Synergistic effects of antibiotics and an N-acyl homoserine lactone analog on Porphyromonas gingivalis biofilms

Aims: To investigate the effects of the combined application of an N‐acyl homoserine lactone (HSL) analog and antibiotics on biofilms of Porphyromonas gingivalis, a major pathogen of periodontal disease. Methods and Results: Antibiotics used were cefuroxime, ofloxacin and minocycline. A flow‐cell model was used for biofilm formation. Samples were divided into four groups: control, analog‐treated, antibiotic‐treated and combined application groups. Biofilm cell survival was determined using adenosine triphosphate (ATP) bioluminescence and confocal laser microscopy (CLSM). In the combined application group, the ATP count in biofilm cells was significantly decreased compared with the antibiotic‐treated group (Games–Howell test, P < 0·05). A combination of cefuroxime and the analog was most effective against the P. gingivalis biofilm. CLSM observations revealed that the proportion of dead cells was highest in the combined application group. Conclusions: The combined application of the N‐acyl HSL analog and antibiotics was effective at reducing the viability of P. gingivalis cells in biofilms. Significance and Impact of the Study: The combined application of the N‐acyl HSL analog and antibiotics may be successful for eradicating infections involving bacterial biofilms, such as periodontitis.     

Parameters of oxidative stress in saliva from patients with aggressive and chronic periodontitis

Objectives: Free radicals play an important role in the onset and progression of many diseases. The aim of this study was to investigate the contribution of oxidative stress in the pathology of aggressive (AgP) and chronic (CP) periodontitis and its relation with the clinical periodontal status.

Methods: Eighty subjects were divided into two groups: 20 patients with AgP and 20 patients with CP with their 20 corresponding matched controls, based on clinical attachment loss (CAL), probing pocket depth (PPD), and bleeding on probing (BOP). Saliva reactive oxygen species (ROS), lipid peroxidation, and non-enzymatic antioxidant defences were measured by luminol-dependent chemiluminescence assay, as thiobarbituric acid-reactive substances (TBARs) and total radical-trapping antioxidant potential (TRAP), respectively. Pearson's correlation and multivariate analysis were used to determine the relationship between ROS and TBARs and the clinical parameters.

Results: ROS and TBARs were increased in AgP while TRAP was decreased, comparing with CP. In AgP, a strong and positive correlation was observed between ROS and TBARs and they were closely associated with CAL and PPD.

Discussion: In AgP, but not in CP, oxidative stress is a high contributor to periodontal pathology and it is closely associated with the clinical periodontal status.     

牙周炎病人牙龈组织PGE2龈下韦荣菌的相关分析

目的 探讨牙周炎病人牙龈组织PGE2的含量及与细菌的关系。方法 采用放射免疫方法测定PGE2含量,以厌氧培养及活菌计数（CFU）的方法检测了链球菌及韦荣菌的含量。结果 牙周炎病人牙龈组织PGE2的含量显著于健康对照组,并与韦菌的量呈显著正相关。结论 PGE2与牙周炎骨质破坏关系密切,韦荣菌在牙周炎发病中具有重大作用.     

Biochemical characterization of the γ-carbonic anhydrase from the oral pathogen Porphyromonas gingivalis,PgiCA

Abstract

Carbonic anhydrases (CAs, EC 4.2.1.1) catalyze a simple but physiologically relevant reaction in all life kingdoms, carbon dioxide hydration to bicarbonate and protons. CAs are present in many pathogenic species and are involved in the bicarbonate metabolism/biosynthetic reactions involving this ion. Ubiquity of these enzymes suggests a pivotal role in microbial virulence and pathogenicity. Porphyromonas gingivalis is an anaerobic bacterium, which colonizes the oral cavity, being involved in the pathogenesis of periodontitis, an inflammatory disease leading to tooth loss. Recently, we reported an anion inhibitory study on the γ-CA (denominated PgiCA) identified in the genome of this Gram-negative bacterium. In this paper we continue our research on PgiCA, and describe the biochemical characterization of the recombinant protein, its thermal stability, the oligomeric state and the enzyme kinetics. PgiCA is a polypeptide chain formed of 192 amino acids and displays an identity of 30–33% when compared with the prototypical γ-CAs, CAM or CAMH (from Methanosarcina thermophila) or CcmM (from Thermosynechococcus elongatus). A subunit molecular mass of 21?kDa was estimated by SDS-PAGE, while HPLC size exclusion chromatography under native conditions gave an estimated molecular mass of 65?kDa suggesting that the recombinant enzyme self-associate in a homotrimer, as all other γ-CAs studied so far. Enzyme kinetic analysis showed that PgiCA is 62 times more effective as a catalyst compared to CAM, the only other γ-CA characterized in detail kinetically. All these features represent an interesting attractive for the drug design of inhibitors/activators of this new enzyme.     

慢性牙周炎患者血清miR-205-5p、miR-28-5p的表达与诊断价值研究

摘要 目的：探讨慢性牙周炎（CP）患者血清微小核糖核酸（miRNA）-205-5p、miR-28-5p表达与牙周指标、炎症反应的关系及诊断价值。方法：选取2021年1月～2022年12月我院口腔科收治的102例CP患者为CP组,根据病情严重程度分为轻度组31例、中度组37例、重度组34例,另选取同期我院65名体检健康者为对照组。采用实时荧光定量聚合酶链式反应（PCR）检测血清miR-205-5p、miR-28-5p表达,酶联免疫吸附法检测白细胞介素（IL）-1β、IL-6、肿瘤坏死因子-α（TNF-α）水平,检查各组牙周指标[菌斑指数（PLI）、牙龈出血指数（BI）、附着丧失（AL）、探诊深度（PD）]。CP患者血清miR-205-5p、miR-28-5p表达与牙周指标和炎症指标的相关性采用Pearson相关性分析。受试者工作特征（ROC）曲线分析血清miR-205-5p、miR-28-5p表达诊断CP的价值。结果：与对照组比较,CP组血清miR-205-5p、miR-28-5p表达降低,PLI、BI、AL、PD和IL-1β、IL-6、TNF-α水平升高（P＜0.05）。轻度组、中度组、重度组血清miR-205-5p、miR-28-5p表达依次降低,PLI、BI、AL、PD和IL-1β、IL-6、TNF-α水平依次升高（P＜0.05）。Pearson相关性分析显示,CP患者血清miR-205-5p、miR-28-5p表达与PLI、BI、AL、PD、IL-1β、IL-6、TNF-α呈负相关（P＜0.05）。ROC曲线分析显示,血清miR-205-5p联合miR-28-5p诊断CP的曲线下面积分别为0.885大于miR-205-5p、miR-28-5p单独检测的0.792、0.790。结论：CP患者血清miR-205-5p、miR-28-5p低表达,与牙周指标、炎症反应密切相关,血清miR-205-5p、miR-28-5p的表达情况可能成为CP辅助诊断指标,且miR-205-5p联合miR-28-5p诊断CP的价值较高。     

龈沟液miR-155、miR-223表达水平与慢性牙周炎伴2型糖尿病患者牙周临床指标、口腔龈下菌群以及Th17/Treg失衡的相关性分析

摘要 目的：探讨龈沟液miR-155、miR-223表达水平与慢性牙周炎伴2型糖尿病（T2DM）患者牙周临床指标、口腔龈下菌群以及外周血辅助性T细胞17（Th17）/调节性T细胞（Treg）失衡的相关性。方法：选择2018年1月至2022年1月安徽理工大学第一附属医院口腔科收治的86例慢性牙周炎患者,根据是否伴T2DM将患者分为慢性牙周炎伴T2DM组15例和单纯慢性牙周炎组71例,另选择65例健康体检志愿者为对照组。检测龈沟液miR-155、miR-223表达水平,口腔龈下菌群以及外周血Th17细胞占比、Treg细胞占比、血清白细胞介素（IL）-17、转化生长因子-β（TGF-β）水平。Pearson相关分析龈沟液miR-155、miR-223表达水平与牙周临床指标、口腔龈下菌群、外周血Th17/Treg以及血清IL-17、TGF-β的相关性。结果：慢性牙周炎伴T2DM组、单纯慢性牙周炎组龈沟液miR-155、miR-223表达水平高于对照组（P＜0.05）,且慢性牙周炎伴T2DM组高于单纯慢性牙周炎组（P＜0.05）。慢性牙周炎伴T2DM组龈沟出血指数（SBI）、菌斑指数（PLI）、探诊深度（PD）、附着丧失（AL）、牙龈卟啉单胞菌、二氧化碳噬纤维菌、中间普氏菌、变黑普氏菌数量、外周血Th17细胞占比、Th17/Treg比值、血清IL-17水平高于单纯慢性牙周炎组（P＜0.05）,外周血Treg细胞占比低于单纯慢性牙周炎组（P＜0.05）。龈沟液miR-155、miR-223表达水平与PLI、SBI、AL、PD、牙龈卟啉单胞菌、二氧化碳噬纤维菌、中间普氏菌、变黑普氏菌数量、外周血Th17细胞占比、Th17/Treg比值、血清IL-17水平呈正相关（P＜0.05）,与外周血Treg细胞占比呈负相关（P＜0.05）。结论：慢性牙周炎伴T2DM患者龈沟液中miR-155、miR-233表达均上调,且与牙周组织破坏程度、龈下菌群紊乱和Th17/Treg失衡有关。     

血清HSP27、YKL-40与侵袭性牙周炎患者Th17、Treg细胞的关系及对牙周-正畸联合治疗后预后的影响分析

摘要 目的：分析血清热休克蛋白27（HSP27）、人软骨糖蛋白(YKL-40)与侵袭性牙周炎（AgP）患者辅助性T细胞17（Th17）、调节性T细胞（Treg）的关系及对牙周-正畸联合治疗后预后的影响。方法：选取2020年5月-2022年4月河北北方学院附属第一医院收治的98例AgP患者为AgP组,另选取同期于医院检查的60例牙周健康志愿者作为对照组。采用酶联免疫法检测血清HSP27、YKL-40水平,流式细胞仪检测外周血Th17、Treg百分比,计算Th17/Treg比值;Pearson法分析血清HSP27、YKL-40与Th17、Treg细胞的相关性。AgP患者经牙周-正畸联合治疗6个月后,复诊检查时根据牙周探针深度（PD）将患者纳入预后良好组（PD＜4 mm）和预后不良组（PD≥4 mm）。采用Logistic回归模型分析AgP患者牙周-正畸联合治疗后预后不良的影响因素。结果：AgP组血清HSP27水平低于对照组,YKL-40水平高于对照组（P＜0.05）。AgP组外周血中Th17细胞百分比、Th17/Treg比值高于对照组,Treg细胞百分比低于对照组（P＜0.05）。Pearson法显示,Th17细胞百分比、Th17/Treg比值与HSP27表达呈负相关,Treg细胞百分比与其呈正相关（P＜0.05）;Th17细胞百分比、Th17/Treg比值与YKL-40表达呈正相关,Treg细胞百分比与其呈负相关（P＜0.05）。复查结果显示,预后良好患者共61例,预后不良共37例。预后良好组与预后不良组在患牙上下、前后分布、根形态、患牙PD最深值、牙槽骨高度、菌斑指数及HSP27、YKL-40水平方面比较差异有统计学意义（P＜0.05）。Logistic回归显示,根形异常、患牙PD深、牙槽骨高度高、菌斑指数大、HSP27水平下降、YKL-40水平上升为AgP患者牙周-正畸联合治疗后预后不良的危险因素（P＜0.05）。结论：AgP患者血清HSP27水平下降、YKL-40水平上升,与Th17、Treg细胞表达密切相关,是影响患者牙周-正畸联合治疗后预后不良的危险因素。     

慢性牙周炎患者唾液中IL-17，miR-146a表达水平与疾病程度的相关性分析

目的:观察和分析慢性牙周炎(CP)患者唾液中白细胞介素-17(IL-17)、微小RNA-146a(miR-146a)表达水平与疾病程度的相关性。方法:选取80例CP患者作为病例组,选取80名健康志愿者作为对照组,对两组研究对象唾液样本中的IL-17、miRNA-146a表达水平进行检测和比较。对病例组患者的菌斑指数(PLI)、牙龈指数(GI)、牙周探诊深度(PD)和附着丧失(AL)等牙周病指标进行检测。结果:病例组患者唾液中IL-17、miR-146a表达水平显著高于对照组,两组之间的差异均有统计学意义(P0.05)。随着疾病程度的加剧,患者唾液中IL-17、miR-146a表达水平也逐渐上升,各组之间的差异均有统计学意义(P0.05)。Spearman等级相关分析结果显示,CP患者唾液中IL-17、miR-146a表达水平与牙周炎严重程度均呈正相关关系(P0.05)。直线相关分析结果显示,CP患者唾液中IL-17、miR-146a表达水平与PLI、GI、PD、AL等牙周炎临床指标均呈正相关关系(P0.05)。结论:CP患者表现为唾液中IL-17、miR-146a表达水平的显著升高,其表达水平与疾病严重程度和临床指标均具有相关性。