Screening and Assessment of Antimicrobial Susceptibility of Periodontopathic Bacteria in Peruvian Patients with Periodontitis: A Pilot Study

Background

Severe periodontal disease is highly prevalent worldwide, affecting 20% of the population between the ages of 35 and 44 years. The etiological epidemiology in Peru is scarce, even though some studies describe a prevalence of 48.5% of periodontal disease in the general population. Periodontitis is one of the most prevalent oral diseases associated with site-specific changes in the oral microbiota and it has been associated with a socioeconomic state. This study aimed to determine the etiology and resistance profile of bacteria identified in a group of Peruvian patients with periodontal disease.

Methods

Six subgingival plaque samples were collected from eight patients with severe periodontitis. Bacterial identification was carried out by an initial culture, PCR amplification, and subsequently DNA sequencing. We evaluated the antibiotic susceptibility by the disk diffusion method.

Results

Variable diversity in oral microbiota was identified in each one of the eight patients. The bacterial genus most frequently found was Streptococcus spp. (15/48, 31.3%) followed by Rothia spp. (11/48, 22.9%), Actinomyces spp. (9/48, 18.8%), and Eikenella spp. (4/48, 8.3%). The most common species found was Rothia dentocariosa (8/48, 16.7%). The antimicrobial susceptibility assay varied according to the species tested; however, among all the isolates evaluated, Actinomyces naeslundii was resistant to penicillin and tetracycline; Eikenella corrodens was resistant to dicloxacillin; and Rothia dentocariosa was resistant to amoxicillin + clavulanic acid and metronidazole but also susceptible to trimethoprim-sulfamethoxazole.

Conclusions

The most prevalent periodontal bacterium found in this study was Rothia dentocariosa. Specific antimicrobial therapy is required to improve the treatment outcomes of patients with periodontal disease and avoid antibiotic resistance.

Association between periodontal disease and vulnerable plaque morphology in patients undergoing carotid endarterectomy

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Periodontal disease is associated with echolucent plaques.

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Periodontal disease is associated with increased macrophages in plaques.

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Periodontal disease is associated with decreased smooth muscle cells in plaques.

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Periodontal disease is associated with plaque instability.

Background

Periodontal disease (PD) is a chronic inflammatory oral condition with potentially important systemic sequelae. We sought to determine whether the presence of PD in patients with severe carotid disease was associated with morphological features consistent with carotid plaque instability.

Methods

A total of 52 dentate patients hospitalized for carotid endarterectomy (CEA) had standardized assessments of their periodontal status, including measurements of probing pocket depth (PPD), clinical attachment level (CAL) and bleeding on probing (BoP). Carotid plaque morphology was assessed by ultrasound using the gray scale median (GSM) score and by immunohistochemistry using anti-CD68 and anti-alpha-actin antibodies, markers for macrophages and smooth muscle cells (SMCs) respectively.

Results

In total 30/52 patients (58%) had PD. Significant associations were noted between low GSM on ultrasound and each mm in PPD (p = 0.001), each mm in CAL (p = 0.002) and with a 10% increase in BoP (p = 0.009). Using the standardized PERIO definition the association remained robust (aOR = 10.4 [95% CI:2.3–46.3], p = .002). Significant associations were also observed with high macrophage accumulation and each individual PD measure (p < 0.01 for PPD, CAL and BoP) and with the PERIO definition (aOR = 15 [95% CI:1.8–127.8], p = .01). Similarly, low SMC density was also significantly associated with individual measures of PD (p < 0.05 for PPD, CAL and BoP), but not with the PERIO definition (aOR 3.4 [95% CI:0.9–12.8], p = .07).

Conclusions

The presence of PD was significantly associated with both ultrasound and immunohistochemistry features of carotid plaque instability in patients undergoing CEA.

Osteopontin regulates the proliferation of rat aortic smooth muscle cells in response to gingipains treatment

OBJECTIVE

The present study aimed to explore the possible effects of osteopontin (OPN) in the proliferation of rat aortic smooth muscle cells (RASMCs) stimulated by gingipains.

METHODS

The proliferation of RASMCs in response to active gingipains treatment was evaluated by CCK-8 assay. OPN siRNA was designed, constructed and transfected into RASMCs at different concentrations. The cell cycle of RASMCs was analyzed by flow cytometry. OPN, α-SMA and calponin expression were examined by real-time PCR and western blot analysis.

RESULTS

Gingipains promoted the proliferation of RASMCs and OPN expression. With siRNA-mediated OPN expression knockdown, the cell cycle of RASMCs was blocked in the G0/G1 phase. Furthermore, the expression of specific differentiation markers, α-SMA and calponin, also decreased.

CONCLUSIONS

These results demonstrate that OPN has an impact on the proliferation and differentiation of RASMCs stimulated by gingipains.

A Fully-Automatic Method to Segment the Carotid Artery Layers in Ultrasound Imaging: Application to Quantify the Compression-Decompression Pattern of the Intima-Media Complex During the Cardiac Cycle

The aim of this study was to introduce and evaluate a contour segmentation method to extract the interfaces of the intima-media complex in carotid B-mode ultrasound images. The method was applied to assess the temporal variation of intima-media thickness during the cardiac cycle. The main methodological contribution of the proposed approach is the introduction of an augmented dimension to process 2-D images in a 3-D space. The third dimension, which is added to the two spatial dimensions of the image, corresponds to the tentative local thickness of the intima-media complex. The method is based on a dynamic programming scheme that runs in a 3-D space generated with a shape-adapted filter bank. The optimal solution corresponds to a single medial axis representation that fully describes the two anatomical interfaces of the arterial wall. The method is fully automatic and does not require any input from the user. The method was trained on 60 subjects and validated on 184 other subjects from six different cohorts and four different medical centers. The arterial wall was successfully segmented in all analyzed images (average pixel size = 57 ± 20 mm), with average segmentation errors of 47 ± 70 mm for the lumen-intima interface, 55 ± 68 mm for the media-adventitia interface and 66 ± 90 mm for the intima-media thickness. The amplitude of the temporal variations in IMT during the cardiac cycle was significantly higher in the diseased population than in healthy volunteers (106 ± 48 vs. 86 ± 34 mm, p = 0.001). The introduced framework is a promising approach to investigate an emerging functional parameter of the arterial wall by assessing the cyclic compression-decompression pattern of the tissues.

Antibodies to periodontal pathogens are associated with coronary plaque remodeling but not with vulnerability or burden

OBJECTIVE

Previous studies have suggested positive associations between periodontal infection and cardiovascular disease. We aimed to investigate the associations of circulating antibodies against periodontal pathogens with 1-year cardiovascular outcome, as well as the extent of coronary atherosclerosis, plaque vulnerability and lesion remodeling on intravascular ultrasound (IVUS) imaging.

METHODS

Between 2008 and 2011, radiofrequency IVUS imaging of a non-culprit coronary artery was performed in 581 patients who underwent coronary angiography. Immunoglobulin G (IgG) and A (IgA) against Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Tannerella forsythia and Prevotella intermedia were measured in plasma.

RESULTS

None of the antibody levels were associated with coronary plaque burden, radiofreqeuncy-IVUS-derived thin-cap fibroatheroma lesion morphology or 1-year incidence of major adverse cardiac events (MACE), which included all-cause mortality, acute coronary syndrome and unplanned coronary revascularization. IgA against A. actinomycetemcomitans, T. forsythia and P. intermedia were inversely associated with extent of positive lesion remodeling (OR for highest versus lowest tertile 0.55, 95%CI 0.35-0.88, p = 0.012; 0.53, 95%CI 0.32-0.87, p = 0.012; and 0.64, 95%CI 0.40-1.02, p = 0.061, respectively). In diabetic patients specifically, IgG against P. gingivalis tended to be associated with coronary plaque burden (p = 0.080), while IgA against P. gingivalis tended to be associated with incident MACE (p = 0.060).

CONCLUSION

Plasma IgG and IgA against major periodontal pathogens were not associated with the extent of coronary atherosclerosis (with the exception of a trend in diabetics) nor with coronary plaque vulnerability. IgA against periodontal pathogens were inversely associated with extent of coronary remodeling. Altogether, these results do not add evidence for a substantial role of systemic exposure to periodontal pathogens in coronary artery disease.

Assessment of carotid calcifications on panoramic radiographs in relation to other used methods and relationship to periodontitis and stroke: a literature review

OBJECTIVES

To assess the literature on carotid calcifications defined from panoramic radiographs (PMX) and concurrent diagnosis of stroke and periodontitis.

MATERIALS AND METHODS

A literature search screening for publications using search terms such as PMX and carotid calcification, stroke and periodontitis was performed in November 2012.

RESULTS

A total of 189 articles were retrieved, among which 30 were included in the review. The sensitivity for PMX findings of carotid calcifications (CC) compared to a diagnosis by Doppler sonography varied between 31.1-100%. The specificity for PMX findings of carotid calcifications compared to a diagnosis by Doppler sonography varied between 21.4-87.5%. Individuals with CC findings from PMX have more periodontitis and risk for stroke.

CONCLUSIONS

There is a shortage of well-designed studies in older dentate individuals assessing the associations between periodontitis and radiographic evidence of CC and in relation to stroke or other cardiovascular diseases. STATEMENT OF CLINICAL RELEVANCE: Carotid calcifications are prevalent in patients with periodontitis and such individuals may have an increased risk for stroke. The absence of signs of carotid calcification on panoramic radiographs is indicative of no calcification of carotid arteries.

Periodontal pathogens and atherosclerosis: implications of inflammation and oxidative modification of LDL

Inflammation is well accepted to play a crucial role in the development of atherosclerotic lesions, and recent studies have demonstrated an association between periodontal disease and cardiovascular disease. Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans, causative agents of destructive chronic inflammation in the periodontium, can accelerate atheroma deposition in animal models. Emerging evidence suggests that vaccination against virulence factors of these pathogens and anti-inflammatory therapy may confer disease resistance. In this review, we focus on the role of inflammatory mechanisms and oxidative modification in the formation and activation of atherosclerotic plaques accelerated by P. gingivalis or A. actinomycetemcomitans in an ApoE-deficient mouse model and high-fat-diet-fed mice. Furthermore, we examine whether mucosal vaccination with a periodontal pathogen or the anti-inflammatory activity of catechins can reduce periodontal pathogen-accelerated atherosclerosis.

Biochemical and C-reactive protein alterations in myocardial infarction periodontitis patients

Periodontitis (PD) is a risk factor for acute myocardial infarction (AMI). C-reactive protein (CRP) is elevated in PD. The aim of this study was to investigate biochemical alterations among AMI with PD. Thirty non-AMI (25 non-PD and only 5 PD) and 30 AMI (13 PD and 17 non-PD) patients were participated. Serum CRP, tumor necrosis factor alpha (TNF-α), total cholesterol, low-density lipoprotein cholesterol, protein carbonyl (PC) contents, soluble vascular cell adhesion molecule-1 (sVCAM-1), adiponectin, creatine kinase, resistin, catalase and superoxide dismutase (SOD) levels were measured. AMI-PD elicited significant differences in percentage hypertension, diabetes, serum creatine kinase, cholesterol and low-density lipoprotein cholesterol. CRP among AMI-PD and non-AMI-PD was increased by 73.4% and 31.3%, respectively. The level of PC contents was increased significantly among AMI-PD and non-AMI-PD by 47.62% and 33.3%, respectively. Catalase and SOD levels were significantly decreased in AMI-PD by 33.7% and 34.1%, respectively; however, their levels among non-AMI-PD were significantly increased by 35.7% and 28%, respectively. TNF-α, sVCAM-1 and resistin levels among AMI-PD were increased by 134.3%, 68.8% and 25.5%, respectively; however, TNF-α and sVCAM-1 levels among non-AMI-PD were increased significantly by 21.4% and 29.4%, respectively. Adiponectin level produced insignificant changes. PD prevalence among AMI associated with elevated serum CRP, PC contents, sVCAM-1, TNF-α and resistin levels concurrent with declines in SOD and catalase enzymes. In conclusion, among nondiabetic, nonsmoking patients suffering from AMI, PD is highly prevalent and associated with elevated serum CRP, PC contents, sVCAM-1, TNF-α and resistin levels, associated with significant declines in antioxidant enzymes with insignificant change in serum adiponectin level.

Chronic exposure to oral pathogens and autoimmune reactivity in acute coronary atherothrombosis

Background. It has been hypothesized that various infective agents may activate immune reactions as part of the atherosclerotic process. We aimed to investigate the interrelationship between chronic exposure to oral pathogens and immune-inflammatory response in patients with acute coronary atherothrombosis. Patients and Methods. The study included 200 participants from Serbia: 100 patients with acute myocardial infarction (MI), and 100 age- and sex-matched controls. Antibodies to oral anaerobes and aerobes were determined as well as autoantibodies to endothelial cells, beta-2 glycoprotein I, platelet glycoprotein IIb/IIIa and anticardiolipin. Interleukin-6 (IL-6) and C-reactive protein (CRP) were measured. Results. The mean serum antibodies to oral anaerobes tended to be higher among subjects with MI (0.876 ± 0.303 versus 0.685 ± 0.172 OD, P < 0.001). Similarly, antibody levels against oral aerobes in patients were significantly different from controls. Antibodies against endothelial cell, beta-2 glycoprotein I, platelet glycoprotein IIb/IIIa, anticardiolipin along with CRP and IL-6 were highly elevated in patients. The levels of antibodies to oral bacteria showed linear correlation with tissue antibodies, CRP and IL-6. Conclusion. Antibody response to chronic oral bacterial infections and host immune response against them may be responsible for the elevation of tissue antibodies and biomarkers of inflammation which are involved in acute coronary thrombosis development.

Periodontitis is associated with endothelial dysfunction in a general population: a cross-sectional study

A large body of evidence underlines an association between periodontal disease and cardiovascular disease. In contrast, data on its relation with endothelial dysfunction as a marker of early subclinical atherosclerosis is inconclusive and limited to patient-cohort studies. We therefore investigated the association between periodontal disease and flow-mediated dilation of the brachial artery (FMD) as a measure of endothelial dysfunction in a general population, and also addressed a possible mediation via inflammation. The study population comprised 1,234 subjects (50.5% men) aged 25–85 years from the 5-year follow-up of the Study of Health in Pomerania, a population-based cohort study. Clinical attachment loss (CAL) and pocket probing depth (PPD) as measures of periodontal disease were assessed half-mouth at four sites per tooth. Subjects were classified according to the periodontitis case definition proposed by Tonetti and Claffey (2005). Measurements of FMD and nitroglycerin-mediated dilation (NMD) were performed using standardized ultrasound techniques. High-sensitive C-reactive protein, fibrinogen and leukocyte count were measured. Fully adjusted multivariate linear regression analyses revealed significant associations of the percentage of sites with PPD ≥6 mm with FMD (p_trend=0.048), with subjects within the highest category having a 0.74% higher FMD compared to subjects within the lowest category (p<0.05). Consistently, FMD values increased significantly across categories of the percentage of sites with CAL ≥6 mm (p_trend=0.01) and the periodontitis case definition (p_trend=0.006). Restrictions to subjects without antihypertensive or statin medication or current non-smokers confirmed previous results. Systemic inflammation did not seem to mediate the relation. Both PPD and CAL were not consistently associated with NMD. In contrast to previous studies, high levels of periodontal disease were significantly associated with high FMD values. This association was not mediated via systemic inflammation. This study revives the discussion on whether and how periodontitis contributes to endothelial dysfunction.

Biomarkers of periodontitis and inflammation in ischemic stroke: A case-control study

Periodontitis is a common infectious disease associated with increased risk for ischemic stroke though presently unclear mechanisms. In a case-control study, we investigated salivary levels of four periodontal pathogens, as well as systemic and local inflammatory markers. The population comprised 98 patients with acute ischemic stroke (mean ± SD, 68.2 ± 9.7 yrs; 45.9% women) and 100 healthy controls (69.1 ± 5.2 yrs; 47.0% women). Patients were more often edentulous and had fewer teeth than controls (13.8 ± 10.8 versus 16.6 ± 10.1). After adjusting for stroke risk factors and number of teeth, controls had higher saliva matrix metalloproteinase-8 (MMP-8), myeloperoxidase (MPO), IL-1β, Aggregatibacter actinomycetemcomitans, and serum LPS activity levels. Patients had higher serum MMP-8 and MPO, and they were more often qPCR-positive for A. actinomycetemcomitans (37.9% versus 19.0%) and for ≥3 periodontopathic species combined (50.0% versus 33.0%). We conclude that controls more often had evidence of current periodontal infection with higher periodontal pathogen amount, endotoxemia, local inflammation and tissue destruction. Stroke patients more often had evidence of end-stage periodontitis with edentulism and missing teeth. They were more often carriers of several periodontopathic pathogens in saliva, especially A. actinomycetemcomitans. Additionally, inflammatory burden may contribute to high systemic inflammation associated with elevated stroke susceptibility.

Orosomucoid, a new biomarker in the association between obesity and periodontitis

Epidemiological data indicate an association between periodontitis and obesity. The biological mechanisms of this relationship remain unclear. A cross-sectional study was conducted to evaluate the relationship between periodontitis and the common systemic inflammatory markers in 32 morbidly obese patients recruited in a Clinical Nutrition department. Periodontal condition was evaluated using pocket depth (PD) measurement, a classical clinical marker of ongoing periodontitis. Major periodontal risk factors were recorded (age, gender, diabetes and smoking status), as well as plasma levels of inflammatory markers (CRP, orosomucoid, IL-6) and adipokines (adiponectin, leptin). All patients included in the sample exhibited evidence of periodontitis, 16 of whom were diagnosed as having severe disease. Adjusted logistic regression analysis indicated that the severity of periodontitis was associated with the plasma level of orosomucoid (p<0.04) after adjustment for age, gender and smoking. Our study thus suggests that the severity of periodontitis, in morbidly obese patients, is associated with the increase of orosomucoid levels.

Longitudinal displacement of the carotid wall and cardiovascular risk factors: associations with aging, adiposity, blood pressure and periodontal disease independent of cross-sectional distensibility and intima-media thickness

The recently discovered longitudinal displacement of the common carotid arterial wall (i.e., the motion along the same plane as the blood flow), may be associated with incident cardiovascular events and represents a novel and relevant clinical information. At present, there have only been a few studies that have been conducted to investigate this longitudinal movement. We propose here a method to assess noninvasively the wall bi-dimensional (two-dimensional [2-D], cross-sectional and longitudinal) motion and present an original approach that combines a robust speckle tracking scheme to guidance by minimal path contours segmentation. Our method is well suited to large clinical population studies as it does not necessitate strong imaging prerequisites. The aim of this study is to describe the association between the longitudinal displacement of the carotid arterial wall and cardiovascular risk factors, among which periodontal disease. Some 126 Indigenous Australians with periodontal disease, an emerging risk factor, and 27 healthy age- and sex-matched non-indigenous control subjects had high-resolution ultrasound scans of the common carotid artery. Carotid intima-media thickness and arterial wall 2-D motion were then assessed using our method in ultrasound B-mode sequences. Carotid longitudinal displacement was markedly lower in the periodontal disease group than the control group (geometric mean (IQR): 0.15 mm (0.13) vs. 0.42 mm (0.30), respectively; p < 0.0001), independent of cardiovascular risk factors, cross-sectional distensibility and carotid intima-media thickness (p < 0.0001). A multivariable model indicated that the strongest correlates of carotid longitudinal displacement in adults with periodontal disease were age (β-coefficient = -.235, p = .03), waist (β-coefficient = -.357, p = 0.001), and pulse pressure (β-coefficient = .175, p = 0.07), independent of other cardiovascular risk factors, cross-sectional distensibility and pulse wave velocity. Carotid longitudinal displacement, estimated with our approach, is impaired in the periodontal disease group, independent of established cardiovascular risk factors and other noninvasive measures of arterial stiffness, and may represent an important marker of cardiovascular risk.

Patterns of Dental Diseases in Diabetic Females in Primary Health Centers in Qatar: Cross-sectional, observational study

Periodontal diseases comprise a large group of predominantly infectious and/or inflammatory disorders affecting periodontal tissues. They are diagnosed by assessment of the dento-gingival area, including the the gingival sulcus depth, and the presence of bleeding with radiographic assessment of the alveolar bone. The prevalence of periodontitis (PD) is reported to be 20-50% worldwide;(1) while the aggressive form of PD is found in less than 10% of the population/2,3). Periodontitis is a chronic infectious/inflammatory disease of multi-factorial etiology(4) with a number of risk factors that are shared with other chronic inflammatory conditions; increasing age, low socio-economic conditions, stress, increased body weight, dyslipidemia, hypertension, metabolic syndrome, cigarette smoking and Diabetes mellitus.(5-6) Systemic reviews have shown a clear association between PD and coronary heart diseases (CHD) emphasizing the need to consider PD as a risk factor for CHD.

Periodontal disease: a new factor associated with the presence of multiple complex coronary lesions

BACKGROUND AND AIM

Periodontal disease, including bone loss, is thought to be involved in coronary artery disease. Multiple complex coronary lesions relate to multifocal destabilization of coronary plaques. We investigated whether bone loss could be associated with the presence of multiple complex coronary lesions.

METHODS

This cross-sectional study included 150 patients with recent myocardial infarction (<1 month). Multiple complex coronary lesions were determined at coronary angiography. A panoramic dental X-ray including bone loss >50% was performed. Patients with no or simple complex lesions were compared to patients with multiple complex lesions.

RESULTS

Over 20% of patients had multiple complex coronary lesions. Patients with multiple complex lesion were less likely to be women and more likely to have multivessel disease or elevated C-reactive protein (CRP) than patients with no or single complex lesion. Bone loss >50% tended to be more frequent in patients with multiple complex lesions (p = 0.063). In multivariate analysis, multivessel disease, gender and CRP were associated with multiple complex lesion. Bone loss >50% increased the risk of multiple complex lesion.

CONCLUSION

Bone loss was associated with complex multiple coronary lesions, beyond systemic inflammation. These findings may bear important clinical implications for the prevention and treatment of coronary artery disease.

Periodontal disease is associated with higher levels of C-reactive protein in non-diabetic, non-smoking acute myocardial infarction patients

OBJECTIVES

A link between periodontal disease (PD) and cardiovascular events has been proposed, but confounding by shared risk factors such as smoking and diabetes remains a concern. We examined the prevalence of PD and its contribution to C-reactive protein (CRP) levels in acute myocardial infarction (AMI) patients and in subjects without AMI and with angiographically nonobstructive coronary disease in the absence of these confounding risk factors.

METHODS

Periodontal status and admission CRP levels were evaluated in 87 non-diabetic and non-smoking subjects undergoing cardiac catheterization. The study group comprised of 47 patients with documented AMI, and 40 subjects without AMI and with angiographically nonobstructive coronary disease (ANCD group).

RESULTS

Both the prevalence of PD and CRP levels were significantly higher in AMI patients compared with ANCD subjects (38.3% vs. 17.5%, p=0.03 and 44.3 vs. 8.5 mg/L, p<0.001 respectively). PD was associated with higher CRP levels in AMI patients (52.5 vs. 36.1 mg/L, p=0.04) as well as in ANCD subjects, however, in this group this was not significant (12.6 vs. 7.6 mg/L, p=0.5). Multivariable regression analysis confirmed two separate measures of PD as strong and independent contributors to elevated CRP levels in AMI patients (R2 = 0.28, R2 = 0.30, p=0.001).

CONCLUSIONS

PD contributes to elevated CRP levels in non-diabetic, non-smoking AMI patients, independently of other confounding factors. These findings imply that periodontitis may emerge as a novel target for reducing future risk in AMI survivors.

Evaluating periodontal risk for patients at risk of or suffering from atherosclerosis: recent biological hypotheses and therapeutic consequences

Cardiovascular disease, such as atherosclerosis, is the main cause of mortality in developed countries. Most atherosclerosis risk factors have been identified and are treated, improving patient cardiovascular status and reducing mortality, but some remain unknown. Periodontal disease is generally defined as inflammatory disease initiated by accumulation of dental bacterial plaque, leading to the destruction of tissues that support the teeth. Severe forms have a high prevalence (15% of the population) and are associated with the presence of virulent pathogens such as Porphyromonas gingivalis. Epidemiological studies have shown that severe periodontal disease negatively influences cardiovascular status. The aim of this paper was to present a synthesis of the most recent biological data related to the link between periodontal and cardiovascular disease. The potential biological mechanisms involved in these two inflammatory diseases (bacteriological theory, inflammatory theory, immune theory) were developed. According to the observed positive effects of periodontal treatment on systemic conditions, the benefit of a reinforced collaboration between dentists and cardiologists was discussed, especially for patients at risk for cardiovascular disease.

Porphyromonas gingivalis participates in pathogenesis of human abdominal aortic aneurysm by neutrophil activation. Proof of concept in rats

Background

Abdominal Aortic Aneurysms (AAAs) represent a particular form of atherothrombosis where neutrophil proteolytic activity plays a major role. We postulated that neutrophil recruitment and activation participating in AAA growth may originate in part from repeated episodes of periodontal bacteremia.

Methods and Findings

Our results show that neutrophil activation in human AAA was associated with Neutrophil Extracellular Trap (NET) formation in the IntraLuminal Thrombus, leading to the release of cell-free DNA. Human AAA samples were shown to contain bacterial DNA with high frequency (11/16), and in particular that of Porphyromonas gingivalis (Pg), the most prevalent pathogen involved in chronic periodontitis, a common form of periodontal disease. Both DNA reflecting the presence of NETs and antibodies to Pg were found to be increased in plasma of patients with AAA. Using a rat model of AAA, we demonstrated that repeated injection of Pg fostered aneurysm development, associated with pathological characteristics similar to those observed in humans, such as the persistence of a neutrophil-rich luminal thrombus, not observed in saline-injected rats in which a healing process was observed.

Conclusions

Thus, the control of periodontal disease may represent a therapeutic target to limit human AAA progression.

Detection of periodontal bacteria in atheromatous plaque by nested polymerase chain reaction

BACKGROUND

In recent years, increasing evidence regarding the potential association between periodontal diseases and cardiovascular diseases has been identified. The available evidence underlines the importance of detecting periodontal pathogens on atheromatous plaque as the first step in demonstrating the causal relationship between the two conditions. The main aim of this investigation is to detect periodontitis-associated bacteria from carotid artery atheromatous plaque from patients who received an endarterectomy using strict sample procurement and laboratory procedures.

METHODS

Atheromatous plaque from endarterectomies from carotid arteries were scraped and homogenized, and bacterial DNA was extracted. To obtain a representative concentration of amplicons, two amplifications of the bacterial 16S ribosomal-RNA gene were carried out for each sample with universal eubacteria primers by a polymerase chain reaction (PCR). A nested PCR with specific primers for the target bacteria was performed next. Statistical tests included the χ(2) test.

RESULTS

Forty-two atheromatous plaque were analyzed. All of them were positive for ≥1 target bacterial species. The bacterial species most commonly found was Porphyromonas gingivalis (78.57%; 33 of 42), followed by Aggregatibacter actinomycetemcomitans (previously Actinobacillus actinomycetemcomitans) (66.67%; 28 of 42), Tannerella forsythia (previously T. forsythensis) (61.90%; 26 of 42), Eikenella corrodens (54.76%; 23 of 42), Fusobacterium nucleatum (50.00%; 21 of 42), and Campylobacter rectus (9.52%; four of 42). The simultaneous presence of various bacterial species within the same specimen was a common observation.

CONCLUSION

Within the limitations of this study, the presence of DNA from periodontitis-associated bacteria in carotid artery atheromatous plaque retrieved by endarterectomy is confirmed.