'Sample-in, answer-out'? Evaluation and comprehensive analysis of the Unyvero P50 pneumonia assay

Diagn Microbiol Infect Dis. 2016 Sep;86(1):5-10. doi: 10.1016/j.diagmicrobio.2016.06.010. Epub 2016 Jun 14.

Abstract

This study aimed to evaluate the performance of the Unyvero P50 pneumonia assay, the first 'sample-in, answer-out' system for rapid identification of pathogens and antibiotic resistance markers directly from clinical specimens. Overall, Unyvero P50 displayed very good sensitivity (>95%); however, specificity was low (33%) mainly because 40% of the specimens were reported as normal flora. Specifically, one or more pathogens were identified in 28 of them. From a detailed analysis of 42 specimens selected at random, 76% of the additionally reported pathogens were confirmed present in primary specimens. Detection of selected resistance markers was compared to routine phenotypic susceptibility testing, supplemented with Checkpoints microarray system, PCR and sequencing. Concordance was mixed, primarily due to issues with panel's choice of markers and detection of some intrinsic beta-lactamases. Finally, we offer a critical analysis of the assay's microbial panel and resistance markers and provide suggestions for improvement.

Keywords: Antimicrobial resistance; Beta-lactamase; PCR; Pneumonia; Rapid diagnostics.

MeSH terms

  • Adult
  • Automation, Laboratory / methods*
  • Humans
  • Lung Diseases, Fungal / diagnosis*
  • Lung Diseases, Fungal / microbiology
  • Microbiological Techniques / methods*
  • Molecular Diagnostic Techniques / methods*
  • Pneumonia, Bacterial / diagnosis*
  • Pneumonia, Bacterial / microbiology
  • Sensitivity and Specificity