Pathogen surrogates based on encapsulated tagged DNA for verification of sanitation and wash water systems for fresh produce
Inventors
Zografos, Antonios • Farquar, George Roy • Carter, John Mark
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Assignees
MemberSafeTracesSafeTracesSafeTraces provides technology-driven solutions for indoor air quality validation, biosafety, and supply chain traceability. The company specializes in aerosol tracing, DNA-based product tagging, rapid qPCR detection, and cloud-based analytics. Clients span healthcare, infrastructure, real estate, food, and government sectors, supporting regulatory compliance, operational safety, and risk management.
SafeTraces provides technology-driven solutions for indoor air quality validation, biosafety, and supply chain traceability. The company specializes in aerosol tracing, DNA-based product tagging, rapid qPCR detection, and cloud-based analytics. Clients span healthcare, infrastructure, real estate, food, and government sectors, supporting regulatory compliance, operational safety, and risk management.
Publication Number
US-10962512-B2
Publication Date
2021-03-30
Expiration Date
Abstract
A pathogen surrogate, formed by a DNA tag or bar code and a carrier, is described for use in the validation and verification of sanitation, such as in food processing operations and for wash water systems for fresh produce. The carrier material is selected so that the pathogen surrogate mimics the behavior of a pathogen when subjected to a sanitation operation. One or more surrogates can be introduced in to an environment, which is then subjected to sanitation process, followed by a detection process using the DNA tag of the surrogate.
Core Innovation
The invention relates to a method of testing an efficacy of a sanitation process using DNA-tagged, non-toxic pathogen surrogates. A first surrogate for a first pathogen comprises a first taggant chemically bound to a first surrogate carrier, and the first surrogate carrier is non-toxic and comprises one or more defined carrier materials. The first surrogate has degradation rates that match degradation rates of the first pathogen, and the first taggant is formed of a first DNA bar code with a DNA degradation rate under the sanitation operation that is independent of the carrier degradation rate.
The method applies a first amount of the first surrogate to one or more processing or product surfaces, and then performs the first sanitation operation. During sanitation, a portion of the first surrogate carrier is degraded by the sanitation operation. After sanitation, a detection operation determines a second amount of the first surrogate present on the one or more surfaces by determining an amount of the first DNA bar code present on the surfaces, and the efficacy is determined from a comparison of the second amount to the first amount.
The disclosure supports validation and verification workflows where surrogate carrier materials are selected to behave under sanitization in a way that matches pathogen degradation. The document further describes surrogate use in wash-water and surface challenge contexts, including addressing cross-contamination or deposition by using surrogates in wash water and on proxies or surfaces. It also describes surrogate formulations for biofilm simulation using edible or GRAS gels or gums.
Claims Coverage
The independent claim set includes one independent claim directed to a method for testing the efficacy of a sanitation process using non-toxic pathogen surrogates with DNA bar codes and controlled degradation behavior. Dependent claims refine carrier structure, taggant association, detection modalities, and parallel use of a second surrogate having different robustness.
DNA bar code taggant on a non-toxic surrogate carrier with matching degradation rates
A first surrogate for a first pathogen comprises a first taggant chemically bound to a first surrogate carrier, the first surrogate carrier is non-toxic and comprises specified carrier constituents, the first surrogate has degradation rates that match degradation rates of the first pathogen, and the first taggant is formed of a first DNA bar code having a DNA degradation rate under the sanitation operation independent of the carrier degradation rate.
Application to surfaces and sanitation with surrogate carrier degradation
Applying a first amount of the first surrogate to one or more processing or product surfaces, subsequently performing the first sanitation operation, whereby a portion of the first surrogate carrier is degraded by the first sanitation operation.
Detection of post-sanitization surrogate amount via DNA bar code and efficacy comparison
Performing a detection operation to determine a second amount of the first surrogate present on the one or more surfaces after performing the first sanitation operation, where determining the second amount is performed by determining an amount of the first DNA bar code present on the one or more surfaces, and determining the efficacy of the sanitation process from a comparison of the second amount to the first amount.
Non-toxic surrogate carrier comprising specified materials
The first surrogate carrier comprises one or more of a bio-degradable polymer, maltodextrin, salt, starch, a non-water-soluble food grade polymers, a protein, a membrane lipid, a gelatin-based polymer, agar agar, carrageenan, gellan, gelatin, latex, glycerol ester of wood rosin, pectins, carnauba, silica, water-soluble carbohydrate, flour, albumin, casein, a particle bearing a core of a functionally ferromagnetic material, or fixed cells of a formerly living microorganism.
DNA bar code formed independently of carrier degradation rate under sanitation
The DNA bar code has a DNA degradation rate under the first sanitation operation independent of the carrier degradation rate.
Carrier and DNA bar code association by encapsulation
The method includes encapsulating the first DNA barcode in a first surrogate carrier.
Detection operation using PCR, LAMP, and/or SERS
The detection operation uses one or more of PCR, loop-mediated isothermal amplification, or surface enhanced Raman spectroscopy.
Parallel use of a second surrogate with different robustness
The method provides a second surrogate for the first pathogen prior to performing the first sanitation operation, and determines a third amount of the second surrogate after sanitation by measuring the amount of the second DNA bar code, where the first and second surrogates have differing robustness relative to the first sanitation operation.
Surrogate carrier including a poly(lactic-co-glycolic acid) polymer
The first non-toxic pathogen surrogate carrier is a poly(lactic-co-glycolic acid) polymer.
Across the independent method claim and its refinements, the inventive approach centers on non-toxic pathogen surrogates bearing a DNA bar code whose degradation behavior under sanitation is decoupled from carrier degradation. The method measures post-sanitization surrogate presence by determining the amount of the DNA bar code and determines sanitation efficacy by comparing pre- and post-sanitization amounts, with refinements including specific carrier materials, DNA bar code encapsulation, specified detection modalities, and optional parallel use of a second surrogate with differing robustness.
Stated Advantages
Efficacy of a sanitation process is determined from a comparison of a post-sanitization surrogate amount to a pre-sanitization amount using DNA bar code measurement.
Determination of surrogate presence after sanitation is enabled by determining an amount of the DNA bar code present on processing or product surfaces.
Surrogate carrier degradation during sanitation provides a measurable basis for efficacy determination where DNA bar code degradation rate is independent of carrier degradation rate.
Documented Applications
Testing efficacy of a sanitation process by applying a first non-toxic pathogen surrogate to processing or product surfaces, performing sanitation, and detecting remaining surrogate via DNA bar code measurement.
Wash-water system validation and verification for sanitation of fresh produce by using DNA-tagged, non-toxic pathogen surrogates in the wash water and on proxies or surfaces to address cross-contamination or deposition.
Biofilm simulation using edible or GRAS gels or gums, where surrogate carriers are used for validation and verification in biofilm contexts.
Detection operations for surrogate readout, including amplification-based methods and label-based methods.
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