Tag Archives: sampling

Recall

Beech-Nut Recalls Infant Single Grain Rice Cereal Due to High Inorganic Arsenic Levels, Pulls Out of Market Segment

By Food Safety Tech Staff
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Recall

Today Beech-Nut Nutrition Company announced a voluntary recall of one lot of its Stage 1 Single Grain Rice Cereal following sampling that revealed the product tested above the guidance level for naturally occurring inorganic arsenic set by FDA last summer. The routine sampling was conducted by the State of Alaska. The recalled item has an expiration date of May 1, 2022.

“The safety of infants and children is Beech-Nut’s top priority. We are issuing this voluntary recall, because we learned through routine sampling by the State of Alaska that a limited quantity of Beech-Nut Single Grain Rice Cereal products had levels of naturally-occurring inorganic arsenic above the FDA guidance level, even though the rice flour used to produce these products tested below the FDA guidance level for inorganic arsenic,” said Jason Jacobs, Vice President, Food Safety and Quality, Beech-Nut, in a company announcement published on FDA’s website.

Perhaps even bigger news is Beech-Nut’s announcement that it is exiting the market for its branded Single Grain Rice Cereal. The company is concerned that it will not be able to consistently obtain rice flour that is well-below FDA’s guidance level (as well as Beech-Nut’s specifications) for naturally occurring inorganic arsenic.

FDA

FDA to Begin Testing Samples of Salinas-Grown Lettuce for E. Coli and Salmonella

By Food Safety Tech Staff
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FDA

Register now for the complimentary virtual event in our Food Safety Hazards Series, “Salmonella Detection, Mitigation, Control and Regulation” | Thursday, July 15, 11:45 am ETAs part of ongoing surveillance efforts resulting from recurring outbreaks, the FDA announced that it will conduct direct sampling and testing of lettuce grown in the Salinas Valley region of California. From May through November 2021, the agency will test samples for Shiga toxin-producing Escherichia coli (STEC), including E. coli O157:H7, and Salmonella spp. Direct sampling will be conducted at commercial cooling and cold storage facilities where field heat is removed from harvested lettuce and product is cold-stored prior to processing. “Sample collection at commercial coolers helps the FDA efficiently obtain samples from multiple farms at centralized locations and facilitates prompt traceback and follow-up if contamination is detected,” according to a CFSAN update.

FDA laboratories plan to test about 500 post-harvest samples of iceberg, leaf and romaine lettuce, with each sample consisting of 10 subsamples (one head of lettuce that is trimmed, cored or wrapped; or romaine lettuce leaves or one package of hearts).

In compliance with COVID-19 safety practices, the agency investigators will preannounce their visits.

Susanne Kuehne, Decernis
Food Fraud Quick Bites

The Automated Nose of a Master of Wine

By Susanne Kuehne
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Susanne Kuehne, Decernis
Wine fraud
Find records of fraud such as those discussed in this column and more in the Food Fraud Database. Image credit: Susanne Kuehne

Since only 417 Masters of Wine exist globally (and their palates and noses)—and they are amazing in identifying wines by grape varietal or blend, type, vintage and location—it is a good idea to have some automated backup when it comes to wine fraud detection. Aside from other analytical methods, nuclear magnetic resonance (NMR) spectroscopy can be used in the authentication of wine. The new proton measurement 1H NMR Method with easier sample preparation is recommended for the investigation of wine fraud, to detect for example the addition of water or sugar. NMR spectroscopy measures several compounds of a wine at once and therefore is able to detect a fingerprint of a wine, such as the geographic origin or grape varietal.

Resource

  1. Solovyev, P.A., et. al. (January 27, 2021) “NMR spectroscopy in wine authentication: An official control perspective”. Comprehensive Reviews in Food Science and Food Safety. Wiley Online Library.
El Abuelito Cheese

Recall Alert: Listeria Outbreak Linked to Hispanic-Style Fresh and Soft Cheeses

By Food Safety Tech Staff
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El Abuelito Cheese

–UPDATE March 9, 2021 — Today the FDA confirmed that the recalled cheeses were also distributed to Rhode Island. “States with confirmed distribution now include: AL, CT, FL, GA, IA, IL, IN, KS, KY, MA, MD, MI, MN, MO, MS, NC, NJ, NY, NE, OH, PA, RI, SC, TN, VA, and WI.”

–UPDATE February 24, 2021 — FDA has expanded its warning related to El Abuelito Cheese to include all cheese branded by the company “until more information is known”.

—END UPDATE—

A multistate outbreak of Listeria monocytogenes has been linked to Hispanic-style fresh and soft cheeses produced by El Abuelito Cheese, Inc. As a result, the company has recalled all Questo Fresco products with sell by dates through March 28 (032821).

Join Food Safety Tech on April 15 for the complimentary Food Safety Hazards Series: Listeria Detection, Mitigation, Control & Regulation“As the FDA stated, about this outbreak investigation, the Connecticut Department of Public Health collected product samples of El Abuelito-brand Hispanic-style fresh and soft cheeses from a store where a sick person bought cheeses. Sample analysis showed the presence of Listeria monocytogenes in samples of El Abuelito Queso Fresco sold in 10 oz packages, marked as Lot A027 with an expiration date of 02/26/2021,” the company stated in an announcement posted on FDA’s website. “Samples are currently undergoing Whole Genome Sequencing (WGS) analysis to determine if the Listeria monocytogenes found in these samples is a match to the outbreak strain. At this time, there is not enough evidence to determine if this outbreak is linked to El Abuelito Queso Fresco.”.

The recalled products were distributed to Connecticut, Maryland, New Jersey, North Carolina, New York, Pennsylvania and Virginia. Thus far seven people, all of whom have been hospitalized, have fallen ill.

FDA recommends that consumers, restaurants and retailers do not consume, sell or serve any of the recalled cheeses. The agency also states that anyone who purchased of received the recalled products use “extra vigilance in cleaning and sanitizing any surfaces and containers that may have come in contact with these products to reduce the risk of cross-contamination.”

FDA

FDA Responds to Subcommittee Report on Toxic Metals in Baby Food

By Food Safety Tech Staff
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FDA

Following a report released nearly two weeks ago about the potential danger posed by toxic heavy metals found in baby foods manufactured by several major companies, FDA has issued a response. The report, “Baby Foods Are Tainted with Dangerous Levels of Arsenic, Lead, Cadmium, and Mercury”, was released by the U.S. House of Representatives Committee on Oversight and Reform Subcommittee on Economic and Consumer Policy on February 4. The Subcommittee stated that FDA should require baby food manufacturers to test their finished products for toxic heavy metals and require any toxic heavy metals be reported on food labeling. It also stated that FDA should set maximum levels of toxic heavy metals allowed in baby foods.

“The FDA has been actively working on this issue using a risk-based approach to prioritize and target the agency’s efforts. Consumers should know that FDA scientists routinely monitor levels of toxic elements in baby foods, along with other foods consumed in the country’s diet, through the Total Diet Study,” the agency stated in a CFSAN update. “Further, the FDA also monitors baby food under the FDA’s compliance program for Toxic Elements in Food and Foodware, and Radionuclides in Food and through targeted sampling assignments.”

FDA cited its work in sampling infant rice cereal for arsenic, which it says has resulted in safer products on the market, along with its recent court order to stop a U.S. company from distributing adulterated juice that had potentially harmful levels of inorganic arsenic and patulin (a mycotoxin).

The CFSAN update, however, did not specifically address the companies or baby foods called out in the Subcommittee’s report.

FDA

FDA to Test Yuma-Grown Romaine Lettuce for E. Coli and Salmonella

By Food Safety Tech Staff
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FDA

Today the FDA announced a new plan to collect samples of romaine lettuce as part of its ongoing surveillance after the spring 2018 multistate outbreak of E. coli O157:H7. The samples, which will be tested for Shiga toxin-producing Escherichia coli (STEC) and Salmonella, will be collected from commercial coolers in Yuma County, Arizona during the current harvest season.

FDA plans to collect and test about 500 samples (each of which will consist of 10 subsamples), beginning in February and continuing through the end of the harvest season. In order to reduce the time between sample collection and reporting results, an independent lab close to the collection sites in Arizona will be testing the samples. FDA expects to receive test results within 24 hours.

“Helping to ensure the safety of leafy greens continues to be a priority of the FDA. This assignment adds to other work underway in collaboration with stakeholders in the Yuma agricultural region to implement actions identified in the Leafy Greens Action Plan, including a multi-year study to assess the environmental factors that impact the presence of foodborne pathogens in this region. Consistent with the action plan, the agency will engage with industry on conducting root cause analyses for any positive samples found during this assignment. Root cause analyses are important in that they seek to identify potential sources and routes of contamination, inform what preventive measures are needed, and help prevent outbreaks of foodborne illness,” FDA stated in a release.

COVID-19 precautions will be taken during the sampling plan. Agency investigators will preannounce visits and wear PPE while conducting the work.

Tanimura & Antle romaine lettuce

Romaine Lettuce Recall Due to Possible E. Coli Contamination

By Food Safety Tech Staff
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Tanimura & Antle romaine lettuce
Tanimura & Antle romaine lettuce
Tanimura & Antle issued a voluntary recall of single-head packaged romaine lettuce.

Tanimura & Antle, Inc. is voluntarily recalling its packaged single head romaine lettuce, out of an abundance of caution, due to possible E. Coli 0157:H7 contamination. The product has a packaged date of 10/15/2020 or 10/16/2020, and the UPC number 0-27918-20314-9.

Although no illnesses have been reported, the recall is based on the test result of a random sample taken and analyzed by the Michigan Department of Agriculture and Rural Development. The company distributed 3,396 cartons to 20 states. Retailers and distributors can identify the affected products using the Product Traceability Initiative stickers (571280289SRS1 and 571280290SRS1) that are attached to the exterior of the case.

Arun Apte, CloudLIMS
In the Food Lab

Is Your Food Testing Lab Prepping for an ISO/IEC 17025 Audit?

By Arun Apte
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Arun Apte, CloudLIMS

With the increasing globalization of the food industry, ensuring that products reaching consumers are safe has never been more important. Local, state and federal regulatory agencies are increasing their emphasis on the need for food and beverage laboratories to be accredited to ISO/IEC 17025 compliance. This complicated process can be simplified and streamlined through the adoption of LIMS, making accreditation an achievable goal for all food and beverage laboratories.

With a global marketplace and complex supply chain, the food industry continues to face increasing risks for both unintentional and intentional food contamination or adulteration.1 To mitigate the risk of contaminated products reaching consumers, the International Organization for Standardization (ISO), using a consensus-based approval process, developed the first global laboratory standard in 1999 (ISO/IEC 17025:1999). Since publication, the standard has been updated twice, once in 2005 and most recently in 2017, and provides general requirements for the competence of testing and calibration laboratories.2

In the recent revision, four key updates were identified:

  1. A revision to the scope to include testing, calibration and sampling associated with subsequent calibration and testing performed by a laboratory.3
  2. An emphasis on the results of a process instead of focusing on prescriptive procedures and policies.4
  3. The introduction of the concept of a risk-based approach used in production quality management systems.2
  4. A stronger focus on information technologies/management systems, specifically Laboratory Information Management System (LIMS).4

As modern-day laboratories reduce their reliance on hard copy documents and transition to electronic records, additional emphasis and guidance for ISO 17025 accreditation in food testing labs using LIMS was greatly needed. Food testing laboratories have increased reliance on LIMS to successfully meet the requirements of accreditation. Food and beverage LIMS has evolved to increase a laboratory’s ability to meet all aspects of ISO 17025.

ISO 17025 requirements
Figure 1. A schematic representation of some of the requirements of ISO/IEC 17025:2017 compliance. (Figure courtesy CloudLIMS)

Traceability

Chain of Custody
A key element for ISO 17025 accredited laboratories is the traceability of samples from accession to disposal.5 Sometimes referred to as chain of custody, properly documented traceability allows a laboratory to tell the story of each sample from the time it arrives until the time it is disposed of.

LIMS software allows for seamless tracking of samples by employing unique sample accession numbers through barcoding processes. At each step of sample analysis, a laboratory technician updates data in a LIMS by scanning the sample barcode, establishing time and date signatures for the analysis. During an ISO 17025 audit, this information can be quickly obtained for review by the auditor.

Procurement and Laboratory Supplies
ISO 17025 requires the traceability of all supplies or inventory items from purchase to usage.6 This includes using approved vendors, documentation of receipt, traceability of supply usage to an associated sample, and for certain products, preparation of supply to working conditions within the laboratory. Supply traceability impacts multiple departments and coordinating this process can be overwhelming. A LIMS for food testing labs helps manage laboratory inventory, track usage of inventory items, and automatically alerts laboratory managers to restock inventory once the quantity falls below a threshold level.

A food LIMS can ensure that materials are ordered from approved vendors only, flagging items purchased outside this group. As supplies are inventoried into LIMS, the barcoding process can ensure accurate storage. A LIMS can track the supply through its usage and associate it with specific analytical tests for which inventory items are utilized. As products begin to expire, a LIMS can notify technicians to discard the obsolete products.

One unique advantage of a fully integrated LIMS software is the preparation and traceability of working laboratory standards. A software solution for food labs can assist a technician in preparing standards by determining the concentration of solvents needed based on the input weight from a balance. Once prepared, LIMS prints out a label with barcodes and begins the supply traceability process as previously discussed.

Quality Assurance of Test and Calibration Data

This section of ISO 17025 pertains to the validity of a laboratory’s quality system including demonstrating that appropriate tests were performed, testing was conducted on properly maintained and calibrated equipment by qualified personnel, and with appropriate quality control checks.

Laboratory Personnel Competency
Laboratory personnel are assigned to a specific scope of work based upon qualifications (education, training and experience) and with clearly defined duties.7 This process adds another layer to the validity of data generated during analysis by ensuring only appropriate personnel are performing the testing. However, training within a laboratory can be one of the most difficult components of the accreditation process to capture due to the rapid nature in which laboratories operate.

With a food LIMS, management can ensure employees meet requirements (qualifications, competency) as specified in job descriptions, have up-to-date training records (both onboarding and ongoing), and verify that only qualified, trained individuals are performing certain tests.

Calibration and Maintenance of Equipment
Within the scope of ISO 17025, food testing laboratories must ensure that data obtained from analytical instruments is reliable and valid.5 Facilities must maintain that instruments are in correct operating condition and that calibration data (whether performed daily, weekly, or monthly) is valid. As with laboratory personnel requirements, this element to the standard adds an additional layer of credibility that sample data is precise, accurate, and valid.

A fully integrated software solution for food labs sends a notification when instrument calibration is out of specification or expired and can keep track of both routine internal and external maintenance on instruments, ensuring that instruments are calibrated and maintained regularly. Auditors often ask for instrument maintenance and calibration records upon the initiation of an audit, and LIMS can swiftly provide this information with minimal effort.

Figure 2. A preconfigured food LIMS to manage instrument calibration and maintenance data. (Figure courtesy of CloudLIMS)

Measurement of Uncertainty (UM)
Accredited food testing laboratories must measure and report the uncertainty associated with each test result.8 This is accomplished by using certified reference materials (CRM), or known spiked blanks. UM data is trended using control charts, which can be prepared using labor-intensive manual input or performed automatically using LIMS software. A fully integrated food LIMS can populate control data from the instrument into the control chart and determine if sample data analyzed in that batch can be approved for release.

Valid Test Methods and Results
Accurate test and calibration results can only be obtained with methods that are validated for the intended use.5 Accredited food laboratories should use test methods that are current and contain embedded quality control standards.

A LIMS for food testing labs can ensure correct method selection by technicians by comparing data from the sample accession input with the test method selected for analysis. Specific product identifiers can indicate if methods have been validated. As testing is performed, a LIMS can track time signatures to ensure protocols are properly performed. At the end of the analysis, results of the quality control samples are linked to the test samples to ensure only valid results are available for clients. Instilling checks at each step of the process allows a LIMS to auto-generate Certificates of Analysis (CoA) knowing that the testing was performed accurately.

Data Integrity
The foundation of a laboratory’s reputation is based on its ability to provide reliable and accurate data. ISO 17025:2017 includes specific references to data protection and integrity.10 Laboratories often claim within their quality manuals that they ensure the integrity of their data but provide limited details on how it is accomplished making this a high priority review for auditors. Data integrity is easily captured in laboratories that have fully integrated their instrumentation into LIMS software. Through the integration process, data is automatically populated from analytical instruments into a LIMS. This eliminates unintentional transcription errors or potential intentional data manipulation. A LIMS for food testing labs restricts access to changing or modifying data, allowing only those with high-level access this ability. To control data manipulation even further, changes to data auto-populated in LIMS by integrated instrumentation are tracked with date, time, and user signatures. This allows an auditor to review any changes made to data within LIMS and determine if appropriate documentation was included on why the change was made.

Sampling
ISO 17025:2017 requires all food testing laboratories to have a documented sampling plan for the preparation of test portions prior to analysis. Within the plan, the laboratory must determine if factors are addressed that will ensure the validity of the testing, ensure that the sampling plan is available to the laboratory (or the site where sampling is performed), and identify any preparation or pre-treatment of samples prior to analysis. This can include storage, homogenization (grinding/blending) or chemical treatments.9

As sample information is entered into LIMS, the software can specify the correct sampling method to be performed, indicate appropriate sample storage conditions, restrict the testing to approved personnel and provide electronic signatures for each step.

Monitoring and Maintenance of the Quality System

Organization within a laboratory’s quality system is a key indicator to assessors during the audit process that the facility is prepared to handle the rigors that come with accreditation.10 Assessors are keenly aware of the benefits that a food LIMS provides to operators as a single, well-organized source for quality and technical documents.

Document Control
An ISO 17025 accredited laboratory must demonstrate document control throughout its facility.6 Only approved documents are available for use in the testing facility, and the access to these documents is restricted through quality control. This reduces the risk of document access or modification by unauthorized personnel.

LIMS software efficiently facilitates this process in several ways. A food LIMS can restrict access to controlled documents (both electronic and paper) and require electronic signatures each time approved personnel access, modify or print them. This digital signature provides a chain of custody to the document, ensuring that only approved controlled documents are used during analyses and that these documents are not modified.

Software, LIMS
Figure 3. A software solution for food labs helps manage documents, track their revision history, and ensure document control. (Figure courtesy of CloudLIMS)

Corrective Actions/Non-Conforming Work
A fundamental requirement for quality systems is the documentation of non-conforming work, and subsequent corrective action plans established to reduce their future occurrence.5

A software solution for food labs can automatically maintain electronic records of deviations in testing, flagging them for review by quality departments or management. After a corrective action plan has been established, LIMS software can monitor the effectiveness of the corrective action by identifying similar non-conforming work items.

Conclusion

Food and beverage testing laboratories are increasingly becoming accredited to ISO 17025. With recent changes to ISO 17025, the importance of LIMS for the food and beverage industry has only amplified. A software solution for food labs can integrate all parts of the accreditation process from personnel qualification, equipment calibration and maintenance, to testing and methodologies.11 Fully automated LIMS increases laboratory efficiency, productivity, and is an indispensable tool for achieving and maintaining ISO 17025 accreditation.

References

  1. Spink, J. (2014). Safety of Food and Beverages: Risks of Food Adulteration. Encyclopedia of Food Safety (413-416). Academic Press.
  2. International Organization for Standardization (October 2017). ISO/IEC 17025 General requirements for the competence of testing and calibration laboratories. Retrieved from: https://www.iso.org/files/live/sites/isoorg/files/store/en/PUB100424.pdf
  3. 17025 Store (2018). Transitioning from ISO 17025:2005 to ISO/IEC 17024:2017. Standards Store.
  4. Perry Johnson Laboratory Accreditation (2019). An Overview of Changes Between 17025:2005 and 17025:2017. ISO/IEC 17025:2017 Transition. https://www.pjlabs.com/downloads/17025-Transition-Book.pdf
  5. Analytical Laboratory Accreditation Criteria Committee. (2018). AOAC INTERNATIONAL Guidelines for Laboratories Performing Microbiological and Chemical Analyses of Food, Dietary Supplements, and Pharmaceuticals, An Aid to Interpretation of ISO/IEC 17025. Oxford, England: Oxford University Press.
  6. Cokakli, M. (September 4, 2020). Transitioning to ISO/IEC 17025:2017. New Food Magazine.
  7. ISO/IEC 17025:2017. General requirements for the competence of testing and calibration laboratories.
  8. Bell, S. (1999). A Beginner’s Guide to Uncertainty of Measurement. Measurement Good Practice Guide. 11 (2).
  9. 17025Store (2018). Clause 7: Process requirements. Standards Store.
  10. Dell’Aringa, J. (March 27, 2017). Best Practices for ISO 17025 Accreditation: Preparing for a Food Laboratory Audit (Part I). Food Safety Tech.
  11. Apte, A. (2020). Preparing for an ISO 17025 Audit: What to Expect from a LIMS?
Department of Justice seal

Blue Bell Hit with Record $17.25 Million in Criminal Penalties for 2015 Listeria Outbreak

By Maria Fontanazza
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Department of Justice seal

Remember the 2015 Listeria outbreak linked to Blue Bell Creameries? The outbreak led to three deaths and 10 illnesses between January 2010 and January 2015. On Thursday the Department of Justice ordered the company to pay $17.25 million in criminal penalties for shipping contaminated products linked to that outbreak. The sentence, enforced by U.S. District Judge Robert Pitman (Austin, Texas), is the largest fine and forfeiture ever imposed in a conviction involving a food safety case.

“American consumers must be able to trust that the foods they purchase are safe to eat,” stated – Acting Assistant Attorney General Jeffrey Bossert Clark, Justice Department’s Civil Division in an agency news release. “The sentence imposed today sends a clear message to food manufacturers that the Department of Justice will take appropriate actions when contaminated food products endanger consumers.”

In May 2020 Blue Bell pleaded guilty to two misdemeanor counts of distributing adulterated ice cream. The following is an excerpt from the Department of Justice news release:

“The plea agreement and criminal information filed against Blue Bell allege that the company distributed ice cream products that were manufactured under insanitary conditions and contaminated with Listeria monocytogenes, in violation of the Food, Drug and Cosmetic Act. According to the plea agreement, Texas state officials notified Blue Bell in February 2015 that samples of two ice cream products from the company’s Brenham, Texas factory tested positive for Listeria monocytogenes, a dangerous pathogen that can lead to serious illness or death in vulnerable populations such as pregnant women, newborns, the elderly, and those with compromised immune systems. Blue Bell directed its delivery route drivers to remove remaining stock of the two products from store shelves, but the company did not recall the products or issue any formal communication to inform customers about the potential Listeria contamination. Two weeks after receiving notification of the first positive Listeria tests, Texas state officials informed Blue Bell that additional state-led testing confirmed Listeria in a third product. Blue Bell again chose not to issue any formal notification to customers regarding the positive tests. Blue Bell’s customers included military installations.”

Raj Rajagopal, 3M Food Safety
In the Food Lab

Pathogen Detection Guidance in 2020

By Raj Rajagopal
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Raj Rajagopal, 3M Food Safety

Food production managers have a critical role in ensuring that the products they make are safe and uncontaminated with dangerous pathogens. Health and wellness are in sharp focus for consumers in every aspect of their lives right now, and food safety is no exception. As food safety becomes a continually greater focus for consumers and regulators, the technologies used to monitor for and detect pathogens in a production plant have become more advanced.

It’s no secret that pathogen testing is performed for numerous reasons: To confirm the adequacy of processing control and to ensure foods and beverages have been properly stored or cooked, to name some. Accomplishing these objectives can be very different, and depending on their situations, processors rely on different tools to provide varying degrees of testing simplicity, speed, cost, efficiency and accuracy. It’s common today to leverage multiple pathogen diagnostics, ranging from traditional culture-based methods to molecular technologies.

And unfortunately, pathogen detection is more than just subjecting finished products to examination. It’s become increasingly clear to the industry that the environment in which food is processed can cross-contaminate products, requiring food manufacturers to be ever-vigilant in cleaning, sanitizing, sampling and testing their sites.

For these reasons and others, it’s important to have an understanding and appreciation for the newer tests and techniques used in the fight against deadly pathogens, and where and how they might be fit for purpose throughout the operation. This article sheds light on the key features of one fast-growing DNA-based technology that detects pathogens and explains how culture methods for index and indicator organisms continue to play crucial roles in executing broad-based pathogen management programs.

LAMP’s Emergence in Molecular Pathogen Detection

Molecular pathogen detection has been a staple technology for food producers since the adoption of polymerase chain reaction (PCR) tests decades ago. However, the USDA FSIS revised its Microbiology Laboratory Guidebook, the official guide to the preferred methods the agency uses when testing samples collected from audits and inspections, last year to include new technologies that utilize loop-mediated isothermal amplification (LAMP) methods for Salmonella and Listeria detection.

LAMP methods differ from traditional PCR-based testing methods in four noteworthy ways.

First, LAMP eliminates the need for thermal cycling. Fundamentally, PCR tests require thermocyclers with the ability to alter the temperature of a sample to facilitate the PCR. The thermocyclers used for real-time PCR tests that allow detection in closed tubes can be expensive and include multiple moving parts that require regular maintenance and calibration. For every food, beverage or environmental surface sample tested, PCR systems will undergo multiple cycles of heating up to 95oC to break open DNA strands and cooling down to 60oC to extend the new DNA chain in every cycle. All of these temperature variations generally require more run time and the enzyme, Taq polymerase, used in PCR can be subjected to interferences from other inhibiting substances that are native to a sample and co-extracted with the DNA.

LAMP amplifies DNA isothermally at a steady and stable temperature range—right around 60oC. The Bst polymerase allows continuous amplification and better tolerates the sample matrix inhibitors known to trip up PCR. The detection schemes used for LAMP detection frees LAMP’s instrumentation from the constraints of numerous moving pieces.

Secondly, it doubles the number of DNA primers. Traditional PCR tests recognize two separate regions of the target genetic material. They rely on two primers to anneal to the subject’s separated DNA strands and copy and amplify that target DNA.

By contrast, LAMP technology uses four to six primers, which can recognize six to eight distinct regions from the sample’s DNA. These primers and polymerase used not only cause the DNA strand to displace, they actually loop the end of the strands together before initiating amplification cycling. This unique looped structure both accelerates the reaction and increases test result sensitivity by allowing for an exponential accumulation of target DNA.

Third of all, it removes steps from the workflow. Before any genetic amplification can happen, technicians must enrich their samples to deliberately grow microorganisms to detectable levels. Technicians using PCR tests have to pre-dispense lysis buffers or reagent mixes and take other careful actions to extract and purify their DNA samples.

Commercialized LAMP assay kits, on the other hand, offer more of a ready-to-use approach as they offer ready to use lysis buffer and simplified workflow to prepare DNA samples. By only requiring two transfer steps, it can significantly reduces the risk of false negatives caused by erroneous laboratory preparation.

Finally, it simplifies multiple test protocols into one. Food safety lab professionals using PCR technology have historically been required to perform different test protocols for each individual pathogen, whether that be Salmonella, Listeria, E. coli O157:H7 or other. Not surprisingly, this can increase the chances of error. Oftentimes, labs are resource-challenged and pressure-packed environments. Having to keep multiple testing steps straight all of the time has proven to be a recipe for trouble.

LAMP brings the benefit of a single assay protocol for testing all pathogens, enabling technicians to use the same protocol for all pathogen tests. This streamlined workflow involving minimal steps simplifies the process and reduces risk of human-caused error.

Index and Indicator Testing

LAMP technology has streamlined and advanced pathogen detection, but it’s impractical and unfeasible for producers to molecularly test every single product they produce and every nook and cranny in their production environments. Here is where an increasing number of companies are utilizing index and indicator tests as part of more comprehensive pathogen environmental programs. Rather than testing for specific pathogenic organisms, these tools give a microbiological warning sign that conditions may be breeding undesirable food safety or quality outcomes.

Index tests are culture-based tests that detect microorganisms whose presence (or detection above a threshold) suggest an increased risk for the presence of an ecologically similar pathogen. Listeria spp. Is the best-known index organism, as its presence can also mark the presence of deadly pathogen Listeria monocytogenes. However, there is considerable skepticism among many in the research community if there are any organisms outside of Listeria spp. that can be given this classification.

Indicator tests, on the other hand, detect the presence of organisms reflecting the general microbiological condition of a food or the environment. The presence of indicator organisms can not provide any information on the potential presence or absence of a specific pathogen or an assessment of potential public health risk, but their levels above acceptable limits can indicate insufficient cleaning and sanitation or operating conditions.

Should indicator test results exceed the established control limits, facilities are expected to take appropriate corrective action and to document the actions taken and results obtained. Utilizing cost-effective, fast indicator tests as benchmark to catch and identify problem areas can suggest that more precise, molecular methods need to be used to verify that the products are uncontaminated.

Process Matters

As discussed, technology plays a large role in pathogen detection, and advances like LAMP molecular detection methods combined with strategic use of index and indicator tests can provide food producers with powerful tools to safeguard their consumers from foodborne illnesses. However, whether a producer is testing environmental samples, ingredients or finished product, a test is only as useful as the comprehensive pathogen management plan around it.

The entire food industry is striving to meet the highest safety standards and the best course of action is to adopt a solution that combines the best technologies available with best practices in terms of processes as well –from sample collection and preparation to monitoring and detection.