Porphyromonas-like Gram-negative rods in naturally occurring periodontitis in dogs

Abstract A total of 259 Gram-negative Porphyromonas -like rods isolated from subgingival plaque samples of 16 family-owned dogs with naturally occurring periodontitis were characterized phenotypically by biochemical reactions, metabolic end products and enzymatic activities (API-ZYM^TM, Rosco^TM). Four distinct groups were found. Group A isolates (63) were asaccharolytic, lipase negative, trypsin positive and produced phenylacetic acid (PAA) from peptone-yeast extract glucose broth. Unlike P. gingivalis strains they were catalase positive. Group B isolates (42) differed from those of group A by a positive lipase reaction and from those of group D by failing to ferment sugars. Group C isolates (88) were asaccharolytic and did not produce PAA. They were α-fucosidase, N -acetyl- β -glucosaminidase (β-NAG) and trypsin negative, resembling P. endodontalis , but unlike human isolates, they were catalase positive. Subgroup C.1 isolates (6) differed from those of parent group C by producing minor amounts of PAA, and subgroup C.2 isolates (12) were β-NAG positive. Group D isolates (46) were weakly fermentative, lipase, catalase and trypsin positive, and produced PAA. They resembled the B. (P.) salivosus type strain which, in our hands, fermented weakly glucose, lactose and mannose. Two isolates could not be assigned to any of the previous groups.     

Rapid detection and quantification of five periodontopathic bacteria by real-time PCR

The quantity of periodontopathic bacteria in plaque samples is an important determinant for understanding the etiologic role of bacteria. The real-time PCR method was used to detect and quantify periodontopathic bacteria, such as Actinobacillus actinomycetemcomitans, Bacteroides forsythus, Porphyromonas gingivalis, Treponema denticola, and Treponema socranskii, in saliva and subgingival plaque samples. There was good agreement between the results of conventional PCR and real-time PCR methods. Using the LightCycler system we were able to determine the amount of periodontopathic bacteria within an hour. The real-time PCR method was linear for samples containing from 10(3) to more than 10(8) cells (r2 = 0.999). The application of the real-time PCR method should be useful in the rapid detection and quantification of periodontopathic bacteria in clinical samples.     

Detection of Streptococcus anginosus from saliva by real-time polymerase chain reaction

AIMS: The purpose of the present investigation was to assess the salivary levels of Streptococcus anginosus in periodontitis patients. METHODS AND RESULTS: The salivary levels of Strep. anginosus were assessed using real-time polymerase chain reaction (PCR). Streptococcus anginosus was detected in 28 of 37 (75.6%) of periodontitis patients and in three of the 20 (15%) healthy subjects. The mean values for bleeding on probing and probing depth in positive patients were statistically higher than those in negative patients. A significant decrease in Strep. anginosus levels was observed after periodontal treatment. CONCLUSIONS: Although the levels of Strep. anginosus are extremely low, they may reflect the status of periodontal health. SIGNIFICANCE AND IMPACT OF THE STUDY: Real-time PCR is a useful method for obtaining the relative quantities of Strep. anginosus from saliva samples and for monitoring the effect of therapy.     

粘接性牙周夹板固定修复在慢性牙周炎患者的临床应用

目的:观察粘接性牙周夹板固定修复治疗慢性牙周炎的临床效果。方法:选择25例(93颗松动患牙)慢性牙周炎患者,记录牙周治疗前、采用粘接性牙周夹板固定修复后即刻、3、6及12个月的牙周状况,包括菌斑指数(PLI)、探针深度(PD)、牙龈出血指数(BOP)、牙龈指数(GI)和附着丧失(AL)的变化;检测牙龈龈沟液中卟啉单胞菌、血链球菌数量的变化;评估患者行固定夹板修复后对美观、舒适、咀嚼、发音等方面的满意度。结果:经牙周夹板固定修复后,各阶段的PLI、PD、GI和AL的指标值与治疗前相比差异均有统计学意义(P0.05),但固定后各阶段之间的牙周临床指标差异无统计学意义(P0.05);牙龈卟啉单胞菌和血链球菌数的数量在固定后各阶段较治疗前均显著减少(P0.05),但固定期间各阶段比较差异不明显(P0.05);固定修复后,各阶段患者的满意度均较高。结论:慢性牙周炎患者经完善的牙周基础治疗后,应用粘接性牙周夹板固定修复,能够有效固定患者松动患牙,恢复其咀嚼功能,有效地控制慢性牙周炎的发展。     

两种龈下刮治和根面平整术对2型糖尿病伴慢性牙周炎疗效的比较

目的:比较一次法龈下刮治和根面平整术(FM-SRP)和常规的四分法龈下刮治和根面平整术(Q-SRP)治疗2型糖尿病伴慢性牙周炎的临床疗效,并观察慢性牙周炎治疗对2型糖尿病患者血糖控制的影响。方法:将48例2型糖尿病伴慢性牙周炎患者随机分为2组:FM-SRP组在l天内完成全口所有象限的刮治和根面平整,Q-SRP组每周进行1个象限的刮治,连续4周完成全口治疗。于治疗前、治疗3个月和6个月时,检测菌斑指数(PLI)、牙周探诊深度(PD)、临床附着水平(CAL)、探诊出血(BOP)及空腹血糖(FPG)与糖化血红蛋白(HbAlc)的变化。结果:有3例患者被剔除。与治疗前相比,2种治疗方式在3个月和6个月时的PLI、PD、CAL和BOP均有显著改善(P<0.05),FPG和HbAlc无显著性改变(P>0.05)。但各项指标的变化在2组间均无显著性差异(P>0.05)。结论:本组资料,FM-SRP和Q-SRP两种方法治疗2型糖尿病伴慢性牙周炎均可达到相同的临床效果,但对2型糖尿病患者血糖控制无明显影响。     

Genotype variation and capsular serotypes of Porphyromonas gingivalis from chronic periodontitis and periodontal abscesses

Porphyromonas gingivalis is considered an important pathogen in periodontal disease. While this organism expresses a number of virulence factors, no study combining different virulence polymorphisms has, so far, been conducted. The occurrence of combined virulence (Cv) genotypes in 62 isolates of P. gingivalis was investigated from subjects displaying either chronic periodontitis or periodontal abscess. The Cv genotypes, based on gene variation of fimbriae (fimA), Lys-specific cystein proteinase (kgp) and Arg-specific cystein proteinase (prpR1/rgpA), were evaluated by PCR. The isolates were also subjected to capsular polysaccharide K-serotyping. A total of 18 Cv genotype variants based on fimA: kgp: rgpA were identified, of which II:I:A and II:II:A Cv genotypes (53.3%) were the two most frequently detected combinations. Moreover, 36% of the isolates were K-typeable, with the K6 serotype being the most prevalent (23%). Two isolates had the same genotype as the virulent strain W83. The results indicate that chronic periodontitis is not associated with a particularly virulent clonal type. A highly virulent genotype (e.g. strain W83) of P. gingivalis can be found in certain periodontitis patients.     

亚甲基蓝/光化学法辅助治疗慢性牙周炎对牙龈卟啉单胞菌的影响

目的研究亚甲基蓝/光化学法辅助治疗慢性牙周炎对牙龈卟啉单胞菌(Porphyromonas gingivalis,Pg)检出率的变化。方法经伦理委员会同意后,本研究拟筛选出45例慢性牙周炎患者(每位患者经过详细牙周检查及X线检查后确认为牙周炎,有4个以上≥5 mm的牙周袋并分布在2个以上口腔区域),随机分3组:其中A组在SRP之后接受1次PERIOWAVE光化学治疗,B组在SRP后接受1次PERIOWAVE治疗以及在6周后再一次接受光化学治疗,而SRP组仅接受SRP治疗,各组患者取治疗前后相同4个位点龈下菌斑,聚合酶链式反应(Poly-merase chain reaction,PCR)检测Pg,观察Pg菌的检出率,采用卡方检验,并计算χ2值。结果 SRP组、A组、B组3组各组治疗后均较治疗前检出率降低(P<0.001),A组与SRP组治疗后比较差异无统计学意义[A组:40%(24/60),SRP组:45%(27/60),χ2=1.4815,P>0.05],B组与SRP治疗后比较检出率降低[SRP组:45%(27/60),B组:20%(12/60)χ2=8.547,P<0.01];B组与A组治疗后比较检出率降低[A组:40%(24/60),B组:20%(12/60),χ2=5.7143,P<0.05]。结论亚甲基蓝/光化学法辅助治疗慢性牙周炎后牙龈卟啉单胞菌的检出率较治疗前降低;结合临床试验结果,尚可认为2次激光疗效较1次激光好。     

Detection and characterization of beta-lactamase genes in subgingival bacteria from patients with refractory periodontitis

Fifty-three beta-lactamase-producing strains of oral bacteria isolated from patients with refractory periodontitis in Norway and USA were screened for the presence of the bla(TEM), bla(SHV), bla(OXA), bla(ampC), bla(cfxA), and bla(cepA/cblA) genes by the polymerase chain reaction (PCR). The PCR products were characterized by direct sequencing of the amplified DNA. Thirty-four of the 53 enzyme-producing strains (64%) were positive in one of the PCR assays. All beta-lactamase-producing Prevotella and Capnocytophaga spp. were CfxA positive. TEM-type beta-lactamases were identified in one strain each of Escherichia coli and Neisseria sp., and one strain of Citrobacter freundii possessed an AmpC-type beta-lactamase. Screening for gene cassettes and genes known to be associated with integrons did not reveal the presence of integrons in these oral bacteria. Sequence analyses showed that most CfxA positive Prevotella and Capnocytophaga isolates from patients with refractory periodontitis harboured variants of the CfxA2 and CfxA3 enzyme. The present study also showed that many different genetic determinants of beta-lactamase production are found in bacteria isolated from refractory periodontitis, many of which remain to be characterized.