title: Association between Staphylococcus aureus alone or combined with Pseudomonas aeruginosa and the clinical condition of patients with cystic fibrosis.
abstract: BACKGROUND
  The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in cystic fibrosis (CF) patients has increased and MRSA seems to be associated with a poorer prognosis. The aim of this study was to assess the prevalence and clinical consequences of MRSA and methicillin-susceptible Staphylococcus aureus (MSSA), associated or not associated with Pseudomonas aeruginosa (PA).
  
  
  METHODS
  In a retrospective study on 419 sputum producer patients (293 adults and 126 children >7 years of age), we recorded patient characteristics, lung function, nutritional status, i.v. antibiotics and hospitalisations, the presence of SA and/or PA and FEV1 decline over 2 years.
  
  
  RESULTS
  SA was found in 72% of the patients: MSSA in 68.2% of children and 48.8% of adults; MRSA in 17.5% of children and 17.8% of adults. Sixty percent of MRSA patients and 60.4% of MSSA patients also harboured PA. The rate of deterioration of clinical status of the various groups, as assessed from respiratory function, i.v. antibiotic courses and hospitalisations, increased in the order: no SA/no PA, MSSA alone, MRSA alone, MSSA/PA, MRSA/PA, and PA alone. Nutritional status did not differ between groups. Results were roughly similar for children and adults. The yearly FEV1 decline was significantly higher only for MRSA/PA patients (p=0.03) compared to no SA/no PA patients.
  
  
  CONCLUSIONS
  Clinical condition of CF patients with MSSA only or MRSA only appeared similar, whereas MRSA/PA patients had more severe respiratory function than MSSA/PA patients. In CF patients, MRSA might be more deleterious than MSSA only when associated with PA.
authors.affiliation: Service de Pneumologie, Hôpital Cochin, AP-HP, Paris, France. dominique.hubert@cch.aphp.fr
authors.forename: Dominique
authors.initials: D
authors.lastname: Hubert
authors.forename: Hélène
authors.initials: H
authors.lastname: Réglier-Poupet
authors.forename: Isabelle
authors.initials: I
authors.lastname: Sermet-Gaudelus
authors.forename: Agnès
authors.initials: A
authors.lastname: Ferroni
authors.forename: Muriel
authors.initials: M
authors.lastname: Le Bourgeois
authors.forename: Pierre-Régis
authors.initials: PR
authors.lastname: Burgel
authors.forename: Raphaël
authors.initials: R
authors.lastname: Serreau
authors.forename: Daniel
authors.initials: D
authors.lastname: Dusser
authors.forename: Claire
authors.initials: C
authors.lastname: Poyart
authors.forename: Joël
authors.initials: J
authors.lastname: Coste
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D015331:Cohort Studies; D003550:Cystic Fibrosis / Q000150:complications* / Q000382:microbiology*; D005260:Female; D006801:Humans; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus; D008875:Middle Aged; D015995:Prevalence; D011552:Pseudomonas Infections / Q000150:complications* / Q000453:epidemiology; D011550:Pseudomonas aeruginosa; D012189:Retrospective Studies; D013203:Staphylococcal Infections / Q000150:complications* / Q000453:epidemiology; D055815:Young Adult
keywords: Cystic fibrosis; Lung function; MRSA; Pseudomonas aeruginosa; Staphylococcus aureus