Rapid Detection of Listeria by Bacteriophage Amplification and SERS-Lateral Flow Immunochromatography

Viruses

Nicholas R. Stambach²  Stephanie A. Carr²  Christopher R. Cox²  Kent J. Voorhees¹  Abram Aertsen² 

[1] Department of Chemistry and Geochemistry, Colorado School of Mines, Golden, CO 80401, USA

关键词: lateral flow immunochromatography;    Listeria monocytogenes;    surface-enhanced Raman spectroscopy;    A511;    phage amplification;   

DOI  :  10.3390/v7122962

来源: mdpi

【 摘 要 】

A rapid Listeria detection method was developed utilizing A511 bacteriophage amplification combined with surface-enhanced Raman spectroscopy (SERS) and lateral flow immunochromatography (LFI). Anti-A511 antibodies were covalently linked to SERS nanoparticles and printed onto nitrocellulose membranes. Antibody-conjugated SERS nanoparticles were used as quantifiable reporters. In the presence of A511, phage-SERS nanoparticle complexes were arrested and concentrated as a visible test line, which was interrogated quantitatively by Raman spectroscopy. An increase in SERS intensity correlated to an increase in captured phage-reporter complexes. SERS limit of detection was 6 × 10⁶ pfu·mL⁻¹, offering detection below that obtainable by the naked eye (LOD 6 × 10⁷ pfu·mL⁻¹). Phage amplification experiments were carried out at a multiplicity of infection (MOI) of 0.1 with 4 different starting phage concentrations monitored over time using SERS-LFI and validated by spot titer assay. Detection of L. monocytogenes concentrations of 1 × 10⁷ colony forming units (cfu)·mL⁻¹, 5 × 10⁶ cfu·mL⁻¹, 5 × 10⁵ cfu·mL⁻¹ and 5 × 10⁴ cfu·mL⁻¹ was achieved in 2, 2, 6, and 8 h, respectively. Similar experiments were conducted at a constant starting phage concentration (5 × 10⁵ pfu·mL⁻¹) with MOIs of 1, 2.5, and 5 and were detected in 2, 4, and 5 h, respectively.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.