Microbial Ecosystem Analysis in Root Canal Infections Refractory to Endodontic Treatment

Introduction To combine Multiple Displacement Amplification (MDA) and checkerboard DNA–DNA hybridization to qualitatively and quantitatively evaluate the microbiota present in infections refractory to endodontic treatment. Methods The subjects of this study were 40 patients presenting periapical lesions refractory to endodontic treatment. Samples were taken by scraping or filing root canal walls with a #10 K-type hand file. Sample DNA was amplified by MDA, and the levels of 107 bacterial taxa were analyzed by checkerboard DNA–DNA hybridization. The taxa were divided into three distinct microbial populations, depending on their mean proportion in samples (% DNA probe counts ± SEM), as follows: dominant (≥3.0%), sub-dominant (\u3e1.6 to 3.0%) and residual (≤1.6%) populations. The significance of differences was determined using the Mann-Whitney test. Results The taxa present with the highest mean proportions (constituting the dominant population) were Corynebacterium diphtheriae (8.03±0.98), Porphyromonas gingivalis (5.42±2.09), Streptococcus sobrinus (5.33±0.69), and Stenotrophomonas maltophilia (4.72±1.73). Among the sub-dominant population were Eubacterium saphenum (3.85±1.06), Helicobacter pylori (3.16±0.62), Dialister pneumosintes (3.12±1.1), Clostridium difficile (2.74±0.41), Enterobacter agglomerans (2.64±0.54), Salmonella enterica (2.51±0.52), Mobiluncus mulieris (2.44±0.6), and Klebsiella oxytoca (2.32±0.66). In the population of bacteria present at the lowest mean proportions (the residual population), Bacteroides ureolyticus (0.04±0.01), Haemophilus influenzae (0.04±0.02), and Prevotella oris (0.01±0.01) were found at the lowest mean proportions. Enterococcus faecalis was detected in the residual population (0.52±0.26). Conclusion The microbial climax community in teeth refractory to endodontic treatment not only harbor medically important species, but also contains distinct microbial consortia present with different population levels

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Catálogo Taxonômico da Fauna do Brasil: setting the baseline knowledge on the animal diversity in Brazil

The limited temporal completeness and taxonomic accuracy of species lists, made available in a traditional manner in scientific publications, has always represented a problem. These lists are invariably limited to a few taxonomic groups and do not represent up-to-date knowledge of all species and classifications. In this context, the Brazilian megadiverse fauna is no exception, and the Catálogo Taxonômico da Fauna do Brasil (CTFB) (http://fauna.jbrj.gov.br/), made public in 2015, represents a database on biodiversity anchored on a list of valid and expertly recognized scientific names of animals in Brazil. The CTFB is updated in near real time by a team of more than 800 specialists. By January 1, 2024, the CTFB compiled 133,691 nominal species, with 125,138 that were considered valid. Most of the valid species were arthropods (82.3%, with more than 102,000 species) and chordates (7.69%, with over 11,000 species). These taxa were followed by a cluster composed of Mollusca (3,567 species), Platyhelminthes (2,292 species), Annelida (1,833 species), and Nematoda (1,447 species). All remaining groups had less than 1,000 species reported in Brazil, with Cnidaria (831 species), Porifera (628 species), Rotifera (606 species), and Bryozoa (520 species) representing those with more than 500 species. Analysis of the CTFB database can facilitate and direct efforts towards the discovery of new species in Brazil, but it is also fundamental in providing the best available list of valid nominal species to users, including those in science, health, conservation efforts, and any initiative involving animals. The importance of the CTFB is evidenced by the elevated number of citations in the scientific literature in diverse areas of biology, law, anthropology, education, forensic science, and veterinary science, among others

Epidemiological analysis and need for endodontic treatment among the indigenous Sateré-Mawé and Tikuna

Abstract: The objective of this study was to analyze the epidemiological profile of oral health of Sateré-Mawé indigenous people living in Barreirinha, Amazonas (AM), Brazil, and the Tikuna indigenous people living in the urban area of Manaus (AM), in addition to characterizing the need for endodontic treatment between the two ethnic groups. A total of 138 individuals participated in the study, of whom 98 were Tikuna and 40 were Sateré-Mawé; they were distributed in age groups ranging from seven to 75 years. A very high prevalence of caries was observed in both ethnic groups. For the Sateré-Mawé in the 7–12 age group, the decayed, missing, and filled teeth (DMFT) index presented a mean value of 3.17. Comparing the DMFT index and the need for endodontic treatment in each of the ethnicities, these variables were found to be correlated, because as the DMFT index increases, the chances of needing endodontic treatment increase. The Sateré-Mawé presented a higher prevalence of need for endodontic treatment compared to the Tikuna. The association of comorbidities and the need for endodontic treatment were demonstrated only in the Tikuna, and there was only a correlation of this necessity with the presence of diabetes mellitus (DM) in one case. The need to expand access to oral health in these communities is emphasized, taking into account geographical access and technological, environmental, linguistic, and cultural barriers

Experimental furcal perforation treated with mineral trioxide aggregate plus selenium: immune response

Abstract The aim of this study is to evaluate the expression of cytokines in response to mineral trioxide aggregate (MTA) plus selenium in germ-free mice with experimental furcal perforation. The first left maxillary molar was opened, and the furcal area was perforated and treated with post-MTA-Se (experimental group). The same surgical intervention was performed for the maxillary right first molar, which was treated with MTA (control group). Fifteen mice were sacrificed 7, 14, and 21 days after furcal perforation, and periapical tissue samples were collected. The mRNA expression levels of the cytokines TGF-β, TNF-α, IFN-γ, HPRT, IL-10, IL-4, RANK, RANKL, IL-1, and IL-17 were assessed by using real-time polymerase chain reaction. In the experimental group, at 21-days post-MTA-Se sealing, the mRNA levels of TNF-α and IL-10 were upregulated compared with those in the control group (p 0.05). In conclusion, MTA+Se sealing favoured increased expression of IL-10 and TNF-α at later time points (day 21)

Evaluation of chemokines and receptors in gnotobiotic root canal infection by F. nucleatum and E. faecalis

Abstract The present study aims to evaluate the longitudinal effects of induced experimental infections in gnotoxenic animals on the expression of inflammatory chemokines and their receptors in periradicular tissues. The null hypothesis tested was that Enterococcus faecalis and Fusobacterium nucleatum had no effect on CCR5, CCL5, CXCL10, CCL2/MCP-1, CXCR2 and CCR1 expression. Two groups of five animals (n = 5) aged between 8 and 12 weeks were used in this study. The animals were anaesthetized, and coronary access was performed in the first molar on the right and left sides. Microorganisms were inoculated into the left molar, and the right molar was sealed without contamination to function as a control. Animals were sacrificed 7 and 14 days after infection, and periapical tissues were collected. The cytokine mRNA expression levels were assessed using real-time PCR. The chemokine mRNA expression levels demonstrated that the experimental infection was capable of inducing increased chemokine expression on day 7 compared to that on day 14, except for CCR5 and CCL5, which showed no changes. The gnotoxenic animal model proved to be effective and allowed evaluation of the immune response against a known infection. Additionally, this study demonstrates that gene expression of chemokines and their receptors against the experimental infection preferentially prevailed during the initial phase of induction of the periradicular alteration (i.e., on day 7 post-infection)