Effects of Nicotine on Streptococcus gordonii Growth, Biofilm Formation, and Cell Aggregation

Abstract

e Streptococcus gordonii is a commensal species of human oral flora. It initiates dental biofilm formation and provides binding sites for later colonizers to attach to and generate mature biofilm. Smoking is the second highest risk factor for periodontal disease, and cigarette smoke extract has been reported to facilitate Porphyromonas gingivalis-S. gordonii dual-species biofilm formation. Our hypothesis is that nicotine, one of the most important and active components of tobacco, stimulates S. gordonii multiplication and aggregation. In the present study, S. gordonii planktonic cell growth (kinetic absorbance and CFU), biofilm formation (crystal violet stain and confocal laser scanning microscopy [CLSM]), aggregation with/without sucrose, and 11 genes that encode binding proteins or regulators of gene expression were investigated. Results demonstrated planktonic cell growth was stimulated by 1 to 4 mg/ml nicotine treatment. Biofilm formation was increased at 0.5 to 4 mg/ml nicotine. CLSM indicated bacterial cell mass was increased by 2 and 4 mg/ml nicotine, but biofilm extracellular polysaccharide was not significantly affected by nicotine. Cell aggregation was upregulated by 4, 8, and 16 mg/ml nicotine with sucrose and by 16 mg/ml nicotine without sucrose. Quantitative reverse transcriptase PCR indicated S. gordonii abpA, scaA, ccpA, and srtA were upregulated in planktonic cells by 2 mg/ml nicotine. In conclusion, nicotine stimulates S. gordonii planktonic cell growth, biofilm formation, aggregation, and gene expression of binding proteins. Those effects may promote later pathogen attachment to tooth surfaces, the accumulation of tooth calculus, and the development of periodontal disease in cigarette smokers.

Bacterial Populations Associated with Smokeless Tobacco Products

“…These findings suggest that this may have resulted from the lower pH or moisture content in the snus and chewing tobacco samples or from the presence of antimicrobial compounds in these products. For example, nicotine has been shown to impact the growth of certain bacteria associated with dental caries (36,37).…”

Nicotine promotes Streptococcus mutans extracellular polysaccharide synthesis, cell aggregation and overall lactate dehydrogenase activity

“…mutans was grown in TSB plus 1% sucrose (TSBS) with 0, 1, 2 and 4 mg/ml nicotine The image processing and analysis program was written according to Heydorn's principles (19) by MATLAB ® R2012a (The MathWorks, Inc.) via the codes reported before (20). …”

“…The q-PCR protocol described previously was followed (20 estimate a unit cell of LDH activity. The crystal violet assay was processed as described before (11).…”

The Interactive Effect of These Bacterial Substrates on the Growth of Streptococcus gordonii, Fusobacterium nucleatum and Porphyromonas gingivalis

“…Huang et al 37) also reported that under the environment of nicotine extract presence, heterogeneous biofilm of P.…”

“…gordonii is an early colony and it provides a place where bacteria causing periodontal disease could be attached to biofilm 37) . F. nucleatum helps bacteria causing periodontal disease attach to teeth or oral epithelial cells at the middle point of physical interaction of gram positive bacteria and gram negative bacteria.…”