title: Differences in biofilm development and antibiotic susceptibility among Streptococcus pneumoniae isolates from cystic fibrosis samples and blood cultures.
abstract: OBJECTIVE
  To compare the capability of biofilm development between Streptococcus pneumoniae isolates from cystic fibrosis (CF) respiratory samples and those from non-CF blood cultures. Antibiotic susceptibility of biofilm-forming isolates, as well as differences between antibiotic susceptibility of sessile cells [minimum biofilm inhibitory concentration (MBIC)] and their planktonic counterparts (conventional MIC), were also assessed.
  
  
  METHODS
  Biofilm formation was performed using a microtitre method in 20 CF and 22 non-CF blood culture S. pneumoniae isolates.
  
  
  CONCLUSIONS
  Biofilm formation occurs more frequently among S. pneumoniae isolates from CF (80%) than among non-CF blood culture isolates (50%) (P = 0.04). Moreover MBICs were significantly higher than conventional planktonic MICs among CF but not among non-CF blood isolates, suggesting a high adaptability of CF strains to form biofilms in adverse conditions.
authors.affiliation: Servicio de Microbiología, Hospital Universitario Ramón y Cajal Ctra. Colmenar Km 9.1, Madrid 28034, Spain.
authors.forename: María
authors.initials: M
authors.lastname: García-Castillo
authors.forename: María Isabel
authors.initials: MI
authors.lastname: Morosini
authors.forename: Aránzazu
authors.initials: A
authors.lastname: Valverde
authors.forename: Felisa
authors.initials: F
authors.lastname: Almaraz
authors.forename: Fernando
authors.initials: F
authors.lastname: Baquero
authors.forename: Rafael
authors.initials: R
authors.lastname: Cantón
authors.forename: Rosa
authors.initials: R
authors.lastname: del Campo
mesh_terms: D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use; D018441:Biofilms / Q000187:drug effects / Q000254:growth & development; D001769:Blood / Q000382:microbiology*; D003550:Cystic Fibrosis / Q000382:microbiology*; D024881:Drug Resistance, Bacterial; D006801:Humans; D008826:Microbial Sensitivity Tests; D011008:Pneumococcal Infections / Q000097:blood / Q000382:microbiology; D013296:Streptococcus pneumoniae / Q000187:drug effects / Q000254:growth & development / Q000302:isolation & purification
chemical_list: D000900:Anti-Bacterial Agents