title: Multiplex sorting of foodborne pathogens by on-chip free-flow magnetophoresis.
abstract: This study reports multiplex sorting of Salmonella typhimurium and Escherichia coli 0157, from broth cultures and from pathogen-spiked skinned chicken breast enrichment broths by employing microfluidic free-flow magnetophoresis. Magnetic beads of different sizes and magnetite content, namely Dynabeads anti-salmonella and Hyglos-Streptavidin beads together with the corresponding pathogen-specific biotinylated recombinant phages, were utilised as affinity solid phases for the capture and concentration of viable S. typhimurium and E. coli 0157. Following optimisation, the protocol was used to demonstrate continuous magnetophoretic sorting of the two pathogen-bound magnetic bead populations from mixed cultures and from pathogen-spiked chicken pre-enrichment broths under the influence of a Halbach magnet array. For example, in the latter case, a pure population of S. typhimurium-bound Dynabeads (72% recovery) was sorted from a 100 μL mixture containing E. coli 0157-bound Hyglos beads (67% recovery) within 1.2 min in the presence of 0.1% Tween 20. This proof-of-principle study demonstrates how more than one pathogen type can be simultaneously isolated/enriched from a single food pre-enrichment broth (e.g. Universal food enrichment broth).
authors.affiliation: The University of Hull, Department of Chemistry, Cottingham Road, Hull HU6 7RX, UK.
authors.forename: Bongkot
authors.initials: B
authors.lastname: Ngamsom
authors.affiliation: The University of Hull, Department of Chemistry, Cottingham Road, Hull HU6 7RX, UK.
authors.forename: Mohammad M N
authors.initials: MM
authors.lastname: Esfahani
authors.affiliation: The University of Hull, Department of Chemistry, Cottingham Road, Hull HU6 7RX, UK.
authors.forename: Chayakom
authors.initials: C
authors.lastname: Phurimsak
authors.affiliation: The University of Hull, Department of Chemistry, Cottingham Road, Hull HU6 7RX, UK.
authors.forename: Maria J
authors.initials: MJ
authors.lastname: Lopez-Martinez
authors.affiliation: bioMérieux Innovation & System Unit, Chemin de I'Orme, Marcy I'Etoile, 69280, France.
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Raymond
authors.affiliation: bioMérieux Innovation & System Lab, 5 rue des Berges, Grenoble, 38 024 France.
authors.forename: Patrick
authors.initials: P
authors.lastname: Broyer
authors.affiliation: bioMérieux Innovation & System Unit, Chemin de I'Orme, Marcy I'Etoile, 69280, France.
authors.forename: Pradip
authors.initials: P
authors.lastname: Patel
authors.affiliation: The University of Hull, Department of Chemistry, Cottingham Road, Hull HU6 7RX, UK. Electronic address: n.pamme@hull.ac.uk.
authors.forename: Nicole
authors.initials: N
authors.lastname: Pamme
mesh_terms: D005516:Food Microbiology; D018189:Immunomagnetic Separation / Q000379:methods*; D008855:Microscopy, Electron, Scanning
keywords: Affinity magnetic separation; Food enrichment broth; Free-flow magnetophoresis; Multiplex sorting; Salmonella & E.coli 0157