Search

Objective: Considering the etiopathogenesis of periodontitis, it is relevant to evaluate the efficacy of the adjunctive use of systemic antimicrobials based on microbial occurrence. This report explores whether patients harboring Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), or Tannerella forsythia (Tf) at baseline could receive greater clinical benefits from adjunctive moxifloxacin (MXF) and amoxicillin plus metronidazole (AM+MT) in comparison to patients without the presence of these microorganisms before therapy for generalized periodontitis. A control group was established that received subgingival debridement (SD) alone. Method and materials: Thirty-six patients younger than 30 years of age were randomly allocated to one of three treatment groups: SD plus placebo, systemic MXF with SD, or AM+MT combined with SD. Subgingival samples were studied. The effects of the therapies on probing depth and clinical attachment level, including interactions with Aa, Pg, or Tf at baseline, were explored using regression models. Results: At 6 months, all treatment groups showed improved clinical outcomes in patients harboring Aa, Pg, or Tf at baseline compared to the patients who did not harbor these microorganisms at baseline. Indeed, in the presence of Aa, Pg, or Tf at baseline, the patients receiving antimicrobial protocols showed the most significant gains compared to the control group. Furthermore, the percentage of sites = 6 mm was reduced in the test groups, compared to the control group; these periodontopathogens were not present in sites with probing depth = 6mm in the MXF group. The interactions of Aa, Pg, and Tf with the test groups significantly improved clinical parameters at 6 months (P < .001). Interestingly, the R2 value in the models that explored clinical attachment gain produced a high degree of correlation (> 0.75), indicating that a high percentage (> 75%) of the total variation in clinical attachment level gain can be explained by the independent variables. Conclusions: Although all patients benefited from the treatments, patients harboring Aa, Pg, or Tf at baseline showed improved clinical benefits at 6 months, suggesting that Aa, Pg, or Tf at baseline may change the effects of systemic MXF and AM+MT in generalized periodontitis. After 6 months, Aa, Pg, and Tf were not present in sites with probing depth = 6 mm in the MXF group. [ABSTRACT FROM AUTHOR]

In this study, the efficacy of using Sauropus androgynus (L) Merr, a katuk leaf chlorophyll photosensitizer, to reduce Aggregatibacter actinomycetemcomitans and Enterococcus faecalis biofilm was investigated. A red and blue diode laser is used as the light source. The sample was split into four groups: a negative control group, a positive control group, a blue laser treatment group (B), and a red laser treatment group (R), both with and without the addition of katuk leaf chlorophyll 1.6 mg/ml, and with varying densities of laser energy exposure of 2.5 J/cm2, 5 J/cm2, 7.5 J/cm2, and 10 J/cm2. Laser exposure and chlorophyll photosensitizer were tested using ELISA and ANOVA. At an energy density of 10 J/cm2, the optimal bacterial mortality rate was obtained in each treatment group. Namely, in the Aggregatibacter actinomycetemcomitans biofilm, the negative group, the number of deaths was 73.30% using a blue diode laser and 63.25% using a red diode laser. In the positive group, the number of deaths was 86.12% using a blue diode laser and 83.29% using a red diode laser. In the Enterococcus faecalis biofilm, in the negative group, the number of deaths was 67.78% using the blue diode laser and 75.33% using the red diode laser, and in the positive group, the number of deaths was 71.71% using the blue diode laser and 86.41 using a red diode laser. Exposure to blue and red diode lasers activates chlorophyll in katuk leaves, killing bacteria and reducing biofilms.

Abstract Background Aggregatibacter actinomycetemcomitans (Aa), previously known as Actinobacillus actinomycetemcomitans, is a slow-growing Gram-negative coccobacillus, member of the HACEK group of bacteria colonizing oral flora. Besides causing infectious diseases in the oral cavity such as dental caries and periodontitis, it is responsible for severe extra-oral infections secondary to hematogenous spread or aspiration, such as endocarditis, soft tissue abscesses and osteomyelitis. The diagnosis depends on prolonged bacterial culture of biological material obtained through biopsy. Aa is susceptible to most antibiotics but complete eradication often requires a long term treatment. Case presentation We report the case of a 15-year-old previously healthy boy diagnosed with both pulmonary empyema and subphrenic chest wall abscess caused by Aa. He was admitted to our Pediatric Emergency department for evaluation of a right mass associated with marked asthenia and dry cough. After radiological findings etiological diagnosis was made by culture of fluid drainage of pleural empyema. He started empirical antibiotic therapy with intravenous piperacillin/tazobactam, whose sensibility was confirmed by the antibiogram, then, for occurrance of hepatopathy it was switched to ciprofloxacin: the patient almost completely recovered after 6-month therapy. Conclusions Extra-oral infections caused by Aa are extremely rare, especially in children, and not well described yet. To our knowledge, there is only another similar case described in literature. However, the case described in our manuscript represents the only one presenting with pulmonary empyema without involvement of lung parenchyma in children. We also conducted a brief review of published cases of Aa infection in the pediatric population. This case report reminds us the importance of an accurate inspection of the oral cavity during the examination of pediatric patients.

Microbes frequently experience nutrient deprivations in the natural environment and may enter dormancy. Aggregatibacter actinomycetemcomitans is known to establish long-term infections in humans. This study examined the dormancy-like phenotype of an A. actinomycetemcomitans strain D7S-1 and its isogenic smooth-colony mutant D7SS. A tissue culture medium RPMI-1640 was nutrient-deficient (ND) and unable to support A. actinomycetemcomitans growth. RPMI-1640 amended with bases was nutrient-limited (NL) and supported limited growth of A. actinomycetemcomitans less than the nutrient-enriched (NE) laboratory medium did. Strain D7S-1, after an initial 2-log reduction in viability, maintained viability from day 4 to day 15 in the NL medium. Strain D7SS, after 1-log reduction in viability, maintained viability from day 3 to day 5. In contrast, bacteria in the NE medium were either non-recoverable (D7S-1; >6-log reduction) or continued to lose viability (D7SS; 3-log reduction) on day 5 and beyond. Scanning and transmission electron microscopy showed that A. actinomycetemcomitans in the NL medium formed robust biofilms similar to those in the NE medium but with evidence of stress. A. actinomycetemcomitans in the ND medium revealed scant biofilms and extensive cellular damage. We concluded that A. actinomycetemcomitans grown in the NL medium exhibited a dormancy-like phenotype characterized by minimum growth, prolonged viability, and distinct cellular morphology.

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 benefits of probiotics on dysbiotic microbiomes and inflammation are dependent on the tested strain, host factors, and the resident microbiome. There is limited knowledge on the effects of probiotics in A. actinomycetemcomitans-associated periodontitis. Thus, Lactobacillus acidophilus LA5 (LA5) was orally inoculated for 30 days in C57Bl/6 mice infected with A. actinomycetemcomitans JP2 (Aa) and S. gordonii (Sg). Alveolar bone loss, gingival gene expression, and oral and gut microbiomes were determined. LA5 controlled bone loss in Aa+Sg-infected mice, downregulated the expression of Il-1β and upregulated Il-10 in gingival tissues, and altered the oral and gut microbiomes. LA5 increased the diversity of the oral microbiome of Aa+Sg infected mice, and Aa+Sg and Aa+Sg+LA5 oral or gut microbiomes clustered apart. LA5 induced shifts in Aa+Sg infected mice by increasing the abundance of Muribaculaceae and decreasing Bifidobacteriaceae in the oral cavity and increasing the abundance of Verrucomicrobiae and Eggerthellales in the gut. In conclusion, LA5 oral administration controls experimental Aa-associated periodontitis by altering inflammatory gene expression and the oral and gut microbiomes.

Peri-implantitis (PI), the most widespread condition in the oral cavity, affects patients globally; thus, advanced research in both in vitro and in vivo studies is required. This study aimed to develop peri-implantitis in the rat model by oral contamination with bacteria responsible for PI in humans. The study was carried out in three stages: the extraction of the maxillary first molar to reproduce the human edentation, the mounting of the implant, and finally, the contamination of the device by gavage with Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum and Streptococcus oralis. The hematological examinations showed statistically significant increases for WBCs (white blood cells), Hb (hemoglobin), RBCs (red blood cells), MCH (mean corpuscular hemoglobin), MCHC (mean corpuscular hemoglobin concentration), and PLTs (platelets), but especially for the level of neutrophils and lymphocytes, and the systemic immunoinflammatory index completed the picture related to the inflammatory response triggered as a result of the activity of microorganisms pathogens on oral tissues. By examining the liver and kidney profile, we hypothesized that peri-implantitis is associated with systemic diseases, and the histopathological examination showed peri-implantitis lesions characterized by a marked inflammatory infiltrate with numerous neutrophils and lymphocytes. By corroborating all the results, we successfully developed a rat peri-implantitis model using a mixed bacterial infection through the oral gavage technique.

Aggregatibacter actinomycetemcomitans is a Gram-negative bacterium associated with localized aggressive periodontitis as well as some systemic diseases. The strains of A. actinomycetemcomitans most closely associated with disease produce more of a secreted leukotoxin (LtxA) than isolates from healthy carriers, suggesting a key role for this toxin in disease progression. LtxA is released into the bacterial cytosol in a free form as well as in association with the surface of outer membrane vesicles (OMVs). We previously observed that the highly leukotoxic A. actinomycetemcomitans strain JP2 produces two populations of OMVs: a highly abundant population of small (300 nm) OMVs. Here, we have developed a protocol to isolate the OMVs produced during each specific phase of growth and used this to demonstrate that small OMVs are produced throughout growth and lack LtxA, while large OMVs are produced only during the exponential phase and are enriched with LtxA. Our results indicate that surface-associated DNA drives the selective sorting of LtxA into large OMVs. This study provides valuable insights into the observed heterogeneity of A. actinomycetemcomitans vesicles and emphasizes the importance of understanding these variations in the context of bacterial pathogenesis.

Aims: This study was designed to investigate the incidence of subgingival Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans infections and their relationship with genetic variability in Saudi Arabian adults with chronic periodontitis and to evaluate the correlation between infection frequency and other variables. Methods: Multiplex polymerase chain reaction (PCR) assays were developed to detect P. gingivalis 16 ​S rDNA, fimbria (fimA), and collagenase (prtC) genes, as well as the A. actinomycetemcomitans 16 ​S rDNA, leukotoxin (lktA), and fimbria-associated protein (fap) genes in saliva samples from 50 patients with periodontitis and 51 healthy subjects. Results: The incidence of both P. gingivalis and A. actinomycetemcomitans infections was higher (72% and 14%) in the “Periodontal disease” group than in the healthy subjects (P ​

Atherosclerosis (AS) is an inflammatory vascular disease that constitutes a major underlying cause of cardiovascular diseases (CVD) and stroke. Infection is a contributing risk factor for AS. Epidemiological evidence has implicated individuals afflicted by periodontitis displaying an increased susceptibility to AS and CVD. This review concisely outlines several prevalent periodontal pathogens identified within atherosclerotic plaques, including Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, and Fusobacterium nucleatum. We review the existing epidemiological evidence elucidating the association between these pathogens and AS-related diseases, and the diverse mechanisms for which these pathogens may engage in AS, such as endothelial barrier disruption, immune system activation, facilitation of monocyte adhesion and aggregation, and promotion of foam cell formation, all of which contribute to the progression and destabilization of atherosclerotic plaques. Notably, the intricate interplay among bacteria underscores the complex impact of periodontitis on AS. In conclusion, advancing our understanding of the relationship between periodontal pathogens and AS will undoubtedly offer invaluable insights and potential therapeutic avenues for the prevention and management of AS. [ABSTRACT FROM AUTHOR]

Periodontitis is caused by the inflammation of tooth-supporting tissue by pathogens such as Aggregatibacter actinomycetemcomitans. Interleukin-1β (IL-1β), a pro-inflammatory cytokine, triggers a series of inflammatory reactions and promotes bone resorption. The aim of this study was to examine the molecular mechanism and anti-inflammatory function of zingerone, a dietary phenolic found in Zingiber officinale, on periodontal inflammation induced by A. actinomycetemcomitans. Zingerone attenuated A. actinomycetemcomitans-induced nitric oxide (NO) production by inhibiting the expression of inducible nitric oxide synthase (iNOS) in THP-1 macrophages. Zingerone also inhibited the expression of tumor necrosis factor (TNF)-α, IL-1β, and their signal pathway molecules including the toll-like receptor (TLR)/mitogen-activated protein kinase (MAPKase). In particular, zingerone suppressed the expression of absent in melanoma 2 (AIM2) inflammasome components on IL-1β production. Moreover, zingerone enhanced autophagosome formation and the expressions of autophagy-associated molecules. Interestingly, zingerone reduced the intracellular survival of A. actinomycetemcomitans. This was blocked by an autophagy inhibitor, which reversed the decrease in IL-1β production by zingerone. Finally, zingerone alleviated alveolar bone absorption in an A. actnomycetemcomitans-induced periodontitis mice model. Our data suggested that zingerone has potential use as a treatment for periodontal inflammation induced by A. actinomycetemcomitans. [ABSTRACT FROM AUTHOR]

Periodontal disease is that condition resulting in the destruction of periodontal tissues, bone resorption, and tooth loss, the etiology of which is linked to immunological and microbiological factors. The aim of this study was to evaluate the potential trigger of periodontal disease in a rat model using bacterial species incriminated in the pathology of human periodontitis and to establish their optimal concentrations capable of reproducing the disease, with the idea of subsequently developing innovative treatments for the condition. In this study, we included 15 male Wistar rats, aged 20 weeks, which we divided into three groups. In each group, we applied ligatures with gingival retraction wire on the maxillary incisors. The ligature and the gingival sac were contaminated by oral gavage with a mixture of fresh cultures of Aggregatibacter actinomycetemcomitans (A.a), Fusobacterium nucleatum (F.n) and Streptococcus oralis (S.o) in concentrations of 108, 109, and 1010 CFU/mL each for 5 days a week for 4 weeks. During the clinical monitoring period of 28 days, overlapped with the period of oral contamination, we followed the expression of clinical signs specific to periodontitis. We also monitored the evolution of body weight and took weekly samples from the oral cavity for the microbiological identification of the tested bacteria and blood samples for hematological examination. At the end of the study, the animals were euthanized, and the ligated incisors were taken for histopathological analysis. The characteristic symptomatology of periodontal disease was expressed from the first week of the study and was maintained until the end, and we were able to identify the bacteria during each examination. Hematologically, the number of neutrophils decreased dramatically (p < 0.0001) in the case of the 109 group, unlike the other groups, as did the number of lymphocytes. Histopathologically, we identified neutrophilic infiltrate in all groups, as well as the presence of coccobacilli, periodontal tissue hyperplasia, and periodontal lysis. In the 109 group, we also observed pulpal tissue with necrotic bone fragments and pyogranulomatous inflammatory reaction. By corroborating the data, we can conclude that for the development of periodontal disease using A.a, F.n, and S.o, a concentration of 109 or 1010 CFU/mL is required, which must necessarily contaminate a ligature thread applied to the level of the rat's dental pack. [ABSTRACT FROM AUTHOR]

Periodontal disease has become a serious public health problem, not only causing tooth loss, but also inducing chronic disorders of extra-oral organs. The present study assessed an intranasal vaccine strategy to prevent periodontal disease using outer membrane vesicles (OMVs) of two major periodontopathic bacteria, Porphyromonas gingivalis (Pg) and Aggregatibacter actinomycetemcomitans (Aa). We compared the morphology, composition, and immune activity between OMVs of Pg strain ATCC 33277 and Aa strain Y4. Aa OMVs had a smoother surface and stronger lipid A activity compared to Pg OMVs. The in vitro immune activity elicited by Aa OMVs in macrophage-like cells was remarkably stronger than that of Pg OMVs. Intranasal immunization of mice with Aa OMVs alone resulted in robust, humoral immune responses in blood and saliva. Despites the intrinsically low mucosal immunogenicity of Pg OMVs alone, using Aa OMVs as a mucosal adjuvant strongly enhanced Pg-specific immune responses, resulting in both serum IgG and salivary IgA, both of which aggregated Pg and Aa cells. Furthermore, Aa OMVs were found to be a more potent mucosal adjuvant than Poly(I:C) in the context of enhancing the production of Pg-specific IgG (especially IgG2a) and IgA. In addition, in a randomized, blinded study, mice oral challenged with Pg and Aa after intranasal immunization with Pg OMVs and Aa OMVs had significantly decreased numbers of both microorganisms compared to mock-immunized mice. Furthermore, in an intracerebral injection mouse model, there were no serious adverse effects on the brain even after administrating a dose of OMVs as same as that used for intranasal administration. Taken together, the bivalent OMV intranasal vaccine may be effective in preventing colonization of periodontopathic bacteria in the oral cavity and related systemic disorders associated with periodontal diseases. [ABSTRACT FROM AUTHOR]

Background: Lactobacillus acidophilus and Aggregatibacter actinomycetemcomitans are gram bacteria that can cause various problems in the oral cavity so that materials that have antibacterial potency are needed. Calcium hydroxide, chlorhexidine, and sodium hypochlorite as antibacterial ingredients have disadvantages such as forming tunnel defects, causing dysgeusia, and damaging periapical tissue, so it is hoped that there will be natural materials as alternatives. The nano brown anchovy has fluor as the active compound which has the potential as an antibacterial agent. Purpose: To analyze the effect of antibacterial potency of nano brown anchovy (Stolephorus insularis) on Lactobacillus acidophilus and Aggregatibacter actinomycetemcomitans. Methods: This research is a laboratory experimental in vitro with the post-test only control group design. Brown anchovy is made into nano and diluted by dilution method into several concentrations. The direct contact method was used between some concentrations and the two bacteria. The values of MIC (Minimum Inhibitory Concentration) and MBC (Minimum Kill Concentration) were obtained by counting the number of bacterial colonies on Mueller Hinton Agar media. Bacterial colony growth was calculated manually in Colony Forming Units (CFU). Results: Antibacterial potency of nano brown anchovy on Lactobacillus acidophilus showed MIC results at 1.56% concentration and MBC at 3.125% concentration. Antibacterial potency of nano brown anchovy on Aggregatibacter actinomycetemcomitans showed MIC results at 3.125% concentration and MBC at 6.25% concentration. Conclusion: Nano brown anchovy has antibacterial activity on Lactobacillus acidophilus and Aggregatibacter actinomycetemcomitans. [ABSTRACT FROM AUTHOR]

The aim of this study was to compare data about the prevalence and proportions of the bacterial species Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, and Parvimonas micra in periodontitis pocket samples collected from young, <35 years, and old, >35-year-old patients, YP and OP, respectively. The results from the analyses of a total of 3447 subgingival plaque samples analyzed for clinical diagnosis purposes by cultivation regarding the proportions of these species were collected from a database and elucidated. The prevalence of A. actinomycetemcomitans was found to be more than twice as high (OR = 2.96, 95% CI; 2.50–3.50) in samples from the younger (42.2%) than the older group (20.4%) (p < 0.001). The prevalence of P. micra was significantly lower in samples from the younger age group (OR = 0.43, 95%) (p < 0.001), whereas P. gingivalis was similarly distributed (OR = 0.78, 95%) in the two age groups (p = 0.006). A similar pattern was noticed for A. actinomycetemcomitans and P. gingivalis when high proportions (>50%) of the samples of these bacterial species were elucidated. In contrast, the proportion of samples containing >50% with P. micra was lower compared with the two other bacterial species. Furthermore, it was noted that the proportion of samples from old patients containing A. actinomycetemcomitans in combination with P. micra was almost three times higher than in samples when P. micra was replaced by P. gingivalis. In conclusion, A.actinomycetemcomitans showed an increased presence and proportion in samples from young patients compared with the old patients, while P. gingivalis was similarly distributed in the two age groups. P. micra showed an increased presence and proportion in samples from old patients compared with the young patients. [ABSTRACT FROM AUTHOR]

The effect of hydrogen peroxide, an antiseptic dental treatment, on Aggregatibacter actinomycetemcomitans, the main causative agent of localized invasive periodontitis, was investigated. Hydrogen peroxide treatment (0.06%, 4× minimum inhibitory concentration) resulted in the persistence and survival of approximately 0.5% of the bacterial population. The surviving bacteria did not genetically acquire hydrogen peroxide resistance but exhibited a known persister behavior. Sterilization with mitomycin C significantly reduced the number of A. actinomycetemcomitans persister survivors. RNA sequencing of hydrogen peroxide-treated A. actinomycetemcomitans showed elevated expression of Lsr family members, suggesting a strong involvement of autoinducer uptake. In this study, we found a risk of A. actinomycetemcomitans persister residual from hydrogen peroxide treatment and hypothesized associated genetic mechanisms of persister from RNA sequencing. [ABSTRACT FROM AUTHOR]

Cytolethal distending toxins (Cdt) are a family of toxins produced by several human pathogens which infect mucocutaneous tissue and induce inflammatory disease. We have previously demonstrated that the Aggregatibacter actinomycetemcomitans Cdt induces a pro-inflammatory response from human macrophages which involves activation of the NLRP3 inflammasome. We now demonstrate that in addition to activating caspase-1 (canonical inflammasome), Cdt treatment leads to caspase-4 activation and involvement of the noncanonical inflammasome. Cdt-treated cells exhibit pyroptosis characterised by cleavage of gasdermin-D (GSDMD), release of HMGB1 at 24 hr and LDH at 48 hr. Inhibition of either the canonical (caspase-1) or noncanonical (caspase-4) inflammasome blocks both Cdt-induced release of IL-1β and induction of pyroptosis. Analysis of upstream events indicates that Cdt induces Syk phosphorylation (activation); furthermore, blockade of Syk expression and inhibition of pSyk activity inhibit both Cdt-induced cytokine release and pyroptosis. Finally, we demonstrate that increases in pSyk are dependent upon Cdt-induced activation of GSK3β. These studies advance our understanding of Cdt function and provide new insight into the virulence potential of Cdt in mediating the pathogenesis of disease caused by Cdt-producing organisms such as A. actinomycetemcomitans.

The Aggregatibacter actinomycetemcomitans cytolethal distending toxin (Cdt) induces lymphocytes to undergo cell-cycle arrest and apoptosis; toxicity is dependent upon the active Cdt subunit, CdtB. We now demonstrate that p21CIP1/WAF1 is critical to Cdt-induced apoptosis. Cdt induces increases in the levels of p21CIP1/WAF1 in lymphoid cell lines, Jurkat and MyLa, and in primary human lymphocytes. These increases were dependent upon CdtB's ability to function as a phosphatidylinositol (PI) 3,4,5-triphosphate (PIP3) phosphatase. It is noteworthy that Cdt-induced increases in the levels of p21CIP1/WAF1 were accompanied by a significant decline in the levels of phosphorylated p21CIP1/WAF1. The significance of Cdt-induced p21CIP1/WAF1 increase was assessed by preventing these changes with a two-pronged approach; pre-incubation with the novel p21CIP1/WAF1 inhibitor, UC2288, and development of a p21CIP1/WAF1-deficient cell line (Jurkatp21-) using clustered regularly interspaced short palindromic repeats (CRISPR)/cas9 gene editing. UC2288 blocked toxin-induced increases in p21CIP1/WAF1, and JurkatWT cells treated with this inhibitor exhibited reduced susceptibility to Cdt-induced apoptosis. Likewise, Jurkatp21- cells failed to undergo toxin-induced apoptosis. The linkage between Cdt, p21CIP1/WAF1, and apoptosis was further established by demonstrating that Cdt-induced increases in levels of the pro-apoptotic proteins Bid, Bax, and Bak were dependent upon p21CIP1/WAF1 as these changes were not observed in Jurkatp21- cells. Finally, we determined that the p21CIP1/WAF1 increases were dependent upon toxin-induced increases in the level and activity of the chaperone heat shock protein (HSP) 90. We propose that p21CIP1/WAF1 plays a key pro-apoptotic role in mediating Cdt-induced toxicity.

ABSTRAK Pendahuluan: Prevalensi periodontitis di Indonesia masih terbilang tinggi. Data Riskesdas 2018 menunjukkan persentase kasus periodontitis di Indonesia sebesar 74,1%. Periodontitis merupakan penyakit inflamasi pada jaringan periodontal yang disebabkan oleh mikroorganisme spesifik seperti Fusobacterium nucleatum dan Aggregatibacter actinomycetemcomitans. Perawatan suportif menggunakan antibiotik, seperti metronidazole, diperlukan dalam perawatan periodontitis tetapi penggunaan antibiotik dapat memberikan efek samping sehingga perlu digantikan oleh tanaman herbal yang memiliki efek samping minimal, yaitu daun singkong (Manihot esculenta crantz). Penelitian ini bertujuan untuk menganalisis daya antibakteri ekstrak daun singkong terhadap Fusobacterium nucleatum dan Aggregatibacter actinomycetemcomitans. Metode: Jenis penelitian in vitro experimental laboratories dengan rancangan penelitian post test only control group design. Daun singkong yang sudah teridentifikasi di ekstrak dengan metode maserasi. Ekstrak kasar yang didapatkan kemudian dijadikan ke dalam beberapa dosis (6,25; 12,5; 25; 50; 100; dan 200 µg/mL). Kelompok dosis tersebut kemudian diuji menggunakan metode disk diffusion dan dibandingkan dengan kontrol positif yaitu metronidazole dan kontrol negatif yaitu propilen glikol.Data hasil penelitian diuji normalitasnya menggunakan uji Shapiro Wilk dan uji homogenitas menggunakan Levene test. Selanjutnya dilakukan uji Mann Whitney untuk melihat perbedaan antara dua kelompok sampel. Hasil: Terdapat zona jernih pada sekeliling kertas cakram dengan ekstrak daun singkong dosis 200 µg/mL yang menandakan adanya hambatan pertumbuhan dari F. nucleatum dan A. actinomycetemcomitans. Hasil statistik terlihat adanya perbedaan yang bermakna antara kelompok ekstrak daun singkong dosis 200 µg/mL dan kontrol positif (p=0,009) untuk F. Nucleatum, dan p=0,05 untuk A. actinomycetemcomitans. Simpulan: Ekstrak daun singkong dapat menghambat pertumbuhan dari F. nucleatum dan A. actinomycetemcomitans. Kata kunci: ekstrak daun singkong; fusobacterium nucleatum; aggregatibacter actinomycetemcomitans; antibakteri ABSTRACT Introduction: The prevalence of periodontitis in Indonesia is relatively high. The 2018 RISKESDAS data shows that the percentage of periodontitis cases in Indonesia is 74.1%. Periodontitis is an inflammatory disease of the periodontal tissue caused by specific microorganisms or groups of microorganisms such as Fusobacterium nucleatum and Aggregatibacter actinomycetemcomitans. Supportive care using antibiotics, such as metronidazole, is required to treat periodontitis. However, antibiotics can have side effects, so they need to be replaced by herbal plants with minimal side effects, namely cassava leaves (Manihot esculenta Crantz). This study aims to analyze the antibacterial effect of cassava leaf extract against Fusobacterium nucleatum and Aggregatibacter actinomycetemcomitans. Methods: This study was an in vitro laboratory experimental study with a post-test only control group design. The identified cassava leaves were extracted by the maceration method. The crude extract obtained was then made into several doses. The dose group was then tested using the disk diffusion method and compared with the positive control, metronidazole, and the negative control, propylene glycol.The research data were tested for normality using the Shapiro Wilk test and the homogeneity test using the Levene test. Then the Mann Whitney test was carried out to see the difference between the two sample groups Results: The results showed a clear zone around the disc paper with a 200 µg/ml dose of cassava leaf extract, which indicates the growth inhibition of F. nucleatum and A. actinomycetemcomitans. The statistical results showed a significant difference between the 200 µg/ml group and the positive control(p= 0,009 for F. Nucleatum; p=0,05 for A. actinomycetemcomitans). Conclusion: Cassava leaves extract can inhibit the growth of F. nucleatum and A. actinomycetemcomitans. Keywords: cassava leaf extract; fusobacterium nucleatum; aggregatibacter actinomycetemcomitans; antibacterial

ABSTRAK Pendahuluan: Mental foramen dan mandibular canal merupakan struktur anatomi penting untuk melakukan tindakan perawatan gigi dan mulut seperti anestesi lokal, penempatan implan, fraktur mandibula, dan intervensi bedah di daerah mandible. Identifikasi tipe visibilitas mental foramen dapat membantu meminimalisir terjadinya resiko cedera saraf mentalis. Tujuan penelitian mengetahui tipe visibilitas mental foramen dengan mandibular canal pada radiograf panoramik berdasarkan usia dan perbedaan jenis kelamin. Metode: Jenis penelitian deskriptif observasional dengan rancangan penelitian cross sectional. Penelitian dilakukan pada rekam medis panoramik pasien RSGM Maranatha pada tahun 2019-2020 yang berusia 17-25 tahun, menggunakan teknik simple random sampling. Tipe visibilitas mental foramen diamati berdasarkan hubungannya dengan mandibular canal pada kedua sisi mandible dari 216 radiograf panoramik. Tipe visibilitas mental foramen dan mandibular canal diklasifikasikan menjadi 4 tipe: 1. Continous type; 2. Separated type; 3. Diffuse type; 4. Unidentified type. Analisis data dilakukan menggunakan metode distribusi frekuensi relatif dan tabulasi silang dengan perhitungan persentase baris. Hasil: Tipe visibilitas mental foramen dengan mandibular canal pada pasien usia 17-25 tahun adalah separated type dengan persentase tertinggi sebesar 44,4%. Pasien laki-laki dengan jumlah 87 responden menunjukkan tipe visibilitas mental foramen tertinggi yaitu continuous type (43,7%) dan pasien perempuan dengan jumlah 129 responden menunjukkan tipe visibilitas mental foramen tertinggi yaitu separated type (48,1%). Simpulan: Tipe visibilitas mental foramen dengan mandibular canal berdasarkan radiografi panoramic pada pasien dengan usia 17-25 tahun menunjukkan tipe visibilitas mental foramen yang paling sering ditemukan adalah separated type, dan terdapat perbedaan tipe visibilitas mental foramen dengan mandibular canal berdasarkan jenis kelamin pada pasien dengan usia 17-25 tahun. Kata kunci: tipe visibilitas; mental foramen; mandibular canal; radiograf panoramik; usia; jenis kelamin ABSTRACT Introduction: Mental foramen and mandibular canal are a clinically critical anatomical landmarks for clinicians when performing dental care, such as local anesthetics, implant placement, mandibular fractures, and surgical intervention in the mandible area. Determining the visibility type of the mental foramen can help to preclude iatrogenic complications such as mental nerve injury that can lead to lower lips paresthesia. This study aimed to determine the visibility type of mental foramen towards the mandibular canal in male and female patients using panoramic radiographs. Methods: The research method used in this study was descriptive observational with a cross sectional research design. Panoramic radiographs were randomly selected using simple random sampling from the dental records of RSGM Maranatha patients between the ages of 17-25 in 2019-2020. Visibility Mental foramen type was observed based on its relationship with the mandibular canal on both sides of the mandible from 216 panoramic radiographs. Visibility of the mental foramen and mandibular canal classified into four types of visibility: 1. Continous type; 2. Separated type; 3. Diffuse type; 4. Unidentified type. Results: The result showed that “separated type” (44.4%) was the highest percentage of the visibility of Mental foramen towards the Mandibular canal in patients aged 17-25 years old. There is a difference in the visibility type of Mental foramen between male and female patients. Out of 87 male patient respondents, the highest visibility of Mental foramen is “continuous type” (43.7%); meanwhile, out of 129 female patient respondents, the highest visibility of Mental foramen is “separated type” (48.1%). Conclusion: “Separated type” is the most common discovery of visibility type of Mental foramen towards the Mandibular canal in patients between the ages of 17-25. The visibility type of Mental foramen may differ according to their sex. Keywords: visibility type; mental foramen; mandibular canal; panoramic radiograph; age; sex

Copyright of Parodontologie: die Zeitschrift für die Praxis (Berlin, Germany) is the property of Quintessenz Verlags GmbH and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background/Purpose: Periodontitis is an inflammatory disease due to microbial plaque that causes bone loss and tooth mobility. Its prevention and treatment include microbial plaque control, which is presently attained by both mechanical and chemical methods. This study aimed to investigate the antimicrobial effect of the hydroalcoholic extract of Elettaria cardamomum on Aggregatibacter actinomycetemcomitans (Aa) which is one of the most important bacterium of periodontitis. Materials and Methods: The hydroalcoholic extract of E. cardamomum was obtained by the maceration method in the Traditional Medicine of Tehran University Medical Sciences Department. The Aa (Jp2nov99) bacterial strain was cultured. The inhibition zone diameter of Aa was measured by agar-well diffusion methods for concentrations of 25% and 50% of E. cardamomum. The mean group’s inhibition zone diameter was analyzed using the SPSS software. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of this extract were determined by the broth microdilution method. Chlorhexidine 0.2% was used as a control and the results were compared. Results: The inhibition zone diameter of this extract was measured at different concentrations. The highest and the lowest diameters of 20.5 mm and 20.0 mm were associated with 50% and 25% concentrations, respectively. The MIC and MBC values for this bacterium were at 0.0039 mg/ml and 0.0039 mg/ml as compared with 0.00065 mg/ml and 0.00098 mg/ml for 0.2% of chlorhexidine. Conclusion: The hydroalcoholic extract of E. cardamomum has an antibacterial effect on the Aa bacterium and may be used in mouthwash as an alternative to chlorhexidine. [ABSTRACT FROM AUTHOR]

Introduction: The role of suppressor of cytokine signaling 2 (SOCS2) in Aggregatibacter actinomycetemcomitans (Aa)-induced alveolar bone loss is unknown; thus, it was investigated in this study. Methods: Alveolar bone loss was induced by infecting C57BL/6 wild-type (WT) and Socs2-knockout (Socs2−/−) mice with Aa. Bone parameters, bone loss, bone cell counts, the expression of bone remodeling markers, and cytokine profile were evaluated by microtomography, histology, qPCR, and/or ELISA. Bone marrow cells (BMC) from WT and Socs2−/− mice were differentiated in osteoblasts or osteoclasts for analysis of the expression of specific markers. Results: Socs2−/− mice intrinsically exhibited irregular phenotypes in the maxillary bone and an increased number of osteoclasts. Upon Aa infection, SOCS2 deficiency resulted in the increased alveolar bone loss, despite decreased proinflammatory cytokine production, in comparison to the WT mice. In vitro, SOCS2 deficiency resulted in the increased osteoclasts formation, decreased expression of bone remodeling markers, and proinflammatory cytokines after Aa-LPS stimulus. Conclusions: Collectively, data suggest that SOCS2 is a regulator of Aa-induced alveolar bone loss by controlling the differentiation and activity of bone cells, and proinflammatory cytokines availability in the periodontal microenvironment and an important target for new therapeutic strategies. Thus, it can be helpful in preventing alveolar bone loss in periodontal inflammatory conditions. [ABSTRACT FROM AUTHOR]

Background: Aggregatibacter actinomycetemcomitans (Aa), previously known as Actinobacillus actinomycetemcomitans, is a slow-growing Gram-negative coccobacillus, member of the HACEK group of bacteria colonizing oral flora. Besides causing infectious diseases in the oral cavity such as dental caries and periodontitis, it is responsible for severe extra-oral infections secondary to hematogenous spread or aspiration, such as endocarditis, soft tissue abscesses and osteomyelitis. The diagnosis depends on prolonged bacterial culture of biological material obtained through biopsy. Aa is susceptible to most antibiotics but complete eradication often requires a long term treatment. Case presentation: We report the case of a 15-year-old previously healthy boy diagnosed with both pulmonary empyema and subphrenic chest wall abscess caused by Aa. He was admitted to our Pediatric Emergency department for evaluation of a right mass associated with marked asthenia and dry cough. After radiological findings etiological diagnosis was made by culture of fluid drainage of pleural empyema. He started empirical antibiotic therapy with intravenous piperacillin/tazobactam, whose sensibility was confirmed by the antibiogram, then, for occurrance of hepatopathy it was switched to ciprofloxacin: the patient almost completely recovered after 6-month therapy. Conclusions: Extra-oral infections caused by Aa are extremely rare, especially in children, and not well described yet. To our knowledge, there is only another similar case described in literature. However, the case described in our manuscript represents the only one presenting with pulmonary empyema without involvement of lung parenchyma in children. We also conducted a brief review of published cases of Aa infection in the pediatric population. This case report reminds us the importance of an accurate inspection of the oral cavity during the examination of pediatric patients. [ABSTRACT FROM AUTHOR]

Advanced platelet-rich fibrin (A-PRF+) and injectable platelet-rich fibrin (i-PRF) have recently been developed and used in periodontal therapy. Few studies have contrasted the antibacterial effectiveness of these autologous materials derived from individuals with healthy gums, gingivitis, and periodontitis. This study aimed to compare the antimicrobial effects of these PRF materials against the periodontal pathogenic bacterium Aggregatibacter actinomycetemcomitans (Aa) in patients with different periodontal conditions. Blood samples were collected from periodontally healthy individuals, patients with gingivitis, or patients with periodontitis to prepare A-PRF+ and i-PRF. The antibacterial capacity of these materials was evaluated through antibiofilm formation, biofilm susceptibility, and the time-kill assay over a 48-h period. A-PRF+ and i-PRF from each patient groups interfered with Aa 's ability to form biofilm on the test tube surface, and the effect of i-PRF was significantly different among the patient groups. In contrast, these plasma preparation had a weak impact on mature biofilm. For products from the gingivitis and periodontitis groups, these effects were significantly stronger for i-PRF than A-PRF+ (p = 0.012 and p = 0.004, respectively). All plasma preparations inhibited Aa growth in the first 12 h after application, and i-PRF exhibited a significantly greater antimicrobial effect than A-PRF + at each time point. A-PRF+ and i-PRF in all three patient groups could inhibit the growth of Aa in vitro , and i-PRF from patients with periodontitis exhibited a more significant effect than PRF from the other groups. [Display omitted] [ABSTRACT FROM AUTHOR]

ObjectivesPeriodontitis and underlying bacteria have been linked to the development of rheumatoid arthritis (RA). One suggested pathogen is Aggregatibacter actinomycetemcomitans (A.a.), which expresses leukotoxin A (LtxA) that can citrullinate human proteins, providing a possible trigger for the production of anti-citrullinated protein antibodies (ACPA). In this study, we seek to determine the presence of antibodies toward LtxA in patients at risk of developing RA.MethodsTwo prospective observational patient cohorts (one Swedish and one British) with symptomatic at-risk patients were studied. Anti-LtxA antibodies were analyzed by a cell-based neutralization assay in baseline serum and compared to 100 Swedish blood donors that served as controls.ResultsSerum anti-LtxA levels or positivity did not differ between patients and blood donors. In the British cohort, anti-LtxA was more prevalent among ACPA-positive arthralgia patients compared with ACPA-negative arthralgia cases (24% vs. 13%, p < 0.0001). In the Swedish at-risk cohort, anti-LtxA positive patients were at increased risk of progression to arthritis (hazard ratio (HR) 2.10, 95% CI 1.04–4.20), but this was not confirmed in the UK at-risk cohort (HR 0.99, CI 0.60–1.65).ConclusionSerum anti-LtxA is not elevated before RA diagnosis, and associations with disease progression and ACPA levels differ between populations. Other features of the oral microbiome should be explored in upcoming periodontitis-related RA research.

Recently, we reported that oral-epithelial cells (OE) are unique in their response to Aggregatibacter actinomycetemcomitans cytolethal distending toxin (Cdt) in that cell cycle arrest (G2/M) occurs without leading to apoptosis. We now demonstrate that Cdt-induced cell cycle arrest in OE has a duration of at least 7 days with no change in viability. Moreover, toxin-treated OE develops a new phenotype consistent with cellular senescence; this includes increased senescence-associated β-galactosidase (SA-β-gal) activity and accumulation of the lipopigment, lipofuscin. Moreover, the cells exhibit a secretory profile associated with cellular senescence known as the senescence-associated secretory phenotype (SASP), which includes IL-6, IL-8 and RANKL. Another unique feature of Cdt-induced OE senescence is disruption of barrier function, as shown by loss of transepithelial electrical resistance and confocal microscopic assessment of primary gingival keratinocyte structure. Finally, we demonstrate that Cdt-induced senescence is dependent upon the host cell protein cellugyrin, a homologue of the synaptic vesicle protein synaptogyrin. Collectively, these observations point to a novel pathogenic outcome in oral epithelium that we propose contributes to both A. actinomycetemcomitans infection and periodontal disease progression.

Copyright of Canadian Journal of Dental Hygiene is the property of Canadian Dental Hygienists Association and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background. Aggregatibacter actinomycetemcomitans (Aa) plays a vital role in some destructive forms of periodontitis. While mechanical and chemical plaque control is the first step in periodontitis treatment, side effects of adjunctive chemical agents such as chlorhexidine (CHX) mouthwash have led to the application of natural alternatives with minimal side effects. Therefore, this study evaluated the antibacterial effect of the hydroalcoholic extract of Quercus infectoria (Qi) galls on Aa in vitro. Methods. The hydroalcoholic extract of Qi was obtained by the maceration method, and Aa bacterial strain was cultured. The inhibition zone diameter was measured through the agar well diffusion method. Also, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values were determined by the broth microdilution method. All the experiments were repeated three times. 0.2% CHX was used as a control. Results. The inhibition zone diameter of Aa increased with increasing concentration of Qi extract. While MIC and MBC values for CHX were 0.0039 and 0.0078 mg/mL, respectively, both MIC and MBC values of the Qi extract for this bacterium were similar, i.e., 2.5 mg/mL, which was significantly higherd. Conclusion. Since other in vivo studies have confirmed the other properties of this extract and its safety in terms of cytotoxicity and mutagenicity, hydroalcoholic extract of Qi may be used in mouthwashes or local delivery systems to affect periodontal biofilm. [ABSTRACT FROM AUTHOR]

Periodontitis is the most common chronic, inflammatory oral disease that affects more than half of the population in the United States. The disease leads to destruction of the tooth-supporting tissue called periodontium, which ultimately results in tooth loss if uncured. The interaction between the periodontal microbiota and the host immune cells result in the induction of a non-protective host immune response that triggers host tissue destruction. Certain pathogens have been implicated periodontal disease formation that is triggered by a plethora of virulence factors. There is a collective evidence on the impact of periodontal disease progression on systemic health. Of particular interest, the role of the virulence factors of the periodontal pathogens in facilitating the evasion of the host immune cells and promotion of carcinogenesis has been the focus of many researchers. The aim of this review is to examine the influence of the periodontal pathogens Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans), Porphyromonas gingivalis (P. gingivalis), and Fusobacterium nucleatum (F. nucleatum) in the modulation of the intracellular signaling pathways of the host cells in order to evade the host immune response and interfere with normal host cell death and the role of their virulence factors in this regard. [ABSTRACT FROM AUTHOR]

The human oral pathobionts Aggregatibacter actinomycetemcomitans, Streptococcus mitis and Streptococcus mutans, in dysbiosis-promoting conditions, lead to oral infections, which also represent a threat to human systemic health. This scenario may be worsened by antibiotic misuse, which favours multi-drug resistance, making the research on pathogen containment strategies more than crucial. Therefore, we aimed to in vitro select the most promising probiotic strains against oral pathogen growth, viability, biofilm formation, and co-aggregation capacity, employing both the viable probiotics and their cell-free supernatants (CFSs). Interestingly, we also assessed probiotic efficacy against the three-pathogen co-culture, mimicking an environment similar to that in vivo. Overall, the results showed that Lactobacillus CFSs performed better than the Bifidobacterium, highlighting Limosilactobacillus reuteri LRE11, Lacticaseibacillus rhamnosus LR04, Lacticaseibacillus casei LC04, and Limosilactobacillus fermentum LF26 as the most effective strains, opening the chance to deeper investigation of their action and CFS composition. Altogether, the methodologies presented in this study can be used for probiotic efficacy screenings, in order to better focus the research on a viable probiotic, or on its postbiotics, suitable in case of infections. [ABSTRACT FROM AUTHOR]

The aims of the present study were to document the presence of Aggregatibacter actinomyctemcomitans and the emerging oral pathogen Filifactor alocis, as well as to identify genotypes of these bacterial species with enhanced virulence. In addition, these data were analyzed in relation to periodontal pocket depth (PPD) and the progression of PPD from the sampled periodontal sites during a two-year period. Subgingival plaque samples were collected from 172 periodontal pockets of 68 Ghanaian adolescents. PPD at sampling varied from 3–14 mm and the progression from baseline, i.e., two years earlier up to 8 mm. The levels of A. actinomycetemcomitans and F. alocis were determined with quantitative PCR. The highly leukotoxic JP2-genotype of A. actinomycetemcomitans and the ftxA a gene of F. alocis, encoding a putative Repeats-in-Toxin (RTX) protein, were detected with conventional PCR. The prevalence of A. actinomycetemcomitans was 57%, and 14% of the samples contained the JP2 genotype. F. alocis was detected in 92% of the samples and the ftxA gene in 52%. The levels of these bacterial species were significantly associated with enhanced PPD and progression, with a more pronounced impact in sites positive for the JP2 genotype or the ftxA gene. Taken together, the results indicate that the presence of both A. actinomycetemcomitans and F. alocis with their RTX proteins are linked to increased PPD and progression of disease. [ABSTRACT FROM AUTHOR]

Background: Aggregatibacter actinomycetemcomitans and Enterococcus faecalis are pathogenic bacteria of the oral cavity that cause various diseases such as periodontitis and endodontics. These bacteria are easily resistant to antibiotics. Photodynamic inactivation (PDI) is a method of inactivating microorganisms that utilizes light to activate a photosensitizer agent (PS) that produces reactive oxygen species causing cell lysis. Methods: This study used the PDI method with a 405 nm diode laser at various energy density with the addition PS curcumin or chlorophyll Alfalfa, as much as 1.6 mg/ml on A. actinomycetemcomitans and E. faecalis bacteria. Results: The study on E. faecalis bacteria showed that the energy density diode laser irradiation of 1.59 J/cm² gave the percentage of E. faecalis bacteria death 36.7% without PS, 69.30% with the addition of chlorophyll Medicago sativa L and 89.42% with the addition of curcumin. Meanwhile, the bacteria A. actinomycetemcomitans showed that the energy density diode laser irradiation of 1.59 J/cm² gave the percentage of bacterial death 35.81% without PS, 64.39% with the addition of chlorophyll Medicago sativa L and 89.82% with the addition of curcumin. PS was critical to the success of the PDI. Conclusions: The addition of PS curcumin increased the effectiveness of reducing bacteria E. faecalis and A. actinomycetemcomitans compared to chlorophyll Medicago sativa L.

This study aims to determine the phytochemical properties of Salvadora persica extracts and their antibacterial activities against Gram-negative oral anaerobes which are responsible of periodontitis such as Porphorymonas gingivalis and Aggregatibacter actinomycetemcomitans. Aqueous and ethanolic extracts were prepared using the root powdered stem of S. persica. The phytochemical compounds were determined with Liquid Chromatography-Mass Spectrometry (LC-MS) and Gas Chromatography-Mass Spectrometry (GC-MS). The antibacterial activities were assessed according to the levels of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The S. persica ethanolic and aqueous extracts contained antibacterial compounds such as Octadecenoic acid, methyl ester, n-Hexadecanoic acid and Pentadecanoic acid, 2,6,10,14-tetramethyl-, methylester, 1-(2,2-Dimethylpropanoyl)-L-prolyl-L-prolyl-N,2-dimethylalaninamide and 2-({4-[(Difluoromethyl)sulfanyl]phenyl} amino) benzoic acid, respectively. Both P. gingivalis (0.025 mg/mL) and A. actinomycetemcomitans (0.125 mg/mL) were susceptible to S. persica ethanolic extract. Ethanolic extract preparation has equal antibacterial activity with 0.2% chlorhexidine gluconate solution (p

Pendahuluan: Penyakit periodontal merupakan salah satu penyakit inflamasi kronis yang menyerang periodonsium yang disebabkan oleh salah satu mikroorganisme yaitu Aggregatibacter actinomycetemcomitans. Perawatan penyakit periodontal dapat dilakukan dengan bahan alam salah satunya daun sirih merah (Piper crocatum). Daun sirih merah memiliki aktivitas senyawa antibakteri yang dapat menghambat pertumbuhan A. actinomycetemcomitans. Tujuan dari penelitian ini adalah untuk mengetahui daya antibakteri ekstrak daun sirih merah (Piper crocatum) terhadap pertumbuhan A. actinomycetemcomitans. Metode: Penelitian dilakukan dengan metode difusi cakram pada media MHA (Mueller Hinton Agar) dengan mengukur zona bening yang terbentuk menggunakan jangka sorong. Jenis penelitian yang digunakan eksperimental laboratoris dengan sampel sebanyak 30 sampel. Hasil: Daya hambat ekstrak daun sirih merah (Piper crocatum) terhadap A. actinomycetemcomitans terdapat pada kelompok perlakuan dengan konsentrasi 25%, 50%, dan 100%. Aktivitas antibakteri konsentrasi 25% dikategorikan sedang, konsentrasi 50% dan 100% dikategorikan kuat. Kelompok kontrol positif terdapat aktivitas daya hambat bakteri dengan nilai rerata diameter 23,42 mm, sedangkan kelompok kontrol negatif tidak menunjukkan adanya zona hambat. Hasil uji Kruskal Wallis menunjukkan bahwa signifikansi (0,00) dengan p

The current study was designed to establish the antibacterial efficacy of various extracts from medicinal plants. The inhibition effects of six plants including Viscus album, Apium graveolens, Melissa officinalis, Plantago ovata, Senna acutifolia, and Vitis vinifera were examined against Aggregatibacter actinomycetemcomitans, which obtained from dental caries patient. The output showed that the tested bacterial isolates were greatly sensitive to M. officinalis and S. acutifolia and their maximum inhibition zones were 35 mm and 33 mm respectively. The tested bacterial isolates were greatly sensitive to M. officinalis and S. acutifolia in comparison with the antibiotic. According to the well-diffusion test results, the crude aqueous extracts from the plants showed varying degrees of inhibition of bacterial growth. Moreover, these medicinal plant extracts were a promising group of natural product sources that can be examined to continue developing products through the use of oral medicines and health care.

Background: Ajwain (Trachyspermum ammi) oil is used widely because of its nutritional value, antioxidant and antibacterial activity against various microorganisms, but there are no studies that relate the antibacterial activity of Ajwain oil against periodontal pathogens. Aim: To evaluate and compare the minimum inhibitory concentration (MIC) and zone of inhibition of T. ammi (Ajwain seed) oil and 0.2% chlorhexidine gluconate against Porphyromonas gingivalis, Fusobacterium nucleatum, and Aggregatibacter actinomycetemcomitans through serial tube dilution and disc diffusion methods. Materials and Methods: An in vitro study was conducted. Ajwain oil (100%) and chlorhexidine solution (0.2%) were purchased. Blood agar media with hemin, Vitamin K and Kanamycin, crystal violet erythromycin blood agar, and thioglycolate broth with 1% horse serum were used to culture P. gingivalis, F. nucleatum, and A. actinomycetemcomitans, respectively. The MIC and minimum bactericidal concentration of test agents were assessed using the serial dilution method, and the zone of inhibition was assessed by the Agar disc diffusion method. Results: Ajwain oil had the ability to exert antibacterial activity against P. gingivalis, F. nucleatum, and A. actinomycetemcomitans at a MIC of 0.4, 0.4, and 0.8 μg/ml, respectively. Ajwain oil exerted bactericidal effect against P gingivalis, F. nucleatum, and A. actinomycetemcomitans at a minimum concentration of 0.4, 0.4, and 6.25 μg/ml, respectively, and bacteriostatic effect at a minimum concentration of 0.2, 0.2, and 3.12 μg/ml, respectively. At 50% μg/ml concentration, Ajwain oil exhibited a higher zone of inhibition compared to chlorhexidine against P. gingivalis, F. nucleatum, and A. actinomycetemcomitans. Conclusion: Ajwain oil demonstrated antibacterial effect against periodontal pathogens in vitro.

Objective: The objective of the study is to assess the effects of adjunctive use of hyaluronic acid (HA), clinically and microbiologically in smokers and nonsmokers, in the management of chronic periodontitis. Material and Methods: 48 sites from 24 chronic periodontitis patients, including smokers and nonsmokers with probing depth >5 mm, were selected for the study. A split-mouth design was followed. Scaling and root planing (SRP) was performed for all the patients. The test sites received 0.8% HA gel whereas the control site received placebo gel. The clinical parameters plaque, gingival and bleeding indices, Pocket Probing Depth (PPD), and clinical attachment level (CAL) were evaluated at baseline, 1 and 3 months. Microbiological parameters were evaluated at baseline and 1 month. Results: The results showed reduction in PPD and gain in CAL in both smokers and nonsmokers at the end of 3rd month. The improvements in the test sites were statistically significant when compared with that of control sites. The microbiological analysis showed a significant reduction in Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis at the test sites when compared to the controls in both the groups. Conclusion: The findings in both groups suggest that the use of locally delivered 0.8% HA gel may be valuable as an adjunct to SRP in the treatment of chronic periodontitis.

ABSTRACT Aggregatibacter actinomycetemcomitans (Aa) is a Gram-negative bacterial pathogen associated with periodontitis and nonoral diseases like rheumatoid arthritis and Alzheimer´s disease. Aa isolates with the serotypes a, b, and c are globally most prevalent. Importantly, isolates displaying these serotypes have different clinical presentations. While serotype b isolates are predominant in severe periodontitis, serotypes a and c are generally encountered in mild periodontitis or healthy individuals. It is currently unknown how these differences are reflected in the overall secretion of virulence factors. Therefore, this study was aimed at a comparative analysis of exoproteomes from different clinical Aa isolates with serotypes a, b, or c by mass spectrometry, and a subsequent correlation of the recorded exoproteome profiles with virulence. Overall, we identified 425 extracellular proteins. Significant differences in the exoproteome composition of isolates with different serotypes were observed in terms of protein identification and abundance. In particular, serotype a isolates presented more extracellular proteins than serotype b or c isolates. These differences are mirrored in their virulence in infection models based on human salivary gland epithelial cells and neutrophils. Remarkably, serotype a isolates displayed stronger adhesive capabilities and induced more lysis of epithelial cells and neutrophils than serotype b or c isolates. Conversely, serotype c isolates showed relatively low leukotoxicity, while provoking NETosis to similar extents as serotype a and b isolates. Altogether, we conclude that the differential virulence presentation by Aa isolates with the dominant serotypes a, b, or c can be explained by their exoproteome heterogeneity. IMPORTANCE Periodontitis is an inflammatory disease that causes progressive destruction of alveolar bone and supporting tissues around the teeth, ultimately resulting in tooth loss. The bacterium Aggregatibacter actinomycetemcomitans (Aa) is a prevalent causative agent of periodontitis, but this oral pathogen is also associated with serious extraoral diseases like rheumatoid arthritis and Alzheimer’s disease. Clinical Aa isolates are usually distinguished by serotyping, because of known serotype-specific differences in virulence. Aa with serotype b is associated with aggressive forms of periodontitis, while isolates with serotypes a or c are usually encountered in cases of mild periodontitis or healthy individuals. The molecular basis for these differences in virulence was so far unknown. In the present study, we pinpoint serotype-specific differences in virulence factor production by clinical Aa isolates. We consider these findings important, because they provide new leads for future preventive or therapeutic approaches to fight periodontitis and associated morbidities.

While HACEK group organisms cause only 1–3% of infective endocarditis (IE) cases, their insidious and varied clinical presentations make for difficult and often delayed diagnoses. We present a 65-year-old male with persistent exertional dyspnea, hemoptysis, and weight loss who was diagnosed with a HACEK aortic graft infection and IE.

The role of Aggregatibacter actinomycetemcomitans bacteria can lead to the occurrence of aggressive periodontitis. The bacterium infects periodontal tissue with its virulence factor. Antibacterial administration such as chlorhexidine mouthwash is one of the treatments for periodontal disease due to bacteria. Long-term use of chlorhexidine can cause irritation of the oral mucosa, burning sensation, changes in taste perception and the appearance of stains on the teeth. One alternative is to gargle the guava leaf extract water. The antibacterial effect of guava leaf extract is obtained from its chemical compounds, namely flavonoids, phenolics, alkaloids, ethanol and tannins. This research aims to know the potential of water guava leaf extract (Syzygium aqueum) in inhibiting the growth of Aggregatibacter actinomycetemcomitans bacteria. A literature review by reviewing research articles from Science Direct and Google Scholar using the keywords "Syzygium aqueum and Aggregatibacter actinomycetemcomitans". Guava leaves contain many derivatives of compounds such as flavonoids, alkaloids, tannins, saponins, and terpenoids. The content of these compounds can be used as antibacterial because they are effective in inhibiting the growth of bacteria. Water guava leaf extract (Syzygium aqueum) can inhibit the growth of Aggregatibacter actinomycetemcomitans bacteria.

Late embryogenesis abundant (LEA) proteins are important players in the management of responses to stressful conditions, such as drought, high salinity, and changes in temperature. Many LEA proteins do not have defined three-dimensional structures, so they are intrinsically disordered proteins (IDPs) and are often highly hydrophilic. Although LEA-like sequences have been identified in bacterial genomes, the functions of bacterial LEA proteins have been studied only recently. Sequence analysis of outer membrane interleukin receptor I (BilRI) from the oral pathogen Aggregatibacter actinomycetemcomitans indicated that it shared sequence similarity with group 3/3b/4 LEA proteins. Comprehensive nuclearcgq magnetic resonance (NMR) studies confirmed its IDP nature, and expression studies in A. actinomycetemcomitans harboring a red fluorescence reporter protein-encoding gene revealed that bilRI promoter expression was increased at decreased temperatures. The amino acid backbone of BilRI did not stimulate either the production of reactive oxygen species from human leukocytes or the production of interleukin-6 from human macrophages. Moreover, BilRI-specific IgG antibodies could not be detected in the sera of A. actinomycetemcomitans culture-positive periodontitis patients. Since the bilRI gene is located near genes involved in natural competence (i.e., genes associated with the uptake of extracellular (eDNA) and its incorporation into the genome), we also investigated the role of BilRI in these events. Compared to wild-type cells, the ΔbilRI mutants showed a lower transformation efficiency, which indicates either a direct or indirect role in natural competence. In conclusion, A. actinomycetemcomitans might express BilRI, especially outside the host, to survive under stressful conditions and improve its transmission potential.

This case report describes the long-term follow-up of a patient with localized aggressive periodontitis over a 30-year period. A 16-year-old woman was referred for periodontal assessment after starting orthodontic treatment. The patient was treated initially by combined nonsurgical and antimicrobial therapy, and autotransplantation of maxillary third molars in place of maxillary first molars, followed by a regular supportive periodontal treatment program. This challenging case demonstrated that elimination of putative bacterial pathogens and long-term supportive periodontal treatments provide an effective treatment modality for localized aggressive periodontitis. [ABSTRACT FROM AUTHOR]

The JP2 genotype of Aggregatibacter actinomycetemcomitans serotype b is associated with aggressive forms of periodontitis and was initially identified as affecting adolescents in North and West Africa. The dissemination of this genotype follows the migration routes and can today be detected in samples from periodontitis patients in a high number of countries. In the present study, we aim to describe findings of the JP2 genotype A. actinomycetemcomits in a clinical laboratory at the Dental School, Odontology, Umeå University, Sweden. The findings of JP2 carriers are documented during a 21-year period, and the age and geographic origin of the sampled individuals are described. In addition, the collected JP2 isolates were separated into North or West African origin by analyses of the presence of a point mutation in the hbpA2 pseudogene of the bacterium. In a total of 2296 sampled individuals during this period in this Swedish population of periodontitis patients, 32 JP2 carriers were detected by cultivation and PCR. The geographic background of these individuals was diverse, including sixteen with African origin, ten with a Swedish origin and six additional ones with a non-African origin. The JP2 genotypes of A. actinomycetemcomitans were mainly isolated from young individuals (<35 years of age), and seven out of the 32 isolates were of a West African origin based on the sequence of hbpA2. We conclude that the JP2 genotype of A. actinomycetemcomitans can be detected world-wide in subgingival plaque samples from adolescents affected by periodontitis. [ABSTRACT FROM AUTHOR]