Development and evaluation of an up-converting phosphor technology-based lateral flow assay for rapid detection of Francisella tularensis

Sci Rep. 2015 Nov 26:5:17178. doi: 10.1038/srep17178.

Abstract

Francisella tularensis is a potential biowarfare/bioterrorism agent and zoonotic pathogen that causes tularemia; thus, surveillance of F. tularensis and first-level emergency response using point-of-care testing (POCT) are essential. The UPT-LF POCT assay was established to quantitatively detect F. tularensis within 15 min, and the sensitivity of the assay was 10(4) CFU · mL(-1) (100 CFU/test). The linear quantitative range covered five orders of magnitude, and the coefficients of variation were less than 10%. Except Shigella dysenteriae, UPT-LF showed excellent specificity to four strains that are also potential biowarfare/bioterrorism agents and 13 food-borne pathogenic strains. Samples with pH 2-13, high ion strengths (≥ 2 mol · L(-1) solution of KCl and NaCl), high viscosities (≤ 50 mg · mL(-1) PEG20000 or ≥ 20% glycerol), and high concentrations of biomacromolecules (≥ 400 mg · mL(-1) bovine serum albumin or ≥ 80 mg · mL(-1) casein) showed little influence on the assay. For practical utilization, the tolerance limits for seven powders and eight viscera were determined, and operation errors of liquid measurement demonstrated a minor influence on the strip. Ftu-UPT-LF is a candidate POCT method because of its excellent sensitivity, specificity, and stability in complex samples, as well as low operation error.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biological Assay / methods*
  • Female
  • Francisella tularensis / isolation & purification*
  • Hydrogen-Ion Concentration
  • Mice, Inbred BALB C
  • Osmolar Concentration
  • Reference Standards
  • Rheology*
  • Sensitivity and Specificity
  • Viscosity