scholarly journals A Pilot Study of Chronological Microbiota Changes in a Rat Apical Periodontitis Model

2020 ◽  
Vol 8 (8) ◽  
pp. 1174
Author(s):  
Ok-Jin Park ◽  
Moon-Hee Jeong ◽  
Eun-Hye Lee ◽  
Mi-Ran Cho ◽  
Jaehong Hwang ◽  
...  
Keyword(s):  
Bacterial Communities ◽  
Bradyrhizobium Japonicum ◽  
Alveolar Bone ◽  
Bacterial Species ◽  
Root Apex ◽  
Apical Periodontitis ◽  
Microbial Infection ◽  
Pulp Chamber ◽  
Experimental Rat Model ◽  
Histopathologic Changes

Apical periodontitis caused by microbial infection in the dental pulp is characterized by inflammation, destruction of the pulpal and periradicular tissues, and alveolar bone resorption. We analyzed the chronological changes in microbiota using a pyrosequencing-based approach combined with radiologic and histopathologic changes in a rat apical periodontitis model. During the three-week observation, the pulp and periapical area showed a typical progress of apical periodontitis. A total of 27 phyla, 645 genera, and 1276 species were identified. The root apex had a lower bacterial species diversity than the pulp chamber. Proteobacteria, Firmicutes, Bacteroidetes, and Actinobacteria were dominant phyla in both the pulp chamber and root apex. Remarkably, bacterial communities showed a tendency to change in the root apex based on the disease progression. At the genus level, Escherichia, Streptococcus, Lactobacillus, Rodentibacter, and Bacteroidetes were dominant genera in the pulp chamber. The most abundant genera in the root apex were Bradyrhizobium, Halomonas, and Escherichia. The species Azospirillum oryzae increased in the pulp chamber, whereas the species Bradyrhizobium japonicum and Halomonas stevensii were highly observed in the root apex as the disease progressed. The experimental rat model of apical periodontitis demonstrated a relationship between the microbiota and the apical periodontitis progression.

NLRP12 Attenuates Inflammatory Bone Loss in Experimental Apical Periodontitis

2019 ◽  
Vol 98 (4) ◽  
pp. 476-484 ◽  
Author(s):  
T.M. Taira ◽  
V. Lima ◽  
D.S. Prado ◽  
T.A. Silva ◽  
J.P.M. Issa ◽  
...  
Keyword(s):  
Immune Response ◽  
Bone Loss ◽  
Bacterial Infection ◽  
Alveolar Bone ◽  
Bone Destruction ◽  
Negative Regulation ◽  
Apical Periodontitis ◽  
Tartrate Resistant Acid Phosphatase ◽  
Inflammatory Disorder ◽  
Microbial Infection

Apical periodontitis is an inflammatory disorder that results from the host immune response to microbial infection through the dental pulp, leading to alveolar bone destruction. The nod-like receptor 12 (NLRP12) is an atypical intracellular sensor of the NLR family that is involved in the negative regulation of several inflammatory conditions and also osteoclastogenesis. However, the role of NLRP12 in the regulation of immune response and bone loss induced by bacterial infection remains unclear. Here we investigated the development of apical periodontitis in wild-type (WT) and NLRP12 knockout (NLRP12–/–) mice by using micro–computed tomography together with histological, immunohistochemical, and molecular analyses. We found that NLRP12–/– mice are highly susceptible to apical periodontitis induced by bacterial infection, which is associated with an elevated infiltration of neutrophils and macrophages, periapical lesion extension, and alveolar bone destruction. Furthermore, NLRP12–/– mice showed a high expression of inflammatory cytokines ( Il1b, Il6, and Tnfa) and the osteoclastogenic markers ( Rankl and Acp5) in the periapical tissues. Consistent with this observation, NLRP12–/– mice showed an increased number of tartrate-resistant acid phosphatase–positive cells lining the apical periodontitis site, which was associated with augmented expression of the osteoclast effector genes, Ctsk and Mmp9. Mechanistically, NLRP12-deficient preosteoclasts showed elevated IκB-α degradation and p65 phosphorylation when stimulated with receptor activator of nuclear factor (NF)–κB ligand (RANKL). Similarly, increased IκB-α degradation was observed in the periapical tissue of NLRP12–/– mice. Furthermore, our in vitro study showed that preosteoclasts from NLRP12–/– mice exhibited higher RANKL-induced osteoclastogenesis, which was synergistically amplified by interleukin-1β and tumor necrosis factor α (mimicking an inflammatory periapical milieu). In conclusion, our data show that NLRP12 exhibits a protective role in the periapical bone destruction by attenuating inflammation and osteoclastogenesis through negative regulation of the NF-κB pathway.

Integration of culture-dependent and independent methods provides a more coherent picture of the pig gut microbiome

2020 ◽  
Vol 96 (3) ◽  
Author(s):  
Gavin J Fenske ◽  
Sudeep Ghimire ◽  
Linto Antony ◽  
Jane Christopher-Hennings ◽  
Joy Scaria
Keyword(s):  
Bacterial Communities ◽  
Bacterial Species ◽  
Shotgun Metagenomics ◽  
Culture Techniques ◽  
Microbiome Composition ◽  
Culture Independent ◽  
Health And Disease ◽  
The Media ◽  
And Function ◽  
Culture Dependent

ABSTRACT Bacterial communities resident in the hindgut of pigs, have profound impacts on health and disease. Investigations into the pig microbiome have utilized either culture-dependent, or far more commonly, culture-independent techniques using next generation sequencing. We contend that a combination of both approaches generates a more coherent view of microbiome composition. In this study, we surveyed the microbiome of Tamworth breed and feral pigs through the integration high throughput culturing and shotgun metagenomics. A single culture medium was used for culturing. Selective screens were added to the media to increase culture diversity. In total, 46 distinct bacterial species were isolated from the Tamworth and feral samples. Selective screens successfully shifted the diversity of bacteria on agar plates. Tamworth pigs are highly dominated by Bacteroidetes primarily composed of the genus Prevotella whereas feral samples were more diverse with almost equal proportions of Firmicutes and Bacteroidetes. The combination of metagenomics and culture techniques facilitated a greater retrieval of annotated genes than either method alone. The single medium based pig microbiota library we report is a resource to better understand pig gut microbial ecology and function. It allows for assemblage of defined bacterial communities for studies in bioreactors or germfree animal models.

Effects of Low-energy Shock Waves on Oral Bacteria

2008 ◽  
Vol 87 (10) ◽  
pp. 928-931 ◽  
Author(s):  
K.F. Novak ◽  
M. Govindaswami ◽  
J.L. Ebersole ◽  
W. Schaden ◽  
N. House ◽  
...  
Keyword(s):  
Alveolar Bone ◽  
Antibacterial Effect ◽  
Bacterial Species ◽  
Extracorporeal Shock Wave Therapy ◽  
Oral Bacteria ◽  
Low Energy ◽  
Shock Wave Therapy ◽  
Extracorporeal Shock Wave ◽  
Bacterial Aggregates ◽  
Viability Determination

We have recently demonstrated that extracorporeal shock-wave therapy (ESWT) is effective in promoting the healing of dermal wounds and in regenerating alveolar bone lost through periodontal disease. The objective of the present study was to determine any antibacterial effect of ESWT on oral bacteria. Monoculture suspensions of 6 bacterial species were treated with 100 to 500 pulses of ESWT at energy flux densities (EFD) of 0.12 mJ/mm2, 0.22 mJ/mm2, and 0.3 mJ/mm2. Following treatment, aliquots were plated for viability determination and compared with untreated controls. ESWT showed a significant microbicidal effect for Streptococcus mutans and an unencapsulated strain of Porphyromonas gingivalis following as few as 100 pulses at 0.3 mJ/mm2 (p ≤ 0.001). In addition, a significant disruption of bacterial aggregates was observed at lower EFDs. No significant reduction in viability was observed for all other bacteria at EFDs and pulses tested (p > 0.05). These findings suggest that low-energy ESWT may be bactericidal for selected oral bacteria.

scholarly journals THE INHIBITORY ACTIVITY OF KELAKAI LEAF EXTRACT AGAINST THE GROWTH OF Porphyromonas gingivalis ATCC® 33277™

2020 ◽  
Vol 5 (2) ◽  
pp. 104
Author(s):  
Destri Khusnul Khotimah ◽  
I Wayan Arya Krishnawan Firdaus ◽  
Maharani Laillyza Apriasari
Keyword(s):  
Porphyromonas Gingivalis ◽  
Leaf Extract ◽  
Alveolar Bone ◽  
Bacterial Species ◽  
Diffusion Method ◽  
Control Group ◽  
Inhibitory Zone ◽  
Mueller Hinton Agar ◽  
Inhibitory Power

ABSTRACTBackground: Chronic periodontitis is an infectious disease that causes damage on periodontal ligament and alveolar bone. The severity of periodontitis is caused by several types of bacterial species which one of them is Porphyromonas gingivalis bacteria with a prevalence of 85% in oral cavity. The extract of kelakai leaf contained antibacterial in the form of flavonoid, alkaloid, tannin, and steroid. Flavonoid consists of some chemical compounds which is one of them is quercetin. The level of quercetin in kelakai leaf is 503.56 mgQE/g. From some secondary metabolites, kelakai leaf has inhibitory power toward gram negative bacterial, Porphyromonas gingivalis. Objective: This research was intended to know the activity of inhibitory power of kelakai leaf toward Porphyromonas gingivalis bacteria. Method: This research was an experimental research consisted of 5 experimental groups that were group of kelakai leaf extract on the concentrations of 100 mh/ml, 75 mg/ml, 50mg/ml, and 25 mg/ml and the control group (0.2% chlorhexidine). Each treatment was done in 4 repetitions. The test of inhibitory power used diffusion method by measuring the inhibitory zone around the growth of Porphyromonas gingivalis on Mueller Hinton Agar media. The data were analyzed by using One Way Anova 95% and then continued with LSD. Results: Based on the LSD test, it was known that the extract of Kelakai leaf had inhibitor power activity toward Porphyromonas gingivalis. The highest inhibitory zone was on the concentration of 100 mg/ml with inhibitory zone of 14.61 mm. Conclusion: The extract of kelakai leaf had inhibitory power activity toward Porphyromonas gingivalis bacteria in vitro. Keywords: 0.2% chlorhexidine, Diffusion method, Inhibitory power, Stenochlaena palustris extract, Porphyromonas gingivalis.

scholarly journals Linearmycins Activate a Two-Component Signaling System Involved in Bacterial Competition and Biofilm Morphology

2017 ◽  
Vol 199 (18) ◽  
Author(s):  
Reed M. Stubbendieck ◽  
Paul D. Straight
Keyword(s):  
Antibiotic Resistance ◽  
Abc Transporter ◽  
Bacterial Communities ◽  
Biofilm Formation ◽  
Bacterial Species ◽  
Bioactive Metabolites ◽  
Signaling System ◽  
Content Type ◽  
Two Component ◽  
Analytical Approaches

ABSTRACT Bacteria use two-component signaling systems to adapt and respond to their competitors and changing environments. For instance, competitor bacteria may produce antibiotics and other bioactive metabolites and sequester nutrients. To survive, some species of bacteria escape competition through antibiotic production, biofilm formation, or motility. Specialized metabolite production and biofilm formation are relatively well understood for bacterial species in isolation. How bacteria control these functions when competitors are present is not well studied. To address fundamental questions relating to the competitive mechanisms of different species, we have developed a model system using two species of soil bacteria, Bacillus subtilis and Streptomyces sp. strain Mg1. Using this model, we previously found that linearmycins produced by Streptomyces sp. strain Mg1 cause lysis of B. subtilis cells and degradation of colony matrix. We identified strains of B. subtilis with mutations in the two-component signaling system yfiJK operon that confer dual phenotypes of specific linearmycin resistance and biofilm morphology. We determined that expression of the ATP-binding cassette (ABC) transporter yfiLMN operon, particularly yfiM and yfiN, is necessary for biofilm morphology. Using transposon mutagenesis, we identified genes that are required for YfiLMN-mediated biofilm morphology, including several chaperones. Using transcriptional fusions, we found that YfiJ signaling is activated by linearmycins and other polyene metabolites. Finally, using a truncated YfiJ, we show that YfiJ requires its transmembrane domain to activate downstream signaling. Taken together, these results suggest coordinated dual antibiotic resistance and biofilm morphology by a single multifunctional ABC transporter promotes competitive fitness of B. subtilis. IMPORTANCE DNA sequencing approaches have revealed hitherto unexplored diversity of bacterial species in a wide variety of environments that includes the gastrointestinal tract of animals and the rhizosphere of plants. Interactions between different species in bacterial communities have impacts on our health and industry. However, many approaches currently used to study whole bacterial communities do not resolve mechanistic details of interspecies interactions, including how bacteria sense and respond to their competitors. Using a competition model, we have uncovered dual functions for a previously uncharacterized two-component signaling system involved in specific antibiotic resistance and biofilm morphology. Insights gleaned from signaling within interspecies interaction models build a more complete understanding of gene functions important for bacterial communities and will enhance community-level analytical approaches.

Symbiotic bacteria of helminths: what role may they play in ecosystems under anthropogenic stress?

2016 ◽  
Vol 90 (6) ◽  
pp. 647-657 ◽  
Author(s):  
N.J. Morley
Keyword(s):  
Climate Change ◽  
Environmental Stress ◽  
Bacterial Communities ◽  
Bacterial Species ◽  
Symbiotic Bacteria ◽  
Anthropogenic Pressure ◽  
Anthropogenic Stress ◽  
Similar Function ◽  
Free Living ◽  
Terrestrial Habitats

AbstractSymbiotic bacteria are a common feature of many animals, particularly invertebrates, from both aquatic and terrestrial habitats. These bacteria have increasingly been recognized as performing an important role in maintaining invertebrate health. Both ecto- and endoparasitic helminths have also been found to harbour a range of bacterial species which provide a similar function. The part symbiotic bacteria play in sustaining homeostasis of free-living invertebrates exposed to anthropogenic pressure (climate change, pollution), and the consequences to invertebrate populations when their symbionts succumb to poor environmental conditions, are increasingly important areas of research. Helminths are also susceptible to environmental stress and their symbiotic bacteria may be a key aspect of their responses to deteriorating conditions. This article summarizes the ecophysiological relationship helminths have with symbiotic bacteria and the role they play in maintaining a healthy parasite and the relevance of specific changes that occur in free-living invertebrate–bacteria interactions under anthropogenic pressure to helminths and their bacterial communities. It also discusses the importance of understanding the mechanistic sensitivity of helminth–bacteria relationships to environmental stress for comprehending the responses of parasites to challenging conditions.

scholarly journals Labour sharing promotes coexistence in atrazine degrading bacterial communities

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Loren Billet ◽  
Marion Devers ◽  
Nadine Rouard ◽  
Fabrice Martin-Laurent ◽  
Aymé Spor
Keyword(s):  
Bacterial Communities ◽  
Gene Loss ◽  
Bacterial Species ◽  
Single Species ◽  
Microbial Consortia ◽  
The Public ◽  
Herbicide Atrazine ◽  
Set Up ◽  
Multiple Species ◽  
Isolated Species

AbstractMicrobial communities are pivotal in the biodegradation of xenobiotics including pesticides. In the case of atrazine, multiple studies have shown that its degradation involved a consortia rather than a single species, but little is known about how interdependency between the species composing the consortium is set up. The Black Queen Hypothesis (BQH) formalized theoretically the conditions leading to the evolution of dependency between species: members of the community called ‘helpers’ provide publicly common goods obtained from the costly degradation of a compound, while others called ‘beneficiaries’ take advantage of the public goods, but lose access to the primary resource through adaptive degrading gene loss. Here, we test whether liquid media supplemented with the herbicide atrazine could support coexistence of bacterial species through BQH mechanisms. We observed the establishment of dependencies between species through atrazine degrading gene loss. Labour sharing between members of the consortium led to coexistence of multiple species on a single resource and improved atrazine degradation potential. Until now, pesticide degradation has not been approached from an evolutionary perspective under the BQH framework. We provide here an evolutionary explanation that might invite researchers to consider microbial consortia, rather than single isolated species, as an optimal strategy for isolation of xenobiotics degraders.

scholarly journals Changes of Bacterial Communities in an Anaerobic Digestion and a Bio-Electrochemical Anaerobic Digestion Reactors According to Organic Load

Energies ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2958 ◽  
Author(s):  
Jun-Gyu Park ◽  
Won-Beom Shin ◽  
Wei-Qi Shi ◽  
Hang-Bae Jun
Keyword(s):  
Anaerobic Digestion ◽  
Methane Production ◽  
Bacterial Communities ◽  
Bacterial Species ◽  
Oxygen Demand ◽  
Optimal Operation ◽  
Organic Load ◽  
Bulk Solution ◽  
Organic Loading Rate ◽  
Operation Condition

Bacterial communities change in bulk solution of anaerobic digestion (AD) and bio-electrochemical anaerobic digestion reactors (BEAD) were monitored at each organic loading rate (OLR) to investigate the effect of voltage supply on bacterial species change in bulk solution. Chemical oxygen demand (COD) degradation and methane production from AD and BEAD reactors were also analyzed by gradually increasing food waste OLR. The BEAD reactor maintained stable COD removal and methane production at 6.0 kg/m3·d. The maximum OLR of AD reactor for optimal operation was 4.0 kg/m3·d. pH and alkalinity decline and volatile fatty acid (VFA) accumulation, which are the problem in high load anaerobic digestion of readily decomposable food wastes, were again the major factors destroying the optimal operation condition of the AD reactor at 6.0 kg/m3·d. Contrarily, the electrochemically activated dense communities of exoelectrogenic bacteria and VFA-oxidizing bacteria prevented VFAs from accumulating inside the BEAD reactor. This maintained stable pH and alkalinity conditions, ultimately contributing to stable methane production.

scholarly journals Harnessing the Potential of Killers and Altruists within the Microbial Community: A Possible Alternative to Antibiotic Therapy?

Antibiotics ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 230 ◽  
Author(s):  
Larisa N. Ikryannikova ◽  
Leonid K. Kurbatov ◽  
Surinder M. Soond ◽  
Andrey A. Zamyatnin
Keyword(s):  
Cell Death ◽  
Bacterial Communities ◽  
Bacterial Population ◽  
Bacterial Species ◽  
Microbial Populations ◽  
Ongoing Research ◽  
Life And Death ◽  
Form Part ◽  
Recent Developments ◽  
New Strategies

In the context of a post-antibiotic era, the phenomenon of microbial allolysis, which is defined as the partial killing of bacterial population induced by other cells of the same species, may take on greater significance. This phenomenon was revealed in some bacterial species such as Streptococcus pneumoniae and Bacillus subtilis, and has been suspected to occur in some other species or genera, such as enterococci. The mechanisms of this phenomenon, as well as its role in the life of microbial populations still form part of ongoing research. Herein, we describe recent developments in allolysis in the context of its practical benefits as a form of cell death that may give rise to developing new strategies for manipulating the life and death of bacterial communities. We highlight how such findings may be viewed with importance and potential within the fields of medicine, biotechnology, and pharmacology.

Bacterial community structure at defined locations ofPinus sylvestris-Suillus bovinusandPinus sylvestris-Paxillus involutusmycorrhizospheres in dry pine forest humus and nursery peat

1998 ◽  
Vol 44 (6) ◽  
pp. 499-513 ◽  
Author(s):  
Sari Timonen ◽  
Kirsten S Jørgensen ◽  
Kielo Haahtela ◽  
Robin Sen
Keyword(s):  
Carbon Source ◽  
Pinus Sylvestris ◽  
Bacterial Communities ◽  
Bacterial Species ◽  
Pine Forest ◽  
Paxillus Involutus ◽  
Carbon Source Utilization ◽  
Associated Bacteria ◽  
Suillus Bovinus ◽  
Forest Humus

Bacteria were isolated and characterized from uncolonized soil, nonmycorrhizal and mycorrhizal short roots, and soil-colonizing external mycelium from intact Pinus sylvestris - Suillus bovinus and Pinus sylvestris - Paxillus involutus mycorrhizospheres developed in microcosms containing dry pine forest humus or nursery peat. Total numbers of colony-forming units (CFU/mg dry weight) in the different locations from all ectomycorrhizospheres indicated an overall bacterial-enrichment gradient towards the roots, whereas sporeformers were more evenly distributed. Fluorescent pseudomonads were commonly isolated from all mycorrhizosphere locations in nursery peat, but they were nearly absent from the forest humus community. In contrast, sporeformers were more abundant at all locations in the latter growth substrate. The bacterial species composition of forest and nursery mycorrhizospheres was clearly divergent when characterized according to their carbon source utilization patterns in Biolog®GN or GP microplates. Factorial-designed ANOVA of a principal component analysis of the carbon source utilization data showed significant differences between isolates from the two soil types and, to a lesser extent, between S. bovinus and Paxillus involutus mycorrhizospheres. Bacterial communities from mycorrhizospheres and uncolonized soil were distinguished by their preferential utilization of carbohydrates and organic and amino acids, respectively. Suillus bovinus associated bacteria appeared to favour mannitol and Paxillus involutus associated bacteria appeared to favour fructose as carbon sources. This study demonstrates the combined effect of soil type, fungal symbiont, and precise location on bacterial communities associated with Pinus sylvestris ectomycorrhizospheres.Key words: Biolog, carbon source utilization, ectomycorrhiza, Scots pine, soil bacteria.

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