Tobacco & Nicotine Products
Characterization of the bacterial microbiota associated with little cigars
(School of Public Health (UMD) MIAEH Staff)
Despite their critical importance in infections and chronic diseases, as well as their active role in the production of tobacco specific N-nitrosamines (TSNAs), microbial constituents of tobacco products lack characterization. Specifically, there has been no comprehensive characterization performed to date on the bacterial species associated with little cigars, and how these bacterial communities might impact the health of little cigar users. Bacterial communities were characterized in time series experiments in four products: Swisher Sweets Cigarillos, Swisher Sweets Little Cigars- Sweet Cherry, Cheyenne Cigars Full Flavor 100's, and Cheyenne Menthol Box. Each product was stored under three different conditions of temperature and relative humidity: room, fridge and pocket. On days 0, 5 ,9, and 14, subsamples were DNA extracted. The DNA was then used to PCR-amplify the V3V4 regions of the bacterial 16S rRNA gene, followed by sequencing on Illumina MiSeq and analysis using the QIIME and Phyloseq software packages. Overall, the little cigar microbiota is diverse: ~2400 species-level operational taxonomic units (OTUs) were identified, a level similar to that of cigarette products. However, bacterial composition of little cigars is very different from that of cigarettes. Independently of temperature and RH storage conditions. a single bacterial phylum, Firmicutes, dominates in the wrapper whereas the tobacco filling is dominated by Proteobacteria. In addition, significant differences in community composition of the wrapper were observed between different lots. At the genus level, Bacillus and Lactobacillus are the two dominant bacterial groups in the wrapper whereas the Staphyloccocus and Pseudomonas genera dominate in the tobacco. These two groups of bacteria comprise well-known opportunistic human pathogens, and are usually very low abundant or absent in the microbiome associated with cigarettes. Additional analyses are currently ongoing to characterize these differences in greater detail. This study is the first to characterize a key component of harmful and potentially harmful constituents in little cigars.
Importance to public health: