Influence of nicotine on the adherence of Candida albicans ATCC 14053 and Candida parapsilosis ATCC 22019 and expression of selected binding-related genes

Effect of Cigarette and E-Cigarette Smoke Condensates on Candida albicans Biofilm Formation and Gene Expression

Smoking triggers environmental changes in the oral cavity and increases the risk of mucosal infections caused by Candida albicans such as oral candidiasis. While cigarette smoke has a significant impact on C. albicans, how e-cigarettes affect this oral pathogen is less clear. Here, we investigated the effect of cigarette and e-cigarette smoke condensates (CSC and ECSC) on C. albicans growth, biofilm formation, and gene expression. Whereas pure nicotine (N) at the minimum inhibitory concentration (MIC, 4 mg/mL) prevented C. albicans growth, enhanced biofilm formation was observed at 0.1 mg/mL. In contrast, at this nicotine sub-MIC (0.1 mg/mL) concentration, CSC and ECSC had no significant effect on C. albicans biofilm formation. Additionally, N, CSC, and ECSC increased the expression of HWP1 and SAP2 genes. The ECSC group exhibited elevated expression levels of the EAP1 and ALS3 genes, compared to the nicotine-free ECSC (-) control. Moreover, our in vitro study illustrated that the antifungal drugs, fluconazole and amphotericin B, alleviated the effect of nicotine on C. albicans gene expression. Overall, the results of the study indicated nicotine from different sources may affect the pathogenic characteristics of C. albicans, including hyphal growth, biofilm formation, and particularly the expression of virulence-related genes.

Nicotine enhances the thickness of biofilm and adherence of Candida albicans ATCC 14053 and Candida parapsilosis ATCC 22019

Candida albicans ATCC 14053 and Candida parapsilosis ATCC 22019 hyphal-wall protein 1 (HWP1) are involved in hyphae formation and pathogenesis. The transcriptional agglutinin-like sequence 3 (ALS3) genes in both species are responsible for the development of biofilm and colonization on tooth surfaces. Therefore, we investigated the expression of HWP1 and ALS3 quantitatively in C. albicans and C. parapsilosis and examined the biofilm structure upon exposure to various nicotine concentrations. In vitro, biofilms of Candida species were developed directly on slides using the Lab-Tek Chamber Slide System and visualized by confocal laser scanning microscopy. Quantitative real-time polymerase chain reaction was used to measure HWP1 and ALS3 expression in C. albicans ATCC 14053 and C. parapsilosis ATCC 22019. The results indicated that nicotine multiplied the number of yeast cells and increased the extracellular polysaccharides of Candida species. We also found that 1-2 mg/mL nicotine could enhance the formation of biofilm. The findings also revealed that the expression of HWP1 and ALS3 in Candida species were increased as the nicotine concentration increased. Therefore, nicotine influences the biofilm development of oral-associated C. albicans ATCC 14053 and C. parapsilosis ATCC 22019.

Effect of tobacco on periodontal disease and oral cancer

INTRODUCTION

Periodontal disease and oral cancer are common health hazards. Epidemiological investigations show that smoking, periodontal disease and oral cancer are closely related. Tobacco is one of the major risk factors for periodontitis and oral cancer.

METHODS

A systematic literature review was performed. To identify relevant studies, the following online databases were searched using specific keywords: PubMed, Web of Science and CNKI.

RESULTS

Tobacco not only possesses an addictive effect, but it aggravates periodontal disease by promoting the invasion of pathogenic bacteria, inhibiting autoimmune defense, aggravating the inflammatory reaction, and aggravating the loss of alveolar bone. According to current evidence, tobacco significantly aggravates the development and progression of periodontal disease and oral cancer, and periodontal disease may be related to the prevalence of oral cancer.

CONCLUSIONS

Clinicians should strongly recommend that smokers undertake a strategy to stop smoking to avoid the exacerbation of nicotine-related periodontal disease and to reduce the incidence of oral cancer.