Study Examines Risk Factors for Bacterial Colonization in Bronchiectasis

Study Examines Risk Factors for Bacterial Colonization in Bronchiectasis

Among people with bronchiectasis, those more than 55 years old or who have bronchiectasis as a result of infection, are at an increased risk of being colonized with the bacteria Pseudomonas aeruginosa.

This finding was published in the European Journal of Clinical Microbiology & Infectious Diseases in an article titled “Predicting factors for chronic colonization of Pseudomonas aeruginosa in bronchiectasis.”

The human body is home for many different kinds of bacteria; most are benign, but some cause health problems. It’s known that people with bronchiectasis who have P. aeruginosa infection in their lungs are at  increased risk of frequent exacerbations and more hospital stays. But the unanswered question remains, what makes an individual more likely to be colonized by P. aeruginosa in the first place?

To find out, researchers reviewed clinical data from 211 people with bronchiectasis who were treated at the Erasmus University Medical Center, Rotterdam, The Netherlands, from 2012 to 2016. Most patients were men (54%), had never smoked (63%), and their average age was 60.

Results showed that one quarter (25%, 53 patients) of the patients were chronically colonized with P. aeruginosa, as determined by culturing sputum samples.

Compared to patients negative for P. aeruginosa, colonized patients were significantly more likely to be older than 55, and to be users of hypertonic saline and inhalation antibiotics. They also werevmore likely to have developed bronchiectasis following an infection or primary ciliary dyskinesia.

P. aeruginosa infection also was significantly more common among smokers, users of macrolides (a type of antibiotic), and patients with worse clinical scores, and more frequent hospital admissions.

However, the team noted, these are only associations, and should be interpreted with caution. For instance, patients who used inhaled antibiotics were more likely to have P. aeruginosa, but that’s probably because “inhalation antibiotics were solely given to patients with Pseudomonas colonization” the researchers wrote. That suggests the bacteria’s presence caused the increased antibiotic use, not the other way around.

“It is hard to determine whether the use of hypertonic saline is a cause or consequence of Pseudomonas colonization,” the team stated.

Still, overall, the data suggest that some bronchiectasis patient populations might be at a greater risk of P. aeruginosa colonization.

“Since prevention of P. aeruginosa colonization is an important aim in the treatment of bronchiectasis, more attention could be directed to these groups at risk for Pseudomonas colonization,” the team concluded.