COM: Lab Tests Find Mold and Pesticides in Marijuana and Cannabis But how bad is it to ingest an edible contaminated with pesticides or mold? But with more and more states on the precipice of legalizing cannabis, the. Over recent years, it has become even more concerning as parents consider Another contaminant commonly found in US medical marijuana is mould and. Recreational cannabis is legal in California but is it safe? of pathogenic molds and fungus that can also grow on cannabis. it can be dangerous to The state now requires testing for 66 pesticides, harmful chemicals, and dangerous fungi. Click here for more stories, photos, and video on marijuana.
Contaminants: & Cannabis Pesticides, More Mold
Additionally, only 31 labs are licensed by the BCC to test cannabis, most of which are located in Northern California. This small base of operations means that if just a few labs struggle with new regulations, the whole state does. Indeed, the recent upheaval has left some retailers with severely depleted inventories. Some labs and dispensaries can be too slow to reform and, along with their customers, end up bearing the brunt of their neglect.
Fortunately, most products are meeting these new standards and consumers are now receiving products that undergo stricter safety checks. Indeed, these new regulations can even be viewed as a positive sign that the Californian cannabis industry is continuing to mature and catch up to the regulatory world of other markets, such as alcohol and food. To get to that level of regulation, more stipulations will need to be put in place — something the BCC is actively working towards.
On January 1, , lab tests such as moisture content and microbial impurities testing became a state requirement, marking the first phase of a new wave of regulation. Moving beyond the recent requirements, come December 31 , testing for terpenoids, heavy metals and other contaminants will also become a requisite for any Californian lab. McClenny 45 recommends longer times and higher temperatures to accurately detect Aspergilli with culture based methods. Aspergillus is arguably the most significant fungal threat in Cannabis cultivation.
Aspergillosis has been reported in numerous immunocompromised patients and, to date accounts for the only clinical reports of fatalities associated with an infectious organism linked to Cannabis consumption 16 — 18 , 46 — Growers may pasteurize Cannabis samples to avoid failing culture-based microbial testing, but Aspergillus spores are pasteurization resistant 50 , as are the toxins they produce 51 , so pasteurization does not eliminate the potential risk from these organisms.
Another interesting observation is the apparent growth inhibition of Penicillium species P. Other classified species that failed to grow in some of those samples include Furcaspora eucalypti and Tilletiopsis pallescens.
Organic growth practices often utilize beneficial bacterial or fungal endophytes 52 to promote crop growth and to enable lower chemical fungicide use. The State of Nevada has issued guidelines for allowable pesticides for use in Cannabis cultivation that include various Trichoderma and Bacillus species However, in most states, the use of such beneficial microbes may be precluded by the requirement for stringent yeast and mold testing that does not discriminate between beneficial and harmful microorganisms.
More specific nucleic acid based testing techniques can resolve this. Finally, as observed in a previous study on the Cannabis fungal microbiome in a different sample set 15 , P. This species has been isolated as a growth promoting endophyte in Cannabis and several other plant species 10 , 11 , 57 — However, the high prevalence of P. These data have several limitations. Quantitative inter-sample comparisons cannot be performed with the sequencing data at present due to the lack of internal controls to help calibrate any pooling or sampling issues throughout the workflow.
The qPCR data can be used to estimate inter-sample bacterial or fungal burden but these data do not always resolve to the genus or species level. Intra-sample comparisons can nonetheless provide information on the relative proportions of bacterial or fungal species. Sampling from BMX cards was straightforward, since it uses a liquid culture medium, but 3M sampling was subject to bias in scraping off colonies from culture plates. Additionally, the use of Nextera shearing and primer amplification may introduce some biases due to transposon integration preferences.
Culture based techniques used to measure the microbial burden and establish safety of Cannabis have several shortcomings. States adopt and implement regulations at different tolerance thresholds for bacteria and fungi without specifically detailing standardized methods or coordinating inter-laboratory ring testing. Yeast and mold counts from the culture-based platforms tested here are confounded by the growth of bacteria - even when antibiotics like chloramphenicol are included.
The microbiome in the plant material tested changes radically after culturing, such that the microbes and counts that are finally observed bear little or no resemblance to those of the starting sample. This is a serious issue, which clearly has implications beyond Cannabis safety testing.
The 3M and BMX platforms tested here are also used widely in the food testing industry. Perhaps the most concerning observation is that one of the most regulated of fungal pathogens, Aspergillus - the only microbe to ever be associated with clinical harm concerning cannabis - grows poorly, and is therefore severely under-reported by current culture-based platforms.
The differential growth of other toxigenic fungi, depending on the companion species present, further influences the results.
Bacterial pathogens are not uncommon, and beneficial bacteria are also capable of influencing the growth or inhibition of other flora. We have demonstrated that molecular testing is capable of accurately quantifying and identifying a wide spectrum of microorganisms present on Cannabis samples, while avoiding false positives due to the presence of bacteria for fungal testing.
Molecular testing is rapid and is capable of distinguishing between harmful and beneficial microbes — permitting the use of the latter in organic cultivation practices to eliminate the need for reliance on chemical fungicides. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
This article represents an area of research that needs more attention. My only concerns are minor, and are regarding the figures in the article. It would be great if there were more reproducibility indicated within the figures, as this article will be highly read and potentially utilized in a growing industry.
I have read this submission. I believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard. We would like to extend our sincere gratitude for the opportunity to provide an open peer review for the work of McKernan and colleagues on the Cannabis microbiome and uses of metagenomics to shed light on the microbial complement of the Cannabis phyllosphere.
As strong proponents of open science, we engage to provide an objective assessment of the work presented here and to make suggestions aimed at improving the clarity and readability of the present work.
The microbiome the collection of microbial genomes present on an organism or in an environment has emerged as an additional dimension in addition to genomic, epigenomic, metabolomic and phenotypic data… from which one can harness cryptic information that may contribute to a particular biological phenomenon. In their paper, McKernan et al. As such, much of our comments relate to improving the transparency of their results.
Overall, the paper is very well written and we do not have any editorial suggestions, except for the spelling of Biomerieux, which in one instance requires the accent aigu: Below, please find minor comments, which we would like to authors to consider:. The above-mentioned will help disentangle some of the concepts introduced here, and send a clearer message to the readership: If there is sufficient evidence that the novel approach outperforms the old is another question that seems rather elusive in the current paper.
We sincerely hope that the authors will find our review useful and we remain available for further discussion through the F research platform. We have read this submission. We believe that we have an appropriate level of expertise to confirm that it is of an acceptable scientific standard.
The purpose of this study was to investigate the composition of microorganisms found on cannabis samples and compare the ability of different culture based testing platforms with a qPCR method. Although the study provides some valuable data into some of the short comings of culture based methods it has some experimental design weaknesses that make it difficult to draw strong conclusions from this data set.
Since the purpose of the study is to discuss the difference between a qPCR based microbial testing platform with culture based methods the introduction should focus more on discussing this in other industries.
For example it's becoming well known that only a small percentage of organisms that exist in nature are easily cultured on the most common forms of media used. Rapid advances in sequencing are allowing metagenomic analysis of soil and plant microbiomes which also demonstrates the limitations of culturing methods.
Issues like specificity between qPCR and culture based methods should be highlighted. Plant material - Nowhere in the methods section is any information provided about the cannabis plant material. Was it cannabis flowers? Was the sample homogenized in anyway? Information about all the samples used in this study should be summarized in a table or in a section within the methods part of the manuscript. I believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard, however I have significant reservations, as outlined above.
This is a very interesting, well written and designed account comparing the accuracy and utility of genetic microbial testing as compared to standard microbiological culture techniques. All aspects of study design, methods and conclusions are well explained and defended, and should easily allow replication if comparable techniques are applied. I would suggest expansion of the study's implications in the abstract if the word count will permit this.
National Center for Biotechnology Information , U. Journal List FRes v. Published online Oct 7. Hudalla , 2 Matthew Silva , 2 and Douglas R. Author information Article notes Copyright and License information Disclaimer. Accepted Oct 3. This is an open access article distributed under the terms of the Creative Commons Attribution Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. This article has been cited by other articles in PMC.
Metagenomic Analysis of Medicinal Cannabis. All data files supporting this work are provided. Introduction Plant associated microbes may present risks of infectious illness for human end consumers.
Methods Samples, culture-based assays and DNA purification Cannabis samples were derived from seven recently-established indoor growth facilities in Massachusetts, Maine and Rhode Island. Total yeast and mold and total aerobic bacteria qPCR assays DNA samples extracted directly from Cannabis samples, or after growth on the two culture-based platforms, were subjected to qPCR analysis.
Library PCR and Illumina sequencing Results Quantitative PCR and colony counts before and after culture Summary results from the different testing platforms evaluated in this study for 15 samples with complete data are presented in Table 1. Quantitative PCR and colony count results. Open in a separate window. Genomic profiles of before and after culturing. Differential growth of toxigenic and beneficial fungi The concordance between the two culture based platforms was much higher overall for fungi than for bacteria.
The following 11 species were grown at RT. Raw data of metagenomic analysis of medicinal Cannabis samples All data files supporting this work are provided. Click here for additional data file. Discussion The samples selected for this study were derived from seven newly established indoor Cannabis growth facilities located in a humid coastal environment Eastern Massachusetts, Maine and Rhode Island.
Conclusions Culture based techniques used to measure the microbial burden and establish safety of Cannabis have several shortcomings. Data availability The data referenced by this article are under copyright with the following copyright statement: Notes [version 1; referees: Funding Statement This project was privately funded by the participating laboratories.
Quorum quenching is an antivirulence strategy employed by endophytic bacteria. Implications of endophyte-plant crosstalk in light of quorum responses for plant biotechnology. Plant growth-promoting bacteria in the rhizo- and endosphere of plants: Their role, colonization, mechanisms involved and prospects for utilization.
Reinhold-Hurek B, Hurek T: Curr Opin Plant Biol. Bonfante P, Genre A: Mechanisms underlying beneficial plant-fungus interactions in mycorrhizal symbiosis. The rhizosphere microbiome and plant health. Understanding cultivar-specificity and soil determinants of the cannabis microbiome.
Taxonomy of Penicillium section Citrina. Isolation of endophytic fungi from Cannabis sativa and study their antifungal potential. Endophytic fungi harbored in Cannabis sativa L.: Eucalyptus growth promotion by endophytic Bacillus spp. Growth and photosynthetic efficiency promotion of sugar beet Beta vulgaris L. Cannabis microbiome sequencing reveals several mycotoxic fungi native to dispensary grade Cannabis flowers [version 2; referees: Inhaled medicinal cannabis and the immunocompromised patient.
Too many mouldy joints - marijuana and chronic pulmonary aspergillosis. Mediterr J Hematol Infect Dis. Chronic necrotising pulmonary aspergillosis in a marijuana addict: Salmonellosis associated with marijuana: But for now it's unclear just how much marijuana growers need to clean up their product. In terms of microbial contamination, it's kind of hard to say what's harmful and what's not," he adds.
What's a safe threshold, and which contaminants do we need to be concerned about? Concentrates and edibles think brownies make up perhaps half of the current Colorado market. Their makers sometimes suggest that their chosen products are healthier than standard weed because they don't involve frequent smoking. But some manufacturers employ potentially harmful compounds like butane to strip the plant of most everything but THC.
Tests also show that marijuana plants can draw in heavy metals from the soil in which they are grown, and concentrating THC can increase the amounts of heavy metals, pesticides or other substances that end up in a product. That means regulations for their production still need to be hammered out, LaFrate says. But what grade of solvents are they using? Are they buying heptane on eBay, and if so, what exactly is in there?
There are a whole bunch of issues to figure out, and right now there are not enough resources and really no watchdog.
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MIC.COM: Lab Tests Find Mold and Pesticides in Marijuana and Cannabis Edibles
sold Jan. 1 could be tainted with pesticides, mold and more be in place. Pot could contain pesticides, molds and other contaminants. Last week, Legalization Nation reported about more contamination one in six contest entries failed lab screening for pesticides, or mold or. Cannabis oils may contain various concentrations of CBD, . agents that entered the plant unintentionally (e.g., heavy metals, molds and bacteria , aflatoxins). If any of these contaminants were present in hemp used for CBD For example, the detection of heavy metals or pesticides present in CBD.