Proteomic Analysis of the Periodontal Pathogen Prevotella Intermedia Secretomes in Biofilm and Planktonic Lifestyles

Prevotella intermedia is an important species associated with periodontitis. Despite the remarkable clinical significance, little is known about the molecular basis for its virulence. The aim of this study was to characterize the secretome of P. intermedia in biofilm and planktonic life mode. The biofilm secretome showed 109 proteins while the planktonic secretome showed 136 proteins. The biofilm and the planktonic secretomes contained 17 and 33 signal-peptide bearing proteins, 13 and 18 lipoproteins, respectively. Superoxide reductase, sensor histidine kinase, C40 family peptidase, elongation factor Tu, threonine synthase etc. were unique to biofilm. Of the ~30 proteins with predicted virulence potential from biofilm and planktonic secretomes, only 6 were common between the two groups, implying large differences between biofilm and planktonic modes of P. intermedia. From gene ontology biofilm secretome displayed a markedly higher percent proteins compared to planktonic secretome in terms of cellular amino acid metabolic process, nitrogen compound metabolic process etc. Inflammatory cytokine profile analysis revealed that only the biofilm secretome, not the planktonic one, induced important cytokines such as MIP-1a/MIP-1b, IL-1b, and IL-8. In conclusion, the revealed differences in the protein profiles of P. intermedia biofilm and planktonic secretomes may trigger further questions about molecular mechanisms how this species exerts its virulence potential in the oral cavity.

An In-Vitro Study Comparing the Effects of Citrus Lemon Extract on Porphyromonas Gingivalis, Aggregatibacter Actinomycetemcomitans, and Prevotella Intermedia

Plant extracts and phytochemicals having antimicrobial characteristics could be immensely beneficial in medicinal treatments. The present study deals with the effect of Citrus lemon extract over Periodontal pathogens which are primary etiologic factors for periodontal diseases. The current study took into account periodontal pathogens such as Prevotella Intermedia, Aggregatibacter Actinomycetemcomitans, and Porphyromonas Gingivalis. Chlorhexidine is a gold standard antimicrobial agent with a wide antibacterial activity that is commonly used for chemical plaque management. When used for an extended period, however, chlorhexidine is known to stain. As a result, the alternatives are to be explored such as herbal-based agents that can be used regularly. Using the microdilution process and the culture method, the antibacterial effect of citrus lemon extract against periodontal pathogens was assessed using the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and zone of inhibition (ZOI). According to the findings of this study, citrus lemon extract can be used as a natural supplement for treatment purposes. Keywords: Antimicrobial, Citrus lemon Extract, Chlorhexidine, Periodontal Pathogens.

Leukoplakia in the Oral Cavity and Oral Microbiota: A Comprehensive Review

We reviewed the current published literature on the impact of oral microbiota on oral cavity leukoplakia (OLK), aiming at clarifying its role in disease transformation. The analysis unveiled that bacterial richness and diversity in the oral cavity tend to be decreased in OLK compared to healthy controls, with a reduction in the prevalent commensals, such as Streptococci, and elevation of anaerobes. Moreover, Fusobacterium nucleatum, Porphyromonas gingivalis and Prevotella intermedia are recurrent findings, and they already have been linked to periodontal disease. These microbial community changes may also represent a marker for the transition from OLK to oral squamous cell carcinoma. Unfortunately, the reviewed studies present several limitations, making an objective comparison difficult. To overcome these biases, longitudinal studies are necessary.

Aktivitas antibakteri ekstrak kulit jeruk nipis (Citrus aurantifolia) terhadap bakteri Prevotella intermediaAntibacterial activity of lime (Citrus aurantifolia) peel extract towards Prevotella intermedia

Pendahuluan: Prevotella intermedia merupakan salah satu bakteri utama pada penyakit periimplantitis. Periimplantitis merupakan inflamasi jaringan lunak dan keras disekitar implan yang dapat dicegah menggunakan ekstrak tanaman antibakteri. Salah satunya yaitu kulit jeruk nipis, yang dapat menghambat proses inflamasi karena mengandung alkaloid, steroid, saponin, flavonoid, tanin sebagai senyawa antibakteri. Penelitian ini bertujuan untuk mengetahui peranan antibakteri kulit jeruk nipis dengan mengukur Konsentrasi Hambat Minimal (KHM) dan Konsentrasi Bunuh Minimal (KBM) ekstrak kulit jeruk nipis terhadap pertumbuhan bakteri Prevotella intermedia. Metode: Eksperimental laboratorium dengan rancangan penelitian post test only control group design. Pengujian KHM dan KBM dilakukan dengan metode dilusi, kulit jeruk nipis dimaserasi menggunakan pelarut etanol 70% sehingga didapatkan ekstrak kulit jeruk nipis dengan konsentrasi 0,78, 1,56, 3,125, 6,25, 12,5, 25, 50, dan 100% dengan chlorhexidine sebagai kontrol positif dan akuades sebagai kontrol negatif. Media kultur bakteri menggunakan Tripton Soya Agar. Hasil: Berdasarkan analisis statistik menggunakan Kruskal Wallis menunjukkan perbedaan penurunan jumlah koloni bakteri yang signifikan (p=0,0001) pada KBM dan KHM dari berbagai konsentrasi ekstrak kulit jeruk nipis terhadap pertumbuhan bakteri Prevotella intermedia, uji lanjutan Mann Whitney menunjukkan perbedaan penurunan jumlah koloni bakteri yang signifikan (p=0,021) antar masing-masing konsentrasi dan kelompok kontrol. Simpulan: Konsentrasi hambat minimal ekstrak kulit jeruk nipis terhadap bakteri Prevotella intermedia 12,5%, konsentrasi bunuh minimalnya 25%. Kata kunci: agen antibakteri; ekstrak jeruk nipis; Prevotella intermediaABSTRACTIntroduction: Prevotella intermedia is one of the main bacteria in periimplantitis. Periimplantitis is inflammation of the soft and hard tissues around the implant that can be prevented using antibacterial plant extracts. One of them is lime peel, which can inhibit the inflammatory process due to its alkaloids, steroids, saponins, flavonoids, and tannins as antibacterial compounds. This study was aimed to determine the antibacterial activity of lime peel by measuring the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of lime peel extract on the growth of Prevotella intermedia. Methods: Experimental laboratory with post-test only control group design. The MIC and MBC tests were performed by the dilution method. The lime peel was macerated using 70% ethanol solvent to obtain lime peel extract with concentrations of 0.78, 1.56, 3.125, 6.25, 12.5, 25, 50, and 100% with chlorhexidine as a positive control and aquadest as a negative control. Bacterial culture media using Tripton Soy Agar. Results: Based on statistical analysis using Kruskal Wallis showed a significant difference in the decrease of the number of bacterial colonies (p=0.0001) in MBC and MIC from various concentrations of lime peel extract on the growth of Prevotella intermedia bacteria. Furthermore, the Mann Whitney follow-up test showed differences in the decrease of the number of bacterial colonies, which was significant (p=0.021) between each concentration and control group. Conclusions: The minimum inhibitory concentration of lime peel extract towards the growth of Prevotella intermedia was 12.5%, with the minimum bactericidal concentration of 25%. Keywords: antibacterial agent; citrus extracts; Prevotella intermedia

DETECTION OF BACTERIAL SPECIES ASSOCIATED WITH PERIODONTAL DISEASE IN A GROUP OF PATIENTS

Objectives. The study aimed to detect the presence/quantification of the 12 bacterial strains more frequently involved in the occurrence and aggravation of periodontal disease in a group of patients. Material and method. The study included 55 patients of both sexes, from the portfolio of the „Dr. Vodiță“ Dental Clinic, with chronic marginal periodontitis, who had not been under regular dental control and hygiene for at least 2 years. During the first treatment session, fluid was collected from each patient from the periodontal bags using sterile paper cones from the collection putty. Subsequently, fluid-soaked paper cones from periodontal bags were sent to the Genetic Lab in Bucharest for DNA extraction and quantification of 12 bacterial species, more common in the etiology of periodontal disease. For the correctness of the results obtained, it is necessary that patients have not taken antibiotics in the last 3 weeks. The data were analyzed and statistically processed with the Microsoft Excel 2016 program. Results. The least common bacteria found were from the species: Capnocytophaga ochracea, Aggregatibacter actinomycetemcomitans, Eikanella corrodens and Campylobacter rectus, closely followed by Capnocytophaga gingivalis, Prevotella intermedia and Capnocytophaga sputigena. The rest of the bacterial species were detected much more frequently. Discussions. In the analyzed group there was no monoinfection with Aggregatibacter actinomycetemcomitans. Porphyromonas gingivalis had an important presence in the studied group, registering increased levels in 89% of cases. In our group, Treponema denticola was present in increased amounts in 76.36% of cases. Tannerella forsythia was present in 92.72% of cases in elevated concentrations. Eikanella corrodens and Campylobacter rectus were present in 18.18% of the cases studied in high quantities. Prevotella intermedia was present in significant amounts in 34.54% of cases. Fusobacterium nucleatum was present in high concentrations in 98.18% of the cases studied. Prevotella nigrescens was present in increased amounts in 56.36% of cases. Capnocytophaga ochracea was present in 9.09% of cases in high amounts, Capnocytophaga sputigena in 38.18% of cases, and Capnocytophaga gingivalis was detected in 24.45% of cases. Conclusions. From the class of bacteria with high pathogenicity, we most frequently encountered in the studied group Tannerella forsythia. From the class of bacteria with moderate pathogenicity, we encountered the most common Fusobacterium nucleatum. From the class of bacteria with low pathogenicity, we encountered the most common Capnocytophaga sputigena. In order to validate the results obtained, it is necessary to extend the study to a larger number of patients.

The influence of oral antimicrobial peptide content on the quantitative microflora composition in periodontal pockets among residents of a large industrial region

The aim was to study the influence of periodontal pocket microecology state on the local nonspecific resistance in steelworkers with generalized periodontitis. Materials and methods. In total, 178 patients were examined. The study group consisted of 126 patients with generalized periodontitis of initial (n = 8), I (n = 32), II (n = 68) and III (n = 18) degree of severity, chronic course, exposed to work-related hazardous agents. The comparison group consisted of 32 patients with periodontitis of initial (n = 5), I (n = 10), II (n = 11) and III (n = 6) degree of severity without exposure to harmful conditions of steel industry. The control group included 20 otherwise healthy individuals. Detection of the main five periodontopathogenic microorganisms in the crevicular fluid was carried out by the polymerase chain reaction method. The levels of lactoferrin and cathelicidin LL-37 were measured by the enzyme-linked immunosorbent assay method. Results. Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis were less common, than other opportunistic bacteria in both study groups with initial severity of generalized periodontitis. With the disease development, there was a tendency to increase the number of positive samples for all microorganisms. A correlation was found between the microorganism presence in the sample and the severity of periodontal disease. In the patients of clinical groups, the concentration of cathelicidin LL-37 in the oral fluid was reduced. In the study group, a moderate inverse correlation between cathelicidin and Porphyromonas gingivalis as well as a weak inverse correlation between cathelicidin and Prevotella intermedia were revealed. Lactoferrin was correlated directly and moderately with Porphyromonas gingivalis and Prevotella intermedia but weakly - with Treponema denticola. In the comparison group, there were a statistically significant moderate inverse correlation between cathelicidin and Porphyromonas gingivalis as well a direct correlation between lactoferrin and Porphyromonas gingivalis. Correlations between the concentrations of cathelicidin and lactoferrin in the oral fluid and other periodontopathogens were revealed to be weak. Conclusions. The studies have shown significant disruptions of the oral cavity microecology in the patients exposed to harmful effects of steel industry. The correlation between the concentration of antimicrobial peptides and periodontal pathogens in the periodontal pockets has been found.