Temporal Variations in Cigarette Tobacco Bacterial Community Composition and Tobacco-Specific Nitrosamine Content Are Influenced by Brand and Storage Conditions.
Tobacco products, specifically cigarettes, are home to microbial ecosystems that may play an important role in the generation of carcinogenic tobacco-specific nitrosamines (TSNAs), as well as the onset of multiple adverse human health effects associated with the use of these products. Therefore, we conducted time-series experiments with five commercially available brands of cigarettes that were either commercially mentholated, custom-mentholated, user-mentholated, or non-mentholated. To mimic user storage conditions, the cigarettes were incubated for 14 days under three different temperatures and relative humidities (i.e., pocket, refrigerator, and room). Overall, 360 samples were collected over the course of 2 weeks and total DNA was extracted, PCR amplified for the V3V4 hypervariable region of the 16S rRNA gene and sequenced using Illumina MiSeq. A subset of samples (n= 32) was also analyzed via liquid chromatography with tandem mass spectrometry for two TSNAs:N'-nitrosonornicotine (NNN) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). Comparative analyses of the five tobacco brands revealed bacterial communities dominated byPseudomonas,Pantoea, andBacillus, withPseudomonasrelatively stable in abundance regardless of storage condition. In addition, core bacterial operational taxonomic units (OTUs) were identified in all samples and includedBacillus pumilus, Rhizobiumsp.,Sphingomonassp., unknownEnterobacteriaceae,Pantoeasp.,Pseudomonassp.,Pseudomonas oryzihabitans, andP. putida. Additional OTUs were identified that significantly changed in relative abundance between day 0 and day 14, influenced by brand and storage condition. In addition, small but statistically significant increases in NNN levels were observed in user- and commercially mentholated brands between day 0 and day 14 at pocket conditions. These data suggest that manufacturing and user manipulations, such as mentholation and storage conditions, may directly impact the microbiome of cigarette tobacco as well as the levels of carcinogens.
Maryland Institute for Applied Environmental Health, School of Public Health, University of Maryland College Park, MD, USA.
Jessica
J
Chopyk
Maryland Institute for Applied Environmental Health, School of Public Health, University of Maryland College Park, MD, USA.
Suhana
S
Chattopadhyay
Maryland Institute for Applied Environmental Health, School of Public Health, University of Maryland College Park, MD, USA.
Prachi
P
Kulkarni
Maryland Institute for Applied Environmental Health, School of Public Health, University of MarylandCollege Park, MD, USA; Institute for Genome Sciences and Department of Microbiology and Immunology, School of Medicine, University of MarylandBaltimore, MD, USA.
Eoghan M
EM
Smyth
Institute for Genome Sciences and Department of Microbiology and Immunology, School of Medicine, University of Maryland Baltimore, MD, USA.
Lauren E
LE
Hittle
Department of Biostatistics and Computational Biology, Dana-Farber Cancer InstituteBoston, MA, USA; Department of Biostatistics, Harvard T.H. Chan School of Public HealthBoston, MA, USA.
Joseph N
JN
Paulson
Center for Bioinformatics and Computational Biology, University of Maryland College Park, MD, USA.
Mihai
M
Pop
Public Health Center for Tobacco Research, Battelle Columbus, OH, USA.
Stephanie S
SS
Buehler
Department of Behavioral and Community Health, School of Public Health, University of Maryland College Park, MD, USA.
Pamela I
PI
Clark
Institute for Genome Sciences and Department of Microbiology and Immunology, School of Medicine, University of Maryland Baltimore, MD, USA.
Emmanuel F
EF
Mongodin
Maryland Institute for Applied Environmental Health, School of Public Health, University of Maryland College Park, MD, USA.
Amy R
AR
Sapkota
16S rRNA gene; bacteria; bacterial community composition; cigarettes; microbiome; storage conditions; tobacco; tobacco-specific nitrosamines