Regulation of urease expression of <i>Actinomyces naeslundii</i> in biofilms in response to pH and carbohydrate

Liu, Yaling; Jiang, Dan; Hu, Tao; Zhou, Xuedong

doi:10.1111/j.1399-302x.2008.00430.x

Cited by 12 publications

(7 citation statements)

References 22 publications

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“…The hydrolysis of urea by the urease enzymes of members of oral microbiota might have a major impact on oral microbial ecology and is closely involved in the maintenance of oral health and/or diseases. In many anatomical locations, such as the oral cavity and female genital tract, the excess carbohydrate availability and neutral pH environments could promote urease expression of Actinomyces in biofilms, but only neutral pH environments could up-regulate the ureC gene expression (as pH regulates ureC gene expression at a transcriptional level) [75,76]. Most of the investigated Actinomyces strains are able to produce cell-associated/extracellular polymers, such as dextran, levan, glycogen, and N-acetylglucosamine-rich slime polysaccharides, therefore, the cells can attach to different (own or foreign) surfaces [77].…”

Section: Actinomyces Species As Members Of the Human Microbiotamentioning

confidence: 99%

The Pathogenic Role of Actinomyces spp. and Related Organisms in Genitourinary Infections: Discoveries in the New, Modern Diagnostic Era

Gajdács

Urbán

2020

Antibiotics

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Actinomycosis is a chronic, suppurative, granulomatous infectious disease, caused by different species of Actinomyces bacteria. To date, 26 validly published Actinomyces species have been described as part of a normal human microbiota or from human clinical specimens. Due to the rapid spread of new, modern diagnostic procedures, 13 of 26 of these species have been described in this century and the Actinomycetaceae family has undergone several taxonomic revisions, including the introduction of many novel species termed Actinomyces-like organisms (ALOs). There is scarce data available on the role of these novel bacterial species in various infectious processes in human medicine. The aim of this review is to provide a comprehensive overview of Actinomyces and closely related organisms involved in human diseases—with a special focus on newly described species—in particular their role in genitourinary tract infections in females and males.

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Section: Actinomyces Species As Members Of the Human Microbiotamentioning

confidence: 99%

The Pathogenic Role of Actinomyces spp. and Related Organisms in Genitourinary Infections: Discoveries in the New, Modern Diagnostic Era

Gajdács

Urbán

2020

Antibiotics

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“…34,35 The expression of oral bacterial ureases is often regulated by multiple inputs. 36,37,38,39 Commonly, the presence of urea or limitation for a nitrogen source can induce urease gene transcription. In some bacteria, urease expression is repressed at neutral pH values, but under acidic conditions the urease genes become activated.…”

Section: Genetics and Regulation Of Alkali Generationmentioning

confidence: 99%

“…Urease gene expression can also be sensitive to carbohydrate availability and rate of growth. 36,37,38 …”

Section: Genetics and Regulation Of Alkali Generationmentioning

confidence: 99%

Progress toward understanding the contribution of alkali generation in dental biofilms to inhibition of dental caries

2012

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Alkali production by oral bacteria is believed to have a major impact on oral microbial ecology and to be inibitory to the initiation and progression of dental caries. A substantial body of evidence is beginning to accumulate that indicates the modulation of the alkalinogenic potential of dental biofilms may be a promising strategy for caries control. This brief review highlights recent progress toward understanding molecular genetic and physiologic aspects of important alkali-generating pathways in oral bacteria, and the role of alkali production in the ecology of dental biofilms in health and disease.

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“…Using a more streamlined technology could also improve the low repeatability observed between the two visits. The variability in the results between the two visits could also be explained by the fact that expression of the genes involved in sugar and urea metabolism in oral bacteria is highly regulated in response to carbohydrate availability, nitrogen availability, and pH (Morou-Bermudez and Burne, 2000; Burne and Marquis 2000; Lemos et al, 2005; Li et al, 2008). To address this issue we utilized a standardized sample collection protocol that was performed under fasting conditions; however, it is possible that the participants followed the fasting requirement in the first visit only, but not the second one.…”

Section: Discussionmentioning

confidence: 99%

Oral Bacterial Acid–Base Metabolism in Caries Screening: A Proof-Of-Concept Study

Morou-Bermúdez

Loza-Herrero

Garcia-Rivas

et al. 2016

JDR Clinical & Translational Research

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The objective of this cross-sectional study was to clinically validate an array of biochemical tests for oral acid/alkali generation as caries screening instruments. 185 adult subjects (mean 33.6±10.6 years) were examined clinically for dental caries using the ICDAS criteria. Bitewing radiographs were used to confirm interproximal surfaces of posterior teeth. For the purposes of this study, subjects were classified as “caries-active” if they had at least one untreated caries lesion with ICDAS 4 or higher. Pooled supragingival plaque and unstimulated saliva samples were collected and assayed for pH changes from sucrose and urea metabolism using colorimetric tests. The validity of each test to discriminate between “caries-inactive” and “caries-active” subjects was assessed and compared to a commercial bacteriological caries-screening test using roc regression and logistic regression models. The AUCs of the plaque-urea (PU: 0.59 (0.51, 0.67)), plaque-urea-glucose (PUG: 0.59 (0.51, 0.67)) and saliva-urea-glucose (SUG: 0.59 (0.51, 0.67)) tests did not differ significantly from the bacteriological tests (CRT-mutans: 0.62 (0.54, 0.70); CRT-lactobacillus: 0.63 (0.56, 0.71) (P>0.05), but the plaque-glucose (SG), saliva-glucose (SG), saliva-urea (SU) and saliva-plaque-glucose (SPG) tests had significantly smaller AUCs (P<0.05). The AUCs for the PU, PUG, SUG, and the CRT-mutans tests were higher in subjects who had no existing dental restorations (PU: 0.90 (0.77, 1.04); PUG: 0.90 (0.79, 1.01); SUG: 0.89 (0.69, 1.08); CRT-mutans: 0.90 (0.73, 1.08)). The incorporation of the biochemical tests into a multidimensional bacteriological/psychosocial caries screening model significantly increased its diagnostic values (Se+Sp: 160.6, AUC: 0.846). In conclusion, as a proof of concept, the results of this study indicate that measuring the ability of dental plaque and saliva to metabolize urea together with the ability to generate acid from sugars may have a promising role in caries screening either independently, or as part of a multidimensional biological test.

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Regulation of urease expression of Actinomyces naeslundii in biofilms in response to pH and carbohydrate

Abstract: Neutral pH environments and excess carbohydrate availability could promote urease expression of A. naeslundii in biofilms, but only neutral pH environments could up-regulate the ureC gene expression and the pH regulates ureC gene expression at a transcriptional level.

Cited by 12 publications

References 22 publications

The Pathogenic Role of Actinomyces spp. and Related Organisms in Genitourinary Infections: Discoveries in the New, Modern Diagnostic Era

The Pathogenic Role of Actinomyces spp. and Related Organisms in Genitourinary Infections: Discoveries in the New, Modern Diagnostic Era

Progress toward understanding the contribution of alkali generation in dental biofilms to inhibition of dental caries

Oral Bacterial Acid–Base Metabolism in Caries Screening: A Proof-Of-Concept Study

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