title: Metagenomic analysis of medicinalCannabissamples; pathogenic bacteria, toxigenic fungi, and beneficial microbes grow in culture-based yeast and mold tests.
abstract: Background: The presence of bacteria and fungi in medicinal or recreationalCannabisposes a potential threat to consumers if those microbes include pathogenic or toxigenic species. This study evaluated two widely used culture-based platforms for total yeast and mold (TYM) testing marketed by 3M Corporation and Biomérieux, in comparison with a quantitative PCR (qPCR) approach marketed by Medicinal Genomics Corporation.Methods: A set of 15 medicinalCannabissamples were analyzed using 3M and Biomérieux culture-based platforms and by qPCR to quantify microbial DNA. All samples were then subjected to next-generation sequencing and metagenomics analysis to enumerate the bacteria and fungi present before and after growth on culture-based media.Results: Several pathogenic or toxigenic bacterial and fungal species were identified in proportions of >5% of classified reads on the samples, includingAcinetobacter baumannii, Escherichia coli, Pseudomonas aeruginosa, Ralstonia pickettii, Salmonella enterica, Stenotrophomonas maltophilia, Aspergillus ostianus, Aspergillus sydowii, Penicillium citrinumandPenicillium steckii.Samples subjected to culture showed substantial shifts in the number and diversity of species present, including the failure ofAspergillusspecies to grow well on either platform. Substantial growth ofClostridium botulinumand other bacteria were frequently observed on one or both of the culture-based TYM platforms. The presence of plant growth promoting (beneficial) fungal species further influenced the differential growth of species in the microbiome of each sample.Conclusions: These findings have important implications for theCannabisand food safety testing industries.
authors.affiliation: Medicinal Genomics Corporation, Woburn, MA, 01801, USA.
authors.forename: Kevin
authors.initials: K
authors.lastname: McKernan
authors.affiliation: Medicinal Genomics Corporation, Woburn, MA, 01801, USA.
authors.forename: Jessica
authors.initials: J
authors.lastname: Spangler
authors.affiliation: Medicinal Genomics Corporation, Woburn, MA, 01801, USA.
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Helbert
authors.affiliation: Medicinal Genomics Corporation, Woburn, MA, 01801, USA.
authors.forename: Ryan C
authors.initials: RC
authors.lastname: Lynch
authors.affiliation: Medicinal Genomics Corporation, Woburn, MA, 01801, USA.
authors.forename: Adrian
authors.initials: A
authors.lastname: Devitt-Lee
authors.affiliation: Medicinal Genomics Corporation, Woburn, MA, 01801, USA.
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Medicinal Genomics Corporation, Woburn, MA, 01801, USA.
authors.forename: Wendell
authors.initials: W
authors.lastname: Orphe
authors.affiliation: Medicinal Genomics Corporation, Woburn, MA, 01801, USA.
authors.forename: Jason
authors.initials: J
authors.lastname: Warner
authors.affiliation: Medicinal Genomics Corporation, Woburn, MA, 01801, USA.
authors.forename: Theodore
authors.initials: T
authors.lastname: Foss
authors.affiliation: ProVerde Laboratories, Milford, MA, 01757, USA.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Hudalla
authors.affiliation: ProVerde Laboratories, Milford, MA, 01757, USA.
authors.forename: Matthew
authors.initials: M
authors.lastname: Silva
authors.affiliation: Medicinal Genomics Corporation, Woburn, MA, 01801, USA.
authors.forename: Douglas R
authors.initials: DR
authors.lastname: Smith
keywords: 3M-Petrifilm; Biomérieux-TEMPO; Cannabis; Illumina; PathogINDICAtor-qPCR; metagenomics; microbiome; safety