Cannabis testing to detect microbial contamination is complicated. It may not be rocket science, but it is life science, which means it’s a moving target, or at least, it should be, as we acquire more and more information about how the world we live in works. We are lucky to be able to carry out that examination in ever increasing detail. For instance, the science of genomics1 was born over 80 years ago, and just twenty years ago, genetics was still a black box. We’ve made tremendous progress since those early days, but we still have a long way to go, to be sure.
Much of that progress is due to our ability to build more accurate tools, a technological ladder, if you will, that raises our awareness, expertise, and knowledge to new levels. When a new process or technology appears, we compare it against accepted practice to create a new paradigm and make the necessary adjustments. But people have to be willing to change. In the cannabis industry, rapid change is a constant, first because that is the nature of a nascent industry, and second because in the absence of some universal and unimpeachable standard, it’s difficult to know who’s right. Especially when the old, reliable reference method (i.e. plating, which is basically growing microorganisms on the surface of a nutritional medium) is deeply flawed in its application to cannabis testing vs. molecular methods (i.e., quantitative polymerase chain reaction, or qPCR for short).
Plating systems have been used faithfully for close to 130 years in the food industry, and has performed reasonably well.2 But cannabis isn’t food and can’t be tested as if it were. In fact, plating methods have a host of major disadvantages that only show up when they’re used to detect cannabis pathogens. They are, in no particular order:
A single plating system can’t enumerate a group of microorganisms and/or detect specific bacterial and fungal pathogens. This is further complicated by the fact that better than 98% of the microbes in the world do not form colonies.3 And there is no ONE UNIVERSAL bacterial or fungal SELECTIVE agar plate that will allow the growth of all bacteria or all fungal strains. For example, the 5 genus species of fungal strains implicated in powderly mildew DO NOT plate at all.
Cannabinoids, which can represent 10-30% of a cannabis flower’s weight, have been shown to have antibacterial activity.4 Antibiotics inhibit the growth of bacteria and in some cases kill it altogether. Salmonella species & shiga toxin producing coli (STEC) bacteria, in particular, are very sensitive to antibiotics, which leads to either a false negative result or lower total counts on plates vs. qPCR methods.
Plating methods cannot detect bacterial and fungal endophytes that live a part or all of their life cycle inside a cannabis plant.5,6 Examples of endophytes are the Aspergillus pathogens (A. flavus, A. fumigatus, A. niger, and A. terreus). Methods to break open the plant cells to access these endophytes to prepare them for plating methods also lyse these microbial cells, thereby killing endophytic cells in the process. That’s why these endophytes will never form colonies, which leads to either false negative results or lower total counts on plates vs. qPCR methods.
Selective plating media for molds, such as Dichloran Rose-Bengal Chloramphenicol (DRBC) actually reduces mold growth—especially Aspergillus—by as much as 5-fold.This delivers false negative results for this dangerous human pathogen. In other words, although the DRBC medium is typically used to reduce bacteria; it comes at the cost of missing 5-fold more yeast and molds than Potato Dextrose Agar (PDA) + Chloramphenicol or molecular methods. These observations were derived from study results of the AOAC emergency response validation.7
Finally, we’ve recently identified four bacterial species, which are human pathogens associated with cannabis that do not grow at the plating system incubation temperature typically used.8 They are Aeromonas hydrophila, Pantoea agglomerans, Yersinia enterocolitica, and Rahnella aquatilis. This lowers total counts on plates qPCR methods.
So why is plating still so popular? Better yet, why is it still the recommended method for many state regulators? Beats me. But I can hazard a couple of guesses.
First, research on cannabis has been restricted for the better part of the last 70 years, and it’s impossible to construct a body of scientific knowledge by keeping everyone in the dark. Ten years ago, as one of the first government-employed scientists to study cannabis, I was tapped to start the first cannabis testing lab at the New Jersey Dept. of Health and we had to build it from ground zero. Nobody knew anything about cannabis then.
Second, because of a shortage of cannabis-trained experts, members of many regulatory bodies come from the food industry—where they’ve used plating almost exclusively. So, when it comes time to draft cannabis microbial testing regulations, plating is the default method. After all, it worked for them before and they’re comfortable with recommending it for their state’s cannabis regulations.
Finally, there’s a certain amount of discomfort in not being right. Going into this completely new area—remember, the legal cannabis industry didn’t even exist 10 years ago—we human beings like to have a little certainty to fall back on. The trouble is, falling back on what we did before stifles badly needed progress. This is a case where, if you’re comfortable with your old methods and you’re sure of your results, you’re probably wrong.
So let’s accept the fact that we’re all in this uncharted territory together. We don’t yet know everything about cannabis we need to know, but we do know some things, and we already have some pretty good tools, based on real science, that happen to work really well. Let’s use them to help light our way.
J. Weissenbach. The rise of genomics. Comptes Rendu Biologies, 339 (7-8), 231-239 (2016).
R. Koch. 1882. Die Aetiologie der Tuberculose. Berliner Klinische Wochenschrift, 19, 221-230 (1882).
W. Wade. Unculturable bacteria—the uncharacterized organisms that cause oral infections. Journal of the Royal Society of Medicine, 95(2), 91-93 (2002).
J.A. Karas, L.J.M. Wong, O.K.A. Paulin, A. C. Mazeh, M.H. Hussein, J. Li, and T. Vekov. Antibiotics, 9(7), 406 (2020).
M. Taghinasab and S. Jabaji, Cannabis microbiome and the role of endophytes in modulating the production of secondary metabolites: an overview. Microorganisms 2020, 8, 355, 1-16 (2020).
P. Kusari, S. Kusari, M. Spiteller and O. Kayser, Endophytic fungi harbored in Cannabis sativa L.: diversity and potential as biocontrol agents against host plant-specific phytopathogens. Fungal Diversity 60, 137–151 (2013).
K. McKernan, Y. Helbert, L. Kane, N. Houde, L. Zhang, S. McLaughlin, Whole genome sequencing of colonies derived from cannabis flowers & the impact of media selection on benchmarking total yeast & mold detection tools, https://f1000research.com/articles/10-624 (2021).
K. McKernan, Y. Helbert, L. Kane, L. Zhang, N. Houde, A. Bennett, J. Silva, H. Ebling, and S. McLaughlin, Pathogenic Enterobacteriaceae require multiple culture temperatures for detection in Cannabis sativa L. OSF Preprints, https://osf.io/j3msk/, (2022)
As the demand for legal cannabis continues to rise and more states come online, it is imperative to enact more rigorous and comprehensive testing solutions to protect the health of consumers. People use cannabis products for wellness and to find relief; they should not be susceptible to consuming pathogens and falling ill. Especially for immunocompromised consumers, the consequences of consuming contaminated cannabis or hemp are dire. Of course, there should be federal standards for pathogen testing requirements like we have for the food industry. But right now, as cannabis is not yet federally legal, testing regulations vary between states and in many states, testing requirements are too loose and enforcement is minimal. It is up to state legislators, regulators and cannabis operators to protect the health of consumers through implementing more stringent testing.
From the outset, the environmental elements needed to grow cannabis – heat, light, humidity, soil – make cannabis ripe for pathogens to proliferate. Even when growers follow strict sanitation procedures through the supply chain from seed to sale, contaminations can still occur. Cannabis companies need to be hypervigilant and proactive about testing, not just reactive. The lack of regulations in some states is alarming, and as the cannabis industry is highly competitive and so many companies have emerged in a short time, there are unfortunately unscrupulous actors that have skated by in a loose regulatory landscape, just in the game to make a quick buck, even at the expense of consumer health. And there are notable instances where states do not have enforcement in place to deter harmful manufacturing practices. For instance, there are some states that don’t mandate moisture control and there have been incidents of companies watering down flower so it has more weight and thus can be sold at a higher cost – all the while that added moisture leads to mold, harming the consumer. This vicious circle driven by selfish human behavior needs to be broken by stricter regulations and enforcement.
While in the short term, looser testing regulations may save companies some money, in the long run these regulatory environments carry significant economic repercussions and damage the industry at large, most importantly injury or death to customers and patients. Recalls can tarnish a company’s brand and reputation and cause sales and stock prices to tank, and since cannabis legalization is such a hotly contested issue, the media gloms onto these recalls, which opponents to legalization then leverage to justify their stance. In order to win the hearts and minds of opponents and bring about federal legalization sooner, we need safer products so cannabis won’t be cast in such a dangerous, risky light.
Certainly, there’s a bit of irony at play here – the lack of federal regulations heightens the risk of contaminated cannabis reaching consumers, and on the flip side recalls are used by opponents to justify stigmatizing the plant and keeping it illegal. Nevertheless, someday in the not-too-distant future, cannabis will be legalized at the federal level. And when that day happens, federal agents will aggressively test and regulate cannabis; they’ll swab every area in facilities and demand thorough records of testing up and down the supply chain; current good manufacturing practices (cGMP) will be mandated. No longer will violations result just in a slap on the wrist – businesses will be shut down. To avoid a massive shock to the system, it makes sense for cannabis companies to pivot and adopt rigorous and wide-sweeping testing procedures today. Wait for federal legalization, and you’ll sink.
Frankly, the current landscape of cannabis regulation is scary and the consequences are largely yet to be seen. Just a few months ago, a Michigan state judge reversed part of a recall issued by the state’s Marijuana Regulatory Agency (MRA) on cannabis that exceeded legal limits of yeast, mold and aspergillus, bringing contaminated cannabis back to shelves without even slapping a warning label on the packaging to inform consumers of the potential contamination. This is a classic case of the power of the dollar prevailing over consumer safety and health. Even in well-established markets, the lack of regulations is jarring. For example, before this year in Colorado, testing for aspergillus wasn’t even required. (Aspergillus inhalation, which can cause Aspergillosis, can be deadly, especially for people who are immunocompromised). Many states still allow trace amounts of aspergillus and other pathogens to be present in cannabis samples. While traces may seem inconsequential in the short term, what will happen to frequent consumers who have been pinging their lungs with traces of pathogens for 30 years? Consistently inhaling trace amounts of pathogens can lead to lung issues and pulmonary disease down the road. Look what happened to people with breathing and lung issues during the last two years with COVID. What’s going to happen to these people when the next pandemic hits?
We need state regulators and MSOs to step up and implement more aggressive testing procedures. These regulators and companies can create a sea of change in the industry to better protect the health and well-being of consumers. Just complying with loose regulations isn’t good enough. We need to bring shortcomings around testing into the limelight and demand better and more efficient regulatory frameworks. And we should adopt the same standards for medical and adult use markets. Right now, several states follow cGMP for medical but not adult use – that’s ridiculous. Potentially harming consumers goes against what activists seeking legalization have been fighting for. Cannabis, untainted, provides therapeutic and clinical value not just to medical patients but to all consumers; cannabis companies should promote consumer health through their products, not jeopardize it.
For best practices, companies should conduct tests at every step in the supply chain, not just test end products. And testing solutions should be comprehensive. Most of the common tests used today are based on petri dishes, an archaic and inefficient technology dating back over a century, which require a separate dish to test for each pathogen of interest. If you’re waiting three to five days to see testing results against fifteen pathogens and a pathogen happens to be present, by the time you see results, the pathogen could have spread and destroyed half of your crops. So, not only do petri dishes overburden state-run labs, but due to their inherent inefficiencies, relying on these tests can significantly eat into cannabis companies’ revenues. At PathogenDx, we’ve created multiplexing solutions that can identify and detect up to 50 pathogens in a single test and yield accurate results in six hours. To save cannabis companies money in the long run and to make sure pathogens don’t slip through the cracks, more multiplexing tests like the ones we’ve created should be implemented in state labs.
Right now, while the regulatory landscape is falling short in terms of protecting consumer health, better solutions already exist. I urge state regulators and cannabis companies to take testing very seriously, be proactive and invest in creating better testing infrastructure today. Together, we can protect the health of consumers and create a stronger, more trustworthy and prosperous cannabis industry.
By Jill Ellsworth MS, RDN, Tess Eidem, Ph.D. No Comments
As an emerging field in cannabis, contaminant testing remains a gray area for many businesses. The vast differences in state-by-state regulations, along with the frequent changes of previously established rules make testing a difficult, time-consuming process. But at its core, the science and reasoning behind why we test cannabis is very clear – consumer safety and quality assurance are key factors in any legal, consumer market. The implications of federal legalization make cannabis testing even more important to the future of the cannabis supply chain. Understanding the types of contaminants, their sources and how to prevent them is essential to avoiding failures, recalls and risking consumer safety.
When talking about cannabis contaminant testing there are four groups of contaminants: pesticides, heavy metals, foreign materials and microbes. The microbes found on cannabis include plant pathogens, post-harvest spoiling microbes, allergens, toxin release and human pathogens. While all of these can be lurking on the surface of cannabis, the specific types that are tested for in each state vary widely. Understanding the full scope of contaminants and looking beyond state-specific compliance requirements, cultivators will be able to prevent these detrimental risks and prepare their business for the future.
Beyond just the health of the plant, both medical patients and adult use consumers can be adversely affected by microbial contaminants. To immunocompromised patients, Aspergillus can be life-threatening and both adult use and medical consumers are susceptible to allergic reactions to moldy flower. But Aspergillus is just one of the many contaminants that are invisible to the human eye and can live on the plant’s surface. Several states have intensive testing regulations when it comes to the full breadth of possible harmful contaminants. Nevada, for example, has strict microbial testing requirements and, in addition to Aspergillus, the state tests for Salmonella, STEC, Enterobacteriaceae, coliforms and total yeast and mold. Over 15 states test for total yeast and mold and the thresholds vary from allowing less than 100,000 colony forming units to allowing less than 1,000 colony forming units. These microbes are not uncommon appearances on cannabis – in fact, they are ever-present – so understanding them as a whole, beyond regulatory standards is a certain way to future-proof a business. With such vast differences in accepted levels of contamination per state, the best preparation for the future and regulations coming down the pipeline is understanding contamination, addressing it at its source and harvesting disease-free cannabis.
The risk of contamination is present at every stage of the cultivation process and encompasses agricultural practices, manufacturing processes and their intersection. From cultivation to manufacturing, there are factors that can introduce contamination throughout the supply chain. A quality control infrastructure should be employed in a facility and checkpoints within the process to ensure aseptic operations.
Cultivators should test their raw materials, including growing substrates and nutrient water to ensure it is free of microbial contamination. Air quality plays an important role in the cultivation and post-harvest processes, especially with mold contamination. Environmental controls are essential to monitor and regulate temperature and humidity and ensure unwanted microbes cannot thrive and decrease the value of the product or make it unsafe for worker handling or consumers. Developing SOPs to validate contact surfaces are clean, using proper PPE and optimizing worker flow can all help to prevent cross-contamination and are part of larger quality assurance measures to prevent microbes from spreading across cultivars and harvests.
Methods of microbial examination include air quality surveillance, ATP surface and water monitoring, raw materials testing, and species identification. Keeping control of the environment that product is coming into contact with and employing best practices throughout will minimize the amount of contamination that is present before testing. The solution to avoiding worst case scenarios following an aseptic, quality controlled process is utilizing a safe, post-harvest kill-step, much like the methods used in the food and beverage industries with the oversight of the FDA.
The goal of the grower should be to grow clean and stay clean throughout the shelf life of the product. In order to do this, it is essential to understand the critical control points within the cultivation and post-harvest processes and implement proper kill-steps. However, if a product is heavily bio-burdened, there are methods to recover contaminated product including decontamination, remediation and destroying the product. These measures come with their own strengths and weaknesses and cannot replace the quality assurance programs developed by the manufacturer.
Risk management is the process of identifying potential hazards, assessing the associated risk, then implementing controls to mitigate those risks. With Salmonella and Aspergillus being two of the leading causes of cannabis contamination that can occur throughout the supply chain, applying upstream risk management strategies can keep supplier contamination issues from impacting your products.
In recent months cannabis products have been recalled for Salmonella and/or Aspergillus contamination in several states, including California, Arizona, Michigan, Florida, as well as Canada. While the recalls impacted retail products, in most cases, the contamination occurred farther back in the supply chain, as evidenced by recalls that impacted several dispensaries or other sales locations.
For example, the November 2021 Arizona recall caused multiple establishments and dispensaries to recall product due to possible contamination with Salmonella or Aspergillus; the Michigan recall of an estimated $229 million in cannabis products due to “inaccurate and/or unreliable results of products tested.” While a lab lawsuit against the recall released some of the product to market, the companies faced significant impact – in both removing and returning the product.
While microbial contamination can occur throughout the supply chain, Aspergillus is ubiquitous in soil and the flower, leaves, roots of the cannabis plant are all susceptible to such contamination. The mold also can colonize the bud both during growing and harvesting. Salmonella can be introduced during growing through, untreated manures, direct contact with animal feces, or contamination of surface water used for irrigation. However, the plant matter also can be compromised during drying, storage and processing from environmental contamination.
Supply chain risk management. To prevent a supplier’s contamination issues from becoming your problem to deal with, each facility at each step of the chain should develop a supply chain risk management program to assess and approve each of its upstream providers. Following are 5 key steps to assessing and managing risk in your supply chain:
Conduct a hazard analysis. A complete supply chain assessment should begin with a hazard assessment of all the ingredients, products or primary packaging you receive. There are two essential steps involved in conducting a hazard analysis: that is the identification of potential hazards – considering those related to the item itself, as well as the supplier environment and process as well as item – and an evaluation to determine if each hazard requires control based on its severity and likely occurrence.
Evaluate the risks. Based on the hazard analysis, the next step is to determine the associated risk. As defined by the European Food Information Council (EUFIC), “a hazard is something that has the potential to cause harm while risk is the likelihood of harm taking place, based on exposure to that hazard.” For example, the higher the exposure, the higher the risk.
Ensure risk control. Once risk is determined, it is critical to ensure that it is being controlled, who is controlling it and how it is being done. Depending on the risk, that control may need to be conducted by the supplier, by you or even by a downstream customer.
Require documentation. No matter which step in the chain is controlling the risk, it is essential that all be documented with records easily accessible – including the controls, any out-of-compliance events and corrective actions. The adage, “If it’s not documented, it didn’t happen,” is very applicable here, particularly should a problem arise and an inspector appear at your door.
Use only approved suppliers. Implementation of the above steps enable the development of a supplier approval program focused on quality, safety and regulatory compliance. Use of only suppliers who have been assessed and found to meet all your standards will help to protect your product and your brand.
Salmonella and Aspergillus contamination can occur throughout the supply chain, but implementing a supply chain risk assessment and management program will enable you to determine where the greatest risks lie among your ingredients and suppliers, allowing you to allocate resources based on that risk.
Medicinal Genomics announced today that they have received AOAC International certification for their PathoSEEK® Salmonella and STEC E. coli multiplex assay. In combination with their SenSATIVAx® extraction kits, labs can simultaneously detect Salmonella spp. and STEC E. coli with a single qPCR reaction for flower, concentrates and infused chocolates using the Agilent AriaMx and the BioRad CFx-96 instruments.
The certification came after the multiplex assay was validated according to the AOAC Performance Tested Method Program. According to the press release, the PathoSEEK platform now has more cannabis matrices accredited for Aspergillus, Salmonella, and STEC E. coli than any other product out on the market, according to their press release.
The PathoSEEK microbiological testing platform uses a qPCR assay and internal plant DNA controls for reactions. The two-step protocol verifies performance while detecting microbes, which allegedly helps minimize false negative results from human error or failing conditions.
“AOAC’s validation of our Salmonella/STEC E. coli assay across the various cannabis matrices is further proof of our platform’s robustness and versatility,” says Dr. Sherman Hom, director of regulatory affairs at Medicinal Genomics. “We are excited that our PathoSEEK® platform is moving in concert with the FDA’s new blueprint to improve food safety by modernizing the regulatory framework, while leveraging the use of proven molecular tools to accelerate predictive capabilities, enhance prevention, and enhance our ability to swiftly adapt to pathogen outbreaks that could impact consumer safety.”
bioMérieux, a leader in the in vitro diagnostics space and a supporter of the cannabis testing market, announced last month that they have achieved the first ever AOAC International approval for PCR Multiplex Detection of STEC and Salmonella in cannabis flower for their GENE-UP® PRO STEC/Salmonella Assay. The performance tested method approval for their new assay accomodates simultaneous enrichment and detection of STEC (Shiga Toxigenic Escherichia coli) and Salmonella spp. in cannabis samples.
The method is aimed at increasing efficiency in cannabis testing labs by reducing sample preparation time for microbiological testing. With the single enrichment and real-time multiplex PCR detection, bioMérieux says their new assay can provide reliable detection of STEC and Salmonella in 24 hours using just a single test.
PCR technology is one of the most widely utilized testing methods for detecting pathogens in a variety of matrices. bioMérieux claims it is easy to use, scientifically robust and reduces costs, time spent testing and errors.
Maria McIntyre, cannabis strategic operations business manager at bioMérieux, says that AOAC performance tested method approval is setting the bar for cannabis testing laboratories and furthering cannabis science. “AOAC International impacts cannabis science by setting analytical method standards that act as the benchmark for method validation,” says McIntyre. “This simplifies the validations needed by cannabis laboratories and assures the utmost confidence in product safety and human health.”
In this “Leaders in Cannabis Testing” series of articles, Green interviews cannabis testing laboratories and technology providers that are bringing unique perspectives to the industry. Particular attention is focused on how these businesses integrate innovative practices and technologies to navigate a rapidly changing landscape of regulatory constraints and B2B demand.
PathogenDx is an Arizona-based provider of microbial testing technologies. Since their inception in 2014, they have broadened their reach to 26 states in the US. In addition to cannabis product testing, PathogenDx also provides technologies for food safety testing, environmental testing and recently started offering human diagnostics testing to support COVID-19 response efforts.
We interviewed Milan Patel, CEO and co-founder of PathogenDx. Milan founded PathogenDx as a spin-off from one of his investments in a clinical diagnostics company testing for genetic markers in transplant organs. Prior to PathogenDx, Milan worked in finance and marketing at Intel and later served as CFO at Acentia (now Maximus Federal).
Aaron Green: What’s the history of PathogenDx?
Milan Patel: PathogenDx was effectively a spin-off of a clinical diagnostics company that my partner Dr. Mike Hogan, the inventor of the technology, had founded when he was a professor at the University of Arizona, but previously at Baylor Medical College back in 2002. I had invested in the company back then and I had realized that his technology had a broad and wide sweeping impact for testing – not just for pathogens in cannabis specifically, but also for pathogens in food, agriculture, water and even human diagnostics. In the last 14 months, this became very personal for every single person on the planet having been impacted by SARS-CoV-2, the viral pathogen causing Covid-19. The genesis of the company was just this, that human health, food and agricultural supply, and the environment has and will continue to be targeted by bacterial, fungal and viral pathogens impacting the safety and health of each human on the planet.
We founded PathogenDx and we pivoted the company from its original human organ transplant genetics market scope into the bigger markets; we felt the original focus was too niche for a technology with this much potential. We licensed the technology, and we repurposed it into primarily cannabis. We felt that achieving commercial success and use in the hands of cannabis testing labs at the state level where cannabis was first regulated was the most logical next step. Ultimately, our goal was and is to move into markets that are approved at the federal regulatory side of the spectrum, and that is where we are now.
Green: What year was that?
Green: So, PathogenDx started in cannabis testing?
Patel: Yes, we started in cannabis testing. We now have over 100 labs that are using the technology. There is a specific need in cannabis when you’re looking at contamination or infection.
In the case of contamination on cannabis, you must look for bacterial and fungal organisms that make it unsafe, such as E. coli, or Salmonella or Aspergillus pathogens. We’re familiar with recent issues like the romaine lettuce foodborne illness outbreaks at Chipotle. In the case of fungal organisms such as Aspergillus, if you smoke or consume contaminated cannabis, it could have a huge impact on your health. Cannabis regulators realized that to ensure public health and safety there was more than just one pathogen – there were half a dozen of these bugs, at a minimum, that could be harmful to you.
The beauty of our technology, using a Microarray is that we can do what is called a multiplex test, which means you’re able to test for all bacterial and fungal pathogens in a single test, as opposed to the old “Adam Smith” model, which tests each pathogen on a one-by-one basis. The traditional approach is costly, time consuming and cumbersome. Cannabis is such a high value crop and producers need to get the answer quickly. Our tests can give a result in six hours on the same day, as opposed to the two or three days that it takes for these other approved methods on the market.
Green: What is your business model? Is there equipment in addition to consumables?
Patel: Our business model is the classic razor blade model. What that means is we sell equipment as well as the consumables – the testing kits themselves.
The PathogenDx technology uses standard, off-the-shelf lab equipment that you can find anywhere. We didn’t want to make the equipment proprietary so that a lab has to buy a specific OEM branded product. They can use almost any equipment that’s available commercially. We wanted to make sure that labs are only paying a fraction of the cost to get our equipment, as opposed to using other vendors. Secondly, the platform is open-ended, meaning it’s highly flexible to work with the volumes that different cannabis labs see daily, from high to low.
One equipment set can process many different types of testing kits. There are kits for regulated testing required by states, as well as required environmental contamination.
Green: Do you provide any in-house or reference lab testing?
Patel: We do. We have a CLIA lab for clinical testing. We did this about a year ago when we started doing COVID testing.
We don’t do any kind of in-house reference testing for cannabis, though we do use specific reference materials or standards from Emerald Scientific, for example, or from NCI. Our platform is all externally third-party reference lab tested whether it’s validated by our external cannabis lab customers or an independent lab. We want our customers to make sure that the actual test works in their own hands, in their own facility by their own people, as opposed to just shrugging our shoulders and saying, “hey, we’ve done it ourselves, believe us.” That’s the difference.
Green: Can you explain the difference between qPCR and endpoint PCR?
Patel: The difference between PathogenDx’s Microarray is it uses endpoint PCR versus qPCR (quantitative real time PCR). Effectively, our test doesn’t need to be enriched. Endpoint PCR delivers a higher level of accuracy, because when it goes to amplify that target DNA, whether it’s E. coli, Salmonella or Aspergillus pieces, it uses all the primer reagent to its endpoint. So, it amplifies every single piece of an E. Coli (for example) in that sample until the primer is fully consumed. In the case of qPCR, it basically reaches a threshold and then the reaction stops. That’s the difference which results in a much greater level of accuracy. This provides almost 10 times greater sensitivity to identify the pathogen in that sample.
The second thing is that we have separated out how the amplified sample hybridizes to the probe. In the case of our assay, we have a microarray with a well in it and we printed the actual probe that has the sequence of E. coli in there, now driving 100% specificity. Whereas in the qPCR, the reaction is not only amplifying, but it’s also basically working with the probe. So, in that way, we have a higher level of efficiency in terms of specificity. You get a definite answer exactly in terms of the organism you’re looking for.
In terms of an analogy, let’s take a zip code for example which has the extra four digits at the end of it. In the case of endpoint PCR, we have nine digits. We have our primer probes which represent the standard five digits of a zip code, and the physical location of the probe itself in the well which serves as the extra four digits of that zip code. The analyte must match both primary and secondary parts of the nine-digit zip code for it to lock in, like a key and a lock. And that’s the way our technology works in a nutshell.
Endpoint PCR is completely different. It drives higher levels of accuracy and specificity while reducing the turnaround time compared to qPCR – down to six hours from sample to result. In qPCR, you must enrich the sample for 24 to 48 hours, depending on bacteria or fungus, and then amplification and PCR analysis can be done in one to three hours. The accuracies and the turnaround times are the major differences between the endpoint PCR and qPCR.
Green: If I understand correctly, it’s a printed microarray in the well plate?
Patel: That’s correct. It’s a 96-well plate, and in each well, you’ve now printed all the probes for all targets in a single well. So, you’re not running more than one well per target, or per organism like you are for qPCR. You’re running just one well for all organisms. With our well plates, you’re consuming fewer wells and our patented foil-cover, you only use the wells you need. The unused wells in the well plate can be used in future tests, saving on costs and labor.
Green: Do you have any other differentiating IP?
Patel: The multiplex is the core IP. The way we process the raw sample, whether it’s flower or non-flower, without the need for enrichment is another part of the core IP. We do triplicate probes in each well for E. Coli, triplicate probes for Salmonella, etc., so there are three probes per targeted organism in each of the wells. We’re triple checking that you’re definitively identifying that bug at the end of the day. This is the cornerstone of our technology.
We were just approved by the State of New York, and the New York Department of Health has 13 different organisms for testing on cannabis. Think about it: one of the most rigorous testing requirements at a state level – maybe even at a federal level – and we just got approved for that. If you had to do 13 organisms separately, whether it’s plate culture or qPCR, it would become super expensive and very difficult. It would break the very backs of every testing lab to do that. That’s where the multiplexing becomes tremendously valuable because what you’re doing is leveraging the ability to do everything as a single test and single reaction.
Green: You mentioned New York. What other geographies are you active in?
Patel: We’re active in 26 different states including the major cannabis players: Florida, Nevada, California, Arizona, Michigan, New York, Oklahoma, Colorado and Washington – and we’re also in Canada. We’re currently working to enter other markets, but it all comes down to navigating the regulatory process and getting approval.
We’re not active currently in other international markets yet. We’re currently going through the AOAC approval process for our technology and I’m happy to say that we’re close to getting that in the next couple of months. Beyond that, I think we’ll scale more internationally.
I am delighted to say that we also got FDA EUA federal level authorization of our technology which drives significant credibility and confidence for the use of the technology. About a year ago, we made a conscious choice to make this technology federally acceptable by going into the COVID testing market. We got the FDA EUA back on April 20, ironically. That vote of confidence by the FDA means that our technology is capable of human testing. That has helped to create some runway in terms of getting federalized with both the FDA and the USDA, and certification by AOAC for our different tests.
Green: Was that COVID-19 EUA for clinical diagnostics or surveillance?
Patel: It was for clinical diagnostics, so it’s an actual human diagnostic test.
Green: Last couple of questions here. Once you find something as a cannabis operator, whether its bacteria or fungus, what can you do?
Patel: There are many services that are tied into our ecosystem. For example, we work with Willow Industries, who does remediation.
There’s been a lot of criticism around DNA based technology. It doesn’t matter if it’s qPCR or endpoint PCR. They say, “well, you’re also including dead organisms, dead DNA.” We do have a component of separating live versus dead DNA with a biomechanical process, using an enzyme that we’ve created, and it’s available commercially. Labs can test for whether a pathogen is living or dead and, in many cases, when they find it, they can partner with remediation companies to help address the issue at the grower level.
Another product we offer is an EnviroX test, which is an environmental test of air and surfaces. These have 50 pathogens in a single well. Think about this: these are all the bad actors that typically grow where soil is – the human pathogens, plant pathogens, powdery mildew, Botrytis, Fusarium – these are very problematic for the thousands of growers out there. The idea is to help them with screening technology before samples are pulled off the canopy and go to a regulated lab. We can help the growers isolate where that contamination is in that facility, then the remediation companies can come in, and help them save their crop and avoid economic losses.
Green: What are you most interested in learning about?
Patel: I would prefer that the cannabis industry not go through the same mistakes other industries have gone through. Cannabis started as a cottage industry. It’s obviously doubled every year, and as it gets scaled, the big corporations come in. Sophistication, standards, maturity all help in legitimacy of a business and image of an industry. At the end of the day, we have an opportunity to learn from other industries to really leapfrog and not have to go through the same mistakes. That’s one of the things that’s important to me. I’m very passionate about it.
One thing that I’ll leave you with is this: we’re dealing with more bugs in cannabis than the food industry. The food industry is only dealing with two to four bugs and look at the number of recalls they are navigating – and this is a multi-billion-dollar industry. Cannabis is still a fraction of that and we’re dealing with more bugs. We want to look ahead and avoid these recalls. How do you avoid some of the challenges around antimicrobial resistance and antibiotic resistance? We don’t want to be going down that road if we can avoid it and that’s sort of a personal mission for myself and the company.
Cannabis itself is so powerful, both medicinally as well as recreationally, and it can be beneficial for both consumers and industry image if we do the right things, and avoid future disasters, like the vaping crisis we went through 18 months ago because of bad GMPs. We must learn from those industries. We’re trying to make it better for the right reasons and that’s what’s important to me.
Green: Okay, great. That concludes the interview. Thank you, Milan.
Patel: Thank you for allowing me to share my thoughts and your time, Aaron.
In a press release sent out this month, bioMérieux announced they have received the very first approvals in cannabis and hemp for AOAC Research Institute Performance Testing Methods (PTM). AOAC approved method validation for the detection of Salmonella and STEC (Shiga toxin-producing E. coli) in cannabis flower utilizing bioMérieux GENE- UP® SLM2 (PTM 121802) and EHEC (PTM 121806) assays.
According to the press release, these validations are the first of their kind in the cannabis and hemp industries. The AOAC-validated testing methods are approved for 1-gram and 10-gram samples.
Dr. Stan Bailey, senior director of scientific affairs at bioMérieux, says these approvals demonstrate the company’s commitment to innovative and validated science in the cannabis and hemp industries. “We are especially proud that the GENE-UP SLM2 and EHEC are the first two AOAC approvals in the United States for cannabis and hemp,” says Dr. Bailey. “This is increasingly important with now over half the population of the US living in states that have approved cannabis for recreational use and most states approving cannabis for medical use.”
The AOAC PTM designations are recognized by the US Department of Agriculture, the Food and Drug Administration, and global regulatory agencies. The validation guidance builds on AOAC’s Cannabis Analytical Science Program (CASP).
bioMérieux is a French in vitro diagnostics company that serves the global testing market. They provide diagnostic solutions such as systems, reagents, software and services.
If you missed the Cannabis Industry Journal’s 3rd Annual Infused Products Virtual Conference last week, one of the speakers, Ellice Ogle, founder and CEO of Tandem Food presented on Food Safety Culture in the Cannabis Industry. An overview of the information in the presentation can be found here, Concentrate On a Food Safety Culture In Your Workplace. Below are answers to some of the post-presentation questions we received, but were unable to answer during the Q&A session. To get your additional questions answered or for a complimentary consultation for your company, specially provided to readers of Cannabis Industry Journal, contact Ellice Ogle at Ellice@tndmfood.com.
Question: What are some recommended digital programs for internal auditing?
Ellice Ogle: Before looking at the tools for conducting an internal audit, understand the goal of the internal audit. One key aspect of internal auditing is knowing which standard(s) to audit against. For example, regulatory audits for cGMP certification are different than optional third-party certifications such as any GFSI scheme (SQF, BRC, PrimusGFS, etc). While the standards ultimately have the same goal of food safety with varying focuses, it is important to have an experienced food safety specialist conduct the audit as realistically as possible. The experienced specialist will then be able to recommend an appropriate tool for internal auditing moving forward, whether it is software such as FoodLogiQ, SafetyChain, Safefood 360°, among many others, or simply providing a template of the audit checklist. Overall, the risk of foodborne illnesses can be minimal, but it takes persistence and commitment to achieve a successful food safety culture. Metrics can assist in assessing the commitment to food safety and, as a result of these efforts, you will minimize the risk of compromising the health and safety of your guests, employees, foods and business. If you want a specific example, I’d like to direct you to a case study in partnership with Heylo LLC in Washington state, posted on the Tandem Food website.
Q: What are examples of ways to share environmental monitoring results to enhance a good edible safety culture?
Ellice: In the Control of Listeria monocytogenes in Ready-To-Eat Foods: Guidance for Industry Draft Guidance (2017), the FDA states that “a well-designed environmental monitoring program promotes knowledge and awareness of the environmental conditions that could result in product contamination and is a more effective program than product testing alone.” In other words, environmental monitoring programs and results can identify environmental conditions within a facility that could cause potential contamination. Publishing these findings, for example in the form of a case study or sharing the details of the practice, can enhance the food safety culture in the specific niche industry. For example, to borrow from the meat industry, Tyson Foods, Inc developed and shared environmental monitoring programs that are used by their peers, promoting a unified food safety culture, rather than competitive, guarded secrecy.
Q: Are the food safety requirements the same for retail and manufacturing?
Ellice: The food safety requirements are not exactly the same for retailers and manufacturers. The difference is inherent that retailers are working with finished product while manufacturers are working with raw ingredients and the manufacturing process to develop the finished product. Let’s take a closer look at cannabis regulation in Washington state. Chapter 314-55-104(12) states “Processors creating marijuana extracts must develop standard operating procedures (SOPs), good manufacturing practices (GMPs), and a training plan prior to producing extracts for the marketplace.” Compare this to the requirements for retailers, 314-55-105(11) which states “A marijuana producer, processor or retailer licensed by the WSLCB must conduct the production, processing, storage, and sale of marijuana-infused products using sanitary practices.” While SOPs and GMPs are not explicitly mentioned for retailers as they are for manufacturers, sanitary practices could be documented as Sanitation Standard Operating Procedures (SSOPs). Proper storage practices can also be an overlapping food safety concern with respect to temperature control or pest management systems. Overall, food safety should remain a top priority in maintaining the integrity of the products throughout the supply chain.
Q: To your knowledge, has there been a food safety outbreak associated with a cannabis-based product?
Ellice: One possible cannabis-related death investigated in 2017 uncovered deadly pathogens in medical cannabis. However, to my knowledge, I have not seen a food safety outbreak associated with a cannabis-based product. There might be any number of reasons that this is so, for example, possibly because a food safety outbreak associated with a cannabis-based product might not have had a large impact to make headlines. Although, with the cannabis industry already misunderstood and a stigma so prevalent to even promote fake news, it is better to prevent an outbreak from ever occurring. One thing to note is that ultimately cannabis is just another ingredient in existing products, of course with special properties. So, the common food safety offenders are present: listeria, Salmonella, E. Coli, among others. On the plant, cannabis food product manufacturers must minimize the risk of mycotoxins produced by molds, pest contamination, and pesticide contamination. For products that contain cannabis infusions or extractions as an ingredient, there is the possibility of the growth of Botulism toxin. Many of these pathogens can be minimized by appropriate heat treatment or maintenance of refrigeration, testing, and by practicing preventive measures. Arguably, the largest potential for pathogenic contamination is due to improper employee handling. To refer to what we discussed earlier, employee training is key, as well as proper enforcement. Having a strong food safety culture ensures that people have the knowledge of food safety risks and the knowledge of preventing outbreaks.
Q: Do any of the panelists know of any efforts to develop a food safety-oriented standard for the cannabis industry?
Ellice: Yes, Tandem Food LLC is positioned to consult on cGMP certification for manufacturing facilities in the cannabis industry. First, a gap assessment can be conducted to obtain useful actionable data for you, rather than be an intimidating experience. Working from the identified baseline, Tandem Food will work with you to create and implement all related documentation and programs, providing training as necessary. Overall, with the right commitment, cGMP certification can take 6-12 months.
Consumers are largely unaware that most commercial cannabis grown today undergoes some form of decontamination to treat the industry’s growing problem of mold, yeast and other microbial pathogens. As more cannabis brands fail regulatory testing for contaminants, businesses are increasingly turning to radiation, ozone gas, hydrogen peroxide or other damaging remediation methods to ensure compliance and avoid product recalls. It has made cannabis cultivation and extraction more challenging and more expensive than ever, not to mention inflaming the industry’s ongoing supply problem.
The problem is only going to get worse as states like Nevada and California are beginning to implement more regulations including even tougher microbial contamination limits. The technological and economic burdens are becoming too much for some cultivators, driving some of them out of business. It’s also putting an even greater strain on them to meet product demand.
It’s critical that the industry establishes new product standards to reassure consumers that the cannabis products they buy are safe. But it is even more critical that the industry look beyond traditional agricultural remediation methods to solve the microbial problems.
Mold and other microbial pathogens are found everywhere in the environment, including the air, food and water that people consume. While there is no consensus yet on the health consequences of consuming these contaminants through cannabis, risks are certainly emerging. According to a 2015 study by the Cannabis Safety Institutei, molds are generally harmless in the environment, but some may present a health threat when inhaled, particularly to immunocompromised individuals. Mycotoxins resulting from molds such as Aspergillus can cause illnesses such as allergic bronchopulmonary aspergillosis. Even when killed with treatment, the dead pathogens could trigger allergies or asthma.
There is an abundance of pathogens that can affect cannabis cultivation, but the most common types are Botrytis (bud rot, sometimes called gray mold) and Powdery Mildew. They are also among the most devastating blights to cannabis crops. Numerous chemical controls are available to help prevent or stem an outbreak, ranging from fungicides and horticultural oils to bicarbonates and biological controls. While these controls may save an otherwise doomed crop, they introduce their own potential health risks through the overexposure and consumption of chemical residues.
The issue is further compounded by the fact that the states in which cannabis is legal can’t agree on which microbial pathogens to test for, nor how to test. Colorado, for instance, requires only three pathogen tests (for salmonella, E. coli, and mycotoxins from mold), while Massachusetts has exceedingly strict testing regulations for clean products. Massachusetts-based testing lab, ProVerde Laboratories, reports that approximately 30% of the cannabis flowers it tests have some kind of mold or yeast contamination.
If a cannabis product fails required microbial testing and can’t be remedied in a compliant way, the grower will inevitably experience a severe – and potentially crippling – financial hit to a lost crop. Willow Industries, a microbial remediation company, says that cannabis microbial contamination is projected to be a $3 billion problem by 2020ii.
Remediation Falls Short
With the financial stakes so high, the cannabis industry has taken cues from the food industry and adopted a variety of ways to remediate cannabis harvests contaminated with pathogens. Ketch DeGabrielle of Qloris Consulting spent two years studying cannabis microbial remediation methods and summarized their pros and consiii.
He found that some common sterilization approaches like autoclaves, steam and dry heat are impractical for cannabis due the decarboxylation and harsh damage they inflict on the product. Some growers spray or immerse cannabis flowers in hydrogen peroxide, but the resulting moisture can actually cause more spores to germinate, while the chemical reduces the terpene content in the flowers.
The more favored, technologically advanced remediation approaches include ozone or similar gas treatment, which is relatively inexpensive and treats the entire plant. However, it’s difficult to gas products on a large scale, and gas results in terpene loss. Microwaves can kill pathogens effectively through cellular rupture, but can burn the product. Ionizing radiation kills microbial life by destroying their DNA, but the process can create carcinogenic chemical compounds and harmful free radicals. Radio frequency (which DeGabrielle considers the best method) effectively kills yeast and mold by oscillating the water in them, but it can result in moisture and terpene loss.
The bottom line: no remediation method is perfect. Prevention of microbial contamination is a better approach. But all three conventional approaches to cannabis cultivation – outdoors, greenhouses and indoor grow operations – make it extremely difficult to control contamination. Mold spores can easily gain a foothold both indoors and out through air, water, food and human contact, quickly spreading into an epidemic.
The industry needs to establish new quality standards for product purity and employ new growing practices to meet them. Advanced technologies can help create near perfect growing ecosystems and microclimates for growing cannabis free of mold contamination. Internet of Things sensors combined with AI-driven robotics and automation can dramatically reduce human intervention in the growing process, along with human-induced contamination. Natural sunlight supplemented with new lighting technologies that provide near full-light and UV spectrum can stimulate robust growth more resistant to disease. Computational fluid dynamic models can help growers achieve optimal temperature, humidity, velocity, filtration and sanitation of air flow. And tissue culture micropropagation of plant stock can eliminate virus and pathogen threats, to name just a few of the latest innovations.
Growing legal cannabis today is a risky business that can cost growers millions of dollars if pathogens contaminate a crop. Remediation methods to remove microbial contamination may work to varying degrees, but they introduce another set of problems that can impact consumer health and comprise product quality.
Strictly Necessary Cookies
Strictly Necessary Cookie should be enabled at all times so that we can save your preferences for cookie settings.
We use tracking pixels that set your arrival time at our website, this is used as part of our anti-spam and security measures. Disabling this tracking pixel would disable some of our security measures, and is therefore considered necessary for the safe operation of the website. This tracking pixel is cleared from your system when you delete files in your history.
If you disable this cookie, we will not be able to save your preferences. This means that every time you visit this website you will need to enable or disable cookies again.