title: Detection and serotyping of pneumococci in community acquired pneumonia patients without culture using blood and urine samples.
abstract: BACKGROUND
  Treatment of community acquired pneumonia (CAP) patients with antibiotics before laboratory-confirmed diagnosis leads to loss of knowledge on the causative bacterial pathogen. Therefore, an increasing number of pneumococcal infections is identified using non-culture based techniques. However, methods for serotyping directly on the clinical specimen remain scarce. Here we present three approaches for detection and serotyping of pneumococci using samples from patients with CAP.
  
  
  METHODS
  The first approach is quantitative PCR (qPCR) analysis on blood samples (n = 211) followed by capsular sequence typing (CST) to identify the serotype. The second approach, a urinary antigen assay (n = 223), designated as inhibition multiplex immunoassay (IMIA), is based on Luminex technology targeting 14 serotypes. The third approach is a multiplex immunoassay (MIA) (n = 171) also based on Luminex technology which detects serologic antibody responses against 14 serotypes. The three alternative assays were performed on samples obtained from 309 adult hospitalized CAP patients in 2007-2010 and the results were compared with those obtained from conventional laboratory methods to detect pneumococcal CAP, i.e. blood cultures, sputum cultures and BinaxNOW urinary antigen tests.
  
  
  RESULTS
  Using qPCR, MIA and IMIA, we were able to detect the pneumococcus in samples of 56% more patients compared to conventional methods. Furthermore, we were able to assign a serotype to the infecting pneumococcus from samples of 25% of all CAP patients, using any of the three serotyping methods (CST, IMIA and MIA).
  
  
  CONCLUSIONS
  This study indicates the usefulness of additional molecular methods to conventional laboratory methods for the detection of pneumococcal pneumonia. Direct detection and subsequent serotyping on clinical samples will improve the accuracy of pneumococcal surveillance to monitor vaccine effectiveness.
authors.affiliation: Centre for Infectious Disease Control Netherlands, National Institute for Public Health and the Environment (RIVM), Laboratory for Infectious Diseases and Perinatal Screening, Antonie van Leeuwenhoeklaan 9, P.O.Box 1, 3720 BA, Bilthoven, The Netherlands. Karin.Elberse@RIVM.nl.
authors.forename: Karin
authors.initials: K
authors.lastname: Elberse
authors.affiliation: Departments of Medical Microbiology & Immunology, Sint Antonius Hospital Nieuwegein, P.O box 2500, 3430 EM, Nieuwegein, The Netherlands. s.van.mens@antoniusziekenhuis.nl.
authors.forename: Suzan
authors.initials: S
authors.lastname: van Mens
authors.affiliation: Laboratory of Pediatric Infectious Diseases, Department of Pediatrics, Radboud University Medical Center, Geert Grooteplein-Zuid 10, 6525 GA, Nijmegen, The Netherlands. Amelieke.Cremers@radboudumc.nl.|Laboratory of Medical Immunology, Department of Laboratory Medicine, Radboud University Medical Center, Geert Grooteplein-Zuid 10, 6525 GA, Nijmegen, The Netherlands. Amelieke.Cremers@radboudumc.nl.
authors.forename: Amelieke J
authors.initials: AJ
authors.lastname: Cremers
authors.affiliation: Department of Internal medicine, Sint Antonius Hospital Nieuwegein, P.O box 2500, 3430 EM, Nieuwegein, The Netherlands. S.C.A.Meijvis@umcutrecht.nl.
authors.forename: Sabine C A
authors.initials: SC
authors.lastname: Meijvis
authors.affiliation: Departments of Medical Microbiology & Immunology, Sint Antonius Hospital Nieuwegein, P.O box 2500, 3430 EM, Nieuwegein, The Netherlands. b.vlaminckx@antonius.net.
authors.forename: Bart
authors.initials: B
authors.lastname: Vlaminckx
authors.affiliation: Laboratory of Pediatric Infectious Diseases, Department of Pediatrics, Radboud University Medical Center, Geert Grooteplein-Zuid 10, 6525 GA, Nijmegen, The Netherlands. M.DeJonge@cukz.umcn.nl.|Laboratory of Medical Immunology, Department of Laboratory Medicine, Radboud University Medical Center, Geert Grooteplein-Zuid 10, 6525 GA, Nijmegen, The Netherlands. M.DeJonge@cukz.umcn.nl.
authors.forename: Marien I
authors.initials: MI
authors.lastname: de Jonge
authors.affiliation: Department of Medical Microbiology, Radboud University Medical Center, Geert Grooteplein-Zuid 10, 6525 GA, Nijmegen, The Netherlands. jacques.meis@gmail.com.|Department of Medical Microbiology and Infectious Diseases, Canisius Wilhelmina Hospital, Weg door Jonkerbos 100, 6532 SZ, Nijmegen, The Netherlands. jacques.meis@gmail.com.
authors.forename: Jacques F
authors.initials: JF
authors.lastname: Meis
authors.affiliation: Centre for Infectious Disease Control Netherlands, National Institute for Public Health and the Environment (RIVM), Laboratory for Infectious Diseases and Perinatal Screening, Antonie van Leeuwenhoeklaan 9, P.O.Box 1, 3720 BA, Bilthoven, The Netherlands. cornelis_blauw@hotmail.com.
authors.forename: Cornelis
authors.initials: C
authors.lastname: Blauwendraat
authors.affiliation: Centre for Infectious Disease Control Netherlands, National Institute for Public Health and the Environment (RIVM), Laboratory for Infectious Diseases and Perinatal Screening, Antonie van Leeuwenhoeklaan 9, P.O.Box 1, 3720 BA, Bilthoven, The Netherlands. Ingrid.van.de.Pol@RIVM.nl.
authors.forename: Ingrid
authors.initials: I
authors.lastname: van de Pol
authors.affiliation: Centre for Infectious Disease Control Netherlands, National Institute for Public Health and the Environment (RIVM), Laboratory for Infectious Diseases and Perinatal Screening, Antonie van Leeuwenhoeklaan 9, P.O.Box 1, 3720 BA, Bilthoven, The Netherlands. Leo.Schouls@RIVM.nl.
authors.forename: Leo M
authors.initials: LM
authors.lastname: Schouls
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019411:Clinical Laboratory Techniques / Q000379:methods; D017714:Community-Acquired Infections / Q000097:blood / Q000382:microbiology* / Q000652:urine; D005260:Female; D006801:Humans; D007118:Immunoassay / Q000379:methods; D008297:Male; D008875:Middle Aged; D011018:Pneumonia, Pneumococcal / Q000097:blood / Q000382:microbiology* / Q000652:urine; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods; D012703:Serotyping / Q000379:methods*; D013296:Streptococcus pneumoniae / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D055815:Young Adult