title: On-chip microbial culture for the specific detection of very low levels of bacteria.
abstract: Microbial culture continues to be the most common protocol for bacterial detection and identification in medicine and agronomics. Using this process may take days to identify a specific pathogen for most bacterial strains. Surface Plasmon Resonance (SPR) detection is an emerging alternative technology that can be used for the detection of bacteria using protein microarrays although typical limits of detection are in the range of 10(3)-10(6) cfu mL(-1), which is not compatible with most Food Safety regulation requirements. In this work, we combine concomitant "on-chip" microbial culture with sensitive SPR detection of bacteria thus allowing rapid specific detection of bacteria pathogens - including Salmonella enterica serovar Enteritidis, Streptococcus pneumoniae and Escherichia coli O157:H7 - cultured on a protein microarray. This Culture-Capture-Measure (CCM) approach significantly decreases both the number of processing steps and the overall assay time for bacterial detection. Signal analysis of SPR responses allowed the fast and quantitative assessment of bacterial concentrations initially present in the sample as low as 2.8 ± 19.6 cfu per milliliter. Altogether, our results show how simple, easy-to-operate, fluidic-less and lo-tec microarrays can be used with unprocessed samples and yield - in a single assay - both qualitative and quantitative information regarding bacterial contamination.
authors.affiliation: CREAB Group, SPrAM, UMR CEA / CNRS / UJF, Institut des Nanosciences et Cryogénie, 38054 Grenoble cedex 9, France. yoann.roupioz@cea.fr.
authors.forename: Sihem
authors.initials: S
authors.lastname: Bouguelia
authors.forename: Yoann
authors.initials: Y
authors.lastname: Roupioz
authors.forename: Sami
authors.initials: S
authors.lastname: Slimani
authors.forename: Laure
authors.initials: L
authors.lastname: Mondani
authors.forename: Maria G
authors.initials: MG
authors.lastname: Casabona
authors.forename: Claire
authors.initials: C
authors.lastname: Durmort
authors.forename: Thierry
authors.initials: T
authors.lastname: Vernet
authors.forename: Roberto
authors.initials: R
authors.lastname: Calemczuk
authors.forename: Thierry
authors.initials: T
authors.lastname: Livache
mesh_terms: D001419:Bacteria / Q000254:growth & development* / Q000302:isolation & purification*; D015374:Biosensing Techniques / Q000379:methods*; D046508:Culture Techniques / Q000379:methods*; D005516:Food Microbiology; D057230:Limit of Detection; D008904:Miniaturization; D040081:Protein Array Analysis / Q000379:methods*