Sequential Burkholderia cenocepacia Isolates from Siblings with Cystic Fibrosis Show Increased Lung Cell Attachment
Abstract
Burkholderia cepacia complex (Bcc) is a group of 20 genetically distinct bacterial species (1) that has a severe impact on the quality of life of people with cystic fibrosis (CF) and is associated with a more rapid decline of lung function than Pseudomonas aeruginosa (2). B. cenocepacia is the most virulent species within the Bcc and is most frequently associated with septicemia, although other Bcc species have also been linked to bloodstream infections (BSI) (2, 3).
Many pathogens alter their phenotype during chronic infection in response to changing selection pressures, coinfecting species, and antimicrobial therapies (4, 5). Studies on bacterial adaptation in the CF context have predominantly focused on P. aeruginosa; however, the adaptive strategies of B. cenocepacia isolates have also been examined (4, 6, 7).
Antimicrobial resistance, loss of motility, tolerance of iron limitation, and increased virulence to host cells over time of chronic infection were reported. In contrast, P. aeruginosa and another member of the Bcc, B. multivorans, showed reduced virulence over time of infection (5, 8).
We have examined two series of sequential isolates from two adult male siblings with CF (referred to as P1 and P2). Both patients became infected with Bcc during their teens and were chronically infected when transitioning to adult care.