The presence of multidrug resistant bacteria in the airways of patients with cystic fibrosis is associated with decreased microbial diversity, according to a study published in Heliyon.

In the study, the researchers recruited six patients with CF from Children’s National during well-child visits. During those appointments, the research team collected respiratory secretions from these volunteers.

The scientists then analyzed each sample in two different ways. They used some to grow cultures in petri dishes. They used another part of the sample to run genetic analyses that searched for antibiotic resistance genes.

Patients who carried MRSA or other antibiotic-resistant bacteria had significantly lower microbial diversity in their samples and more aggressive disease. Their samples also were more likely to contain bacteria of the genus Alcaligenes, whose role in CF is not yet known.