Presence Of Aggregatibacter Actinomycetemcomitans Research Articles

Presence and Immunoreactivity of Aggregatibacter actinomycetemcomitans in Rheumatoid Arthritis.

The presence of periodontal pathogens is associated with an increased prevalence of rheumatoid arthritis (RA). The systemic antibody response to epitopes of these bacteria is often used as a proxy to study correlations between bacteria and RA. The primary aim of the present study is to examine the correlation between the presence of Aggregatibacter actinomycetemcomitans (Aa) in the oral cavity and serum antibodies against the leukotoxin (LtxA) produced by this bacterium. The salivary presence of Aa was analyzed with quantitative PCR and serum LtxA ab in a cell culture-based neutralization assay. The analyses were performed on samples from a well-characterized RA cohort (n = 189) and a reference population of blood donors (n = 101). Salivary Aa was present in 15% of the RA patients and 6% of the blood donors. LtxA ab were detected in 19% of RA-sera and in 16% of sera from blood donors. The correlation between salivary Aa and serum LtxA ab was surprisingly low (rho = 0.55 [95% CI: 0.40, 0.68]). The presence of salivary Aa showed no significant association with any of the RA-associated parameters documented in the cohort. A limitation of the present study is the relatively low number of individuals with detectable concentrations of Aa in saliva. Moreover, in the comparison of detectable Aa prevalence between RA patients and blood donors, we assumed that the two groups were equivalent in other Aa prognostic factors. These limitations must be taken into consideration when the result from the study is interpreted. We conclude that a systemic immune response to Aa LtxA does not fully reflect the prevalence of Aa in saliva. In addition, the association between RA-associated parameters and the presence of Aa was negligible in the present RA cohort.

The influence of the tooth preparation finish line position on the expression of matrix metalloproteinase-9 and the presence of periodontopathogens in the gingival crevicular fluid.

The objective of the study was to determine the concentration of matrix metalloproteinase 9 (MMP-9) and changes in the presence of periodontopathogens in the gingival crevicular fluid before and after tooth preparation with the subgingival and equigingival finish line position. The clinical prospective study included 20 subjects with an indication for upper canine preparation, with the subgingival (group 1) and equigingival finish line (group 2). Samples were taken in four observation intervals: 5 minutes before (control samples), as well as 15 minutes, 24 and 72 hours after tooth preparation (experimental samples). Measurement of MMP-9 was done using Enzyme-linked Immunosorbent Assay (ELISA). The presence of bacteria in the gingival fluid was proven by the Polymerase chain reaction (PCR) analysis. The MMP-9 values did not differ statistically significantly between the groups (p=0.524). The MMP-9 values showed a statistically significant difference in the given observation period (p<0.001) with a significant linear increase in values (p<0.001). A significant quadratic trend recorded a decrease in the MMP-9 values 15 minutes after preparation, and an increase 24 hours after preparation, without a significant difference in the interaction between groups (p=0.392). After preparation, a significant difference in the presence of periodontopathogens was confirmed, i.e., a decrease in the presence of Prevotella intermedia (p=0.025) and Tannerella forsythia (p=0.016) in group 1, and an increase in the presence of Aggregatibacter actinomycetemcomitans in both groups (p=0.029, p=0.026). The study is a good basis for determining the influence of tooth preparation on gingival inflammation, with therapeutic (choice of preparation technique) and preventive significance regarding the protection of the periodontal tissue from possible iatrogenic damage.

Short-term comparison between clinical and microbial profiles in diabetic and non-diabetic patients with chronic periodontitis after non-surgical periodontal therapy

Aim: To compare clinical and microbial profiles in type 2 diabetic (DM) and non-diabetic (NDM) patients with chronic periodontitis after non-surgical periodontal therapy. Methods: 30 subjects with periodontitis were separated into two groups: 15 DM and 15 NDM. Blood parameters and clinical parameters were assessed. Subgingival biofilm samples were collected from periodontal pockets (PD &gt; 5mm) and ckecked by the presence of Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), Tannerella forsythia (Tf), Prevotella intermedia (Pi), Campylobacter rectus (Cr), Candida albicans (Ca), Candida glabrata (Cg), Candida tropicalis (Ct), Candida dublinienses (Cd) by Polymerase Chain Reaction. Data were statistically analyzed, considering p &lt; 0.05. Results: PI, PD, and CAL significantly reduced after 3 months of periodontal therapy in both groups. Only levels of HbA1c reduced in the DM group after 3 months. Comparisons between baseline and 3 months after periodontal therapy revealed a reduction of Aa, Pg, Tf, Pi, Ct and Cd for the NDM group and Aa, Pg, Tf, and Ca for the DM group. Conclusions: The periodontal therapy was effective in reducing clinical parameters and microbial levels, regardless the presence of the diabetes mellitus. However, high levels of Candida ssp. remained in periodontal pockets of diabetic patients even after therapy.

Microbiological Changes during Orthodontic Aligner Therapy: A Prospective Clinical Trial

The purpose of this study is to assess the variations induced by Clear Aligner Treatment (CAT) on the periodontal status and microbiological composition of oral microbiota. A total of 20 orthodontic patients were submitted to professional oral hygiene and, subsequently, underwent CAT (Group one, trials). A total of 20 non orthodontic patients (Group two, controls) remained untreated after oral hygiene. At T0 (baseline) and T1 (after 2 months), the participants were clinically examined for Probing Pocket Depth (PPD), Bleeding on Probing (BOP) and Plaque Index (PI), and microbiological tests were performed to detect bacteria of the red and orange complexes as well as the presence of Aggregatibacter actinomycetemcomitans. No significant inter- or intra-group differences were shown neither for PPD, PI and BOP (p &gt; 0.05), nor for bacteria expressed in copies/microlitre or in percentages (p &gt; 0.05). The only significant difference was assessed from T0 (baseline) to T1 (2 months) in both groups and is related to the total bacteria count increase. However, this parameter encompasses all the bacteria of the common oral microbiota, thus, not representing a significant result from a clinical point of view. Despite the limitations of this study, CAT does not significantly affect periodontal and microbiological parameters with respect to untreated patients for the first two months of therapy.

Comparison of the frequency of periodontal pathogenic species of diabetics and non-diabetics and its relation to periodontitis severity, glycemic control and body mass index.

ObjectivesTo investigate common pathogenic bacteria of periodontal diseases (PD) in patients with type 2 diabetes mellitus (T2DM) and its relationship with PD severity, glycemic control and body mass index (BMI).Material and MethodsThis case–control study consisted of 55 patients with T2DM and 55 individuals as control. Samples were collected from periodontal pockets. After DNA extraction, using 16srRNA‐specific primers, the presence of Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), Tannerella forsythia (Tf), Prevotella intermedia (Pi), and Fusobacterium nucleatum (Fn) were examined based on polymerase chain reaction method.ResultsAa frequency was significantly higher in in T2DM group than control. There were no significant differences in the frequencies of Pg, Tf, Pi, and Fn between studied groups. There were no significant differences between frequencies of studied bacteria in different severities of periodontitis in T2DM group. Prevalence of Tf in T2DM patients with moderate periodontitis was significantly higher than non‐diabetics with moderate periodontitis. There was no significant difference between the frequency of bacteria in diabetics with good and poor glycemic control. There was a significant difference between the frequencies of Pg in T2DM individuals with different BMI levels.ConclusionsA higher frequency of detection of Aa was found in diabetic when compared to non‐diabetics. Glycemic control did not affect the frequency distribution of studied bacteria in T2DM. Pg was identified in higher frequency in overweight T2DM patients.

Aggregatibacter actinomycetemcomitans mediates protection of Porphyromonas gingivalis from Streptococcus sanguinis hydrogen peroxide production in multi-species biofilms

Mixed species biofilms are shaped and influenced by interactions between species. In the oral cavity, dysbiosis of the microbiome leads to diseases such as periodontitis. Porphyromonas gingivalis is a keystone pathogen of periodontitis. In this study, we showed that polymicrobial biofilm formation promoted the tolerance of Porphyromonas gingivalis to oxidative stress under micro-aerobic conditions. The presence of Streptococcus sanguinis, an oral commensal bacterium, inhibited the survival of P. gingivalis in dual-species biofilms via the secretion of hydrogen peroxide (H2O2). Interestingly, this repression could be attenuated by the presence of Aggregatibacter actinomycetemcomitans in tri-species biofilms. It was also shown that the katA gene, encoding a cytoplasmic catalase in A. actinomycetemcomitans, was responsible for the reduction of H2O2 produced by S. sanguinis, which consequently increased the biomass of P. gingivalis in tri-species biofilms. Collectively, these findings reveal that polymicrobial interactions play important roles in shaping bacterial community in biofilm. The existence of catalase producers may support the colonization of pathogens vulnerable to H2O2, in the oral cavity. The catalase may be a potential drug target to aid in the prevention of periodontitis.

High salivary levels of JP2 genotype of Aggregatibacter actinomycetemcomitans is associated with clinical attachment loss in Moroccan adolescents.

It has previously been shown that the presence of Aggregatibacter actinomycetemcomitans in subgingival plaque is significantly associated with increased risk for clinical attachment loss. The highly leukotoxic JP2 genotype of this bacterium is frequently detected in adolescents with aggressive forms of periodontitis. The aims of the study were to quantify the levels of JP2 and non‐JP2 genotypes of A. actinomycetemcomitans in saliva of Moroccan adolescents with the JP2 genotype earlier detected in the subgingival plaque. The salivary concentrations of inflammatory proteins were quantified and linked to the clinical parameters and microbial findings. Finally, a mouth rinse with leukotoxin‐neutralizing effect was administrated and its effect on the levels the biomarkers and A. actinomycetemcomitans examined. The study population consisted of 22 adolescents that previously were found to be positive for the JP2 genotype in subgingival plaque. Periodontal registration and sampling of stimulated saliva was performed at baseline. A mouth rinse (active/placebo) was administrated, and saliva sampling repeated after 2 and 4 weeks rinse. The salivary levels of JP2 and non‐JP2 were analyzed by quantitative PCR and inflammatory proteins by ELISA. Both the JP2 and the non‐JP2 genotype were detected in all individuals with significantly higher levels of the non‐JP2. Enhanced levels of the JP2 genotype of A. actinomycetemcomitans was significantly correlated to the presence of attachment loss (≥3 mm). Salivary concentrations of inflammatory biomarkers did not correlate to periodontal condition or levels of A. actinomycetemcomitans. The use of active or placebo leukotoxin‐neutralizing mouth rinse did not significantly interfered with the levels of these biomarkers. Saliva is an excellent source for detection of A. actinomycetemcomitans on individual basis, and high levels of the JP2 genotype were significantly associated with the presence of clinical attachment loss.

Effect of orthodontic treatment on the subgingival microbiota: A systematic review and meta-analysis.

The aim of this systematic review was to assess qualitative changes induced by fixed appliance orthodontic treatment on the subgingival microbiota. Seven databases were searched up to August 2017 for randomized and nonrandomized clinical studies assessing the effect of orthodontic appliances on the subgingival bacteria in human patients. After elimination of duplicate studies, data extraction and risk of bias assessment according to the Cochrane guidelines, random-effects meta-analyses of relative risks (RR) and their 95% confidence intervals (CIs) were performed. According to controlled studies, the presence of Aggregatibacter actinomycetemcomitans in the subgingival crevicular fluid of orthodontic patients was increased 3-6months after fixed appliance insertion compared to untreated patients (2 studies; RR=15.54; 95% CI=3.19-75.85). There was still increased subgingival prevalence of Aggregatibacter actinomycetemcomitans (3 studies; RR=3.98; 95% CI=1.23-12.89) and Tannerella forsythia in orthodontic patients up to 6months after appliance removal compared to untreated patients. However, caution is warranted due to high risk of bias and imprecision. Insertion of orthodontic fixed appliances seems to be associated with a qualitative change of subgingival microbiota, which reverts to some extent back to normal in the first months after appliance removal. However, there is limited evidence on the timing and extent of these changes.

Modulation of neutrophil chemotaxis by Aggregatibacter actinomycetemcomitans leukotoxin

ABSTRACTObjective: Aggressive periodontitis (AgP) is frequently associated with the presence of Aggregatibacter actinomycetemcomitans, a Gram-negative pathogen, which expresses leukotoxin (Ltx) as a virulence factor. Ltx is known to disturb neutrophil function and to activate these cells. This study was aimed at investigating the ability of Ltx to alter the chemotactic behaviour of neutrophils, the most abundant leukocyte in periodontitis.Methods: Neutrophils from healthy blood donors were isolated and stimulated or primed with low concentrations of Ltx (1, 5 and 10 ng/mL). Neutrophil migration in response to Ltx gradients and to the biofilm-derived chemotactic agent fMLP after Ltx-priming was monitored by real-time video microscopy using an Insall chamber.Results: Although Ltx alone enhanced neutrophil movement at all concentrations, low directional accuracy was observed compared to the positive control (fMLP). Ltx priming led to directional movement towards fMLP with significantly enhanced speed. In case of 10 ng/mL Ltx, however, this chemotactic response towards fMLP appeared to be delayed.Conclusion: The results indicate that Ltx induces non-directional neutrophil movement, whilst enhancing migration towards fMLP. Clincially, this may lead to the presence of a higher number of activated neutrophils in the periodontal tissues, potentially causing more pronounced host tissue damage.

Age-related prevalence and characteristics of Aggregatibacter actinomycetemcomitans in periodontitis patients living in Sweden

ABSTRACTBackground: The presence of Aggregatibacter actinomycetemcomitans in patients with periodontitis has been extensively studied for decades.Objective: To study the prevalence of A. actinomycetemcomitans in younger and older periodontitis patients and to genetically characterize isolates of this bacterium.Design: Data from microbiological analyses of 3459 subgingival plaque samples collected from 1445 patients, 337 ‘younger’ patients (≤35 yrs) and 1108 ‘older’ patients (>35 yrs) during 15 years (2000–2014), has been summerized. Isolates of A. actinomycetemcomitans were serotyped, leukotoxin promoter typed (JP2 and non JP2) and arbitrarily primed PCR (AP-PCR) genotyped. The origin of the JP2 genotype detected in the study population was determined.Results: The prevalence of A. actinomycetemcomitans was higher among younger than older patients and samples from the younger patients contained higher proportions of the bacterium. Serotype b was more prevalent among younger patients and the majorty of these isolates was from the same AP-PCR genotype. The JP2 genotype was detected in 1.2% of the patients, and the majority of these carriers were of non-African origin.Conslusions: For presence and charcteristics of A. actinomycetemcomitans in clinical samples the age of the carriers were a discriminating factor. Additional, apparently non-African carriers of the JP2 genotype of A. actinomycetemcomitans were identified.

Effects of Aggregatibacter actinomycetemcomitans leukotoxin on neutrophil migration and extracellular trap formation

BackgroundAggressive periodontitis is associated with the presence of Aggregatibacter actinomycetemcomitans, a leukotoxin (Ltx)-producing periodontal pathogen. Ltx has the ability to lyse white blood cells including neutrophils.ObjectivesThis study was aimed at investigating the interactions between neutrophils and Ltx with regard to the chemotactic properties of Ltx and the release of neutrophil extracellular traps (NETs).MethodsNeutrophils from healthy blood donors were isolated and incubated for 30 min and 3 h with increasing concentrations of Ltx (1, 10, and 100 ng/mL) as well as with A. actinomycetemcomitans strains (NCTC 9710 and HK 1651) producing different levels of Ltx. Formation of NETs and cell lysis were assessed by microscopy, fluorescence-based assays, and measurement of released lactate dehydrogenase. Neutrophil migration in response to different Ltx gradients was monitored by real-time video microscopy, and image analysis was performed using ImageJ software.ResultsAlthough Ltx (10 and 100 ng/mL) and the leukotoxic A. actinomycetemcomitans strain HK 1651 lysed some neutrophils, other cells were still capable of performing NETosis in a concentration-dependent manner. Low doses of Ltx and the weakly leukotoxic strain NCTC 9710 did not lead to neutrophil lysis, but did induce some NETosis. Furthermore, all three concentrations of Ltx enhanced random neutrophil movement; however, low directional accuracy was observed compared with the positive control (fMLP).ConclusionsThe results indicate that Ltx acts both as a neutrophil activator and also causes cell death. In addition, Ltx directly induces NETosis in neutrophils prior to cell lysis. In future studies, the underlying pathways involved in Ltx-meditated neutrophil activation and NETosis need to be investigated further.

Quantitative proteomics reveal distinct protein regulations caused by Aggregatibacter actinomycetemcomitans within subgingival biofilms.

Periodontitis is an infectious disease that causes the inflammatory destruction of the tooth-supporting (periodontal) tissues, caused by polymicrobial biofilm communities growing on the tooth surface. Aggressive periodontitis is strongly associated with the presence of Aggregatibacter actinomycetemcomitans in the subgingival biofilms. Nevertheless, whether and how A. actinomycetemcomitans orchestrates molecular changes within the biofilm is unclear. The aim of this work was to decipher the interactions between A. actinomycetemcomitans and other bacterial species in a multi-species biofilm using proteomic analysis. An in vitro 10-species “subgingival” biofilm model, or its derivative that included additionally A. actinomycetemcomitans, were anaerobically cultivated on hydroxyapatite discs for 64 h. When present, A. actinomycetemcomitans formed dense intra-species clumps within the biofilm mass, and did not affect the numbers of the other species in the biofilm. Liquid chromatography-tandem mass spectrometry was used to identify the proteomic content of the biofilm lysate. A total of 3225 and 3352 proteins were identified in the biofilm, in presence or absence of A. actinomycetemcomitans, respectively. Label-free quantitative proteomics revealed that 483 out of the 728 quantified bacterial proteins (excluding those of A. actinomycetemcomitans) were accordingly regulated. Interestingly, all quantified proteins from Prevotella intermedia were up-regulated, and most quantified proteins from Campylobacter rectus, Streptococcus anginosus, and Porphyromonas gingivalis were down-regulated in presence of A. actinomycetemcomitans. Enrichment of Gene Ontology pathway analysis showed that the regulated groups of proteins were responsible primarily for changes in the metabolic rate, the ferric iron-binding, and the 5S RNA binding capacities, on the universal biofilm level. While the presence of A. actinomycetemcomitans did not affect the numeric composition or absolute protein numbers of the other biofilm species, it caused qualitative changes in their overall protein expression profile. These molecular shifts within the biofilm warrant further investigation on their potential impact on its virulence properties, and association with periodontal pathogenesis.

Microbial signature profiles of periodontally healthy and diseased patients.

To determine microbial profiles that discriminate periodontal health from different forms of periodontal diseases. Subgingival biofilm was obtained from patients with periodontal health (27), gingivitis (11), chronic periodontitis (35) and aggressive periodontitis (24), and analysed for the presence of >250 species/phylotypes using HOMIM. Microbial differences among groups were examined by Mann-Whitney U-test. Regression analyses were performed to determine microbial risk indicators of disease. Putative and potential new periodontal pathogens were more prevalent in subjects with periodontal diseases than periodontal health. Detection of Porphyromonas endodontalis/Porphyromonas spp. (OR 9.5 [1.2-73.1]) and Tannerella forsythia (OR 38.2 [3.2-450.6]), and absence of Neisseria polysaccharea (OR 0.004 [0-0.15]) and Prevotella denticola (OR 0.014 [0-0.49], p < 0.05) were risk indicators of periodontal disease. Presence of Aggregatibacter actinomycetemcomitans (OR 29.4 [3.4-176.5]), Cardiobacterium hominis (OR 14.9 [2.3-98.7]), Peptostreptococcaceae sp. (OR 35.9 [2.7-483.9]), P. alactolyticus (OR 31.3 [2.1-477.2]), and absence of Fretibacterium spp. (OR 0.024 [0.002-0.357]), Fusobacterium naviforme/Fusobacterium nucleatum ss vincentii (OR 0.015 [0.001-0.223]), Granulicatella adiacens/Granulicatella elegans (OR 0.013 [0.001-0.233], p < 0.05) were associated with aggressive periodontitis. There were specific microbial signatures of the subgingival biofilm that were able to distinguish between microbiomes of periodontal health and diseases. Such profiles may be used to establish risk of disease.

Dental Implant Sites in Healthy versus Diabetic Subjects: A Two-Year Clinical and Bacteriological Assessment

The aim of this study was to analyze by Real-Time Polymerase Chain Reaction (PCR) possible differences in periimplant microbiota of patients without significant systemic diseases versus patients affected by non-insulin-dependent diabetes mellitus (NIDDM), both treated with dental implants with the same implant-abutment system. Patients suffering from NIDDM, and those with no history of major systemic diseases, treated with dental implants at the Prosthodontics Operative Unit of “Sapienza” University of Rome in the period February 2009 - March 2010 were considered. Clinical parameters as well as microbiological profile were evaluated for each implant site at 3, 6,12, and 24 month follow-up. Crevicular fluid was collected for microbial sampling and analyzed by Real-Time PCR in order to identify the possible presence of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Fusobacterium nucleatum and Prevotella intermedia. Eight patients suffering from NIDDM and 22 with no history of major systemic diseases were included in the present investigation, each having received one to three dental implants. All the implants had been loaded 3 months after surgery, and the average follow-up after implant placement was 26.37±3.86. Clinical parameters showed no noticeable difference between the two groups, except for the Implant Stability Quotient (ISQ) that showed significantly lower values in NIDDM patients. A slightly higher amount of the considered pathogenic bacteria were retrieved in samples collected from patients with NIDDM (7.38×105) in comparison with those of healthy subjects (6.78×105), though the differences were below statistical significance. Within the limitations of the present study, a slight correlation was empirically detected between gene expression profiles of microbial populations and history of NIDDM, which however remained below the statistical significance. Further well-designed clinical studies may be useful to conclusively clarify the impact of subgingival microflora on the increased susceptibility of diabetic patients to periimplantitis.

The periodontal health of lead-exposed children living in a shipyard industrial area

In a cross-sectional design, 292 schoolchildren living around a shipyard area, known to be contaminated with lead from shipyard industry, were examined to verify the association between lead exposure and periodontal health. The probing pocket depth (PD), bleeding on probing, plaque and calculus, and the presence of Aggregatibacter actinomycetemcomitans (Aa) in subgingival crevices were recorded. Gingival inflammation was the most common (98%) among children in the area. No significant difference in gingival inflammation was observed between high blood lead (PbB) and low PbB children. The prevalence rate of probing PD of ≥5mm was 14%. The high PbB group showed more deep pockets at tooth 16 (upper right first permanent molar) and tooth 46 (lower right first permanent molar) than the low PbB group. The odds ratios (ORs) for having probing PD≥5mm after adjusting for other factors were 3.63 (95% confidence interval (CI), 1.24-10.61; p=0.02) for tooth 16 and 3.93 (95% CI, 1.18-13.00; p=0.02) for tooth 46. The presence of Aa was observed in 17% of the children and it significantly increased in high PbB compared with low PbB children at tooth 46 (OR=5.53, 95% CI: 1.68-18.15; p=0.005). This study may suggest no association between lead exposure and gingival inflammation, yet there was the involvement of deeper periodontal tissue in lead-exposed children.

Evaluación de la terapia mecánica periodontal en bolsas profundas: Respuesta clínica y bacteriológica

ObjectivesTo evaluate the microbial composition and clinical parameters of periodontal pockets with probing depth ≥5mm at baseline, 1 week, 3 and 12 months after scaling and root planning. MethodsClinical parameters were measured and bacterial samples were collected from 44 sites in 11 patients with chronic periodontitis. By means of Polymerase Chain Reaction (PCR) the presence of Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), Treponema denticola (Td), Tannerella forsythia (Tf) and Prevotella intermedia (Pi) was estimated. The patients received mechanical periodontal therapy and were evaluated after 1 week, 3 months and 12 months. ResultsAfter treatment, all clinical parameters (Plaque, Bleeding on Probing, Supuration, Probing Pocket Depth and Clinical Attachment Level) were significantly reduced, and the values obtained were maintained up to the 12 months that the study lasts. At baseline, the most prevalent species were Pg, present in 66% of the sites, Tf (55%) and Td (41%). The deepest sites were related to the association Tf-Td (6.8mm) and Tf-Td-Pi (7mm). The number of positive sites for Td, Tf and Pg was significantly reduced after therapy. ConclusionsScaling and root planning improve significantly clinical parameters as well as reduce the prevalence of periodontal pathogens Pg, Td and Tf in deep periodontal pockets. The results obtained were maintained up to 12 months. No further clinical attachment loss was found in 86% of the sites at 3 months and 79% at 12 months. The sites where the treatment failed in removing pathogens developed at 12 months greater probing pocket depths.

The importance of the presence of aggregatibacter actinomycetemcomitans in sulcus gingivalis of patients with cardiovascular diseases

SummaryBackgroundOver-replication of periodontal pathogens in the periodontium induces production of proinflammatory cytokines and C-reactive protein that can stimulate systemic inflammatory status and can initiate atherosclerosis and its consequences. In our pilot study we examined whether periodontal status and serum levels of interleukin-6 and C-reactive protein are associated with the presence of Aggregatibacter actinomycetemcomitans in the periodontium of patients with cardiovascular diseases (CVD).Material/MethodsWe randomly selected 38 of 166 outpatients with CVD, of which 21 patients had chronic ischemic heart disease (IHD) only and 17 had both IHD and essential hypertension (HT). The presence of Aggregatibacter actinomycetemcomitans (A.a.) in the periodontium evaluated by PCR was compared with the values of periodontal indices, namely probe depth (PD) and Community Periodontal Index of Treatment Need (CPITN), as well as with interleukin-6 (IL-6) and CRP serum levels.ResultsWhen comparing A.a.-positive and A.a.-negative groups of patients, no statistically significant differences were noticed as to the age and values of PD and CPITN, respectively. However, the proportion of CRP and IL-6 positive values was significantly higher (p≤0.001) among A.a.-positive than in A.a.-negative patients.ConclusionsThe presence of A.a. in patients with CVD may be associated with significantly higher serum levels of some proinflammatory markers.

Antimicrobial Susceptibility of Moxifloxacin Against Gram‐Negative Enteric Rods From Colombian Patients With Chronic Periodontitis

Gram-negative enteric rods were associated with periodontal diseases in several populations. The association between enteric and putative periodontal pathogens has received little attention in the literature. The present investigation determined the occurrence and in vitro antimicrobial susceptibility of isolates of Gram-negative enteric rods from Colombian patients with chronic periodontitis. Clinical parameters and the in vitro antimicrobial sensitivity of isolates of Gram-negative enteric rods were examined in 76 patients with chronic periodontitis in Medellin, Colombia. Subgingival samples were processed using culture and biochemical tests for the detection of periodontal and superinfecting pathogens. Selected colonies of Gram-negative enteric rods from pure cultures were used to test the susceptibility to amoxicillin/clavulanic acid, ciprofloxacin, and moxifloxacin. Chi-square and Mann-Whitney tests were used to determine differences in clinical variables versus the presence or absence of Gram-negative enteric rods. Klebsiella pneumoniae was found in 12 patients, Pseudomonas aeruginosa was found in four patients, and three other species were recovered with a lower prevalence. Men (38.75%) tended to harbor more of the studied organisms than women (17.7%) (P = 0.04). Gram-negative enteric rods in periodontal pockets correlated positively with the presence of Aggregatibacter actinomycetemcomitans (previously Actinobacillus actinomycetemcomitans), Porphyromonas gingivalis, and Prevotella intermedia/nigrescens (respectively, r = 0.66, 0.31, and 0.32; P <0.001). All superinfecting organisms demonstrated a high susceptibility to moxifloxacin and ciprofloxacin but exhibited a variable susceptibility to amoxicillin/clavulanic acid. This study found high levels of Gram-negative enteric rods in patients with chronic periodontitis. Moxifloxacin and ciprofloxacin appeared capable of eradicating these organisms from periodontal pockets. Its good activity against Gram-negative enteric rods and periodontopathogens suggests the potential use of moxifloxacin as an adjunctive antibiotic in the treatment of mixed periodontal infections.

Aggressive periodontitis in children: a 14–19‐year follow‐up

The objective was to assess the recurrence of disease in subjects with a history of localized aggressive periodontitis (LAP). Initially, 11 children (7-13 years) with LAP were examined. Samples from the subgingival microbiota and soft tissue biopsies were obtained. Non-surgical periodontal therapy was performed and the affected deciduous and two permanent molars were extracted. The subjects were enrolled in a recall programme within the public dental services. Fourteen to 19 years after the initial examination, the subjects were recalled for clinical and radiographic examinations. The re-examination disclosed that two of the subjects exhibited recurrence of disease with probing pocket depth > or = 6 mm and bone loss of 3-4 mm at several teeth, while another two subjects presented a limited number of sites with the disease. While bleeding on probing was a general finding in the group, no further loss of attachment was detected in seven subjects. Advanced attachment loss at the deciduous teeth as well as the presence of Aggregatibacter actinomycetemcomitans and its specific clone JP at the initial examination did not correlate with the recurrence of disease at the 14-19-year follow-up. Children treated for LAP do not always exhibit recurrence of periodontitis in the absence of supportive periodontal therapy over periods of 14-19 years.

Quantitative detection of periodontopathic bacteria in atherosclerotic plaques from coronary arteries

Oral pathogens, including periodontopathic bacteria, are thought to be aetiological factors in the development of cardiovascular disease. In this study, the presence of Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum-periodonticum-simiae group, Porphyromonas gingivalis, Prevotella intermedia, Prevotella nigrescens and Tannerella forsythia in atheromatous plaques from coronary arteries was determined by real-time PCR. Forty-four patients displaying cardiovascular disease were submitted to periodontal examination and endarterectomy of coronary arteries. Approximately 60-100 mg atherosclerotic tissue was removed surgically and DNA was obtained. Quantitative detection of periodontopathic bacteria was performed using universal and species-specific TaqMan probe/primer sets. Total bacterial and periodontopathic bacterial DNA were found in 94.9 and 92.3 %, respectively, of the atheromatous plaques from periodontitis patients, and in 80.0 and 20.0 %, respectively, of atherosclerotic tissues from periodontally healthy subjects. All periodontal bacteria except for the F. nucleatum-periodonticum-simiae group were detected, and their DNA represented 47.3 % of the total bacterial DNA obtained from periodontitis patients. Porphyromonas gingivalis, A. actinomycetemcomitans and Prevotella intermedia were detected most often. The presence of two or more periodontal species could be observed in 64.1 % of the samples. In addition, even in samples in which a single periodontal species was detected, additional unidentified microbial DNA could be observed. The significant number of periodontopathic bacterial DNA species in atherosclerotic tissue samples from patients with periodontitis suggests that the presence of these micro-organisms in coronary lesions is not coincidental and that they may in fact contribute to the development of vascular diseases.