title: Usefulness of FTA® cards as a Pneumocystis-DNA extraction method in bronchoalveolar lavage samples.
abstract: BACKGROUND
  FTA® cards (Fast Technology for Analysis of Nucleic Acids) are an alternative DNA extraction method in bronchoalveolar lavage (BAL) samples for Pneumocystis jirovecii molecular analyses. The goal was to evaluate the usefulness of FTA® cards to detect P. jirovecii-DNA by PCR in BAL samples compared to silica adsorption chromatography (SAC).
  
  
  METHODS
  This study used 134 BAL samples from immunocompromised patients previously studied to establish microbiological aetiology of pneumonia, among them 15 cases of Pneumocystis pneumonia (PCP) documented by staining and 119 with other alternative diagnoses. The FTA® system and SAC were used for DNA extraction and then amplified by nested PCR to detect P. jirovecii. Performance and concordance of the two DNA extraction methods compared to P. jirovecii microscopy were calculated. The influence of the macroscopic characteristics, transportation of samples and the duration of the FTA® card storage (1, 7, 10 or 12 months) were also evaluated.
  
  
  RESULTS
  Among 134 BAL samples, 56% were positive for P. jirovecii-DNA by SAC and 27% by FTA®. All 15 diagnosed by microscopy were detected by FTA® and SAC. Specificity of the FTA® system and SAC were 82.4% and 49.6%, respectively. Compared to SAC, positivity by FTA® decreased with the presence of blood in BAL (62% vs 13.5%). The agreement between samples at 7, 10 and 12 months was 92.5% for FTA®. Positive cases by FTA® remained the same after shipment by mail.
  
  
  CONCLUSIONS
  Results suggest that FTA® is a practical, safe and economical method to preserve P. jirovecii-DNA in BAL samples for molecular studies.
authors.affiliation: a Grupo Investigador de Problemas en Enfermedades Infecciosas (GRIPE), Facultad de Medicina ;
authors.forename: Jenniffer M
authors.initials: JM
authors.lastname: Rodiño
authors.affiliation: a Grupo Investigador de Problemas en Enfermedades Infecciosas (GRIPE), Facultad de Medicina ;|b Corporación de Ciencias Básicas Biomédicas, Universidad de Antioquia , Medellín , Colombia ;
authors.forename: Yudy A
authors.initials: YA
authors.lastname: Aguilar
authors.affiliation: c Facultad de Medicina, Universidad Pontificia Bolivariana , Medellín , Colombia ;
authors.forename: Zulma Vanessa
authors.initials: ZV
authors.lastname: Rueda
authors.affiliation: a Grupo Investigador de Problemas en Enfermedades Infecciosas (GRIPE), Facultad de Medicina ;|d Sección de Enfermedades Infecciosas, Facultad de Medicina, Universidad de Antioquia , Medellín , Colombia.
authors.forename: Lázaro A
authors.initials: LA
authors.lastname: Vélez
mesh_terms: D001992:Bronchoalveolar Lavage Fluid / Q000382:microbiology*; D002846:Chromatography, Affinity; D004271:DNA, Fungal / Q000032:analysis / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D016867:Immunocompromised Host; D058889:Molecular Typing / Q000379:methods*; D016533:Mycological Typing Techniques / Q000379:methods*; D011010:Pneumocystis / Q000235:genetics*; D016720:Pneumocystis Infections / Q000175:diagnosis* / Q000382:microbiology; D016133:Polymerase Chain Reaction / Q000379:methods*
chemical_list: D004271:DNA, Fungal
keywords: FTA®; Pneumocystis jirovecii; affinity chromatography; bronchoalveolar lavage; polymerase chain reaction