Tag Archives: Listeria

The Power of Prevention: Pathogen Monitoring in Cannabis Cultivation and Processing Facilities

By Nathan Libbey
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As the cannabis market matures and the value chain becomes modernized, it’s important to address product safety in a comprehensive way. In other areas of manufacturing, Hazard Analysis & Critical Control Points (HACCP) has been the standard for reducing hazards both for employees and for the products themselves. A Critical Control Point (CCP) is any spot from conception to consumption where a loss of control can potentially result in risk (Unnevehr, 1996). In the food realm, HACCP has been used to drive quality enhancements since the 1980s (Cichy, 1982).

In a nutshell, HACCP seeks to help identify where a problem may enter a product or environment and how that problem may be addressed before it escalates. In cannabis, these hazards include many of the same problems that food products have: specifically molds, yeasts, and pathogenic bacteria (Listeria, E. coli, etc.). While the current industry standard is to test products at the end stage for these contaminants, this late-stage pass/fail regimen leads to huge lots of destroyed product and a risk for consumer distrust (Yamashiro, 2019). HACCP, therefore, should be applied at every stage of the production process.

Pathogen Environmental Monitoring (PEM) is a tool that can be used to identify CCPs in a cannabis cultivation or processing facility. The main goal of a PEM program is to find a contaminant before it reaches a surface that touches the product or the product itself. PEM is conducted using a pre-moistened swab or a sponge to collect a sample from the cannabis environment. The swab can then be sent to a lab for microbial testing. Keys to an effective PEM are:

1. Start with a broad stroke – When the FDA comes to a facility suspected of producing pathogen-laced food products, they conduct what is known as a Swab-a-thon. A Swab-a-thon is a top to bottom collection of samples, usually totaling 100 or more. Similarly, preemptively swabbing should be the first step in any PEM—swab everything to see what exists as a baseline.

2. Map your scene – identify on a map of your facility the following:

  • Cannabis contact surfaces (CCS) (belts, clippers, tables, etc)
  • Non-cannabis contact surfaces (Non-CCS) (floors, lighting, drains, etc)
  • Flow of air and people (where do air and people enter and where do they go?

Identifying the above zones will help deepen your understanding of where contaminants may come into contact with cannabis and how they may migrate from a Non-CCS to a CCS. 

3. Plan and execute:

  • Based on the results of mapping, and Swab-a-thon, identify where and when you will be collecting samples on a consistent and repeatable basis. Emphasis should be placed on areas that are deemed a risk based on 1) and 2). Samples should be collected at random in all zones to ensure comprehensive screening.

4. Remediate and modify:

  • If you get a positive result during PEM, don’t panic—pathogens are ubiquitous.
  • Remediate any trouble spots with deep cleaning, remediation devices or other protocols.
  • Re-test areas that were positive for pathogens to ensure remediation is successful.
  • Revisit and modify the plan at least once a year and each time a new piece of equipment is added or production flow is otherwise changed.

The steps above are a good starting point for a grower or processor to begin a PEM. Remember that this is not a one-size-fits-all approach to safety; each facility has its own unique set of hazards and control points.

Comprehensive guides for PEM can be found at the links below, many of the concepts can be applied to cannabis production.


https://affifoodsafety.org/lcp/advanced-search/

http://www.centerforproducesafety.org/amass/documents/document/263/Listeria%20Guidance%20UFPA%202013.pdf

Cichy, R. (1982). HACCP as a quality assurance tool in a commissary food-service system. International Journal of Hospitality Management, 1(2), 103-106.

Unnevehr, L., & Jensen, H. (1996). HACCP as a Regulatory Innovation to Improve Food Safety in the Meat Industry. American Journal of Agricultural Economics, 78(3), 764-769.

Yamashiro, C, & Baca, Y. (2019).  Prevent high-value cannabis crop loss with innovative environmental monitoring tool.

Rapid Pathogen Detection for the 21st Century: A Look at PathogenDx

By Aaron G. Biros
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In 1887, Julius Petri invented a couple of glass dishes, designed to grow bacteria in a reproducible, consistent environment. The Petri dish, as it came to be known, birthed the scientific practice of agar cultures, allowing scientists to study bacteria and viruses. The field of microbiology was able to flourish with this handy new tool. The Petri dish, along with advancements in our understanding of microbiology, later developed into the modern field of microbial testing, allowing scientists to understand and measure microbial colonies to detect harmful pathogens in our food and water, like E. coli and Salmonella, for example.

The global food supply chain moves much faster today than it did in the late 19th century. According to Milan Patel, CEO of PathogenDx, this calls for something a little quicker. “Traditional microbial testing is tedious and lengthy,” says Patel. “We need 21st century pathogen detection solutions.”

Milan Patel first joined the parent company of PathogenDx back in 2012, when they were more focused on clinical diagnostics. “The company was predominantly built on grant funding [a $12 million grant from the National Institute of Health] and focused on a niche market that was very specialized and small in terms of market size and opportunity,” says Patel. “I realized that the technology had a much greater opportunity in a larger market.”

Milan Patel, CEO of PathogenDx
Photo: Michael Chansley

He thought that other markets could benefit from that technology greatly, so the parent company licensed the technology and that is how PathogenDx was formed. Him and his team wanted to bring the product to market without having to obtain FDA regulatory approval, so they looked to the cannabis market. “What we realized was we were solving a ‘massive’ bottleneck issue where the microbial test was the ‘longest test’ out of all the tests required in that industry, taking 3-6 days,” says Patel. “We ultimately realized that this challenge was endemic in every market – food, agriculture, water, etc. – and that the world was using a 140-year-old solution in the form of petri dish testing for microbial organisms to address challenges of industries and markets demanding faster turnaround of results, better accuracy, and lower cost- and that is the technology PathogenDx has invented and developed.”

While originally a spinoff technology designed for clinical diagnostics, they deployed the technology in cannabis testing labs early on. The purpose was to simplify the process of testing in an easy approach, with an ultra-low cost and higher throughput. Their technology delivers microbial results in less than 6 hours compared to 24-36 hours for next best option.

The PathogenDx Microarray

Out of all the tests performed in a licensed cannabis testing laboratory, microbial tests are the longest, sometimes taking up to a few days. “Other tests in the laboratory can usually be done in 2-4 hours, so growers would never get their microbial testing results on time,” says Patel. “We developed this technology that gets results in 6 hours. The FDA has never seen something like this. It is a very disruptive technology.”

When it comes to microbial contamination, timing is everything. “By the time Petri dish results are in, the supply chain is already in motion and products are moving downstream to distributors and retailers,” Patel says. “With a 6-hour turnaround time, we can identify where exactly in the supply chain contaminant is occurring and spreading.”

The technology is easy to use for a lab technician, which allows for a standard process on one platform that is accurate, consistent and reproduceable. The technology can deliver results with essentially just 12 steps:

  1. Take 1 gram of cannabis flower or non-flower sample. Or take environmental swab
  2. Drop sample in solution. Swab should already be in solution
  3. Vortex
  4. Transfer 1ml of solution into 1.5ml tube

    A look at how the sample is added to the microarray
  5. Conduct two 3-minute centrifugation steps to separate leaf material, free-floating DNA and create a small pellet with live cells
  6. Conduct cell lysis by adding digestion buffer to sample on heat blocks for 1 hour
  7. Conduct Loci enhancement PCR of sample for 1 hour
  8. Conduct Labelling PCR which essentially attaches a fluorescent tag on the analyte DNA for 1 hour
  9. Pipette into the Multiplex microarray well where hybridization of sample to probes for 30 minutes
  10. Conduct wash cycle for 15 minutes
  11. Dry and image the slide in imager
  12. The imager will create a TIFF file where software will analyze and deliver results and a report

Their DetectX product can test for a number of pathogens in parallel in the same sample at the same time down to 1 colony forming unit (CFU) per gram. For bacteria, the bacterial kit can detect E. coli, E. coli/Shigella spp., Salmonella enterica, Listeria and Staph aureus, Stec 1 and Stec 2 E.coli. For yeast and mold, the fungal kit can test for Aspergillus flavus, Aspergillus fumigatus, Aspergillus niger and Aspergillus terreus.

Their QuantX is the world’s first and only multiplex quantification microarray product that can quantify the microbial contamination load for key organisms such as total aerobic bacteria, total yeast & mold, bile tolerant gram negative, total coliform and total Enterobacteriaceae over a dynamic range from 100 CFU/mL up to 1,000,000 CFU/mL.

Not all of the PathogenDx technology is designed for just microbial testing of cannabis or food products. Their EnviroX technology is designed to help growers, processors or producers across any industry identify areas of microbial contamination, being used as a tool for quality assurance and hazard analysis. They conducted industry-wide surveys of the pathogens that are creating problems for cultivators and came up with a list of more than 50 bacterial and fungal pathogens that the EnviroX assay can test for to help growers identify contamination hotspots in their facilities.

Using the EnviroX assay, growers can swab surfaces like vents, fans, racks, workbenches and other potential areas of contamination where plants come in contact. This helps growers identify potential areas of contamination and remediate those locations. Patel says the tool could help growers employ more efficient standard operating procedures with sanitation and sterilization, reducing the facility’s incidence of pathogens winding up on crops, as well as reduction in use of pesticides and fungicides on the product.

Deploying this technology in the cannabis industry allowed Milan Patel and the PathogenDx team to bring something new to the world of microbial testing. Their products are now in more than 90 laboratories throughout the country. The success of this technology provides another shining example of how the cannabis market produces innovative and disruptive ideas that have a major impact on the world, far beyond cannabis itself.