Clinical impact of Achromobacter xylosoxidans colonization/infection in patients with cystic fibrosis

Braz J Med Biol Res. 2016;49(4):e5097. doi: 10.1590/1414-431X20155097. Epub 2016 Feb 23.


The rate of diagnosis of colonization/infection of the airways with Achromobacter xylosoxidans has increased in cystic fibrosis patients, but its clinical significance is still controversial. This retrospective, case-control study aimed to evaluate the clinical impact of A. xylosoxidans colonization/infection in cystic fibrosis patients. Individuals who were chronically colonized/infected (n=10), intermittently colonized/infected (n=15), and never colonized/infected with A. xylosoxidans (n=18) were retrospectively evaluated during two periods that were 2 years apart. Demographic characteristics, clinical data, lung function, and chronic bacterial co-colonization data were evaluated. Of the total study population, 87% were pediatric patients and 65.1% were female. Individuals chronically colonized/infected with A. xylosoxidans had decreased forced expiratory volume in 1 s (51.7% in the chronic colonization/infection group vs 82.7% in the intermittent colonization/infection group vs 76% in the never colonized/infected group). Compared with the other two groups, the rate of co-colonization with methicillin-resistant Staphylococcus aureus was higher in individuals chronically colonized/infected with A. xylosoxidans (P=0.002). Changes in lung function over 2 years in the three groups were not significant, although a trend toward a greater decrease in lung function was observed in the chronically colonized/infected group. Compared with the other two groups, there was a greater number of annual hospitalizations in patients chronically colonized/infected with A. xylosoxidans (P=0.033). In cystic fibrosis patients, there was an increased frequency of A. xylosoxidans colonization/infection in children, and lung function was reduced in patients who were chronically colonized/infected with A. xylosoxidans. Additionally, there were no differences in clinical outcomes during the 2-year period, except for an increased number of hospitalizations in patients with A. xylosoxidans.

MeSH terms

  • Achromobacter denitrificans / isolation & purification*
  • Adolescent
  • Adult
  • Age Factors
  • Analysis of Variance
  • Case-Control Studies
  • Child
  • Child, Preschool
  • Cystic Fibrosis / microbiology*
  • Female
  • Forced Expiratory Volume
  • Gram-Negative Bacterial Infections / microbiology*
  • Humans
  • Infant
  • Lung / physiopathology
  • Male
  • Methicillin-Resistant Staphylococcus aureus / isolation & purification
  • Reference Values
  • Retrospective Studies
  • Statistics, Nonparametric
  • Time Factors
  • Young Adult