1226. Clinical Outcomes of Achromobacter Species in Adult Cystic Fibrosis Patients: A Cohort Study
Session: Poster Abstract Session: Clinical Infectious Diseases: Respiratory Infections
Friday, October 28, 2016
Room: Poster Hall
  • Achromobacter IDSA.pdf (1.2 MB)
  • Background:

    The clinical significance of lung infection in cystic fibrosis (CF) due to classic pathogens is well established. However, Achromobacter species are Gram-negative pathogens increasingly recognized in CF with unclear clinical impact as the evidence is restricted to small European studies (De Baets, J Cyst Fibros 2007).


    We conducted a cohort study of CF patients attending a Canadian CF clinic who cultured Achromobacter species in their sputum between 1984-2015 to assess the prevalence and clinical impact of infection. Achromobacter was categorized as intermittent (minimum 1 positive culture) or chronic infection (≥2 positive cultures) in the preceding 12 months. Data was collected for a 2-year period prior to and following first Achromobacter isolation. Primary outcome was the proportion of patients with pulmonary exacerbation (PEx) at time of first isolation. Next, those with chronic infection were matched with 2:1 age and sex-matched controls with no history of Achromobacter infection. Multivariable mixed effects models were used to assess rate of PEx and lung function decline.


    There were 34 patients (11% of clinical cohort) with median age 24.8 (IQR 20.6-30.8) and median BMI of 19.4 kg/m2 (IQR 18.1-22.1) included. Of these, 10 patients (29%) developed chronic infection in the study period, though they did not differ in baseline lung function. 14 patients (41%; 95% CI 25-58%) had a PEx at first isolation and of these, 4 (29%) were severe PEx. Achromobacter isolates displayed multi-drug resistance with resistance rates of 80% to aztreonam, 86% to tobramycin, and 43% to ticarcillin. There was no association of infection with rate of PEx or lung function decline in the total cohort (pre vs. post index infection) or in the matched cohort.


    In this Canadian CF cohort, Achromobacter species infection was associated with frequent PEx, including severe PEx, at time of initial isolation but not with increased subsequent PEx risk or lung function decline. Larger multi-center studies are required to further understand the impact of Achromobacter infection in CF.

    Brett Edwards, M.D.1, Ranjani Somayaji, M.D.2, Jasper Greysson-Wong, B.Sc.3, Harvey Rabin, M.D.4 and Michael Parkins, MD4, (1)Department of Medicine, University of Calgary, Calgary, AB, Canada, (2)Department of Medicine; Division of Microbiology & Infectious Diseases, University of Calgary and Alberta Health Services - Calgary zone, Calgary, AB, Canada, (3)University of Calgary, Calgary, AB, Canada, (4)Department of Medicine; Division of Microbiology & Infectious Diseases, University of Calgary, Calgary, AB, Canada


    B. Edwards, None

    R. Somayaji, None

    J. Greysson-Wong, None

    H. Rabin, None

    M. Parkins, None

    Findings in the abstracts are embargoed until 12:01 a.m. CDT, Wednesday Oct. 26th with the exception of research findings presented at the IDWeek press conferences.