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

摘要

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 10⁴ 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 or ≥20% glycerol), and high concentrations of biomacromolecules (≥400 mg · mL⁻¹ bovine serum albumin or≥80 mg · mL⁻¹casein) showed little influence on the assay. For practical utilization, thetolerance limits for seven powders and eight viscera were determined, and operationerrors of liquid measurement demonstrated a minor influence on the strip. Ftu-UPT-LFis a candidate POCT method because of its excellent sensitivity, specificity, andstability in complex samples, as well as low operation error.