Understanding microbial-host interactions in the oral cavity is essential for elucidating oral disease pathogenesis and its systemic implications. In vitro bacteria-host cell coculture models have enabled fundamental studies to characterize bacterial infection and host responses in a reductionist yet reproducible manner. However, existing in vitro coculture models fail to establish conditions that are suitable for the growth of both mammalian cells and anaerobes, thereby hindering a comprehensive understanding of their interactions. Here, we present an asymmetric gas coculture system that simulates the oral microenvironment by maintaining distinct normoxic and anaerobic conditions for gingival epithelial cells and anaerobic bacteria, respectively. Using a key oral pathobiont, Fusobacterium nucleatum, as the primary test bed, we demonstrate that the system preserves bacterial viability and supports the integrity of telomerase-immortalized gingival keratinocytes. Compared to conventional models, this system enhanced bacterial invasion, elevated intracellular bacterial loads, and elicited more robust host pro-inflammatory responses, including increased secretion of CXCL10, IL-6, and IL-8. In addition, the model enabled precise evaluation of antibiotic efficacy against intracellular pathogens. Finally, we validate the ability of the asymmetric system to support the proliferation of a more oxygen-sensitive oral pathobiont, Porphyromonas gingivalis. These results underscore the utility of this coculture platform for studying oral microbial pathogenesis and screening therapeutics, offering a physiologically relevant approach to advance oral and systemic health research.
Coculture Techniques/methods* ; Humans ; Fusobacterium nucleatum/physiology* ; Gingiva/microbiology* ; Keratinocytes/microbiology* ; Host Microbial Interactions ; Mouth/microbiology* ; Host-Pathogen Interactions ; Epithelial Cells/microbiology* ; Cells, Cultured ; Porphyromonas gingivalis

Adult ; Bacteriophages ; physiology ; Chronic Periodontitis ; microbiology ; Clustered Regularly Interspaced Short Palindromic Repeats ; genetics ; Female ; Gingiva ; microbiology ; Humans ; Middle Aged ; Oral Health

Periodontal disease has been recently linked to a variety of systemic conditions such as diabetes, cardiovascular disease, preterm delivery, and oral cancer. The most common bacteria associated with periodontal disease, Porphyromonas gingivalis (P. gingivalis) has not yet been studied in the malignant gingival tissues. The objective of this study was to investigate the presence of P. gingivalis in specimens from squamous cell carcinoma patients. We have performed immunohistochemical staining to investigate the presence of P. gingivalis and Streptococcus gordonii (S. gordonii), a non invasive oral bacteria, in paraffin embedded samples of gingival squamous cell carcinoma (n = 10) and normal gingiva (n = 5). Staining for P. gingivalis revealed the presence of the bacteria in normal gingival tissues and gingival carcinoma, with higher levels (more than 33%, P < 0.05) detected in the carcinoma samples. The staining intensity was also significantly enhanced in the malignant tissue by 2 folds (P < 0.023) compared to specimens stained for the non-invasive S. gordonii. P. gingivalis is abundantly present in malignant oral epithelium suggesting a potential association of the bacteria with gingival squamous cell carcinoma.
Carcinoma, Squamous Cell ; microbiology ; Gingiva ; microbiology ; Gingival Neoplasms ; microbiology ; Humans ; Porphyromonas gingivalis ; isolation & purification ; Retrospective Studies ; Statistics, Nonparametric ; Streptococcus gordonii ; isolation & purification

OBJECTIVETo establish the model of cellular inflammatory responses of gingival epithelial cells in vitro induced by Porphyromonas gingivalis vesicle and to probe into the pathogenesis of Porphyromonas gingivalis in periodontitis.

METHODSThe effect of Porphyromonas gingivalis vesicle on prostaglandin E(2) (PGE(2)) production of gingival epithelial cells was detected by ELISA and the effects of Porphyromonas gingivalis vesicle on cyclooxygenase-2 (COX-2), interleukin (IL)-6 and IL-8 mRNA expression in gingival epithelial cells were determined by Real-time reverse transcription-polymerase chain reaction (RT-PCR).

RESULTSPorphyromonas gingivalis vesicle dose-dependently induced PGE(2) production and up-regulated COX-2, IL-6 and IL-8 mRNA expression in gingival epithelial cells significantly.

CONCLUSIONSCellular inflammatory responses of gingival epithelial cells induced by Porphyromonas gingivalis vesicle may contribute to the initiation and progression of periodontitis.

Bacterial Adhesion ; Cells, Cultured ; Cyclooxygenase 2 ; immunology ; metabolism ; Dinoprostone ; immunology ; metabolism ; Epithelial Cells ; immunology ; metabolism ; microbiology ; Gingiva ; immunology ; metabolism ; microbiology ; Humans ; Interleukin-6 ; immunology ; metabolism ; Interleukin-8 ; immunology ; metabolism ; Porphyromonas gingivalis ; immunology ; pathogenicity

OBJECTIVEThe study is to investigate the microbial composition of interdental and subgingival plaques of periodontitis patients with or without malodor, to explore the relationships between periodontitis and oral malodor.

METHODS20 patients of periodontitis with malodor were chosen from 210 patients of periodontitis, and the clinical parameter of plaque index (PLI), gingival bleeding index (GBI) and probing depth (PD) were measured and compared with the control group which had periodontal disease without malodor. During the experiment, the interdental and subgingival microbial samples in both groups were collected and sent to anaerobic culture for 48 hrs, then the total CFU/ml of each sample were counted, and each type of bacteria was separated and identified. All of the data were analyzed by using the statistical software SPSS 10.0.

RESULTS(1) There were no satistical differences on PLI, GBI, PD between experimental group and control group. (2) The percents of leptospira in both interdental and subgingival plaques of test group were significantly higher than that of the control group (P < 0.01). (3) Either the interdental or in subgingival plaques, the count results of CFU/ml were similar in both groups (P > 0.05). (4) The proportions of malodor producing anaerobic bacteria in interdental gingival plaque, such as P. gingivalis and Veillonelia, were singnificantly different between test group and control group.

CONCLUSIONThe proportions of VSC's producing anaerobic bacteria in interdental gingival plaque may be play the significant roles in oral malodor. Further studies should be taken to elucidate the relationship between malodor and periodontitis.

Bacteria, Anaerobic ; classification ; Dental Plaque ; microbiology ; pathology ; Dental Plaque Index ; Gingiva ; microbiology ; pathology ; Halitosis ; microbiology ; Humans ; Odorants ; Periodontitis ; microbiology ; pathology

OBJECTIVETo study the relativity between Streptococcus sanguis group (SSG) and coronary heart disease (CHD).

METHODS41 individuals were diagnosed with CHD and 18 normals served as controls. All of them had undergone coronary angiography. Their social class (including education and wages), smoking, drinking, blood lipids and oral health were also recorded. SSG in saliva and subgingival plaque were cultivated in NAYS-B agar plates and counted. SSG were identified into species with routine biochemical reaction and AP-PCR.

RESULTSIn the multiple step regression analysis, the amount of SSG in saliva and subgingival plaque were positively associated with severe coronary atheromatosis after adjusting the classical risk factors of CHD. The average amount of SSG in saliva was (435 +/- 422) x 10(8) CFU/L in CHD group and (358 +/- 540) x 10(8) CFU/L in control group, F = 2.72, P = 0.08; the average amount of SSG in incisor was (331 +/- 484) x 10(7) CFU/L in CHD group and (98 +/- 164) x 10(7) CFU/L in control group, F = 5.54, P = 0.02; the average amount of SSG in molar was (352 +/- 381) x 10(7) CFU/L in CHD group and (185 +/- 232) x 10(7) CFU/L in control group, F = 2.86, P = 0.10. S. sanguis and S. gordonii were more in CHD group than in control group (P < 0.05), whereas S. mitis and S. oralis were the same in two groups (P > 0.05).

CONCLUSIONThe increase of SSG in oral floras may play an important role in the occurrence of CHD.

Aged ; Coronary Disease ; complications ; Dental Plaque ; microbiology ; Educational Status ; Gingiva ; microbiology ; Humans ; Middle Aged ; Molar ; microbiology ; Risk Factors ; Saliva ; microbiology ; Smoking ; Socioeconomic Factors ; Statistics as Topic ; Streptococcal Infections ; complications ; microbiology ; Streptococcus sanguis ; isolation & purification