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Gut Jun 2018We aimed to characterise the microbial changes associated with histological stages of gastric tumourigenesis.
OBJECTIVES
We aimed to characterise the microbial changes associated with histological stages of gastric tumourigenesis.
DESIGN
We performed 16S rRNA gene analysis of gastric mucosal samples from 81 cases including superficial gastritis (SG), atrophic gastritis (AG), intestinal metaplasia (IM) and gastric cancer (GC) from Xi'an, China, to determine mucosal microbiome dysbiosis across stages of GC. We validated the results in mucosal samples of 126 cases from Inner Mongolia, China.
RESULTS
We observed significant mucosa microbial dysbiosis in IM and GC subjects, with significant enrichment of 21 and depletion of 10 bacterial taxa in GC compared with SG (q<0.05). Microbial network analysis showed increasing correlation strengths among them with disease progression (p<0.001). Five GC-enriched bacterial taxa whose species identifications correspond to , , , and had significant centralities in the GC ecological network (p<0.05) and classified GC from SG with an area under the receiver-operating curve (AUC) of 0.82. Moreover, stronger interactions among gastric microbes were observed in -negative samples compared with -positive samples in SG and IM. The fold changes of selected bacteria, and strengths of their interactions were successfully validated in the Inner Mongolian cohort, in which the five bacterial markers distinguished GC from SG with an AUC of 0.81.
CONCLUSIONS
In addition to microbial compositional changes, we identified differences in bacterial interactions across stages of gastric carcinogenesis. The significant enrichments and network centralities suggest potentially important roles of , , , and in GC progression.
Topics: Adult; Aged; Aged, 80 and over; Area Under Curve; Carcinogenesis; Cell Transformation, Neoplastic; China; Dysbiosis; Female; Gastric Mucosa; Humans; Male; Microbiota; Middle Aged; RNA, Ribosomal, 16S; Stomach; Stomach Neoplasms; Young Adult
PubMed: 28765474
DOI: 10.1136/gutjnl-2017-314281 -
Microorganisms Mar 2023(SE) is a recently identified intestinal microbe, which recent oral surveys suggest may be associated with oral diseases including caries and periodontal disease. Based...
(SE) is a recently identified intestinal microbe, which recent oral surveys suggest may be associated with oral diseases including caries and periodontal disease. Based upon the lack of information regarding this organism, the primary objective of this study was to determine the oral prevalence of this microbe and any potential associations with patient characteristics such as age, sex, or the presence of orthodontic appliances. This retrospective study involved the screening of an existing saliva repository composed of previously collected unstimulated clinical saliva samples. More specifically, N = 266 were identified and screened using a spectrophotometer at absorbances of A260 and A280 nm to determine their DNA purity and concentration. qPCR screening of these samples revealed a higher prevalence of positive samples among pediatric patients (63.1%) compared with adults (36.9%) in this clinic population, = 0.0007. In addition, higher percentages of were observed among orthodontic patients (71.2%) compared with non-orthodontic patients (28.8%), = 0.0001. These results did not vary by sex with nearly equal percentages of positive males and females among adult and pediatric patients, as well as orthodontic and non-orthodontic samples. These results suggest a strong potential for association between the prevalence of this organism with age as well as orthodontic status, given that younger patients and those with orthodontic brackets (regardless of age) were most likely to harbor this pathogen in sufficient levels to be detected in saliva. More research will be needed to determine any associations with specific outcomes, such as caries or periodontal disease, among positive patients within these specific populations.
PubMed: 37110290
DOI: 10.3390/microorganisms11040867 -
Journal of Pharmacy & Bioallied Sciences 2017Periodontitis is a polymicrobial disease caused by complex interactions between distinct pathogens in a biofilm resulting in the destruction of periodontal tissues. It... (Review)
Review
Periodontitis is a polymicrobial disease caused by complex interactions between distinct pathogens in a biofilm resulting in the destruction of periodontal tissues. It seems evident that unknown microorganisms might be involved in onset or progression of periodontitis. For many decades, research in the field of oral microbiology failed to identify certain subgingival microbiota due to technical limitations but, over a period of 12 years using molecular approaches and sequencing techniques, it became feasible to reveal the existence of new periodontal pathogens. Therefore, it is evident that in addition to conventional periodontal pathogens, other microbes might be involved in onset and progression of periodontitis. The novel pathogens enlisted under periodontal phylogeny include , , , , , , , , and . The polymicrobial etiology of periodontitis has been elucidated by comprehensive techniques, and studies throwing light on the possible virulence mechanisms possessed by these novel periodontal pathogens are enlisted.
PubMed: 28979069
DOI: 10.4103/jpbs.JPBS_288_16 -
Autopsy & Case Reports 2023We report a fatal subdural empyema caused by in a 66-year-old female who developed acute onset of confusion, dysarthria, and paresis in her left extremities. A CT scan...
We report a fatal subdural empyema caused by in a 66-year-old female who developed acute onset of confusion, dysarthria, and paresis in her left extremities. A CT scan showed hypodensity in a crescentic formation with a mild mid-line shift. She had a bruise on her forehead caused by a fall several days before admission, which initially raised subdural hematoma (SDH) diagnosis, and a burr hole procedure was planned. However, her condition deteriorated on the admission night, and she died before dawn. An autopsy revealed that she had subdural empyema (SDE) caused by and . Both microorganisms are oral microorganisms that rarely cause extra-oral infection. In our case, head trauma caused a skull bone fracture, and sinus infection might have expanded to the subdural space causing SDE. CT/MRI findings were not typical for either SDH or SDE. Early recognition of subdural empyema and prompt initiation of treatment with antibiotics and surgical drainage is essential for cases of SDE. We present our case and a review of four reported cases.
PubMed: 37415644
DOI: 10.4322/acr.2023.433 -
Journal of Oral Microbiology Jan 2021: The aim of this study was to compare the subgingival microbiota of people with Alzheimer´s disease (AD), mild cognitive impairment (MCI), subjective cognitive decline...
: The aim of this study was to compare the subgingival microbiota of people with Alzheimer´s disease (AD), mild cognitive impairment (MCI), subjective cognitive decline (SCD) and cognitively healthy individuals. : The study population was recruited from 2013 to 2017 and comprised 132 cases recently diagnosed with AD (n = 46), MCI (n = 40) or SCD (n = 46), and 63 cognitively healthy controls. Subgingival samples were collected, and the microbiotas were characterized by gene sequencing. : The relative abundance of the ten most common genera did not differ between the cases and control groups. However, the microbial richness and evenness were higher in cases than in controls and differed across the four groups. The variables with the greatest influence on the microbial community composition were related to periodontal disease followed by body mass index, study group affiliation and smoking. Ten taxa exhibited significant differences between case participants and controls. Two Operational Taxonomic Units were particularly abundant in AD compared to controls: , which was also associated with deep periodontal pockets, and a [G-7] bacterium. : It is concluded that in individuals with cognitive impairment or AD, the subgingival microbiota exhibits shifts typical of periodontal disease.
PubMed: 33537116
DOI: 10.1080/20002297.2020.1854552 -
Journal of Clinical Microbiology Apr 2010Eleven clinical strains isolated from infected wound specimens were subjected to polyphasic taxonomic analysis. Sequence analysis of the 16S rRNA gene showed that all 11...
Eleven clinical strains isolated from infected wound specimens were subjected to polyphasic taxonomic analysis. Sequence analysis of the 16S rRNA gene showed that all 11 strains were phylogenetically related to Slackia exigua. Additionally, conventional and biochemical tests of 6 of the 11 strains were performed as supplementary methods to obtain phenotypic identification by comparison with the phenotypes of the relevant type strains. S. exigua has been considered an oral bacterial species in the family Coriobacteriaceae. This organism is fastidious and grows poorly, so it may easily be overlooked. The 16S rRNA gene sequences and the biochemical characteristics of four of the S. exigua strains isolated for this study from various infections indicative of an intestinal source were almost identical to those of the validated S. exigua type strain from an oral source and two of the S. exigua strains from oral sources evaluated in this study. Thus, we show for the first time that S. exigua species can be isolated from extraoral infections as well as from oral infections. The profiles of susceptibility to selected antimicrobials of this species were also investigated for the first time.
Topics: Abscess; Actinobacteria; Bacterial Typing Techniques; Cluster Analysis; DNA, Bacterial; DNA, Ribosomal; Gram-Positive Bacterial Infections; Humans; Microbial Sensitivity Tests; Molecular Sequence Data; Mouth; Phylogeny; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Wound Infection
PubMed: 20107092
DOI: 10.1128/JCM.01576-09 -
International Journal of Infectious... Nov 2015
PubMed: 26432408
DOI: 10.1016/j.ijid.2015.09.015 -
The FEBS Journal Apr 2016The biosynthetic pathway for the branched-chain amino acids is present in plants, fungi and bacteria, but not in animals, making it an attractive target for herbicidal...
UNLABELLED
The biosynthetic pathway for the branched-chain amino acids is present in plants, fungi and bacteria, but not in animals, making it an attractive target for herbicidal and antimicrobial drug discovery. Ketol-acid reductoisomerase (KARI; EC 1.1.1.86) is the second enzyme in this pathway, converting in a Mg(2+) - and NADPH-dependent reaction either 2-acetolactate or 2-aceto-2-hydroxybutyrate to their corresponding 2,3-dihydroxy-3-alkylbutyrate products. Here, we have determined the crystal structure of Mycobacterium tuberculosis (Mt) KARI, a class I KARI, with two magnesium ions bound in the active site. X-ray data were obtained to 1.0 Å resolution and the final model has an Rfree of 0.163. The structure shows that the active site is solvent-accessible with the two metal ions separated by 4.7 Å. A comparison of this structure with that of Mg(2+) -free Pseudomonas aeruginosa KARI suggests that upon magnesium binding no movement of the N domain relative to the C domain occurs. However, upon formation of the Michaelis complex, as illustrated in the structure of Slackia exigua KARI in complex with NADH.Mg(2+) . N-hydroxy-N-isopropyloxamate (IpOHA, a transition state analog), domain movements and reduction of the metal-metal distance to 3.5 Å are observed. This inherent flexibility therefore appears to be critical for initiation of the KARI-catalyzed reaction. This study provides new insights into the complex structural rearrangements required for activity of KARIs, particularly those belonging to class I, and provides the framework for the rational design of Mt KARI inhibitors that can be tested as novel antituberculosis agents.
DATABASE
Coordinates and structure factors for the Mt KARI.Mg(2+) complex are available in the Protein Data Bank under accession number 4YPO.
Topics: Antitubercular Agents; Bacterial Proteins; Binding Sites; Biocatalysis; Catalytic Domain; Crystallography, X-Ray; Drug Discovery; Enzyme Inhibitors; Humans; Ketol-Acid Reductoisomerase; Magnesium; Models, Molecular; Molecular Targeted Therapy; Mycobacterium tuberculosis; Protein Multimerization; Protein Structure, Tertiary; Solutions; Tuberculosis
PubMed: 26876563
DOI: 10.1111/febs.13672 -
Frontiers in Cellular and Infection... 2020The use of stem cells from the apical papilla (SCAPs) has been proposed as a means of promoting root maturation in permanent immature teeth, and plays a significant role...
The use of stem cells from the apical papilla (SCAPs) has been proposed as a means of promoting root maturation in permanent immature teeth, and plays a significant role in regenerative dental procedures. However, the role of SCAPs may be compromised by microenvironmental factors, such as hypoxic conditions and the presence of bacteria from infected dental root canals. We aim to investigate oral bacterial modulation of SCAP in terms of binding capacity using flow cytometry and imaging, real-time cell proliferation monitoring, and cytokine secretion (IL-6, IL-8, and TGF-β isoforms) under anaerobic conditions. SCAPs were exposed to key species in dental root canal infection, namely , , , and , as well as two probiotic strains, strain B6 and (DSM 17938). We found that , , , and , but not the probiotic strains bind to SCAPs on anaerobic conditions. and exhibited the strongest binding capacity, resulting in significantly reduced SCAP proliferation. Notably, , but not , induce production of the proinflammatory chemokine IL-8 and IL-10 from SCAPs. Production of TGF-β1 and TGF-β2 by SCAPs was dependent on species, cell line, and time, but secretion of TGF-β3 did not vary significantly over time. In conclusion, SCAP response is compromised when exposed to bacterial stimuli from infected dental root canals in anaerobic conditions. Thus, stem cell-mediated endodontic regenerative studies need to include microenvironmental conditions, such as the presence of microorganisms to promote further advantage in the field.
Topics: Actinobacteria; Cell Differentiation; Cell Proliferation; Stem Cells
PubMed: 33718256
DOI: 10.3389/fcimb.2020.620801 -
Biomedicines Apr 2022The widespread increase of antibiotic resistance highlights the need for alternative treatments such as antimicrobial photodynamic therapy (aPDT). This study aimed to...
Antimicrobial Behavior and Cytotoxicity of Indocyanine Green in Combination with Visible Light and Water-Filtered Infrared A Radiation against Periodontal Bacteria and Subgingival Biofilm.
The widespread increase of antibiotic resistance highlights the need for alternative treatments such as antimicrobial photodynamic therapy (aPDT). This study aimed to evaluate the antimicrobial behavior and cytotoxicity of aPDT with indocyanine green (ICG) in combination with visible light (Vis) and water-filtered infrared A (wIRA). Representative periodontal bacteria (, , , , , , , and ) and subgingival in situ biofilms from periodontal patients were treated with aPDT for 5 min. ICG was used at different concentrations (50-500 µg/mL) and the number of viable cells was determined in colony forming units (CFU). Untreated negative controls and 0.2% chlorhexidine as a positive control were also prepared. The cytotoxicity test on human keratinocytes in vitro was analyzed with the AlamarBlue assay after 5, 10, and 20 min, with four ICG concentrations, and at two temperatures (room temperature and 37 °C). The tested periodontal pathogens treated with aPDT were eliminated in a range between 1.2 and 6.7 log CFU, except for , which was killed at a lower range. The subgingival biofilm treated with aPDT expressed significant differences to the untreated controls except for at 300 µg/mL ICG concentration. The cytotoxicity was directly related to the concentration of ICG and irradiation time. These observations raise questions concerning the use of this specific aPDT as an adjuvant to periodontal treatments due to its possible toxicity towards human gingival cells.
PubMed: 35625693
DOI: 10.3390/biomedicines10050956