1例成年猛性龋患者龈上菌斑中小韦荣球菌的分离及代谢特性OA

Objective:To isolate and cultivate Veillonella parvula(V.parvula)from the supragingival plaque of adult patients intact teeth surfaces with rampant caries,to investigate its growth and metabolic properties,and to preliminarily explore its interaction with Streptococcus mutans(S.mutans).Methods:V.parvula was isolated from the supragingival plaque of intact teeth surfaces in an adult patient with ram-pant caries using Veillonella agar medium.Identification was performed based on colony morphology,bio-chemical tests,and 16S rRNA gene sequencing.The clinically isolated strain was cultured in brain heart infusion broth(BHI)supplemented with 120 mmol/L lactate in an anaerobic chamber.Its growth curve and lactate metabolism over 24 h were assessed.Co-culture with S.mutans was conducted to measure lactate accumulation and pH value changes in the culture system.Biofilm structure was observed by scan-ning electron microscopy(SEM),and the biofilm biomass was compared using crystal violet staining,providing initial insights into their interaction.Results:Through biochemical identification and 16S rRNA gene sequencing,one wild type strain of V.parvula was isolated from the supragingival plaque of intact teeth surfaces in an adult patient with rampant caries.When the wild type V.parvula and the reference strain V.parvula were cultured over 24 h,their growth curves and the trends in the residual lactate concentration in the medium differed,with the differences being statistically significant(F=10.431,P＜0.001;F=5.641,P＜0.05).In co-culture with S.mutans,the group with the wild type V.parvu-la formed a denser bacterial biofilm structure and had a greater biofilm biomass at 12 h compared with the group with the reference strain V.parvula(P＜0.001).At 24 h,the cumulative lactate concentration produced by the co-culture group with the wild type V.parvula reached as high as 65 mmol/L,which was significantly higher than that in the co-culture group with the reference strain V.parvula and the S.mutans mono-culture group(P＜0.001).Conclusion:The strain of V.parvula which we isolated from supragingival dental plaque exhibited superior growth,lactate metabolism,and a greater capacity to promote S.mutans biofilm formation than the reference strain,ultimately accelerating the initiation of early carious lesions.