Saliva is a non ‐negligible factor in the spread of COVID‐19
SummarySARS ‐CoV‐2, a novel emerging coronavirus, has caused severe disease (COVID‐19), and rapidly spread worldwide since the beginning of 2020. SARS‐CoV‐2 mainly spreads by coughing, sneezing, droplet inhalation, and contact. SARS‐CoV‐2 has been detected in saliva samples, making saliva a potent ial transmission route for COVID‐19. The participants in dental practice confront a particular risk of SARS‐CoV‐2 infection due to close contact with the patients and potential exposure to saliva‐contaminated droplets and aerosols generated during dental procedures. In addition, saliva‐con taminated surfac...
Source: Molecular Oral Microbiology - May 3, 2020 Category: Microbiology Authors: Yuqing Li,
Biao Ren,
Xian Peng,
Tao Hu,
Jiyao Li,
Tao Gong,
Boyu Tang,
Xin Xu,
Xuedong Zhou Tags: ORIGINAL ARTICLE Source Type: research
Lipoteichoic acid of Enterococcus faecalis interferes with Porphyromonas gingivalis lipopolysaccharide signaling via IRAK ‐M upregulation in human periodontal ligament cells
AbstractPeriodontitis is a chronic inflammatory disease of the gums caused by infection with multispecies oral bacteria. Since the periodontopathic bacteriaPorphyromonas gingivalis together withEnterococcus faecalis are frequently detected in patients with a severe form of periodontitis, interactions between their virulence factors might play an important role in progression of the disease.P. gingivalis andE. faecalis possess lipopolysaccharide (Pg.LPS) and lipoteichoic acid (Ef.LTA), respectively, as the major virulence factors inducing inflammatory responses. However, the combinatorial effect of these virulence factors o...
Source: Molecular Oral Microbiology - April 19, 2020 Category: Microbiology Authors: Jintaek Im,
Jung Eun Baik,
Dongwook Lee,
Kee ‐Yeon Kum,
Cheol‐Heui Yun,
Ok‐Jin Park,
Seung Hyun Han Tags: ORIGINAL ARTICLE Source Type: research
Issue Information
Molecular Oral Microbiology, Volume 35, Issue 2, Page i-iii, April 2020. (Source: Molecular Oral Microbiology)
Source: Molecular Oral Microbiology - March 7, 2020 Category: Microbiology Tags: ISSUE INFORMATION Source Type: research
The S. mutans mntE gene encodes a manganese efflux transporter
In conclusion, theS. mutans SMU_1176 gene, which we renamedmntE, is a manganese efflux transporter that contributes to essential metal ion homeostasis as part of the SloR regulon. (Source: Molecular Oral Microbiology)
Source: Molecular Oral Microbiology - March 4, 2020 Category: Microbiology Authors: Joseph O ’Brien,
Alexander Pastora,
Andrew Stoner,
Grace Spatafora Tags: ORIGINAL ARTICLE Source Type: research
Aggregatibacter actinomycetemcomitans leukotoxin: From mechanism to targeted anti ‐toxin therapeutics
AbstractAggregatibacter actinomycetemcomitans is a Gram ‐negative bacterium associated with localized aggressive periodontitis, as well as other systemic diseases. This organism produces a number of virulence factors, all of which provide some advantage to the bacterium. Several studies have demonstrated that clinical isolates from diseased patients, p articularly those of African descent, frequently belong to specific clones ofA. actinomycetemcomitans that produce significantly higher amounts of a protein exotoxin belonging to the repeats ‐in‐toxin (RTX) family, leukotoxin (LtxA), while isolates from healthy patient...
Source: Molecular Oral Microbiology - February 15, 2020 Category: Microbiology Authors: Eric Krueger,
Angela C. Brown Tags: REVIEW ARTICLE Source Type: research
CRISPR ‐Cas systems in oral microbiome: From immune defense to physiological regulation
CRISPR ‐Cas system, found in bacteria and archaea, provides sequence‐based adaptive immunity against mobile genetic elements, including phages and plasmids. The oral cavity contains approximately 700 prokaryote species harboring known CRISPR‐Cas systems. Here, we review the canonical and novel functi ons of the CRISPR‐Cas systems in oral microbiome, including defense against foreign mobile elements, biofilm formation, acquisition of resistance genes, DNA repair, regulation of interspecific competition and intraspecific diversification, stress responses, and gene expression regulation. AbstractThe clustered regularl...
Source: Molecular Oral Microbiology - February 14, 2020 Category: Microbiology Authors: Tao Gong,
Jumei Zeng,
Boyu Tang,
Xuedong Zhou,
Yuqing Li Tags: REVIEW ARTICLE Source Type: research
Streptococcus mutans SpxA2 relays the signal of cell envelope stress from LiaR to effectors that maintain cell wall and membrane homeostasis
In this study, the role of thespxA2 transcriptional regulator in these two pathways, and overall cell envelope homeostasis, was examined. Loss ofspxA2 resulted in an increase in the proportion of saturated fatty acids in theS. mutans membrane and altered transcription of several genes involved in the production of these membrane fatty acids, includingfabT andfabM. Furthermore, activity of the F1F0‐ATPase was increased in the ∆spxA2 strain. Transcription ofspxA2 was elevated in the presence of a variety of membrane stressors, and highly dependent on theliaR component of the LiaFSR system, which is known to sense cell en...
Source: Molecular Oral Microbiology - February 11, 2020 Category: Microbiology Authors: Jonathon L. Baker,
Sarah Saputo,
Roberta C. Faustoferri,
Robert G. Quivey Tags: ORIGINAL ARTICLE Source Type: research
Quantitative proteomic analysis of the type IX secretion system mutants in Porphyromonas gingivalis
AbstractPorphyromonas gingivalis is an anaerobic, Gram ‐negative human oral pathogen highly associated with chronic periodontitis.P. gingivalis utilises the type IX secretion system (T9SS) to transport many of its virulence factors including the gingipains to the cell surface. The T9SS is comprised of at least 16 proteins and the involvement of these 16 proteins in the T9SS has been verified by creating gene deletion mutants inP. gingivalis. These T9SS mutants are regularly utilised to understand how these proteins function together to allow the secretion of the T9SS substrates. We performed label ‐free quantitative pr...
Source: Molecular Oral Microbiology - February 11, 2020 Category: Microbiology Authors: Dhana G. Gorasia,
Michelle D. Glew,
Paul D. Veith,
Eric C. Reynolds Tags: ORIGINAL ARTICLE Source Type: research
Ribosomal Protein L4 of Lactobacillus rhamnosus LRB alters resistance to macrolides and other antibiotics
In this study, we isolated a nontargeted mutant that was particularly sensitive to acid stress. Using next generation sequencing, we further mapped the putative mutations in the genome and found that the mutant had acquired a deletion of 75 base pairs in therplD gene that encodes the large ribosomal subunit L4. The mutant had a growth defect at 37 °C and at ambient temperature. Further antibiotic sensitivity analyses indicated that the mutant is relatively more resistant to erythromycin and chloramphenicol; two antibiotics that target the 50S subunit. In contrast, the mutant was more sensitive to tetracycline, which targe...
Source: Molecular Oral Microbiology - February 5, 2020 Category: Microbiology Authors: Saswati Biswas,
Andrew Keightley,
Indranil Biswas Tags: ORIGINAL ARTICLE Source Type: research
CRISPR ‐Cas system in oral microbiome: from immune defense to physiological regulation
AbstractThe clustered regularly interspaced short palindromic repeats with CRISPR ‐associated proteins (CRISPR‐Cas) system, found in bacteria and archaea, provides sequence‐based adaptive immunity against mobile genetic elements, including phages and plasmids. The oral cavity contains approximately 700 prokaryote species harboring known CRISPR‐Cas systems, including type I, type II, type III, type V, and type VI, and unidentified CRISPR‐Cas systems. There is increasing evidence to suggest that different CRISPR‐Cas systems in the human oral microbiome can affect bacterial physiology through different mechanisms....
Source: Molecular Oral Microbiology - January 28, 2020 Category: Microbiology Authors: Tao Gong,
Jumei Zeng,
Boyu Tang,
Xuedong Zhou,
Yuqing Li Tags: REVIEW ARTICLE Source Type: research
Identification of functional domains of the minor fimbrial antigen involved in the interaction of Porphyromonas gingivalis with oral streptococci
AbstractPorphyromonas gingivalis is associated with chronic periodontitis and may initially colonize the oral cavity by adhering to streptococci. Adhesion to streptococci is driven by interaction of the minor fimbrial antigen (Mfa1) with streptococcal antigen I/II. We identified the region of antigen I/II required for this interaction and developed small molecule mimetics that inhibitedP. gingivalis adherence. However, the functional motifs of Mfa1 involved in the interaction with antigen I/II remain uncharacterized. A series of N ‐ and C‐terminal peptide fragments of Mfa1 were expressed and tested for inhibition ofP. ...
Source: Molecular Oral Microbiology - January 27, 2020 Category: Microbiology Authors: Mohammad Roky,
John O. Trent,
Donald R. Demuth Tags: ORIGINAL ARTICLE Source Type: research
Heterogeneity of Streptococcus anginosus ß‐hemolysis in relation to CRISPR/Cas
AbstractStreptococcus anginosus is a commensal of the oral mucosa that can cause severe invasive infections. A considerable proportion ofStreptococcus anginosus strains are ß‐hemolytic due to the presence of an SLS‐like gene cluster. However, the majority of strains do not display ß‐hemolysis. To investigate ß‐hemolysin heterogeneity inS. anginosus, we determined the presence ofsag genes and correlated it with the presence of CRISPR/Cas genes in a collection of ß‐hemolytic and non‐ß‐hemolytic strains. All of the ß‐hemolytic strains carried thesag gene cluster. In contrast to other streptococci, clinic...
Source: Molecular Oral Microbiology - January 23, 2020 Category: Microbiology Authors: Richard Bauer,
Nathalie Neffgen,
Aline Grempels,
Martina Furitsch,
Stefanie Mauerer,
Salome Barbaqadze,
Gerhard Haase,
Hans Kestler,
Barbara Spellerberg Tags: ORIGINAL ARTICLE Source Type: research
Nanoscale Adhesion Forces of glucosyltransferase B and C genes regulated streptococcal mutans probed by AFM
AbstractGlucosyltransferases (Gtfs), represented by GtfB and GtfC, are important virulence factors ofStreptococcus mutans and the major etiologic pathogens of tooth decay. However, the individual roles ofgtfB andgtfC in the initial attachment ofS. mutan are not known. We used atomic force microscopy to explore the contribution ofgtfB andgtfC, as well as enamel ‐surface roughness, on the initial attachment ofS. mutans. Adhesion forces of fourS. mutans strains (wild ‐type, ΔgtfB, ΔgtfC and ΔgtfBC), onto etched enamel surfaces, were determined.Force curves showed that, with increasing etching time from 0 s to 10 s, the...
Source: Molecular Oral Microbiology - January 19, 2020 Category: Microbiology Authors: Rui Wang,
Ling Deng,
Dong Chen,
Peiyao Wu,
Liying Hao,
Yigan Wang,
Tianjiao Li,
Li Jiang Tags: ORIGINAL ARTICLE Source Type: research
