40-year single center experience of Burkholderia cystic fibrosis airway infections.

OBJECTIVES: To resolve the epidemiology of airway infections with Burkholderia cepacia complex (Bcc) in people with cystic fibrosis (pwCF) over 40 years at a single treatment center. METHODS: All Bcc and Burkholderia gladioli airway isolates were collected from pwCF who presented at the CF outpatient and the lung transplantation clinics from 1983 to 2022. RESULTS: The collection of 1205 strains is dominated by B. multivorans (56 %) followed by B. cenocepacia (16 %), B. stabilis (10 %) and B. orbicola (9%). Twenty-seven pwCF experienced a single self-limiting episode of airway infection with Bcc. Thirteen pwCF were harboring Bcc for 1.7 to 13.6 years and 15 pwCF were persistently infected with Bcc. Sixteen Bcc-positive CF patients received a lung transplant. Fatal post-transplant sepsis happened in one B. multivorans-, two B. cenocepacia- and two B. orbicola-positive patients. CONCLUSIONS: After the first acquisition of Bcc, transient carriage was 2.7 times more frequent than persistent colonization. Infections with B. cenocepacia or B. orbicola confer a higher risk for post-transplant sepsis than an infection with B. multivorans.

Effective prevention of Pseudomonas aeruginosa cross-infection at a cystic fibrosis centre - results of a 10-year prospective study.

Pseudomonas aeruginosa is the major pathogen in chronic lung infections of individuals with cystic fibrosis (CF). Unrelated CF patients may acquire P. aeruginosa from the environment or by cross-infection in the CF setting. We tested the efficacy of measures to prevent nosocomial acquisition of P. aeruginosa at a Paediatric CF centre in a prospective 10-year study. P. aeruginosa-positive and P. aeruginosa-negative patients were seen in alternating weeks at the outpatient clinic. Faucets were equipped with filters to prevent bacterial contamination of tap water. Serial isolates were collected since the first documentation of a P. aeruginosa-positive culture and genotyped with a multimarker microarray. During the 10-year study, the annual prevalence of patients with at least one P. aeruginosa-positive culture was 39±6% in a population of 149±12 patients. P. aeruginosa was detected for the first time in 54 patients of whom 11 patients became chronically colonised with P. aeruginosa. Transient colonisations were recorded 97 times. A nosocomial acquisition of P. aeruginosa at the CF centre probably happened in one case. The worldwide dominant clones in the global P. aeruginosa population were also the most abundant clones in the panel of 324 early CF isolates. No rare clone had expanded by nosocomial transmission. It can be concluded that cross-infection with P. aeruginosa was prevented with simple hygienic measures at a CF centre that had experienced local outbreaks of nosocomial spread among unrelated patients in the past.

EuroCareCF quality assessment of diagnostic microbiology of cystic fibrosis isolates.

The identification of microbial species from respiratory specimens and their susceptibility to antimicrobial agents are among the most important diagnostic measures of care for patients with cystic fibrosis (CF). Under the umbrella of EuroCareCF, two quality assurance trials of CF microbiology were performed in 2007 and 2008. Nine formulations with CF bacterial isolates were dispatched. A total of 31/37 laboratories from 18/21 European countries participated in the 2007 and 2008 trials. The common CF pathogens Pseudomonas aeruginosa and Staphylococcus aureus were correctly identified by almost all participants in both trials, even if the strains presented uncommon phenotypes. Burkholderia cenocepacia IIIB and Burkholderia vietnamensis CF isolates, however, were correctly assigned to the species level by only 26% and 27% of the laboratories, respectively. Emerging pathogens such as Achromobacter xylosoxidans, Inquilinus limosus, and Pandoraea pnomenusa were also not detected or were misclassified by many laboratories. One participant correctly identified all CF isolates in both trials. The percentages of correct classifications (susceptible, intermediate, resistant) by antimicrobial susceptibility testing ranged from 55 to 100% (median, 96%) per isolate and drug. The shortcomings in the diagnostics of rare and emerging pathogens point to the need for continuing education in CF microbiology and suggest the establishment of CF microbiology reference laboratories.