Article
Microbiology
Agata Anna Cisek, Iwona Bak, Bozena Cukrowska
Summary: Methanogenic archaea are important but often ignored in studies of human and animal intestinal microbiota. This research focused on improving the quantification of methanogens using qPCR, by refining the protocol and increasing the specificity and sensitivity of the assay. The results showed increased detection range and successful validation parameters, allowing for improved detection and quantification of methanogens in stool samples, such as chicken droppings in this study.
Article
Multidisciplinary Sciences
Ebru Destan, Busra Yuksel, Bradley B. Tolar, Esra Ayan, Sam Deutsch, Yasuo Yoshikuni, Soichi Wakatsuki, Christopher A. Francis, Hasan DeMirci
Summary: The protein encoded by Nmar_1308 plays a crucial role in the ammonia-oxidizing thaumarchaeal 3HP/4HB cycle by acting as both CCAH and 3HPD, thereby reducing the number of enzymes required for CO2 fixation and lowering the overall cost of biosynthesis. The high-resolution crystal structure of this bifunctional enzyme provides insights into key catalytic residues in the thaumarchaeal 3HP/4HB pathway.
SCIENTIFIC REPORTS
(2021)
Review
Microbiology
Aleksei Gendron, Kylie D. Allen
Summary: Methyl-coenzyme M reductase (MCR) is an enzyme involved in methane metabolism, playing a crucial role in methane production and the conversion of alkanes. It is a dimer composed of heterotrimers and requires unique post-translational modifications and a specific coenzyme for its catalytic activity. Understanding the catalysis of MCR and its production in heterologous hosts is important for optimizing biocatalytic systems.
FRONTIERS IN MICROBIOLOGY
(2022)
Review
Microbiology
Gunter Wegener, Rafael Laso-Perez, Victoria J. Orphan, Antje Boetius
Summary: This article reviews recent discoveries in the anaerobic oxidation of alkanes, with a specific focus on archaea that use specific methyl coenzyme M reductases to activate their substrates. Through environmental metagenomics and enrichment cultures, our understanding of the diversity of uncultured alkane-oxidizing archaea has expanded, revealing a group of archaea that directly couples long-chain alkane degradation with methane formation.
ANNUAL REVIEW OF MICROBIOLOGY
(2022)
Article
Multidisciplinary Sciences
Cedric J. Hahn, Olivier N. Lemaire, Joerg Kahnt, Sylvain Engilberge, Gunter Wegener, Tristan Wagner
Summary: The study reveals the high-resolution structure of an ethane-activating enzyme and its distinguishing features from other enzymes, such as a widened catalytic chamber and a sulfur replacing oxygen as the lower-axial ligand. A long hydrophobic tunnel guides ethane to the buried active site.
Article
Microbiology
Bert Engelen, Tien Nguyen, Benedikt Heyerhoff, Saskia Kalenborn, Katharina Sydow, Houssem Tabai, Richard N. Peterson, Gunter Wegener, Andreas Teske
Summary: The surficial hydrothermal sediments of Guaymas Basin support diverse microbial communities with overlapping populations involved in oxidative and reductive processes. DGGE analysis revealed gradual changes in microbial community structure on a 2-millimeter scale, including sulfate-reducing bacteria, fermentative bacteria, and other uncultured clades. The presence of aerobic, nitrifying, sulfate-reducing, and fermentative bacteria and archaea in the sediments suggests a dynamic and complex ecosystem sustained by redox and thermal gradients.
FRONTIERS IN MICROBIOLOGY
(2021)
Review
Chemistry, Multidisciplinary
Chen Cai, Xueqin Zhang, Mengxiong Wu, Tao Liu, Chun-Yu Lai, Joshua Frank, Bingqing He, Esteban Marcellin, Jianhua Guo, Shihu Hu, Zhiguo Yuan
Summary: Reducing methane emissions is crucial for addressing climate change, and recent studies suggest that anaerobic oxidation of methane (AOM) could play a key role in producing liquid fuels/chemicals, acting as a net sink for CO2, and powering bioelectrochemical and biosynthesis cells.
ENERGY & ENVIRONMENTAL SCIENCE
(2021)
Article
Multidisciplinary Sciences
Jonathan Gropp, Qusheng Jin, Itay Halevy
Summary: This paper develops a metabolic-isotopic model of methanogenesis and explains multiple isotopic patterns in laboratory and natural settings. It also provides predictions for the biomass-specific methanogenesis rates.
Article
Microbiology
Christian Heryakusuma, Dwi Susanti, Hang Yu, Zhou Li, Endang Purwantini, Robert L. Hettich, Victoria J. Orphan, Biswarup Mukhopadhyay
Summary: Anaerobic methanotrophic archaea (ANME) oxidize methane in marine sediments through associations with sulfate-reducing bacteria. The study showed that FsrII from ANME-2c functions as F-420-dependent nitrite reductase (FNiR), revealing functional specialization within the Fsr protein family.
JOURNAL OF BACTERIOLOGY
(2022)
Article
Dentistry, Oral Surgery & Medicine
Rodrigo Arruda-Vasconcelos, Marlos Barbosa-Ribeiro, Lidiane M. Louzada, Beatriz I. N. Lemos, Adriana de-Jesus-Soares, Caio C. R. Ferraz, Jose F. A. Almeida, Marina A. Marciano, Brenda P. F. A. Gomes
Summary: This study aimed to monitor the effects of chemomechanical preparation and intracanal medication on the levels of bacteria, endotoxins, and lipoteichoic acid in teeth with symptomatic irreversible pulpitis. The results showed that chemomechanical preparation and intracanal medication effectively reduced the microbial load and levels of endotoxins and lipoteichoic acid in the root canals of the affected teeth.
JOURNAL OF ENDODONTICS
(2022)
Article
Medicine, General & Internal
Susanne Schulz, Jamal M. Stein, Anne Schumacher, David Kupietz, Sareh S. Yekta-Michael, Florian Schittenhelm, Georg Conrads, Hans-Guenter Schaller, Stefan Reichert
Summary: Different periodontal treatment methods have varying effects on subgingival colonization. Clinical parameters improved within three months but deteriorated after six months. Investigating subgingival microbiota helps evaluate periodontal treatment and implement personalized therapy.
JOURNAL OF CLINICAL MEDICINE
(2022)
Article
Microbiology
Yuting Shi, Christian Bergs, Mohamed M. H. Abdelbary, Andrij Pich, Georg Conrads
Summary: This study introduces a new method for synthesizing nanogels and tests their antimicrobial activity against peri-implantitis-associated bacteria. Two nanogels showed inhibitory effects on bacteria at higher concentrations, making them potential building blocks for implant coatings.
Article
Infectious Diseases
Mohamed M. H. Abdelbary, Florian Schittenhelm, Sareh Said Yekta-Michael, Stefan Reichert, Susanne Schulz, Adrian Kasaj, Andreas Braun, Georg Conrads, Jamal M. Stein
Summary: This study compared the clinical and microbiological effects of four different treatment methods for periodontitis stage III/IV. The results showed that full-mouth approaches were slightly more effective in bacterial reduction compared to quadrant/week-wise debridement. In addition, a potential effect of one full-mouth approach on the key pathogen P. gingivalis was observed.
Article
Infectious Diseases
Aline Silva Braga, Mohamed Mostafa Hefny Abdelbary, Rafaela Ricci Kim, Fernanda Pereira de Souza Rosa de Melo, Luiz Leonardo Saldanha, Anne Ligia Dokkedal, Georg Conrads, Marcella Esteves-Oliveira, Ana Carolina Magalhaes
Summary: This study investigated the effects of herbal toothpaste on bacterial counts and enamel demineralization. The results showed that toothpaste containing different herbal ingredients can significantly reduce bacterial counts and minimize enamel demineralization.
Article
Multidisciplinary Sciences
Mohamed M. H. Abdelbary, Christoph Kuppe, Sareh Said-Yekta Michael, Thilo Kruger, Jurgen Floege, Georg Conrads
Summary: This study investigated the effects of a Fe(3+)-based phosphate binder on the oral and gastrointestinal microbiome of hemodialysis patients. Overall, the microbiome did not change significantly, but there were individual differences. Bacterial taxa that benefited from iron abundance lacked iron-binding siderophores or alternatives, while those that declined under iron abundance possessed these alternatives. Patients with microbiome shift were younger and had higher serum phosphate concentrations.
SCIENTIFIC REPORTS
(2022)
Article
Dentistry, Oral Surgery & Medicine
Jamal M. Stein, Georg Conrads, Mohamed M. H. Abdelbary, Sareh Said Yekta-Michael, Patricia Buttler, Joanna Glock, Gelareh Sadvandi, Robert Kaufmann, Christian Apel
Summary: This study investigated the efficiency of different implant decontamination methods and their effects on biofilm modification and potential cytotoxicity. The results showed that air-polishing methods and ultrasonic devices were effective in removing biofilm and had favorable cytocompatibility on titanium and zirconium surfaces. However, the application of chemical agents on implant surfaces may cause potential cytotoxic effects.
CLINICAL ORAL IMPLANTS RESEARCH
(2023)
Article
Immunology
Mohamed M. H. Abdelbary, Maximilian Hatting, Alexandra Bott, Andrea Dahlhausen, Doris Keller, Christian Trautwein, Georg Conrads
Summary: Inflammatory bowel disease (IBD) patients showed significant alterations in the microbial composition of saliva, with higher abundance of Veillonella and Prevotella compared to healthy controls, while Neisseria, Streptococcus, Haemophilus, and Fusobacterium were associated with a healthy gut state. Additionally, the IBD group had higher abundance of pathogenic bacteria such as Clostridium sensu stricto 1 and Escherichia-Shigella in fecal microbiome compared to control group.
FRONTIERS IN CELLULAR AND INFECTION MICROBIOLOGY
(2022)
Article
Anatomy & Morphology
Corinna Marie Schoen, Rogerio B. Craveiro, Christian Niederau, Georg Conrads, Holger Jahr, Thomas Pufe, Michael Wolf
Summary: Porphyromonas gingivalis lipopolysaccharide (PG-LPS) is an important virulence factor in periodontal tissue destruction. Toll-like receptor 4 (Tlr4) plays a key role in the NF-kB activation during pathogen recognition. This study investigated the effects of PG-LPS on cell morphology, cell viability, and downstream molecules in cementoblasts, revealing significant changes in Tlr4, I Kappa B alpha, and downstream signaling kinases.
ANNALS OF ANATOMY-ANATOMISCHER ANZEIGER
(2023)
Article
Microbiology
Tim Klomp, Holger Jahr, Mohamed M. H. Abdelbary, Georg Conrads
Summary: This study investigated the growth-stimulating effect of hydrocortisone (HC) on Porphyromonas gingivalis. The results showed that HC significantly stimulated the lag-phase growth of P. gingivalis, with a concentration-dependent effect between 2.5 and 5 μg/ml, while lower and higher concentrations did not stimulate or inhibited growth.
Review
Dentistry, Oral Surgery & Medicine
Lucas Peixoto de Araujo, Leandro Bueno Gobbo, Tamares Andrade da Silva, Wellington Luiz de Oliveira da Rosa, Jose Flavio Affonso de Almeida, Brenda P. F. A. Gomes, Caio Cezar Randi Ferraz
Summary: The aim of this study was to evaluate the efficacy of supplementary photodynamic therapy (PDT) on primary tooth pulpectomy through a systematic review. Four studies met the inclusion criteria, but no significant conclusions could be drawn due to the moderate-to-low certainty of the available evidence.
INTERNATIONAL JOURNAL OF PAEDIATRIC DENTISTRY
(2023)
Article
Oncology
Esdras Gabriel Alves-Silva, Rodrigo Arruda-Vasconcelos, Lidiane Mendes Louzada, Adriana de-Jesus-Soares, Caio Cezar Randi Ferraz, Jose Flavio Affonso Almeida, Marina Angelica Marciano, Carolina Steiner-Oliveira, Joao Miguel Marques Santos, Brenda P. F. A. Gomes
Summary: This study evaluated the effectiveness of supplemental photodynamic therapy (aPDT) in improving bacterial removal and reducing the levels of lipopolysaccharide (LPS) and lipoteichoic acid (LTA) in root canals. The results showed that aPDT significantly decreased bacterial counts and levels of LPS and LTA.
PHOTODIAGNOSIS AND PHOTODYNAMIC THERAPY
(2023)
Article
Dentistry, Oral Surgery & Medicine
Lucia Kottmann, Rene Franzen, Georg Conrads, Stefan Wolfart, Juliana Marotti
Summary: This study aimed to evaluate the effectiveness of an Er,Cr:YSGG laser with side-firing tip in decontaminating titanium discs. The results showed that Perioflow and the Er,Cr:YSGG laser had similar efficacy in decontamination.
INTERNATIONAL JOURNAL OF IMPLANT DENTISTRY
(2023)
Article
Dentistry, Oral Surgery & Medicine
Hendrik Leonhard Meyer, Mohamed M. H. Abdelbary, Eva Miriam Buhl, Christoph Kuppe, Georg Conrads
Summary: This study investigates the diversity within FimA and FimB, the key components of Porphyromonas gingivalis' long fimbriae. The phylogenetic analysis reveals two new subtypes of FimA and confirms the close relationship between Porphyromonas gulae fimA-type A and human P. gingivalis strains of cluster Ib. Transmission electron microscopy and scanning electron microscopy images show a wide range of fimbrial structures, including bundling, cell-cell knotting, and brick-wall formation. This study also highlights the importance of investigating the role and variations of accessory proteins FimC-E in superstructure formation and/or adhesion.
MOLECULAR ORAL MICROBIOLOGY
(2023)
Article
Infectious Diseases
Sarah Boecher, Hendrik L. Meyer, Evdokia Dafni, Georg Conrads
Summary: This study investigated the prevalence and phylogenetic origin of the lipoprotein-gene ragB-1 in Porphyromonas gingivalis (P.g.) strains worldwide. The research found a 16% prevalence of ragB-1 in P.g. strains, with variations in amino acid sequences in some strains. The study suggests that rag-1 was originally transferred from animals to humans and evolved into less virulent commensal variants over time.