as the foundational knowledge the CF community has relied on is being rewritten.  

“In some ways, it’s a new chapter” Dr. Nguyen reflects. “Patients are healthier, they cough less, they produce less sputum. But that also makes it harder to detect and track infections.”  

Her lab is adapting by using technologies and methods than span from test tubes to mouse models to understand how these bacterial infections may or may not be cleared. And by working with collaborators across North America, they’re able to have access to sputum samples and clinical data from a wide range of patients.  

Community Connection 

After more than 20 years in CF research, Dr. Nguyen feels deeply connected to the CF research community. 

“This field is filled with people who are committed for the long haul. Many of my colleagues have been working in CF for decades. We share a common goal and support each other.” 

Even though her lab work doesn’t directly involve patients, Dr. Nguyen makes a point to regularly invite people with CF to share their story. 

“Hearing from patients reminds us why this work matters” she says. “It motivates our trainees and helps them understand that what they’re doing isn’t just an experiment.” 

She is honored to have received the Cathleen Morrison Award – awarded by Cystic Fibrosis Canada’s community reviewers that believe this research has the greatest potential to impact people living with CF. 

“It’s validation that we are on the right track – the questions we are asking are the ones that matter.” 

Dr. Nguyen is not just advancing science; she is helping build the next generation of CF researchers. She has been invested in mentoring young scientists and supporting their growth. Her team includes a postdoctoral fellow – Justine Mathe – who is a recipient of a Cystic Fibrosis Canada 2024 Research Fellowship Award.  

As CF care enters a new era, research like Dr. Nguyen’s will help ensure that better treatments are possible.