Flow cytometry for rapid detection of Salmonella spp. in seed sprouts

dc.contributor.author Bisha, Bledar
dc.contributor.author Brehm-Stecher, Byron
dc.contributor.department Food Science and Human Nutrition
dc.date 2018-02-19T07:32:53.000
dc.date.accessioned 2020-06-30T03:58:54Z
dc.date.available 2020-06-30T03:58:54Z
dc.date.copyright Wed Jan 01 00:00:00 UTC 2014
dc.date.issued 2014-12-31
dc.description.abstract <p>Seed sprouts (alfalfa, mung bean, radish, etc.) have been implicated in several recent national and international outbreaks of salmonellosis. Conditions used for sprouting are also conducive to the growth of <em>Salmonella</em>. As a result, this pathogen can quickly grow to very high cell densities during sprouting without any detectable organoleptic impact. Seed sprouts typically also support heavy growth (~108 CFU g−1) of a heterogeneous microbiota consisting of various bacterial, yeast, and mold species, often dominated by non-pathogenic members of the family <em>Enterobacteriaceae</em>. This heavy background may present challenges to the detection of <em>Salmonella</em>, especially if this pathogen is present in relatively low numbers. We combined DNA-based fluorescence <em>in situ</em> hybridization (FISH) with flow cytometry (FCM) for the rapid molecular detection of <em>Salmonella enterica</em> ser. Typhimurium in artificially contaminated alfalfa and other seed sprouts. Components of the assay included a set of cooperatively binding probes, a chemical blocking treatment intended to reduce non-specific background, and sample concentration via tangential flow filtration (TFF). We were able to detect <em>S</em>. Typhimurium in sprout wash at levels as low as 103 CFU ml−1 sprout wash (104 CFU g−1 sprouts) against high microbial backgrounds (~108 CFU g−1 sprouts). Hybridization times were typically 30 min, with additional washing, but we ultimately found that <em>S</em>. Typhimurium could be readily detected using hybridization times as short as 2 min, without a wash step. These results clearly demonstrate the potential of combined DNA-FISH and FCM for rapid detection of <em>Salmonella</em> in this challenging food matrix and provide industry with a useful tool for compliance with sprout production standards proposed in the Food Safety Modernization Act (FSMA).</p>
dc.description.comments <p>This article is published as Bisha, B. and <strong>Brehm-Stecher, B.F.</strong> Flow cytometry for rapid detection of <em>Salmonella</em> spp. In seed sprouts. ScienceOpen Research: doi: <a href="https://dx.doi.org/10.14293/S2199-1006.1.SORLIFE.AJ19WR.v1" target="_blank">10.14293/S2199-1006.1.SORLIFE.AJ19WR.v1</a> (2014). Posted with permission.</p>
dc.format.mimetype application/pdf
dc.identifier archive/lib.dr.iastate.edu/fshn_ag_pubs/172/
dc.identifier.articleid 1175
dc.identifier.contextkey 11375766
dc.identifier.s3bucket isulib-bepress-aws-west
dc.identifier.submissionpath fshn_ag_pubs/172
dc.identifier.uri https://dr.lib.iastate.edu/handle/20.500.12876/37463
dc.language.iso en
dc.source.bitstream archive/lib.dr.iastate.edu/fshn_ag_pubs/172/2014_Brehm_StecherBF_FlowCytometryRapid.pdf|||Fri Jan 14 21:18:31 UTC 2022
dc.source.uri 10.14293/S2199-1006.1.SOR-LIFE.AJ19WR.v1
dc.subject.disciplines Food Microbiology
dc.subject.disciplines Food Science
dc.subject.disciplines Human and Clinical Nutrition
dc.subject.disciplines Molecular, Genetic, and Biochemical Nutrition
dc.subject.disciplines Plant Sciences
dc.title Flow cytometry for rapid detection of Salmonella spp. in seed sprouts
dc.type article
dc.type.genre article
dspace.entity.type Publication
relation.isAuthorOfPublication f603d350-bdd5-4d2a-8d8c-a08c96eb8d85
relation.isOrgUnitOfPublication 4b6428c6-1fda-4a40-b375-456d49d2fb80
Original bundle
Now showing 1 - 1 of 1
No Thumbnail Available
2.66 MB
Adobe Portable Document Format