title: Aptamer selection for the detection of Escherichia coli K88.
abstract: In this study, the first group of single-stranded DNA aptamers that are highly specific to enterotoxigenic Escherichia coli (ETEC) K88 was obtained from an enriched oligonucleotide pool by the SELEX (Systematic Evolution of Ligands by Exponential Enrichment) procedure, during which the K88 fimbriae protein was used as the target and bovine serum albumin as counter targets. These aptamers were applied successfully in the detection of ETEC K88. They were then grouped under different families based on the similarity of their secondary structure and the homology of their primary sequence. Four sequences from different families were deliberately chosen for further characterization by fluorescence analysis. Having the advantage of high sensitivity, fluorescence photometry was selected as single-stranded DNA quantification method during the SELEX process. Aptamers with the highest specificity and affinity were analyzed to evaluate binding ability with E. coli. Since ETEC K88 is the only type of bacterium that expressed abundant K88 fimbriae, the selected aptamers against the K88 fimbriae protein were able to specifically identify ETEC K88 among other bacteria. This method of detecting ETEC K88 by aptamers can also be applied to bacteria other than ETEC K88.
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, People's Republic of China.
authors.forename: Hua
authors.initials: H
authors.lastname: Li
authors.forename: Xinghua
authors.initials: X
authors.lastname: Ding
authors.forename: Zhihui
authors.initials: Z
authors.lastname: Peng
authors.forename: Le
authors.initials: L
authors.lastname: Deng
authors.forename: Dan
authors.initials: D
authors.lastname: Wang
authors.forename: Hui
authors.initials: H
authors.lastname: Chen
authors.forename: Qizhi
authors.initials: Q
authors.lastname: He
mesh_terms: D000818:Animals; D052157:Aptamers, Nucleotide / Q000737:chemistry*; D001483:Base Sequence; D002417:Cattle; D004277:DNA, Single-Stranded / Q000737:chemistry; D054307:Enterotoxigenic Escherichia coli / Q000302:isolation & purification*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D036781:Fimbriae Proteins / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D052156:SELEX Aptamer Technique; D013045:Species Specificity
chemical_list: D052157:Aptamers, Nucleotide; D004277:DNA, Single-Stranded; D029968:Escherichia coli Proteins; D036781:Fimbriae Proteins