Development of novel digital PCR assays for the rapid quantification of Gram-negative bacteria biomarkers using RUCS algorithm

Methods. 2024 Dec:232:72-80. doi: 10.1016/j.ymeth.2024.10.011. Epub 2024 Oct 30.

Abstract

Rapid and accurate identification of bacterial pathogens is crucial for effective treatment and infection control, particularly in hospital settings. Conventional methods like culture techniques and MALDI-TOF mass spectrometry are often time-consuming and less sensitive. This study addresses the need for faster and more precise diagnostic methods by developing novel digital PCR (dPCR) assays for the rapid quantification of biomarkers from three Gram-negative bacteria: Acinetobacter baumannii, Klebsiella pneumoniae, and Pseudomonas aeruginosa. Utilizing publicly available genomes and the rapid identification of PCR primers for unique core sequences or RUCS algorithm, we designed highly specific dPCR assays. These assays were validated using synthetic DNA, bacterial genomic DNA, and DNA extracted from clinical samples. The developed dPCR methods demonstrated wide linearity, a low limit of detection (∼30 copies per reaction), and robust analytical performance with measurement uncertainty below 25 %. The assays showed high repeatability and intermediate precision, with no cross-reactivity observed. Comparison with MALDI-TOF mass spectrometry revealed substantial concordance, highlighting the methods' suitability for clinical diagnostics. This study underscores the potential of dPCR for rapid and precise quantification of Gram-negative bacterial biomarkers. The developed methods offer significant improvements over existing techniques, providing faster, more accurate, and SI-traceable measurements. These advancements could enhance clinical diagnostics and infection control practices.

Keywords: Biomarkers; Digital PCR (dPCR); Gram-negative bacteria; Pathogen detection; RUCS algorithm; Respiratory infections.

MeSH terms

  • Acinetobacter baumannii* / genetics
  • Acinetobacter baumannii* / isolation & purification
  • Algorithms*
  • Biomarkers* / analysis
  • DNA, Bacterial* / analysis
  • DNA, Bacterial* / genetics
  • Gram-Negative Bacteria* / genetics
  • Gram-Negative Bacteria* / isolation & purification
  • Gram-Negative Bacterial Infections / diagnosis
  • Gram-Negative Bacterial Infections / microbiology
  • Humans
  • Klebsiella pneumoniae / genetics
  • Klebsiella pneumoniae / isolation & purification
  • Polymerase Chain Reaction* / methods
  • Pseudomonas aeruginosa* / genetics
  • Pseudomonas aeruginosa* / isolation & purification
  • Reproducibility of Results
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization* / methods

Substances

  • DNA, Bacterial
  • Biomarkers