title: Molecular Diagnosis of Urinary Tract Infections by Semi-Quantitative Detection of Uropathogens in a Routine Clinical Hospital Setting.
abstract: BACKGROUND
  The objective of our study was the development of a semi-quantitative real-time PCR to detect uropathogens. Two multiplex PCR reactions were designed to detect Escherichia coli, Klebsiella spp., Enterobacter spp., Citrobacter spp., Proteus mirabilis, Enterococcus faecalis, and Pseudomonas aeruginosa. 16S based PCR was performed in parallel to detect Gram-positive and Gram-negative bacteria. Firstly to identify non-targeted agents of infection in the same urine specimen, and secondly to quantify background flora. The method was evaluated in comparison with standard bacterial culture, and a commercial PCR kit for detection of uropathogens.
  
  
  RESULTS
  Analysis with a known panel of 116 clinical isolates yielded a PCR specificity of 100%. Analysis of urine specimens from 211 patients revealed a high correlation of PCR Cq values with both culture positivity and quantity. Concordance between PCR and culture was 98% when both methods yielded results. PCR was found to be more sensitive than culture. With a cut-off Cq value of 33, the negative predictive value of PCR was 94%. The 16S PCR confirmed most results. One specimen was positive by 16S PCR suggesting another cause of infection not detected by the specific PCR assays.
  
  
  CONCLUSIONS
  We conclude that it is feasible to detect and identify uropathogens by multiplex real-time PCR assay.
authors.affiliation: Medical Microbiology, and Molecular Diagnostics Unit, Maasstad Hospital, Rotterdam, The Netherlands.
authors.forename: Anneke
authors.initials: A
authors.lastname: van der Zee
authors.affiliation: Medical Microbiology, and Molecular Diagnostics Unit, Maasstad Hospital, Rotterdam, The Netherlands.
authors.forename: Lieuwe
authors.initials: L
authors.lastname: Roorda
authors.affiliation: Medical Microbiology, and Molecular Diagnostics Unit, Maasstad Hospital, Rotterdam, The Netherlands.
authors.forename: Gerda
authors.initials: G
authors.lastname: Bosman
authors.affiliation: Medical Microbiology, and Molecular Diagnostics Unit, Maasstad Hospital, Rotterdam, The Netherlands.|Erasmus Medical Centre, Rotterdam, The Netherlands.
authors.forename: Jacobus M
authors.initials: JM
authors.lastname: Ossewaarde
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001424:Bacterial Infections / Q000175:diagnosis / Q000382:microbiology; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D060885:Multiplex Polymerase Chain Reaction; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D011933:Reagent Kits, Diagnostic; D060888:Real-Time Polymerase Chain Reaction; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014552:Urinary Tract Infections / Q000175:diagnosis* / Q000382:microbiology*; D055815:Young Adult
chemical_list: D012336:RNA, Ribosomal, 16S; D011933:Reagent Kits, Diagnostic