Composition and Ecological Functionality of Fungal Communities Associated with Smokeless Tobacco Products Mainly Consumed in India

Sajid, Mohammad; Srivastava, Sonal; Yadav, Ravi Kumar; Singh, Harpreet; Singh, Shalini; Bharadwaj, Mausumi

doi:10.1128/spectrum.02273-21

Cited by 10 publications

(8 citation statements)

References 85 publications

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“…The most abundant fungal genera were Pichia, Sterigmatomyces, and Morisolated fungi were investigated. The genera Pichia, Sterigmatomyces, and Mortierella belong to the phyla Ascomycota, Basidiomycota, and Mucoromycota, respectively (Sajid et al, 2022). The highest dominance of A. flavus in the present study is similar to Hristeva et al, (2021).…”

Section: Discussionsupporting

confidence: 90%

Detection and Isolation of Aflatoxin-producing Aspergillus sp. in Chewing and Smokeless Tobacco by Microbial and Molecular Detection Methods and Its Influence on Hepatocellular Carcinomas in Wistar Rats

Mahzari

2023

Egyptian Academic Journal of Biological Sciences. C, Physiology

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Tobacco contains many harmful chemicals, toxins, and carcinogens which cause serious health hazards. Mycotoxins and Aflatoxins are present in all tobacco including chewing and smokeless tobacco. We detected and isolated the aflatoxins-producing fungi Aspergillus sp. by microbial and molecular-based techniques. 50 samples were collected randomly and grown on SDA media by spread plate method. Isolates of A. flavus were analyzed for Aflatoxin production by Ammonia vapor test and the DNA of isolates was extracted and subjected for further molecular identification. Different fungal genera were observed including the most common Aspergillus while the other were Penicillium, Rhizopus, candida, and Trichophyton. Aspergillus flavus was isolated and characterized as a white soft velvety surface. The diameter of colonies was observed as 50 -70 mm. Coconut-based medium detection by UV light of 365 nm showed the production of blue-green fluorescence on the reverse of colonies on coconut agar medium. DNA extracted from all the strains producing aflatoxins was quantified by VICAM. High levels of Aflatoxin ranging from 21 -47 ug/kg were detected in 10 different samples while the remaining samples had a range of 10 -20 ug/kg. the study showed both quantitative and qualitative techniques for the detection of aflatoxin-producing fungi in chewing tobacco. aflR and aflS were observed as potential candidates for the detection of aflatoxigenic fungi.

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Section: Discussionsupporting

confidence: 90%

Detection and Isolation of Aflatoxin-producing Aspergillus sp. in Chewing and Smokeless Tobacco by Microbial and Molecular Detection Methods and Its Influence on Hepatocellular Carcinomas in Wistar Rats

Mahzari

2023

Egyptian Academic Journal of Biological Sciences. C, Physiology

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“…high moisture content does not influence the levels of free nicotine. Further, our previous studies determined the presence of a complex diversity of microbes (both bacterial and fungal) in Indian SLT products 17 18 19 . Interestingly, the SLTs having higher moisture content exhibited elevated levels of microbes, both in terms of diversity and number, which is corroborated with the previous studies 33 .…”

Section: Discussionmentioning

confidence: 99%

“…Estimation of bacterial and fungal diversity : As described in the previous studies performed, the V 3 -V 4 region of 16S rDNA and the ITS1 amplicon-sequencing techniques were used to identify the bacterial and fungal diversity by estimating operational taxonomic units (OTUs), respectively, of 22 SLT products 17 18 19 .…”

Section: Methodsmentioning

confidence: 99%

Characterization of physiochemical parameters & their effect on microbial content of smokeless tobacco products marketed in north India

Shahid,

Srivastava,

Shukla

et al. 2023

Indian Journal of Medical Research

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Background & objectives: Smokeless tobacco (SLT) product consumption has profound public health implications for its users. The pH and moisture of SLTs determine the bioavailability of nicotine, the microbial structure dynamics and the amount of microbial conversion of tobacco alkaloids to carcinogenic tobacco-specific nitrosamines. This study aimed to characterize and compare the pH, moisture and alkaloid content of various SLT products. Methods: Thirty-seven SLT samples including khaini, snus, moist snuff, gul, pan masala, zarda, Mainpuri kapoori and qiwam were collected from the retail market around the National Capital Region in north India and their pH, moisture, nicotine and alkaloid content were measured. The pH and total nicotine were used to calculate the amount of free nicotine, the readily absorbed form, for each product by applying the Henderson–Hasselbalch equation. Results: The investigation showed that the SLTs varied drastically in their pH (5.36 to 10.27), moisture content (4.7 to 51.7%) and alkaloid content (0.82 to 35.87 mg/g). The pH and free nicotine levels of a product were found to be positively correlated, and the highest free nicotine content was reported in snus samples. Further, the moisture content was seen to impact the bacterial and fungal diversity in these samples. Interpretation & conclusions: Studies to detect the presence of pathogenic microbiological genera as well as potentially toxic constituents are warranted. The use of SLTs as an alternative to cigarette smoking should be discouraged, and cessation programmes must call attention to their detrimental effects and emphasize on benefits of quitting SLT consumption.

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“…Previous studies conducted on STPs have largely employed culture-based methods that may have skewed data results and inaccurately depicted community diversity estimates (Saleem et al 2018 ; Shetty and Hegde 2015 ). Recent studies using next-generation sequencing techniques identified actual microbial community composition (bacterial as well as fungal) in different categories of STPs (Chopyk et al 2017 ; Rivera and Tyx 2021 ; Sajid et al 2021 ; Sajid et al 2023 ; Sajid et al 2022 ; Srivastava et al 2022 ; Vishwakarma et al 2022 ). Several studies applying 16S rRNA gene-targeted sequencing determined the bacterial population in numerous Indian STPs (Monika et al 2020 ; Sajid et al 2021 ; Srivastava et al 2022 ; Vishwakarma et al 2022 ).…”

Section: Introductionmentioning

confidence: 99%

“…Several studies applying 16S rRNA gene-targeted sequencing determined the bacterial population in numerous Indian STPs (Monika et al 2020 ; Sajid et al 2021 ; Srivastava et al 2022 ; Vishwakarma et al 2022 ). Further, the fungal population was identified in the commercial as well as indigenous (loosely sold) Indian STPs using internal transcribed spacer (ITS) rRNA gene analysis (Sajid et al 2023 ; Sajid et al 2022 ).…”

Section: Introductionmentioning

confidence: 99%

Microbial community and functions involved in smokeless tobacco product: a metagenomic approach

Sajid,

Sharma,

Srivastava

et al. 2024

Appl Microbiol Biotechnol

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Smokeless tobacco products (STPs) are attributed to oral cancer and oral pathologies in their users. STP-associated cancer induction is driven by carcinogenic compounds including tobacco-specific nitrosamines (TSNAs). The TSNAs synthesis could enhanced due to the metabolic activity (nitrate metabolism) of the microbial populations residing in STPs, but identifying microbial functions linked to the TSNAs synthesis remains unexplored. Here, we rendered the first report of shotgun metagenomic sequencing to comprehensively determine the genes of all microorganisms residing in the Indian STPs belonging to two commercial (Moist-snuff and Qiwam) and three loose (Mainpuri Kapoori, Dohra, and Gudakhu) STPs, specifically consumed in India. Further, the level of nicotine, TSNAs, mycotoxins, and toxic metals were determined to relate their presence with microbial activity. The microbial population majorly belongs to bacteria with three dominant phyla including Actinobacteria, Proteobacteria, and Firmicutes. Furthermore, the STP-linked microbiome displayed several functional genes associated with nitrogen metabolism and antibiotic resistance. The chemical analysis revealed that the Mainpuri Kapoori product contained a high concentration of ochratoxins-A whereas TSNAs and Zink (Zn) quantities were high in the Moist-snuff, Mainpuri Kapoori, and Gudakhu products. Hence, our observations will help in attributing the functional potential of STP-associated microbiome and in the implementation of cessation strategies against STPs. Key points •Smokeless tobacco contains microbes that can assist TSNA synthesis. •Antibiotic resistance genes present in smokeless tobacco-associated bacteria. •Pathogens in STPs can cause infections in smokeless tobacco users.

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Composition and Ecological Functionality of Fungal Communities Associated with Smokeless Tobacco Products Mainly Consumed in India

Abstract: Smokeless tobacco products (STPs) contain complex microbial communities that influence the synthesis of carcinogens, such as tobacco-specific nitrosamines (TSNAs). Research on STP-associated bacterial populations revealed connections between bacterial metabolism and TSNA synthesis.

Cited by 10 publications

References 85 publications

Detection and Isolation of Aflatoxin-producing Aspergillus sp. in Chewing and Smokeless Tobacco by Microbial and Molecular Detection Methods and Its Influence on Hepatocellular Carcinomas in Wistar Rats

Detection and Isolation of Aflatoxin-producing Aspergillus sp. in Chewing and Smokeless Tobacco by Microbial and Molecular Detection Methods and Its Influence on Hepatocellular Carcinomas in Wistar Rats

Characterization of physiochemical parameters & their effect on microbial content of smokeless tobacco products marketed in north India

Microbial community and functions involved in smokeless tobacco product: a metagenomic approach

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