title: Achromobacter xylosoxidansinfection in cystic fibrosis siblings with different outcomes: Case reports.
abstract: BACKGROUND
  The clinical relevance ofAchromobacter xylosoxidansinfection in cystic fibrosis (CF) remains controversial. This emerging agent in CF has been associated with increased lung inflammation, more frequent exacerbations and more severe lung disease. We describe a pair of CF siblings chronically colonized by the same multilocus genotype ofA. xylosoxidanswith different clinical courses, and assess whether this species may have developed any virulence traits and antimicrobial resistance that could have contributed to their singular outcomes.
  
  
  METHODS
  Two siblings were positive for the F508del and Y1092X mutations, and were chronically colonized byPseudomonas aeruginosaandStaphylococcus aureus. The female patient had a more severe CF phenotype and faster clinical deterioration than her brother. Her pulmonary function and computed tomography scan lesions were worse than those of her brother, and both parameters progressively declined. She died at 14 years of age, when he was 18. All isolates ofA. xylosoxidanswere biofilm producers.Achromobacter xylosoxidansshowed less swarming motility in the female patient.
  
  
  CONCLUSIONS
  Biofilm production and diminution of motility allow persistence. Only swarming motility differed between the isolates recovered from the two siblings, but this finding is not sufficient to explain the different clinical outcomes despite their similar genotypes. Modifier genes, unknown environmental factors and female gender can partially explain differences between these siblings. We were unable to correlate any microbiological findings with their clinical courses, and more translational studies are necessary to decrease the gap of knowledge between laboratory and clinical data to promote better clinical interventions.
authors.affiliation: Postgraduate Programme in Medical Sciences, School of Medical Sciences, State University of Rio de Janeiro, Av. Prof. Manoel de Abreu, 444, 2º andar, Vila Isabel, 20550-170, Rio de Janeiro, Brazil.
authors.forename: Mônica Cássia
authors.initials: MC
authors.lastname: Firmida
authors.affiliation: Postgraduate Programme in Medical Sciences, School of Medical Sciences, State University of Rio de Janeiro, Av. Prof. Manoel de Abreu, 444, 2º andar, Vila Isabel, 20550-170, Rio de Janeiro, Brazil; Department of Microbiology, Immunology and Parasitology, School of Medical Sciences, State University of Rio de Janeiro, Av. Prof. Manoel de Abreu, 444, 3º andar, Vila Isabel, 20550-170, Rio de Janeiro, Brazil; Bacteriology Laboratory, University Hospital Pedro Ernesto, State University of Rio de Janeiro, Boulevard 28 de Setembro, 77, 1º andar, Vila Isabel, 20551-030, Rio de Janeiro, Brazil.
authors.forename: Elizabeth Andrade
authors.initials: EA
authors.lastname: Marques
authors.affiliation: Postgraduate Programme in Medical Sciences, School of Medical Sciences, State University of Rio de Janeiro, Av. Prof. Manoel de Abreu, 444, 2º andar, Vila Isabel, 20550-170, Rio de Janeiro, Brazil; Department of Microbiology, Immunology and Parasitology, School of Medical Sciences, State University of Rio de Janeiro, Av. Prof. Manoel de Abreu, 444, 3º andar, Vila Isabel, 20550-170, Rio de Janeiro, Brazil; Bacteriology Laboratory, University Hospital Pedro Ernesto, State University of Rio de Janeiro, Boulevard 28 de Setembro, 77, 1º andar, Vila Isabel, 20551-030, Rio de Janeiro, Brazil.
authors.forename: Robson Souza
authors.initials: RS
authors.lastname: Leão
authors.affiliation: Department of Microbiology, Immunology and Parasitology, School of Medical Sciences, State University of Rio de Janeiro, Av. Prof. Manoel de Abreu, 444, 3º andar, Vila Isabel, 20550-170, Rio de Janeiro, Brazil.
authors.forename: Rosana Helena Vicente
authors.initials: RH
authors.lastname: Pereira
authors.affiliation: Bacteriology Laboratory, University Hospital Pedro Ernesto, State University of Rio de Janeiro, Boulevard 28 de Setembro, 77, 1º andar, Vila Isabel, 20551-030, Rio de Janeiro, Brazil.
authors.forename: Elenice Rosa Aguiar
authors.initials: ER
authors.lastname: Rodrigues
authors.affiliation: Department of Biochemistry, School of Medical Sciences, State University of Rio de Janeiro, Boulevard 28 de Setembro, 77, 4º andar, Vila Isabel, 20551-030, Rio de Janeiro, Brazil.
authors.forename: Rodolpho Mattos
authors.initials: RM
authors.lastname: Albano
authors.affiliation: Postgraduate Programme in Medical Sciences, School of Medical Sciences, State University of Rio de Janeiro, Av. Prof. Manoel de Abreu, 444, 2º andar, Vila Isabel, 20550-170, Rio de Janeiro, Brazil; Department of Pediatric Pulmonology, Fernandes Figueira Institute, Av. Rui Barbosa, 716, Flamengo, Rio de Janeiro, Brazil.
authors.forename: Tania Wrobel
authors.initials: TW
authors.lastname: Folescu
authors.affiliation: Department of Biochemistry, School of Medical Sciences, State University of Rio de Janeiro, Boulevard 28 de Setembro, 77, 4º andar, Vila Isabel, 20551-030, Rio de Janeiro, Brazil.
authors.forename: Vagner
authors.initials: V
authors.lastname: Bernardo
authors.affiliation: Department of Radiology, Fernandes Figueira Institute, Av. Rui Barbosa, 716, Flamengo, Rio de Janeiro, Brazil.
authors.forename: Pedro
authors.initials: P
authors.lastname: Daltro
authors.affiliation: Postgraduate Programme in Medical Sciences, School of Medical Sciences, State University of Rio de Janeiro, Av. Prof. Manoel de Abreu, 444, 2º andar, Vila Isabel, 20550-170, Rio de Janeiro, Brazil.
authors.forename: Domenico
authors.initials: D
authors.lastname: Capone
authors.affiliation: Postgraduate Programme in Medical Sciences, School of Medical Sciences, State University of Rio de Janeiro, Av. Prof. Manoel de Abreu, 444, 2º andar, Vila Isabel, 20550-170, Rio de Janeiro, Brazil.
authors.forename: Agnaldo José
authors.initials: AJ
authors.lastname: Lopes
keywords: Achromobacter spp.; Achromobacter xylosoxidans; Cystic fibrosis