Identification of bacterial and fungal components in tobacco and tobacco smoke

Abstract

The microbiological composition of tobacco products was studied using culture and chemical analysis (of tobacco leaves) or chemical analysis only (tobacco and tobacco smoke). The chemical analyses utilized gas chromatography-tandem mass spectrometry for determining 3-hydroxy fatty acids, muramic acid, and ergosterol as markers of respectively lipopolysaccharide (LPS), peptidoglycan, and fungal biomass. Mesophilic bacteria dominated in both fresh and cured tobacco leaves; a range of additional bacteria and fungi were also found albeit in minor amounts. The peptidoglycan and LPS concentrations were approximately the same in tobacco leaves as in cigarette tobacco. The concentrations of the measured microbial components were much lower in some cigarettes locally produced in China, Korea, and Vietnam than in cigarettes of international brands purchased in the same countries, and the concentrations in the smoke were in general agreement with the concentrations in cigarette tobacco. No differences in microbial load in tobacco of "light" and "full flavor" cigarettes were seen. Storing cigarettes at high humidity resulted in elevated levels of fungi in the cigarette tobacco leading to increased ergosterol concentrations in the smoke. The fact that tobacco smoke is a bioaerosol may help to explain the high prevalence of respiratory disorders among smokers and non-smokers exposed to second hand smoke since the same symptoms are also commonly associated with exposure to bioaerosols.

TLR4 genotype and environmental LPS mediate RSV bronchiolitis through Th2 polarization

“…In a comparison of the frequency of risk factors in the low-and middle-income groups, exposure to cigarette smoke (24) was observed more often in low-income families (Supplemental Table 3). Only age and number of siblings under the age of 14 years living at home influenced the severity of RSV bronchiolitis (Supplemental Table 4).…”

Cigarette smoke induces CXCL8 production by human neutrophils via activation of TLR9 receptor

“…In accordance with this concept, we and others [17,23,41,42] have shown that cigarette smoke modulates TLR2 and TLR4 expression. In addition, CSE contains LPS [43] which is a potent activator of TLR4 signalling. Using a neutralising antibodies against TLR4 and TLR2, we have shown a partial involvement of TLR4 in CSE-induced CXCL8 expression in primary human neutrophils.…”

Impact of cigarette smoke exposure on host-bacterial pathogen interactions

“…Mesophilic bacteria have been found in both fresh and cured tobacco leaves. A range of additional bacteria and fungi have been found in minor amounts; moreover, storing cigarettes at high humidity results in elevated levels of fungi in the cigarette tobacco, leading to increased ergosterol concentrations in the smoke [14]. In addition, the bacterial metagenome of a cigarette-based study revealed 15 different classes of bacteria and a broad range of potential pathogens (Acinetobacter, Bacillus, Burkholderia, Clostridium, Klebsiella, Pseudomonas aeruginosa, Serratia, Campylobacter, Enterococcus, Proteus and Staphylococcus) [15,16].…”