Isolation and identification of Prevotella nigrescens in patients with chronic periodontitis and analysis of its tumorigenic role in esophageal squamous carcinogenesis / 中华微生物学和免疫学杂志

ABSTRACT

Objective To isolate and identify Prevotella nigrescens (P.nigrescens) in gingival cre-vicular fluid of patients with chronic periodontitis and to analyze its tumor-promoting role in esophageal squa-mous cell carcinoma (ESCC). Methods Samples of gingival crevicular fluid were collected from patients with chronic periodontitis and cultured on GAM agar medium under anaerobic conditions. Black colonies on GAM agar plates were picked for subculture, and then the bacteria were isolated and purified. Bacterial identification was conducted using Gram staining and 16S rDNA sequencing analysis. The isolated bacterial species was used to infect ESCC NE6-T cells and the changes in biological characteristics of the infected cells were evaluated. Results Multiple bacterial colonies were observed after anaerobic culturing of gingival cre-vicular fluid samples for 120 h on GAM agar plates. A single bacterial colony with pure black and smooth appearance was obtained from grey black bacterial colonies with streak method. It was a Gram-negative bac-terium with bead-like shape. It showed 99. 78％ 16S rDNA sequence identity with P. nigrescens F0103 and was named P. nigrescens LY01. P. nigrescens LY01 infection promoted the in vitro proliferation, migration and invasion of NE6-T cells and the growth of subcutaneous xenograft in nude mice. In addition, it could al-so induce the upregulation of Ki67 and activation of p-STAT3. Conclusions P.nigrescens inhabiting in gin-gival sulcus might promote the progression of ESCC in human with chronic periodontitis.