title: Analytical bioconjugates, aptamers, enable specific quantitative detection of Listeria monocytogenes.
abstract: As a major human pathogen in the Listeria genus, Listeria monocytogenes causes the bacterial disease listeriosis, which is a serious infection caused by eating food contaminated with the bacteria. We have developed an aptamer-based sandwich assay (ABSA) platform that demonstrates a promising potential for use in pathogen detection using aptamers as analytical bioconjugates. The whole-bacteria SELEX (WB-SELEX) strategy was adopted to generate aptamers with high affinity and specificity against live L. monocytogenes. Of the 35 aptamer candidates tested, LMCA2 and LMCA26 reacted to L. monocytogenes with high binding, and were consequently chosen as sensing probes. The ABSA platform can significantly enhance the sensitivity by employing a very specific aptamer pair for the sandwich complex. The ABSA platform exhibited a linear response over a wide concentration range of L. monocytogenes from 20 to 2×10(6) CFU per mL and was closely correlated with the following relationship: y=9533.3x+1542.3 (R(2)=0.99). Our proposed ABSA platform also provided excellent specificity for the tests to distinguish L. monocytogenes from other Listeria species and other bacterial genera (3 Listeria spp., 4 Salmonella spp., 2 Vibrio spp., 3 Escherichia coli and 3 Shigella spp.). Improvements in the sensitivity and specificity have not only facilitated the reliable detection of L. monocytogenes at extremely low concentrations, but also allowed for the development of a 96-well plate-based routine assay platform for multivalent diagnostics.
authors.affiliation: Department of Microbiology, Chungbuk National University, 1 Chungdae-Ro, Seowon-Gu, Cheongju 362-763, South Korea.
authors.forename: Sang-Hee
authors.initials: SH
authors.lastname: Lee
authors.affiliation: Department of Microbiology, Chungbuk National University, 1 Chungdae-Ro, Seowon-Gu, Cheongju 362-763, South Korea.
authors.forename: Ji-Young
authors.initials: JY
authors.lastname: Ahn
authors.affiliation: Department of Microbiology, Chungbuk National University, 1 Chungdae-Ro, Seowon-Gu, Cheongju 362-763, South Korea.
authors.forename: Kyeong-Ah
authors.initials: KA
authors.lastname: Lee
authors.affiliation: Department of Microbiology, Chungbuk National University, 1 Chungdae-Ro, Seowon-Gu, Cheongju 362-763, South Korea.
authors.forename: Hyun-Ju
authors.initials: HJ
authors.lastname: Um
authors.affiliation: Department of Microbiology, Chungbuk National University, 1 Chungdae-Ro, Seowon-Gu, Cheongju 362-763, South Korea.
authors.forename: Simranjeet Singh
authors.initials: SS
authors.lastname: Sekhon
authors.affiliation: Division of Endocrinology & Metabolism, Department of Internal Medicine, Chonbuk National University Medical School, 634-18 Geumam-Dong, Duckjin-Gu, Jeonju 561-712, South Korea.
authors.forename: Tae
authors.initials: T
authors.lastname: Sun Park
authors.affiliation: Graduate School of Semiconductor and Chemical Engineering, Chonbuk National University, 664-14 Deokjin-dong, 1Ga Deokjin-Gu, Jeonju 561-756, South Korea. Electronic address: jihomin@jbnu.ac.kr.
authors.forename: Jiho
authors.initials: J
authors.lastname: Min
authors.affiliation: Department of Microbiology, Chungbuk National University, 1 Chungdae-Ro, Seowon-Gu, Cheongju 362-763, South Korea. Electronic address: kyh@chungbuk.ac.kr.
authors.forename: Yang-Hoon
authors.initials: YH
authors.lastname: Kim
mesh_terms: D015374:Biosensing Techniques; D004926:Escherichia coli / Q000302:isolation & purification; D006801:Humans; D008089:Listeria monocytogenes / Q000302:isolation & purification* / Q000472:pathogenicity; D008088:Listeriosis / Q000175:diagnosis* / Q000382:microbiology; D052156:SELEX Aptamer Technique; D012475:Salmonella / Q000302:isolation & purification; D013045:Species Specificity
keywords: Analytical bioconjugates; Aptamer; Aptamer-based Sandwich Assay (ABSA) platform; Listeria monocytogenes; Whole-bacteria SELEX (WB-SELEX)