scholarly journals Interdental Supragingival Plaque—A Natural Habitat of Actinobacillus actinomycetemcomitans, Bacteroides forsythus, Campylobacter rectus, and Prevotella nigrescens

1994 ◽  
Vol 73 (8) ◽  
pp. 1421-1428 ◽  
Author(s):  
R. Gmur ◽  
B. Guggenheim

The aim of this study was to test the hypothesis that suspected periodontal pathogens form a minor component of the supragingival plaque of individuals without periodontal diseases. Twenty-one dental hygienist trainees with a mean age of 23.5 years were twice sampled for interdental plaque between 1st and 2nd molars in all quadrants. The samples were assessed for Actinobacillus actinomycetemcomitans, Bacteroides forsythus, Campylobacter rectus, Porphyromonas gingivalis, and the Prevotella intermedia/Prevotella nigrescens group of organisms. Bacteria of this group were predominantly P. nigrescens and showed both the highest prevalence (100%) and the highest colonization density of the investigated species. Seven of 21 samples harbored A. actinomycetemcomitans. Serotypes a, b, and c were found in three samples each, while serotype e was present in one sample. Three subjects had two different A. actinomycetemcomitans serotypes. Bacteroides forsythus and C. rectus were detected in 10 (48%) and nine (43%) subjects, respectively. The detected cell numbers accounted for approximately 0.01% to 1% of the sampled flora. In contrast, P. gingivalis was found only in a single sample, which in addition harbored B. forsythus, C. rectus, A. actinomycetemcomitans (serotypes b and e), and P. intermedia. These results suggest that the investigated periodontal bacteria are not "exogenous pathogens", but amphibiotic, opportunistic microorganisms which may have a natural habitat in the supragingival plaque of the interproximal area of molars.

1960 ◽  
Vol 13 (1) ◽  
pp. 69 ◽  
Author(s):  
IJ O'donnell ◽  
EOP Thompson

The effect of ionic strength (range 0,15-0, 3), pH (range 7-9), and temperature (range I-25�C) on the chromatographic behaviour of three samples of insulin on diethylaminoethyl (DEAE)-cellulose columns has been studied. These three factors have a similar effect, a decrease of temperature or pH and an increase in ionic strength lowering the elution volume of the protein. The marked effect of temperature is not due to aggregation-disaggregation of the insulin since bovine plasma albumin which does not aggregate reversibly also showed this effect. The desamido component of insulin could not be detected in commercial insulin under the conditions studied but a minor component varying from 2-6 per cent. of the insulin was separated, as well as various amounts of bound ammonia. Removal of zinc from the insulin did not affect the elution curve.


Author(s):  
Jageer Chinna ◽  
Jannat Sharma

Periodontal diseases are inflammatory and destructive diseases of the dentogingival complex associated with specific periodontal pathogens inhabiting periodontal pockets. Periodontal diseases lead to damage of the periodontal tissues supporting the teeth (bone and connective tissue) and affect the quality of life of the affected individuals: poor alimentation, tooth loss, social and financial problems. Although it is generally considered that the disease has multifactorial etiology, data show that some specific Gram-negative microorganisms in the subgingival plaque biofilm play a major role in the initiation and progression of periodontitis. Porphyromonas gingivalis, Treponema denticola and Tannerella forsythia form a consortium in the subgingival biofilm and are regarded as the principal periodontopathogenic bacteria. Other microorganisms that have been implicated as predominant species in the disease process are: Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, Prevotella intermedia, Campylobacter rectus, Peptostreptococcus migros, Eikenella corrodens. In periodontitis, the initiation of the disease is the colonization of the tissues by these pathogenic species. The next step is bacterial invasion or invasion by pathogenic products into the periodontal tissues, interactions of bacteria or their substances with host cells, and this directly/indirectly causes degradation of the periodontium, resulting in tissue destruction. Keywords: periodontal disease, periodontal pathogens, microbiology.


Author(s):  
З. Хаджиева ◽  
С. Поройский ◽  
И. Фирсова ◽  
А. Струсовская ◽  
В. Бавлакова ◽  
...  

Исследованы биофармацевтические свойства модельных гелевых композиций c экстрактом корня барбариса и использованием в качестве гелеобразователей метилцеллюлозы, натриевой соли карбоксиметилцеллюлозы, натриевой соли альгиновой кислоты и поливинилового спирта методами прямой диффузии в агаровый гель и диализа через полупроницаемую мембрану. Определены кинетические закономерности процесса и скорости набухания исследуемых гелевых основ. Показана целесообразность использования натриевой соли альгиновой кислоты для получения стоматологического геля с экстрактом корня барбариса, обладающего специфической бактериостатической активностью в отношении таких пародонтопатогенных микроорганизмов, как Porphyromonas gingivalis, Prevotella intermedia, Prevotella nigrescens и Actinobacillus actinomycetemcomitans, для профилактики и лечения воспалительных заболеваний пародонта.


2018 ◽  
Vol 68 (12) ◽  
pp. 2853-2856 ◽  
Author(s):  
Igor Jelihovschi ◽  
Cristian Drochioi ◽  
Aida Corina Badescu ◽  
Raoul Vasile Lupusoru ◽  
Alexandra Elena Munteanu ◽  
...  

The diagnosis of periodontal disease is mainly based on use of clinical and radiographic evidence. In this study we employed a quantitative PCR analysis of Aggregatibacter actinomycetemcomitans and Treponema denticola as species strongly involved in periodontal diseases, burden in periodontal pockets to detect the main sampling factors that interfere with qPCR results. From 22 patients with advanced periodontal disease, subgingival plaque was comparatively collected by paper points and periodontal Gracey curettes. Samples were collected from the same situs in presence of gingival bleeding and absence of bleeding. The concordance and agreement of results between samples were assessed. The present study demonstrates that subgingival plaque sampling with sterile absorbable paper points is often accompanied by gingival bleeding resulting in quantification biases of periodontal pathogens.


2009 ◽  
Vol 74 (10) ◽  
pp. 1543-1557 ◽  
Author(s):  
Herman P. Van Leeuwen ◽  
Raewyn M. Town

The degree of (de)protonation of aqueous metal species has significant consequences for the kinetics of complex formation/dissociation. All protonated forms of both the ligand and the hydrated central metal ion contribute to the rate of complex formation to an extent weighted by the pertaining outer-sphere stabilities. Likewise, the lifetime of the uncomplexed metal is determined by all the various protonated ligand species. Therefore, the interfacial reaction layer thickness, μ, and the ensuing kinetic flux, Jkin, are more involved than in the conventional case. All inner-sphere complexes contribute to the overall rate of dissociation, as weighted by their respective rate constants for dissociation, kd. The presence of inner-sphere deprotonated H2O, or of outer-sphere protonated ligand, generally has a great impact on kd of the inner-sphere complex. Consequently, the overall flux can be dominated by a species that is a minor component of the bulk speciation. The concepts are shown to provide a good description of experimental stripping chronopotentiometric data for several protonated metal–ligand systems.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Isamu Kado ◽  
Junzo Hisatsune ◽  
Keiko Tsuruda ◽  
Kotaro Tanimoto ◽  
Motoyuki Sugai

AbstractFixed orthodontic appliances are common and effective tools to treat malocclusion. Adverse effects of these appliances, such as dental caries and periodontitis, may be associated with alteration of the microbiome. This study investigated the impact of these appliances on the dynamics of the oral microbiome. Seventy-one patients were selected. Supragingival plaque samples were collected before placement (T0) and six months after placement (T1). Saliva samples were collected at T0 and T1, and then when appliance removal (T2). Microbial DNA was analyzed by 16S rRNA meta-sequencing. The diversity analysis indicated dynamic changes in the structure of the oral microbiome. Taxonomic analysis at phylum level showed a significant increase in Bacteroidetes and Saccharibacteria (formally TM7) and decrease in Proteobacteria and Actinobacteria over time, in both plaque and saliva. Genus level analysis of relative abundance indicated a significant increase in anaerobic and facultative anaerobes in both plaque and saliva. Fixed orthodontic appliances induced measurable changes in the oral microbiome. This was characterized by an increase in relative abundance of obligate anaerobes, including periodontal pathogens. It can be concluded that this dysbiosis induced by fixed orthodontic appliances is likely to represent a transitional stage in the shift in microbiome from healthy to periodontitis.


1994 ◽  
Vol 6 (4) ◽  
pp. 517-527 ◽  
Author(s):  
Duncan Pirrie

Late Cretaceous sedimentary rocks assigned to the Santa Marta (Herbert Sound Member) and López de Bertodano (Cape Lamb and Sandwich Bluff members) formations of the Marambio Group, crop out on Cape Lamb, Vega Island. Although previous studies have recognized that these sedimentary rocks were derived from the northern Antarctic Peninsula region, the work presented here allows the provenance and palaeogeographical evolution of the region to be described in detail. On the basis of both sandstone petrography and clay mineralogy, the Herbert Sound and Cape Lamb members reflect sediment input from a low relief source area, with sand grade sediment sourced from low grade metasediments, and clay grade sediment ultimately derived from the weathering of an andesitic source area. In contrast, the Sandwich Bluff Member reflects a switch to a predominantly andesitic volcaniclastic source. However, this sediment was largely derived from older volcanic suites due to renewed source area uplift, with only a minor component from coeval volcanism. Regional uplift of both the arc terrane and the western margin of the James Ross Basin was likely during the Maastrichtian.


1988 ◽  
Vol 254 (1) ◽  
pp. 67-71 ◽  
Author(s):  
B Rüstow ◽  
Y Nakagawa ◽  
H Rabe ◽  
K Waku ◽  
D Kunze

1. Phosphatidylinositol (PI) is a minor component of lung surfactant which may be able to replace the functionally important phosphatidylglycerol (PG) [Beppu, Clements & Goerke (1983) J. Appl. Physiol. 55, 496-502] without disturbing lung function. The dipalmitoyl species is one of the main species for both PI (14.4%) and PG (16.9%). Besides the C16:0--C16:0 species, the C16:0--C18:0, C16:0--C18:1, C16:0--C18:2 and C18:0--C18:1 species showed comparable proportions in the PG and PI fractions. These similarities of the species patterns and the acidic character of both phospholipids could explain why surfactant PG may be replaced by PI. 2. PI and PG were radiolabelled by incubation of microsomal fractions with [14C]glycerol 3-phosphate (Gro3P). For 11 out of 14 molecular species of PI and PG we measured comparable proportions of radioactivity. The radioactivity of these 11 species accounted together for more than 80% of the total. The addition of inositol to the incubation system decreased the incorporation in vitro of Gro3P into PG and CDP-DG (diacylglycerol) of lung microsomes (microsomal fractions), but did not change the distribution of radioactivity among the molecular species of PG. These results supported the idea that both acidic surfactant phospholipids may be synthesized de novo from a common CDP-DG pool in lung microsomes.


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