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What the CFU?


An environmental sample screened for bacteria. This sample has a high concentration of bacteria and a diverse population, which makes for a very competitive environment. There are several Bacillus species present and can be identified by its classic trademark of a wrinkled appearance.

What the CFU are you talking about? The term CFU has come up a lot lately in regards to medical marijuana, especially in the state of Arizona. The program in Arizona is still in its infancy stage when compared to states like California, Colorado, Washington and Oregon. With such a new program, items were overlooked when developing the law. One important item which was ignored is the safety for the end user in reference to microbial testing. By leaving this out, dispensaries were able to sell medication that had mold and was treated with harmful pesticides. As the program begins to advance, proper laws are introduced and implemented. We are here today to bring some clarity to the situation surrounding microbial testing, but more importantly how to interpret those results.

Coming back to the question, what are CFUs? A CFU, or colony forming unit, is a unit of measurement used to quantify bacterial cells or fungal cells in a given sample. They are what we can actually see on a petri dish plate. The concern is not the number of cells, it is that we have no idea what those CFUs are. Nothing is identified or even separated into groups. The test results states the total number of cells per sample and nothing more. This is a problem that I worry about and so should you.


Colony Forming Units of yeasts and molds. This shows a variety of different microbes living in the same environment, one specie was identified as Penicillium. A beneficial microorganism which is not a contaminate

The first being the numbers and detection limits put in place. Arizona dispensaries do not have to meet any state requirements  in regards to microbial detection, but other states like Colorado and Washington set the stage at 10,000 CFU/ml. To the average patient out there this may seem like a high count and may cause some worry,  but in the world of microbiology this is practically nothing. You could swab the back of your hand right now, get a plate count, and find out that there is more than 10,000 CFUs in that sample. There are millions of bacteria cells on your skin and to call them all contaminants is a misinterpretation. Don’t get me wrong I’m for regulation and testing, anything to make the medication safer for our patients, but is a plate count the type of testing that needs to be done? In certain situations yes a plate count would be needed. Right now it may be hurting the program because a plate count is general and vague.  

Now what really gets me is the statement or idea that all of these CFUs are contaminants. Let’s look at the word contaminant and what it actually means. Contaminant, the action of introducing a substance that pollutes or makes something impure. From a microbiology point of view, a contaminant would be an unwanted microorganism introduced into a pure bacterial culture. How does this translate to microbial cannabis testing, well it really doesn’t.

Cultivating cannabis indoors is a measure put in place to control the environment. It allows the grower to monitor the temperature, control the humidity, and maintain lights and nutrients. What it does not do is limit the amount of microbial cells that may be present on the plant. Cannabis naturally grows outdoors and will have millions to billions of microbial cells present at any stage of its development, this includes the stem, leaves, flowers, and of course the roots. In comparison to the human body there are 39 trillion bacterial cells. Please try and convince a trained microbiologist that all 39 trillion bacterial cells are contaminations, easier said than done.  

Each location of the plant will have a different population of microbes and concentration. Upon further investigation into each area it would be safe to say that not all of these microbes are contaminants. In reality microorganisms and plants can share a symbiotic relationship, meaning that they can co-exist together without causing harm to each other. Some of them can be the beneficial Bacillus and Streptomyces species that have been covered in past articles. If we didn’t have any microbial activity present on the plant, then there would be no plant it would just die. Microbes play an important role in plant development, their ability to release nutrients and minerals is absolutely necessary.

The idea that a plant, which is naturally covered with millions to billions of microbes is suppose to produce an end product that has little to no CFUs is absurd. Some of the tests that should be considered for review are E. coli screening for pathogenic strains, Salmonella spp., and Listeria spp. These tests are required for food safety and would be an excellent starting point for the dispensary program in Arizona. Implementing specific safety tests would ensure all products are safe for human consumption. Reasons why this may have been overlooked is because common consumption practices. A majority of cannabis is consumed by smoking in some shape or form, this ensures that any living organisms will be killed or destroyed during use. However this may not be the case for edibles and other medications that are ingested.

Overall starting a new medical marijuana program has proved challenging for that state of Arizona. Even as the programs begins to progress we will still face obstacles, which may slow us down. Problems that cannot be ignored any longer is safety to the end user. This is an issue that can be solved by adopting a handful of select tests to screen for specific human pathogens. Current testing standards should be reviewed thoroughly to understand if the measures in place are providing adequate safety for the patients. Still this is Arizona and we operate like the Wild West out here. It maybe some time before the proper laws and regulations are put into place, but you are now armed with some knowledge. Feel free to ask your local dispensary about their medication, where and how it was tested, see if they can explain the results. Go as far as calling  the lab that processed the sample, find out what they can tell you. Talk to anyone and everyone associated with your medication, let’s find out if they know what the CFUs they’re talking about. Or you can contact us, your local scientists at HyKreations and we can talk you through the results.

For more from HyKreations, click here.

HyKreations is a Scientific Solutions company offering Microbials, Fertilizers, Consulting, and Writing Services. HyKreations is located in Goodyear, AZ and can be reached at: 602-527-5678 (Derex) or 602-527-3767 (Anthony). Check out our website at, visit our Facebook page @HyKreations, and give us a follow and a like on Instagram @hykreations_az.



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