Selective identification of specific aptamers for the detection of non-typhoidal salmonellosis in an apta-impedimetric sensing format
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The authors report on an aptamer-based method for the detection of S. Typhimurium. The aptamers were identified by using a modified cell-based SELEX method (cell-SELEX) by adopting an alternating negative-positive selection strategy. Each cross-reactive population was used separately, with a focus on generating strain-specific aptamers in order to enhance selectivity. The aptamers were characterized and chemically modified with thiol groups at the 5′ end which enables covalent binding to gold nanoparticles on a screen printed carbon electrode (GNP-SPCE). The aptamer-modified GNP-SPCE was subsequently applied to impedimetric sensing of S. Typhimurium in water and food samples. Response is linear in the 10 to 105 CFU⋅mL−1 concentration range, and the limit of detection is ~10 CFU⋅mL−1. The assay can distinguish S. Typhimurium from S. Typhi and has been validated in water and spiked egg samples.
KeywordsS. Typhimurium Modified cell-SELEX Gold nanoparticles Impedimetry Aptasensor Microbial pathogen
The authors thank DBT, India (Grant No. BT/IN/FINNISH/09/CRS/2013) for providing the financial support for this project. Authors also thank Dr. Priyanka Sabherwal and Munish Shorie for the technical support, and Mr. Deepak Bhatt for confocal studies.
Compliance with ethical standards
The authors declare that there is no conflict of interest regarding the publication of this paper.
- 2.Singh V (2013) Salmonella serovars and their host specificity. J Vet Sci 1(3):2348–9790Google Scholar
- 3.Gordon MA, Kankwatira AM, Mwafulirwa G, Walsh AL, Hopkins MJ, Parry CM, Faragher EB, Zijlstra EE, Heyderman RS, Molyneux ME (2010) Invasive non-typhoid salmonellae establish systemic intracellular infection in HIV-infected adults: an emerging disease pathogenesis. Infect Dis 50:953–962CrossRefGoogle Scholar
- 4.Centers for Disease Control and Prevention (CDC) (2016). Surveillance for foodborne disease outbreaks, United States, 2014, Annual Report. US Department of Health and Human Services, CDC, Atlanta, GeorgiaGoogle Scholar
- 9.Law JW, Ab-Mutalib NS, Chan KG, Lee LH (2016) An insight into the isolation, enumeration, and molecular detection of Listeria monocytogenes in food. Front Microbiol 5:770Google Scholar
- 33.Lei P, Tang H, Ding S, Ding X, Zhu D, Shen B, Cheng Q, Yan Y (2015) Determination of the invA gene of Salmonella using surface plasmon resonance along with streptavidin aptamer amplification. Microchim Acta 182:289–296Google Scholar
- 34.Park JY, Jeong HY, Kim MI, Park TJ (2015) Colorimetric detection system for Salmonella typhimurium based on peroxidase-like activity of magnetic nanoparticles with DNA aptamers. J Nanomater 2015:9Google Scholar