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ARS Home » Pacific West Area » Albany, California » Western Regional Research Center » Produce Safety and Microbiology Research » Research » Publications at this Location » Publication #139391

Title: SENSOR COMPONENTS FOR PCR DETECTION OF SALMONELLA IN ALFALFA SPROUT IRRIGATION WATER

Author
item JACKSON, ERIC
item DELWICHE, MICHAEL
item Barak Cunningham, Jeri
item CHARKOWSKI, AMY
item SUSLOW, TREVOR

Submitted to: Transactions of the ASABE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/1/2004
Publication Date: 12/1/2004
Citation: Jackson, E., Delwiche, M., Barak Cunningham, J.D., Charkowski, A., Suslow, T. 2004. Sensor components for pcr detection of salmonella in alfalfa sprout irrigation water. Transactions of the ASABE.47(6):2137-2144.

Interpretive Summary: Bacterial human pathogens have been associated with a number of recent outbreaks of foodborne illness involving sprouted seeds. Sprout production is unusual compared with other fresh produce because conditions that encourage germination and growth of the seeds (temperature, available moisture, and nutrients) also encourage the growth of bacterial pathogens. A real-time assay was developed for the detection of human pathogens, based on polymerase chain reaction (PCR) to amplify DNA and a fluorescent dye to label and measure the DNA. Using the assay, a detection limit of between 100 and 1000 cells in sprout irrigation water was reached. As the first phase in the development of a fully automated system, a sensor was designed to implement the real-time assay, including a thermal cycler for PCR and a fluorescent optical sensor. Bacterial human pathogen DNA was detected in sterile water to approximately 10,000 cells, and in sprout irrigation water to approximately 1,000,000 cells.

Technical Abstract: Salmonella has been associated with a number of recent outbreaks of foodborne illness involving sprouted seeds. Sprout production is unusual compared with other fresh produce because conditions that encourage germination and growth of the seeds (temperature, available moisture, and nutrients) also encourage the growth of bacterial pathogens. A real-time assay was developed for the detection of Salmonella, based on polymerase chain reaction (PCR) to amplify Salmonella DNA and a fluorescent dye to label and measure the DNA. S. enterica serovar Newport was detected using the assay, with a detection limit of between 2 102 and 2 103 CFU in sprout irrigation water. As the first phase in the development of a fully automated system, a sensor was designed to implement the real-time assay, including a thermal cycler for PCR and a fluorescent optical sensor. S. Newport was detected in sterile water to approximately 7.3 104 CFU, and in sprout irrigation water to approximately 1.5 106 CFU.