Enrichment and Detection of Escherichia coli O157:H7 from Water Samples Using an Antibody Modified Microfluidic Chip

摘要

Low abundant (<100 cells mL-1) E. coli O157:H7 cellsnwere isolated and enriched from environmental waternsamples using a microfluidic chip. The poly(methylmethacrylate),nPMMA, chip contained 8 devices, eachnequipped with 16 curvilinear high aspect ratio channelsnthat were covalently decorated with polyclonalnanti-O157 antibodies (pAb) and could search for rarencells through a pAb mediated process. The chip couldnprocess independently 8 different samples or onensample using 8 different parallel inputs to increasenvolume processing throughput. After cell enrichment,ncells were released and enumerated using benchtopnreal-time quantitative polymerase chain reaction (PCR),ntargeting genes which effectively discriminated thenO157:H7 serotype from other nonpathogenic bacteria.nThe recovery of target cells from water samples wasndetermined to be ∼72%, and the limit-of-detection wasnfound to be 6 colony forming units (cfu) using the slt1ngene as a reporter. We subsequently performed analysisnof lake and wastewater samples. The simplicity innmanufacturing and ease of operation makes this devicenattractive for the selection of pathogenic species fromna variety of water supplies suspected of containingnbacterial pathogens at extremely low frequencies.