Achromobacter xylosoxidans airway infection is associated with lung disease severity in children with cystic fibrosis

Background Despite the increasing prevalence of Achromobacter xylosoxidans (A. xylosoxidans) lung infection in patients with cystic fibrosis (CF), its clinical pathogenicity remains controversial. The objective of this study was to evaluate the effects of this emerging bacterium on lung disease severity in CF children.

Methods This case-control retrospective study took place in two French paediatric CF centres. Forty-five cases infected by A. xylosoxidans were matched for age, sex, CFTR genotypes and pancreatic status, to 45 never infected controls. Clinical data were retrieved from clinical records over the 2 years before and after A. xylosoxidans initial infection.

Results At infection onset, lung function was lower in the cases compared to controls (p=0.006). Over the 2 years prior A. xylosoxidans acquisition, compared to controls, cases had more frequent pulmonary exacerbations (p=0.02), hospitalisations (p=0.05), as well as intravenous (p=0.03) and oral (p=0.001) antibiotic courses. In the 2 years following A. xylosoxidans infection, the cases remained more severe with more frequent pulmonary exacerbations (p=0.0001), hospitalisations (p=0.0001), as well as intravenous (p=0.0001) and oral antibiotic courses (p=0.0001). Lung function decline tended to be faster in the cases (−5.5%/year) compared to controls (−0.5%/year).

Conclusions This case-control study demonstrates that A. xylosoxidans occurs more frequently in the patients with the worse lung disease. Further studies assessing the pathogenicity of this emerging pathogen and international treatment recommendations are warranted.