According to a press release published earlier this week, PathogenDx, Inc., is expanding their product portfolio and doing some rebranding. The DNA-based pathogen detection testing provider, headquartered in Scottsdale, Arizona, produces microarray testing platforms for the cannabis, agriculture and food and beverage industries. Their rapid testing technology can reportedly identify and detect 50+ pathogens all in a single test, including common pathogens such as E. Coli, Salmonella and Aspergillus.
DetectX – Tests for the presence of pathogenic microbial organisms down to a single organism, at less than 0.1 CFU/gram for state regulated compliance. Test 96 or more samples a day for multiple state mandated microbial pathogens, with product safety certainty delivered in 6 hours, far more rapid than current industry standards of 72 hours or more.
QuantX – The world’s first quantification microarray test for Cannabis. This test measures the microbial load in a sample, while also providing discrimination of the organism content relative to testing standards. Regulatory agencies will now have the opportunity to improve microbial testing standards to ensure safety.
EnviroX – With a single swab, one can identify 50+ species and classes of microbes, with quick-turn results, by simply swabbing a grower/cultivation facility surfaces and vents. Submit, identify, and remediate. It’s that simple to mitigate risk to high-value crops.
PhytoX – Coming in Summer of 2019,PathogenDx will introduce the ultra-rapid, easy plant pathogen test to detect powdery mildew, gray mold, mites and other microbial bugs that can become destructive threats to one’s crop. Acquire results in 6 hours to intercept and redress infestation that can destroy one’s yield.
According to CEO and Co-Founder Milan Patel, they want their technology to set the standard for product safety testing. “We’re making the accurate testing of cannabis, food and agriculture faster, more definitive and less expensive with trackable results benefitting growers, producers, regulators and consumers worldwide,” says Patel. “Our new brand is inspired by our unique microplex array and is bright, fresh, memorable and expansive, enabling us to move from cannabis only to much larger global consumable markets where we can continue to offer new products and applications for the technology.”
Have you paused to consider that quality assurance is a moving target rather than a destination? It is culture within a company that requires constant improvement and change, rather than the work of a select few to reach one defined end goal. Quality, therefore, is not a box that must simply be checked but an overarching and driving force propelling organizations forward.
For those within the cannabis industry and specifically cannabis testing labs, quality assurance is critical to having a successful and thriving business within the rapidly evolving industry. Dr. Kim Ross, who earned her Ph.D. at the University of Colorado in Molecular Biology, and also has worked with multiple cannabis labs, says, “It is not that often that you get a new testing industry born these days and people are scrambling to borrow processes from other industries and apply these to the cannabis industry.” Those within cannabis testing labs are looking towards established industries like water and food testing labs to serve as a quality assurance beacon. Ross elaborates:
The cannabis industry is operating in the absence of federal oversight. If you think about it, the water, food, and pharmaceutical industries have federal oversight. In lieu of that, it is up to states to adopt regulatory practices and enforcement strategies to uphold a level of compliance and data defensibility that these types of regulators have seen in their careers working in the FDA, EPS, NELAC or ISO.
For cannabis testing labs, the stakes are high. First, there is the need to keep up with the rapidly evolving industry climate as more and more states and governing bodies are setting requirements and expectations for quality and compliance. It is in nobody’s best interest to fall behind or be a late adopter to the increasingly regulatory compliance environment.
Additionally, untrustworthy data sets can have detrimental impacts on people and patients. Medical applications of cannabis require specific results in order to ensure the safety of patients, many of which are immunocompromised. Beyond damage to people and patients, businesses themselves can be hurt if a cannabis testing lab were to present inaccurate or flawed data sets. Ross shared hypothetical examples of potential negative impacts:
If, for example, you fail a product for microbiology based on false-positive results then it incurs damages to the client because now their product can’t go to market. Additionally, falsely inflated THC results are also a huge problem in the industry, and can result in downstream problems with edible dosing or consumer satisfaction.
A quality assurance system can minimize risk and maximize adherences to proper procedure, resulting in reliable data. Recalls, product issues and lawsuits cost organizations tremendous amounts of time and money, both to manage the problem at hand and prevent future incidents. Not to mention, the immeasurable damage done to the brand & industry by being viewed as untrustworthy–especially as a consumable product. “Ensuring data defensibility and data integrity protects the laboratory from lawsuits,” says Ross. “That is a really important piece of a quality assurance system for a laboratory.”
One common misconception is viewing quality assurance as a cost center rather than a profitability maximizer. A robust quality assurance system is a competitive advantage–especially for those who are not yet mandated to be compliant to a particular standard, like ISO/IEC 17025, but choose to pursue that accreditation knowing it reflects reliability. In many ways, quality assurance can be summarized as “say what you do, and do what you say”, with a willingness to allow third-party confirmation of your commitment and practice. “Accreditation gives an unbiased stamp of approval that helps ensure data defensibility in the laboratory,” affirms Ross.
Accreditation as a result of quality assurance ultimately leads to reliable and trustworthy data sets. Ross shared:
It might appear to be easy to buy expensive instrumentation, accept samples, and produce data. There are so many ways to do that, some of which are incorrect, and therefore accreditation is really an opportunity to have professionals evaluate methodology and post-analytical data processing to ensure that it is scientifically sound. It is an opportunity for a laboratory to be confident that their processes and reporting procedures are robust and error free.
Remember: this is a new industry. There aren’t firmly established methods and procedures like other legacy industries. “We are operating in a time and space where there is no standard methodology and that makes oversight by a third party even more important,” shares Ross. When a company opts to pursue accreditation they are indicating a willingness to be honest and transparent with their business processes, procedures, outcomes and data. Accreditation, therefore, is necessary for this emerging industry. Having a robust, inclusive quality assurance system in place will ease and quicken their pursuit of accreditation.The stress on an audit day when there is a digitized system is vastly lower than a system that is printed and physically maintained.
Not all quality assurance systems are created equal. There are still some companies seeking to implement systems that lack the modernization necessary to truly propel them forward towards continuous improvement and scalability. Quality assurance software with widespread use and adaptation across organizations is both scalable and in support of continuous improvements. Binders, rows of filing cabinets and complicated excel spreadsheets are not a scalable backbone for a quality system.
Beyond the accessibility and traceability that a digital system creates, it also protects. “We can protect that data with credentialed logins for key personnel and have information at our fingertips to reduce the regulatory stress on all personnel,” says Ross. The stress on an audit day when there is a digitized system is vastly lower than a system that is printed and physically maintained.
For those in the cannabis industry, specifically cannabis testing labs, there is an unequivocal advantage to implementing a system that supports continuous improvement, reliable data sets and the very best in business practices. Doing so will help sustain and grow the industry, and could be pivotal in transforming the production, market and research of cannabis.
Across the country, there is a patchwork of regulatory requirements that vary from state to state. Regulations focus on limiting microbial impurities (such as mold) present in cannabis in order for consumers to receive a safe product. When cultivators in Colorado and Nevada submit their cannabis product to laboratories for testing, they are striving to meet total yeast and mold count (TYMC) requirements.In a nascent industry, it is prudent for state regulators to reference specific testing methodologies so that an industry standard can be established.
TYMC refers to the number of colony forming units present per gram (CFU/g) of cannabis material tested. CFU is a method of quantifying and reporting the amount of live yeast or mold present in the cannabis material being tested. This number is determined by plating the sample, which involves spreading the sample evenly in a container like a petri dish, followed by an incubation period, which provides the ideal conditions for yeast and mold to grow and multiply. If the yeast and mold cells are efficiently distributed on a plate, it is assumed that each live cell will give rise to a single colony. Each colony produces a visible spot on the plate and this represents a single CFU. Counting the numbers of CFU gives an accurate estimate on the number of viable cells in the sample.
The plate count methodology for TYMC is standardized and widely accepted in a variety of industries including the food, cosmetic and pharmaceutical industries. The FDA has published guidelines that specify limits on total yeast and mold counts ranging from 10 to 100,000 CFU/g. In cannabis testing, a TYMC count of 10,000 is commonly used. TYMC is also approved by the AOAC for testing a variety of products, such as food and cosmetics, for yeast and mold. It is a fairly easy technique to perform requiring minimal training, and the overall cost tends to be relatively low. It can be utilized to differentiate between dead and live cells, since only viable living cells produce colonies.
Petri dish containing the fungus Aspergillus flavus. Photo courtesy of USDA ARS & Peggy Greb.
There is a 24 to 48-hour incubation period associated with TYMC and this impedes speed of testing. Depending on the microbial levels in a sample, additional dilution of a cannabis sample being tested may be required in order to count the cells accurately. TYMC is not species-specific, allowing this method to cover a broad range of yeast and molds, including those that are not considered harmful. Studies conducted on cannabis products have identified several harmful species of yeast and mold, including Cryptococcus, Mucor, Aspergillus, Penicillium and Botrytis Cinerea. Non-pathogenic molds have also been shown to be a source of allergic hypersensitivity reactions.The ability of TYMC to detect only viable living cells from such a broad range of yeast and mold species may be considered an advantage in the newly emerging cannabis industry.
After California voted to legalize recreational marijuana, state regulatory agencies began exploring different cannabis testing methods to implement in order to ensure clean cannabis for the large influx of consumers.
Unlike Colorado, California is considering a different route and the recently released emergency regulations require testing for specific species of Aspergillus mold (A. fumigatus, A. flavus, A. niger and A. terreus). While Aspergillus can also be cultured and plated, it is difficult to differentiate morphological characteristics of each species on a plate and the risk of misidentification is high. Therefore, positive identification would require the use of DNA-based methods such as polymerase chain reaction testing, also known as PCR. PCR is a molecular biology technique that can detect species-specific strains of mold that are considered harmful through the amplification and analysis of DNA sequences present in cannabis. The standard PCR testing method can be divided into four steps:
The double stranded DNA in the cannabis sample is denatured by heat. This refers to splitting the double strand into single strands.
Primers, which are short single-stranded DNA sequences, are added to align with the corresponding section of the DNA. These primers can be directly or indirectly labeled with fluorescence.
DNA polymerase is introduced to extend the sequence, which results in two copies of the original double stranded DNA. DNA polymerases are enzymes that create DNA molecules by assembling nucleotides, the building blocks of DNA.
Once the double stranded DNA is created, the intensity of the resulting fluorescence signal can uncover the presence of specific species of harmful Aspergillus mold, such as fumigatus.
These steps can be repeated several times to amplify a very small amount of DNA in a sample. The primers will only bind to the corresponding sequence of DNA that matches that primer and this allows PCR to be very specific.
PCR testing is used in a wide variety of applications Photo courtesy of USDA ARS & Peggy Greb.
PCR is a very sensitive and selective method with many applications. However, the instrumentation utilized can be very expensive, which would increase the overall cost of a compliance test. The high sensitivity of the method for the target DNA means that there are possibilities for a false positive. This has implications in the cannabis industry where samples that test positive for yeast and mold may need to go through a remediation process to kill the microbial impurities. These remediated samples may still fail a PCR-based microbial test due to the presence of the DNA. Another issue with the high selectivity of this method is that other species of potentially harmful yeast and mold would not even be detected. PCR is a technique that requires skill and training to perform and this, in turn, adds to the high overall cost of the test.
Both TYMC and PCR have associated advantages and disadvantages and it is important to take into account the cost, speed, selectivity, and sensitivity of each method. The differences between the two methodologies would lead to a large disparity in testing standards amongst labs in different states. In a nascent industry, it is prudent for state regulators to reference specific testing methodologies so that an industry standard can be established.
The cannabis industry is probably more informed about patients and consumers of their products than the general food industry. In addition to routine illness and stress in the population, cannabis consumers are fighting cancer, HIV/AIDS and other immune disorders. Consumers who are already ill are immunocompromised. Transplant recipients purposely have their immune system suppressed in the process of a successful transplant. These consumers have pre-existing conditions where the immune system is weakened. If the immunocompromised consumer is exposed to viral or bacterial pathogens through cannabis products, the consumer is more likely to suffer from a viral infection or foodborne illness as a secondary illness to the primary illness. In the case of consumers with weakened immune systems, it could literally kill them.Bacteria, yeast, and mold are present in all environments.
The cannabis industry shoulders great responsibility in both the medical and adult use markets. In addition to avoiding chemical hazards and determining the potency of the product, the cannabis industry must manufacture products safe for consumption. There are three ways to control pathogens and ensure a safe product: prevent them from entering, kill them and control their growth.
Prevent microorganisms from getting in
Think about everything that is outdoors that will physically come in a door to your facility. Control the quality of ingredients, packaging, equipment lubricants, cleaning agents and sanitizers. Monitor employee hygiene. Next, you control everything within your walls: employees, materials, supplies, equipment and the environment. You control receiving, employee entrance, storage, manufacturing, packaging and distribution. At every step in the process, your job is to prevent the transfer of pathogens into the product from these sources.
Kill microorganisms
Colorized low-temperature electron micrograph of a cluster of E. coli bacteria. Image courtesy of USDA ARS & Eric Erbe
The combination of raw materials to manufacture your product is likely to include naturally occurring pathogens. Traditional heat methods like roasting and baking will kill most pathogens. Remember, sterility is not the goal. The concern is that a manufacturer uses heat to achieve organoleptic qualities like color and texture, but the combination of time and temperature may not achieve safety. It is only with a validated process that safety is confirmed. If we model safety after what is required of food manufacturers by the Food and Drug Administration, validation of processes that control pathogens is required. In addition to traditional heat methods, non-thermal methods for control of pathogens includes irradiation and high pressure processing and are appropriate for highly priced goods, e.g. juice. Killing is achieved in the manufacturing environment and on processing equipment surfaces after cleaning and by sanitizing.
If you have done everything reasonable to stop microorganisms from getting in the product and you have a validated step to kill pathogens, you may still have spoilage microorganisms in the product. It is important that all pathogens have been eliminated. Examples of pathogens include Salmonella, pathogenic Escherichia coli, also called Shiga toxin-producing E. coli (STEC) and Listeria monocytogenes. These three common pathogens are easily destroyed by proper heat methods. Despite steps taken to kill pathogens, it is theoretically possible a pathogen is reintroduced after the kill step and before packaging is sealed at very low numbers in the product. Doctors do not know how many cells are required for a consumer to get ill, and the immunocompromised consumer is more susceptible to illness. Lab methods for the three pathogens mentioned are designed to detect very low cell numbers. Packaging and control of growth factors will stop pathogens from growing in the product, if present.
Control the growth of microorganisms
These growth factors will control the growth of pathogens, and you can use the factors to control spoilage microbes as well. To grow, microbes need the same things we do: a comfortable temperature, water, nutrients (food), oxygen, and a comfortable level of acid. In the lab, we want to find the pathogen, so we optimize these factors for growth. When you control growth in your product, one hurdle may be enough to stop growth; sometimes multiple hurdles are needed in combination. Bacteria, yeast, and mold are present in all environments. They are at the bottom of the ocean under pressure. They are in hot springs at the temperature of boiling water. The diversity is immense. Luckily, we can focus on the growth factors for human pathogens, like Salmonella, pathogenic E. coli, and Listeria monocytogenes.
The petri dishes show sterilization effects of negative air ionization on a chamber aerosolized with Salmonella enteritidis. The left sample is untreated; the right, treated. Photo courtesy of USDA ARS & Ken Hammond
Temperature. Human pathogens prefer to grow at the temperature of the human body. In manufacture, keep the time a product is in the range of 40oF to 140oF as short as possible. You control pathogens when your product is at very hot or very cold temperatures. Once the product cools after a kill step in manufacturing, it is critical to not reintroduce a pathogen from the environment or personnel. Clean equipment and packaging play key roles in preventing re-contamination of the product.
Water. At high temperatures as in baking or roasting, there is killing, but there is also the removal of water. In the drying process that is not at high temperature, water is removed to stop the growth of mold. This one hurdle is all that is needed. Even before mold is controlled, bacterial and yeast growth will stop. Many cannabis candies are safe, because water is not available for pathogen growth. Packaging is key to keep moisture out of the product.
Nutrients. In general, nutrients are going to be available for pathogen growth and cannot be controlled. In most products nutrients cannot be removed, however, recipes can be adjusted. Recipes for processed food add preservatives to control growth. In cannabis as in many plants, there may be natural compounds which act as preservatives.
Oxygen. With the great diversity of bacteria, there are bacteria that require the same oxygen we breathe, and mold only grows in oxygen. There are bacteria that only grow in the absence of oxygen, e.g. the bacteria responsible for botulism. And then there are the bacteria and yeast in between, growing with or without oxygen. Unfortunately, most human pathogens will grow with or without oxygen, but slowly without oxygen. The latter describes the growth of Salmonella, E. coli, and Listeria. While a package seals out air, the growth is very slow. Once a package is opened and the product is exposed to air, growth accelerates.
Acid. Fermented or acidified products have a higher level of acid than non-acid products; the acid acts as a natural preservative. The more acid, the more growth is inhibited. Generally, acid is a hurdle to growth, however and because of diversity, some bacteria prefer acid, like probiotics which are non-pathogenic. Some pathogens, like E. coli, have been found to grow in low acid foods, e.g. juice, even though the preference is for non-acidic environments.
I have been studying microorganisms for over 35 years, and the elusive critters still fascinate me! Here in Microbiology 101, I write about the foundation of knowledge on which all microbiologists build. You may have a general interest in microbiology or have concerns in your operation. By understanding microbiology, you understand the diversity of microorganisms, their source, control of microorganisms and their importance.
Part 1
The term microbiology covers every living being we cannot see with the naked eye. The smallest microbe is a virus. Next in size are the bacteria, then yeast and mold cells, and the largest microbes are the protozoans. The tiny structure of a virus may be important in the plant pathology of cannabis, but will not grow in concentrates or infused products. A virus is not living, until it storms the gate of a living cell and overtakes the functions within the cell. Viruses are the number one cause of foodborne illness, with the number one virus called Norovirus. Think stomach flu. Think illness on cruise ships. Viruses are a food service problem and can be prevented by requiring employees to report sickness, have good personal hygiene including good hand washing, and, as appropriate, wear gloves. Following Good Manufacturing Practices (GMPs) is critical in preventing the transfer of viruses to a product where the consumer can be infected.
The petri dishes show sterilization effects of negative air ionization on a chamber aerosolized with Salmonella enteritidis. The left sample is untreated; the right, treated. Photo courtesy of USDA ARS & Ken Hammond
The largest microbial cell is the protozoan. They are of concern in natural water sources, but like viruses, will not grow in cannabis products. Control water quality through GMPs, and you control protozoans. Viruses and protozoans will not be further discussed here. Bacteria, yeast and mold are the focus of further discussion. As a food microbiologist, my typical application of this information is in the manufacturing of food. Because Microbiology 101 is a general article on microbiology, you can apply the information to growing, harvesting, drying, manufacture of infused products and dispensing.
It is not possible to have sterile products. Even the canning process of high temperature for an extended time allows the survival of resistant bacterial spores. Astronauts take dehydrated food into space, and soldiers receive MREs; both still contain microbes. Sterility is never the goal. So, what is normal? Even with the highest standards, it is normal to have microbes in your products. Your goal is to eliminate illness-causing microorganisms, i.e. pathogens. Along the way, you will decrease spoilage microbes too, making a product with higher quality.
Petri dish containing the fungus Aspergillus flavus. It produces carcinogenic aflatoxins, which can contaminate foods and cause an invasive fungal disease. Photo courtesy of USDA ARS & Peggy Greb.
Yeast and mold were discussed on CIJ in a previous article, Total Yeast & Mold Count: What Cultivators & Business Owners Need to Know. Fuzzy mold seen on the top of food left in the refrigerator too long is a quality issue, not a safety issue. Mold growth is a problem on damaged cannabis plants or cuttings and may produce mycotoxin, a toxic chemical hazard. Following Good Agricultural Practices (GAPs) will control mold growth. Once the plant is properly dried, mold will not grow and produce toxin. Proper growing, handling and drying prevents mycotoxins. Like mold, growth of yeast is a quality issue, not a safety issue. As yeast grow, they produce acid, alcohol and carbon dioxide gas. While these fermentation products are unwanted, they are not injurious. I am aware that some states require cannabis-infused products to be alcohol-free, but that is not a safety issue discussed here.
What are the sources of microorganisms?
People. Employees who harvest cannabis may transfer microorganisms to the plant. Later, employees may be the source of microbes at the steps of trimming, drying, transfer or portioning, extract processing, infused product manufacture and packaging.
Ingredients, Supplies and Materials. Anything you purchase may be a source of microorganisms. Procure quality merchandise. Remember the saying, “you get what you pay for.”
Environment. Starting with the outdoors, microbes come from wind, soil, pests, bird droppings and water. When plants are harvested outdoors or indoors, microbes come from the tools and bins. Maintain clean growing and harvesting tools in good working condition to minimize contamination with microbes. For any processing, microbes come from air currents, use of water, and all surfaces in the processing environment from dripping overhead pipes to floor drains and everything in between.
In Part 2 I will continue to discuss the diversity of microorganisms, and future articles will cover Hazard Analysis and Critical Control Points (HACCP) and food safety in more detail. What concerns do you have at each step of operations? Are you confident in your employees and their handling of the product? As each state works to ensure public health, cannabis-infused products will receive the same, if not more, scrutiny as non-cannabis food and beverages. With an understanding and control of pathogens, you can focus on providing your customers with your highest quality product.
Editor’s note: This article should serve as a foundation of knowledge for yeast and mold in cannabis. Beginning in January 2018, we will publish a series of articles focused entirely on yeast and mold, discussing topics such as TYMC testing, preventing yeast and mold in cultivation and treatment methods to reduce yeast and mold.
Cannabis stakeholders, including cultivators, extractors, brokers, distributors and consumers, have been active in the shadows for decades. With the legalization of recreational adult use in several states, and more on the way, safety of the distributed product is one of the main concerns for regulators and the public. Currently, Colorado1, Nevada and Canada2 require total yeast and mold count (TYMC) compliance testing to evaluate whether or not cannabis is safe for human consumption. As the cannabis industry matures, it is likely that TYMC or other stringent testing for yeast and mold will be adopted in the increasingly regulated medical and recreational markets.
The goal of this article is to provide general information on yeast and mold, and to explain why TYMC is an important indicator in determining cannabis safety.
Yeast & Mold
Photo credit: Steep Hill- a petri dish of mold growth from tested cannabis
Yeast and mold are members of the fungi family. Fungus, widespread in nature, can be found in the air, water, soil, vegetation and in decaying matter. The types of fungus found in different geographic regions vary based upon humidity, soil and other environmental conditions. In general, fungi can grow in a wide range of pH environments and temperatures, and can survive in harsh conditions that bacteria cannot. They are not able to produce their own food like plants, and survive by breaking down material from their surroundings into nutrients. Mold cannot thrive in an environment with limited oxygen, while yeast is able to grow with or without oxygen. Most molds, if grown for a long enough period, can be detected visually, while yeast growth is usually detected by off-flavor and fermentation.
Due to their versatility, it is rare to find a place or surface that is naturally free of fungi or their spores. Damp conditions, poor air quality and darker areas are inviting environments for yeast and mold growth.
Cannabis plants are grown in both indoor and outdoor conditions. Plants grown outdoors are exposed to wider ranges and larger populations of fungal species compared to indoor plants. However, factors such as improper watering, the type of soil and fertilizer and poor air circulation can all increase the chance of mold growth in indoor environments. Moreover, secondary contamination is a prevalent risk from human handling during harvest and trimming for both indoor and outdoor-grown cannabis. If humidity and temperature levels of drying and curing rooms are not carefully controlled, the final product could also easily develop fungi or their growth by-product.
What is TYMC?
TYMC, or total yeast and mold count, is the number of colony forming units present per gram of product (CFU/g). A colony forming unit is the scientific means of counting and reporting the population of live bacteria or yeast and mold in a product. To determine the count, the cannabis sample is plated on a petri dish which is then incubated at a specific temperature for three to five days. During this time, the yeast and mold present will grow and reproduce. Each colony, which represents an individual or a group of yeast and mold, produces one spot on the petri dish. Each spot is considered one colony forming unit.
Why is TYMC Measured?
TYMC is an indicator of the overall cleanliness of the product’s life cycle: growing environment, processing conditions, material handling and storage facilities. Mold by itself is not considered “bad,” but having a high mold count, as measured by TYMC, is alarming and could be detrimental to both consumers and cultivators.
Aspergillus species niger Photo: Carlos de Paz, Flickr
The vast majority of mold and yeast present in the environment are indeed harmless, and even useful to humans. Some fungi are used commercially in production of fermented food, industrial alcohol, biodegradation of waste material and the production of antibiotics and enzymes, such as penicillin and proteases. However, certain fungi cause food spoilage and the production of mycotoxin, a fungal growth by-product that is toxic to humans and animals. Humans absorb mycotoxins through inhalation, skin contact and ingestion. Unfortunately, mycotoxins are very stable and withstand both freezing and cooking temperatures. One way to reduce mycotoxin levels in a product is to have a low TYMC.
Aspergillus flavus on culture. Photo: Iqbal Osman, Flickr
Yeast and mold have been found to be prevalent in cannabis in both current and previous case studies. In a 2017 UC Davis study, 20 marijuana samples obtained from Northern California dispensaries were found to contain several yeast and mold species, including Cryptococcus, Mucor, Aspergillus fumigatus, Aspergillus niger, and Aspergillus flavus.3 The same results were reported in 1983, when marijuana samples collected from 14 cannabis smokers were analyzed. All of the above mold species in the 2017 study were present in 13 out of 14 marijuana samples.4
Aspergillus species niger, flavus, and fumigatus are known for aflatoxin production, a type of dangerous mycotoxin that can be lethal.5 Once a patient smokes and/or ingests cannabis with mold, the toxins and/or spores can thrive inside the lungs and body.6, 7 There are documented fatalities and complications in immunocompromised patients smoking cannabis with mold, including patients with HIV and other autoimmune diseases, as well as the elderly.8, 9, 10, 11
For this reason, regulations exist to limit the allowable TYMC counts for purposes of protecting consumer safety. At the time of writing this article, the acceptable limit for TYMC in cannabis plant material in Colorado, Nevada and Canada is ≤10,000 CFU/g. Washington state requires a mycotoxin test.12 California is looking into testing for specific Aspergillus species as a part of their requirement. As the cannabis industry continues to grow and advance, it is likely that additional states will adopt some form of TYMC testing into their regulatory testing requirements.
Centre for Disease control and prevention. 2004 Outbreak of Aflatoxin Poisoning – Eastern and central provinces, Kenya, Jan – July 2004. Morbidity and mortality weekly report.. Sep 3, 2004: 53(34): 790-793
Cescon DW, Page AV, Richardson S, Moore MJ, Boerner S, Gold WL. 2008. Invasive pulmonary Aspergillosis associated with marijuana use in a man with colorectal cancer. Diagnosis in Oncology. 26(13): 2214-2215.
Szyper-Kravits M, Lang R, Manor Y, Lahav M. 2001 Early invasive pulmonary aspergillosis in a leukemia patient linked to aspergillus contaminated marijuana smoking. Leukemia Lymphoma 42(6): 1433 – 1437.
Verweii PE, Kerremans JJ, Voss A, F.G. Meis M. 2000. Fungal contamination of Tobacco and Marijuana. JAMA 2000 284(22): 2875.
Ruchlemer R, Amit-Kohn M, Raveh D, Hanus L. 2015. Inhaled medicinal cannabis and the immunocompromised patient. Support Care Cancer. 23(3):819-822.
McPartland JM, Pruitt PL. 1997. Medical Marijuana and its use by the immunocompromised. Alternative Therapies in Health and Medicine. 3 (3): 39-45.
Hamadeh R, Ardehali A, Locksley RM, York MK. 1983. Fatal aspergillosis associated with smoking contaminated marijuana, in a marrow transplant recipient. Chest. 94(2): 432-433.
The Colorado Department of Public Health and Environment’s (CDPHE) Marijuana Laboratory Inspection Program issued a bulletin on January 30th regarding updates required for licensed cannabis testing labs. The updated method for microbial contaminant testing includes a longer incubation period in yeast and mold testing.
“After careful consideration of emerging data regarding the use and effectiveness of 3M Total Yeast and Mold Rapid Petrifilms in marijuana, CDPHE has concluded that 48 hours is not a sufficient incubation period to obtain accurate results,” the letter states. “Based upon the review of this information, marijuana/marijuana products require 60-72 hours of incubation as per the manufacturer’s product instructions for human food products, animal feed and environmental products.” The letter says they determined it was necessary to increase the incubation period based on data submitted from several labs, along with a paper found in the Journal of Food Protection.
An incubator (Right) at TEQ Analytical Labs
According to Alexandra Tudor, manager of the microbiology department at TEQ Analytical Labs (a cannabis testing lab in Aurora, CO), the update is absolutely necessary. “The incubation time extension requirement from CDPHE offers more reliable and robust data to clients by ruling out the possibility of a false yeast and mold result during analysis,” says Tudor.
Alexandra Tudor, microbiology department manager at TEQ Analytical Labs
“3M, the maker of Petrifilm, recommends an incubation time of 48-72 hours, but during TEQ’s method validation procedure, we learned that 48-hour incubation was not sufficient time to ensure accurate results. Although some laboratories in industry had been incubating for the minimum amount of time recommended by the manufacturer, the 48-hour incubation time does not provide a long enough window to ensure accurate detection of microbiological contaminants present in the sample.” Tudor says the update will help labs provide more confident results to clients, promoting public health sand safety.
As a result of the update in testing methodology, cultivators and infused product manufacturers in Colorado need to submit a batch test for yeast and mold. The point of requiring this batch test is to determine if the producer’s process validation is still effective, given the new yeast and mold testing method.
The Emerald Test advisory panel recently convened to review the results from the Fall 2016 round of the semi-annual Inter-Laboratory Comparison and Proficiency Test (ILC/PT), ahead of the third annual Emerald Conference just a few weeks away. After reviewing and analyzing the results, the panel noticed a significant improvement across the board over their Spring 2016 round of proficiency testing.
Emerald Scientific’s ILC/PT program is a tool laboratories use to check how accurate their testing capabilities are compared to other labs. A lab receiving The Emerald Test badge indicates their testing meets the criteria established by the panel to demonstrate competency. This means that they were within two standard deviations of the consensus mean for all analytes tested, according to Wes Burk, vice president of Emerald Scientific. He says the labs performed better than expected on both the microbial and pesticide tests.
Wes Burk, vice president of Emerald Scientific.
Each lab has access to raw, anonymized data including a consensus mean, z-scores and kernel density plots. This round measured how well 35 cannabis labs perform in testing for potency, pesticides, residual solvents and microbial contaminants such as E. coli, Salmonella, Coliform, yeast and mold.
The advisory panel includes: Robert Martin, Ph.D., founder of CW Analytical, Cynthia Ludwig, director of technical services at AOCS, Rodger Voelker, Ph.D., lab director, OG Analytical, Tammie Mussitsch, QA manager at RJ Lee Group, Shawn Kassner, senior scientist at Neptune & Company, Inc., Jim Roe, scientific director at Steep Hill Labs, Chris Hudalla, Ph.D., founder and chief scientific officer at ProVerde Labs, Sytze Elzinga, The Werc Shop and Amanda Rigdon, Chief Technical Officer at Emerald Scientific.
Amanda Rigdon, chief technical officer at Emerald Scientific
According to Amanda Rigdon, chief technical officer at Emerald Scientific, the labs performed very well in potency, residual solvents and microbial testing PTs. This is the first year the proficiency testing includes pesticides. “All of the labs did a great job identifying every pesticide in our hemp-based PT, but some more work will most likely have to be done to bring quantitative results in line,” says Rigdon. “Since this was the first pesticide PT we had offered, we were pretty conservative when choosing analytes and their levels. For the most part, analytes and levels were taken from the Oregon pesticide list, which is widely recognized to be the most reasonable and applicable pesticide list out there to date.” They covered pesticides of high concern, like abamectin and Myclobutanil, but also included a wide range of other pesticides that labs are expected to encounter.
Shawn Kassner, senior scientist at Neptune & Company, Inc.
Shawn Kassner, senior scientist at Neptune & Company, Inc., believes microbial contamination proficiency testing should be a priority for improving public health and safety going forward. Although five participating labs did not receive badges for the microbial contamination PTs, panel members say the overall performance was really quite good. “Microbiology testing are essential analyses for all cannabis products and it’s just slower in regulatory implementation than potency testing,” says Kassner. “The risk of Salmonella and E. coli to an individual using a medical cannabis product could be very life threatening. Microbiology contamination is a huge concern for any public health agency, which is why we have seen that microbiology testing is usually the first analytical test required after potency.” Kassner notes that there were few outliers and with each Emerald PT program, he is seeing an improvement in overall laboratory performance.
For The Emerald Test’s next round, the panel hopes to make some improvements in the test’s robustness and consistency, like obtaining assigned values for all samples and comparing to a consensus mean. “We want to develop permanent badge criteria, streamline the appeals process and possibly implement a qualitative performance review in the pesticide PT,” says Burk. For the next round of pesticide PTs, they want to build a better list of pesticides to cover more states, allowing labs to pick a set based on their state’s regulations. Burk says they also want to collect data on whether or not matrix-matched curves were used for pesticides.
Rodger Voelker, Cynthia Ludwig and Shawn Kassner, all members of the advisory panel, will be speaking at the Emerald Conference, discussing some of their findings from this round of proficiency testing. The Emerald Conference will take place February 2nd and 3rd in San Diego, CA.
Last week, Steep Hill Labs, Inc. announced plans to expand on the East Coast, including licensing for laboratories in Washington, D.C. and Pennsylvania. The cannabis testing company now is operating or developing in seven states, the District of Columbia along with an official arrangement with a research university in Jamaica, according to Cathie Bennett Warner, director of public relations at Steep Hill.
The same team of physicians that oversees the Steep Hill laboratory in Maryland will operate the Pennsylvania and D.C. labs. Heading that team is chief executive officer Dr. Andrew Rosenstein, chief of the division of Gastroenterology at University of Maryland Saint Joseph Medical Center and assistant clinical professor of Gastroenterology and Hepatology at the University of Maryland Medical Center. Dr. Rosenstein has been recognized by Baltimore Magazine as a top doctor in the Baltimore area, according to a press release.
Dr. Andrew Rosenstein, CEO of Steep Hill Maryland, PA and D.C.
According to Dr. Rosenstein, they want to provide accurate clinical results for trials with patients using cannabis. “All clinical trials will require a competent, credible and reliable lab partner and that is what we are bringing to the field- and that is why we are working with Steep Hill,” says Dr. Rosenstein. With team members having backgrounds in pathology, molecular diagnostics, clinical chemistry, microbiology and genetics, it should come as no surprise that they plan to participate in clinical research.
Dr. Rosenstein’s vested interest in cannabis safety stems from prior experience with his patients using cannabis. “Over the past five years, we have seen an increased number of patients using cannabis, particularly for managing the side effects of Crohn’s disease and cancer treatment,” says Dr. Rosenstein. “They would bring it up to us and at the time I didn’t know much about it, but anecdotally it’s really clear that a lot of patients have great responses to it.” Not knowing much about the preparation or safety of cannabis at the time led Dr. Rosenstein to advise patients to be very careful if they are immunocompromised.
Examination of cannabis prior to testing- credit: Steep Hill Labs, Inc.
“When a patient is immunocompromised, a bacterial or fungal infection can be lethal, so because we had patients using cannabis, we wanted to make sure it was safe,” says Dr. Rosenstein. So when Maryland legalized medical cannabis, Dr. Rosenstein and his team saw the need to protect patient safety and Steep Hill was a perfect fit. “We really didn’t want to reinvent the wheel so we looked for someone to partner with,” says Dr. Rosenstein. “Steep Hill has the best technology and the best credibility and we didn’t want to compromise on quality and safety issues. They felt the same way so we partnered with them and culturally it has been a great fit.”
Steep Hill Express in Berkeley, CA- MD,PA and D.C. will have a similar offering of instant potency analysis
The new laboratories plan to offer a similar range of services that are offered at other Steep Hill labs, such as rapid potency testing for THC-A, ∆-9-THC, CBD, CBD-A and moisture. But Dr. Rosenstein sees clinical opportunities in the East Coast medical hubs. “We want to provide the testing component for studies, providing clinical reproducibility and consistency, and those are the things as a top-notch lab that we are interested in doing.”
A petri dish of mold growth from tested cannabis- Photo credit: Steep Hill Labs, Inc.
With a physician-led group that has experience in molecular diagnostics, partnering with Steep Hill is about being medically focused, according to Dr. Rosenstein. “First and foremost, this is about patient safety.” Because of that, he emphasizes the need for required microbiological contaminant testing, particularly because of his experience with patients. “If you’re a cancer patient and you get a toxic dose of salmonella or E. coli, that can kill you, so testing for microbiologic contamination is of the highest priority.”
According to Warner, bridging the medical cannabis science gap with Steep Hill’s professionalism and experienced doctors practicing medicine is a big deal. “We are working very closely with their medical team to make sure these standards are medically superior,” says Warner. “To have these doctors with such a high level of knowledge in medicine working with us in cannabis analytics is a breakthrough.”
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According to CEO and Co-Founder Milan Patel, they want their technology to set the standard for product safety testing. “We’re making the accurate testing of cannabis, food and agriculture faster, more definitive and less expensive with trackable results benefitting growers, producers, regulators and consumers worldwide,” says Patel. “Our new brand is inspired by our unique microplex array and is bright, fresh, memorable and expansive, enabling us to move from cannabis only to much larger global consumable markets where we can continue to offer new products and applications for the technology.”
Each lab has access to raw, anonymized data including a consensus mean, z-scores and kernel density plots. This round measured how well 35 cannabis labs perform in testing for potency, pesticides, residual solvents and microbial contaminants such as E. coli, Salmonella, Coliform, yeast and mold.
