How Cystic Fibrosis Canada Funded Researchers Are Tackling The Problem Of Bacterial Infections In Lungs Of People With CF

Paul Naphtali in the lab - image

AUGUST 24, 2021

Over the past 60 years, much progress has been made by the cystic fibrosis (CF) research community to improve quality of life and care for CF patients, and that progress continues today. In fact, new discoveries and ongoing research are taking place that continue to change the course of care for people living with CF. It is because of advancements in research that antimicrobial therapy, which kills or inhibits the growth of microorganisms such as bacteria, fungi, or protozoans, has helped to nearly double the life expectancy of Canadian CF patients. Despite these advances, bacterial infections continue to drive pulmonary exacerbations and raise the risk of death for CF patients. To reduce these risks, patients are often treated with inhaled antibiotics. Even with intense antibiotic treatment, bacteria can still grow in the CF airways, generating chronic infections.  

Pseudomonas aeruginosa (PA)is the most notorious of these bacteria, and it is the most prevalent bacterium in adults with CF. Worse yet, P. aeruginosa can survive antibiotic treatment, even when clinical labs diagnose the isolated bacterium as antibiotic susceptible.  Topping it off, P. aeruginosa can produce an arsenal of toxins that cause inflammation in the CF airways. Developing a way to keep this harmful bacterium at bay is crucial for ensuring long-term care for CF patients. In this regard, new research can provide hope.

To that end, Canadian CF researchers at McGill University are working hard to understand how to best prevent P. aeruginosa from growing in the CF airways. The team led by Dr. Dao Nguyen, funded by Cystic Fibrosis Canada, recently published a study that details a possible way in which P. aeruginosa can survive intense antibiotic treatment. Her team identified a group of CF children still positive for P. aeruginosa a month after first detection, even after 28 days of twice-daily antibiotic therapy.

Some immune cells are specialized in destroying bacteria. One way immune cells can help kill bacteria is by swallowing them up. Dr. Nguyen’s team found that P. aeruginosa cells that survived antimicrobial treatment were better able to resist these immune cells, the key finding from the study.


Through their work, the Nguyen Lab highlighted the importance of studying how PA interacts with the immune system of a CF patient. How well a PA population can withstand antibiotic treatment may depend either on the immune system’s ability to kill the cells or the PA strain’s ability to evade killing by the immune system. Either of these scenarios provide great opportunities toward developing additional therapies that make it easier for immune cells to kill infecting bacterial populations.

Dr. Dao Nguyen

Associate Professor, Department of Medicine, McGill University
Physician, Div Respirology, McGill University Health Centre 
Scientist, Meakins Christie Laboratories and RESP program, Research Institute of the McGill University Health Centre 
Director, McGill Antimicrobial Resistance Centre


Paul Naphtali

Paul Naphtali is a PhD Candidate studying the microbial communities in the CF airways and Prairie Epidemic Strain infections. Paul’s thesis focuses on identifying the genes that may contribute to microbial infection dynamics in the CF airways through RNA sequencing. His research specialties include microbiology, bioinformatics, and gene expression analysis. 


Cystic Fibrosis Canada is pleased to announce our Grants and Fellowships competition this fall to support outstanding Canadian research on Cystic Fibrosis.  We will be accepting applications from scientists and clinicians at Canadian institutions for a variety of grants and awards. New for this year, applicants to the basic or clinical grants and early career investigator awards competitions will be asked to describe how their research aligns to the top research priorities of the Canadian CF community.  Following scientific review, a CF community stakeholder review panel will help determine which research grants should be funded.  More information on how to apply can be found here.

Dr. Nguyen with lab team