title: Highly specific and cost-efficient detection of Salmonella Paratyphi A combining aptamers with single-walled carbon nanotubes.
abstract: In this paper, a panel of single-stranded DNA aptamers with high affinity and specificity against Salmonella Paratyphi A was selected from an enriched oligonucleotide pool by a whole-cell-Systematic Evolution of Ligands by Exponential Enrichment (SELEX) procedure, during which four other Salmonella serovars were used as counter-selection targets. It was determined through a fluorescence assay that the selected aptamers had high binding ability and specificity to this pathogen. The dissociation constant of these aptamers were up to nanomolar range, and aptamer Apt22 with the lowest Kd (47 ± 3 nM) was used in cell imaging experiments. To detect this bacteria with high specificity and cost-efficiently, a novel useful detection method was also constructed based on the noncovalent self-assembly of single-walled carbon nanotubes (SWNTs) and DNAzyme-labeled aptamer detection probes. The amounts of target bacteria could be quantified by exploiting chemoluminescence intensity changes at 420 nm and the detection limit of the method was 103 cfu/mL. This study demonstrated the applicability of Salmonella specific aptamers and their potential for use in the detection of Salmonella in food, clinical and environmental samples.
authors.affiliation: The Co-Construction Laboratory of Microbial Molecular Biology of Province Department and Ministry of Science and Technology, College of Life Sciences, Hunan Normal University, Changsha 410081, China. young02468@yahoo.cn
authors.forename: Ming
authors.initials: M
authors.lastname: Yang
authors.forename: Zhihui
authors.initials: Z
authors.lastname: Peng
authors.forename: Yi
authors.initials: Y
authors.lastname: Ning
authors.forename: Yongzhe
authors.initials: Y
authors.lastname: Chen
authors.forename: Qin
authors.initials: Q
authors.lastname: Zhou
authors.forename: Le
authors.initials: L
authors.lastname: Deng
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry*; D001422:Bacterial Adhesion; D002947:Cities; D003362:Cost-Benefit Analysis; D005434:Flow Cytometry; D005453:Fluorescence; D008163:Luminescent Measurements; D037742:Nanotubes, Carbon / Q000737:chemistry*; D052156:SELEX Aptamer Technique / Q000191:economics* / Q000379:methods*; D012482:Salmonella paratyphi A / Q000302:isolation & purification*; D012996:Solutions; D014871:Water Microbiology
chemical_list: D052157:Aptamers, Nucleotide; D037742:Nanotubes, Carbon; D012996:Solutions