探讨牛胰蛋白酶对牙周炎相关微生物多菌种生物膜的降解作用,为探索控制牙周炎相关微生物生物膜的新方法提供实验参考。建立了牙周炎相关微生物的多菌种生物膜。牙龈卟啉单胞菌的标准菌株,具核梭杆菌亚种。多态,粘性放线菌,和Aggregatibacter放线菌共培养形成生物膜。实验组用牛胰蛋白酶处理,采用蒸馏水作为空白对照组,以磷酸盐缓冲液(pH=7.4)作为阴性对照组。胞外聚合物(EPS)的形态观察和定量分析,活的细菌,和死亡细菌使用激光共聚焦显微镜进行。用扫描电子显微镜观察了EPS和细菌的形态变化。建模的形态学观察结果如下。以团聚体形式聚集的EPS,细菌被它们包裹,呈现三维网络结构,和通道样结构在生物膜内部。活的细菌分布在EPS的表面或嵌入其中,死菌聚集在活菌群和生物膜底层之间。用牛胰蛋白酶处理后,三维网络结构和通道状结构消失了,EPS和活菌和死菌减少。定量分析结果如下。当生物膜处理30s时,1分钟,和3分钟,牛胰蛋白酶降低EPS的最低有效浓度为2mg/ml(P<0.05),0.5mg/ml(P<0.05),和0.25mg/ml(P<0.05),分别。牛胰蛋白酶减少活菌或死菌的最低有效浓度为2mg/ml(P<0.05),0.5mg/ml(P<0.05),和0.5mg/ml(P<0.05),分别。用浓度为0.25、0.5、1和2mg/ml的牛胰蛋白酶处理生物膜30s后,活菌/死菌比例差异无统计学意义(P>0.05)。治疗1min和3min后,降低活菌/死菌比例的最低有效浓度为0.25mg/ml(P<0.05)。因此,牛胰蛋白酶可以破坏生物膜结构,分散生物膜和细菌菌群,并减少EPS和细菌生物量,与施用时间和浓度呈正相关。
To investigate the degradation effect of bovine trypsin on multispecies biofilm of periodontitis-related bacteria and to provide an experimental reference for exploring new methods for controlling biofilms of periodontitis-related microorganisms, the multispecies biofilm of periodontitis-related microorganisms was established. Standard strains of Porphyromonas gingivalis, Fusobacterium nucleatum subsp. polymorpha, Actinomyces viscosus, and Aggregatibacter actinomycetemcomitans were co-cultured to form the biofilm. The experimental groups were treated with bovine trypsin, distilled water was applied as the blank control group, and phosphate saline buffer (pH = 7.4) as the negative control group. Morphological observation and quantitative analysis of extracellular polymeric substances (EPS), live bacteria, and dead bacteria were conducted using a laser confocal microscope. The morphological changes of EPS and bacteria were also observed using a scanning electron microscope. The results of morphological observations of modeling were as follows. EPS aggregated as agglomerates, and bacteria flora were wrapped by them, showing a three-dimensional network structure, and channel-like structures were inside the biofilm. Live bacteria were distributed on the surface of the EPS or embedded in them, dead bacteria aggregated between live flora and the bottom layer of biofilms. After being treated with bovine trypsin, the three-dimensional network structure and the channel-like structure disappeared, and the EPS and live and dead bacteria decreased. Quantitative analysis results are as follows. When biofilm was treated for 30 s, 1 min, and 3 min, the minimum effective concentrations of bovine trypsin to reduce EPS were 2 mg/ml (P < 0.05), 0.5 mg/ml (P < 0.05), and 0.25 mg/ml (P < 0.05), respectively. The minimum effective concentrations of bovine trypsin to reduce the live or dead bacteria were 2 mg/ml (P < 0.05), 0.5 mg/ml (P < 0.05), and 0.5 mg/ml (P < 0.05), respectively. There was no significant difference in the ratio of live/dead bacteria after the biofilm was treated for 30 s with bovine trypsin at the concentration of 0.25, 0.5, 1, and 2 mg/ml (P > 0.05), and the minimum effective concentration to reduce the ratio of live bacteria/dead bacteria was 0.25 mg/ml (P < 0.05) after treatment for 1 min and 3 min. Therefore, bovine trypsin can destroy biofilm structure, disperse biofilm and bacteria flora, and reduce the EPS and bacterial biomass, which are positively correlated with the application time and concentration.