Please use this identifier to cite or link to this item: http://hdl.handle.net/1822/27313

TitleA bacteriophage detection tool for viability assessment of Salmonella cells
Author(s)Fernandes, Elisabete Ramos
Martins, V. C.
Nóbrega, Cláudia
Carvalho, Carla A. O. C. M.
Cardoso, F. A.
Cardoso, S.
Dias, J.
Deng, D.
Kluskens, Leon
Freitas, P. P.
Azeredo, Joana
KeywordsBacteriophage
Salmonella
Cell viability
Viable but non-culturable bacteria
Magnetoresistive biochip
Magnetic nanoparticles
Issue date2014
PublisherElsevier
JournalBiosensors & Bioelectronics
Abstract(s)Salmonellosis, one of the most common food and water-borne diseases, has a major global health and economic impact. Salmonella cells present high infection rates, persistence over inauspicious conditions and the potential to preserve virulence in dormant states when cells are viable but non-culturable (VBNC). These facts are challenging for current detection methods. Culture methods lack the capacity to detect VBNC cells, while biomolecular methods (e.g. DNA- or protein-based) hardly distinguish between dead innocuous cells and their viable lethal counterparts. This work presents and validates a novel bacteriophage (phage)-based microbial detection tool to detect and assess Salmonella viability. Salmonella Enteritidis cells in a VBNC physiological state were evaluated by cell culture, flow-cytometry and epifluorescence microscopy, and further assayed with a biosensor platform. Free PVP-SE1 phages in solution showed the ability to recognize VBNC cells, with no lysis induction, in contrast to the minor recognition of heat-killed cells. This ability was confirmed for immobilized phages on gold surfaces, where the phage detection signal follows the same trend of the concentration of viable plus VBNC cells in the sample. The phage probe was then tested in a magnetoresistive biosensor platform allowing the quantitative detection and discrimination of viable and VBNC cells from dead cells, with high sensitivity. Signals arising from 3 to 4 cells per sensor were recorded. In comparison to a polyclonal antibody that does not distinguish viable from dead cells, the phage selectivity in cell recognition minimizes false-negative and false-positive results often associated with most detection methods.
TypeArticle
DescriptionAvailable online 7 September 2013
URIhttp://hdl.handle.net/1822/27313
DOI10.1016/j.bios.2013.08.053
ISSN0956-5663
Publisher versionhttp://www.sciencedirect.com/science/article/pii/S0956566313006027
Peer-Reviewedyes
AccessOpen access
Appears in Collections:CEB - Publicações em Revistas/Séries Internacionais / Publications in International Journals/Series
ICVS - Artigos em Revistas Internacionais com Referee

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