scholarly journals Evidence for Proline Utilization by Oral Bacterial Biofilms Grown in Saliva

2021 ◽  
Vol 11 ◽  
Author(s):  
Leanne M. Cleaver ◽  
Rebecca V. Moazzez ◽  
Guy H. Carpenter

Within the mouth bacteria are starved of saccharides as their main nutrient source between meals and it is unclear what drives their metabolism. Previously oral in vitro biofilms grown in saliva have shown proteolytic degradation of salivary proteins and increased extracellular proline. Although arginine and glucose have been shown before to have an effect on oral biofilm growth and activity, there is limited evidence for proline. Nuclear magnetic resonance (NMR) spectroscopy was used to identify extracellular metabolites produced by bacteria in oral biofilms grown on hydroxyapatite discs. Biofilms were inoculated with stimulated whole mouth saliva and then grown for 7 days using sterilized stimulated whole mouth saliva supplemented with proline, arginine or glucose as a growth-medium. Overall proline had a beneficial effect on biofilm growth—with significantly fewer dead bacteria present by biomass and surface area of the biofilms (p < 0.05). Where arginine and glucose significantly increased and decreased pH, respectively, the pH of proline supplemented biofilms remained neutral at pH 7.3–7.5. SDS-polyacrylamide gel electrophoresis of the spent saliva from proline and arginine supplemented biofilms showed inhibition of salivary protein degradation of immature biofilms. NMR analysis of the spent saliva revealed that proline supplemented biofilms were metabolically similar to unsupplemented biofilms, but these biofilms actively metabolized proline to 5-aminopentanoate, butyrate and propionate, and actively utilized glycine. This study shows that in a nutrient limited environment, proline has a beneficial effect on in vitro oral biofilms grown from a saliva inoculum.

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Lopez-Nguyen Darrene ◽  
Badet Cecile

The oral ecosystem is a very complex environment where more than 700 different bacterial species can be found. Most of them are organized in biofilm on dental and mucosal surfaces. Studying this community is important because a rupture in stability can lead to the preeminence of pathogenic microorganisms, causing dental decay, gingivitis, or periodontitis. The multitude of species complicates biofilm analysis so its reproduction, collection, and counting are very delicate. The development of experimental models of dental biofilms was therefore essential and multiplein vitrodesigns have emerged, each of them especially adapted to observing biofilm formation of specific bacteria within specific environments. The aim of this review is to analyze oral biofilm models.


2016 ◽  
Vol 7 ◽  
Author(s):  
Barbara Klug ◽  
Elisabeth Santigli ◽  
Christian Westendorf ◽  
Stefan Tangl ◽  
Gernot Wimmer ◽  
...  

2020 ◽  
Vol 9 (1) ◽  
pp. 59
Author(s):  
Tracy Young ◽  
Om-Alkhir Alshanta ◽  
Ryan Kean ◽  
David Bradshaw ◽  
Jonathan Pratten ◽  
...  

Background: Existing standardized biofilm assays focus on simple mono-species or bacterial-only models. Incorporating Candida albicans into complex biofilm models can offer a more appropriate and relevant polymicrobial biofilm for the development of oral health products. Aims: This study aimed to assess the importance of interkingdom interactions in polymicrobial oral biofilm systems with or without C. albicans, and test how these models respond to oral therapeutic challenges in vitro. Materials and Methods: Polymicrobial biofilms (two models containing 5 and 10 bacterial species, respectively) were created in parallel in the presence and absence of C. albicans and challenged using clinically relevant antimicrobials. The metabolic profiles and biomasses of these complex biofilms were estimated using resazurin dye and crystal violet stain, respectively. Quantitative PCR was utilized to assess compositional changes in microbial load. Additional assays, for measurements of pH and lactate, were included to monitor fluctuations in virulence “biomarkers.” Results: An increased level of metabolic activity and biomass in the presence of C. albicans was observed. Bacterial load was increased by more than a factor of 10 in the presence of C. albicans. Assays showed inclusion of C. albicans impacted the biofilm virulence profiles. C. albicans did not affect the biofilms’ responses to the short-term incubations with different treatments. Conclusions: The interkingdom biofilms described herein are structurally robust and exhibit all the hallmarks of a reproducible model. To our knowledge, these data are the first to test the hypothesis that yeasts may act as potential “keystone” components of oral biofilms.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tim Verspecht ◽  
Wannes Van Holm ◽  
Nico Boon ◽  
Kristel Bernaerts ◽  
Carlo A. Daep ◽  
...  

AbstractPrevious research identified potential prebiotic substrates for oral health like the structural analogues N-acetyl-d-mannosamine (NADM) and N-acetyl-d-glucosamine (NADG). The main hypothesis of the current study was twofold. Firstly, it was hypothesized that the modulatory effects of NADM are not limited to changes in multi-species oral biofilm composition, but also include effects on metabolism, virulence, and inflammatory potential. Secondly, the presence and orientation of their N-acetyl group could play a role. Therefore, a comparison was made between the effects of NADM, NADG and d-(+)-mannose on multi-species oral biofilms. Besides a beneficial compositional shift, NADM-treated biofilms also showed an altered metabolism, a reduced virulence and a decreased inflammatory potential. At a substrate concentration of 1 M, these effects were pronounced for all biofilm aspects, whereas at ~ 0.05 M (1%(w/v)) only the effects on virulence were pronounced. When comparing between substrates, both the presence and orientation of the N-acetyl group played a role. However, this was generally only at 1 M and dependent on the biofilm aspect. Overall, NADM was found to have different effects at two concentrations that beneficially modulate in vitro multi-species oral biofilm composition, metabolism, virulence and inflammatory potential. The presence and orientation of the N-acetyl group influenced these effects.


2018 ◽  
Author(s):  
Irina M. Velsko ◽  
Luciana M. Shaddox

AbstractBackground: Several in vitro oral biofilm growth systems can reliably construct oral microbiome communities in culture, yet their stability and reproducibility through time has not been well characterized. Long-term in vitro growth of natural biofilms would enable use of these biofilms in both in vitro and in vivo studies that require complex microbial communities with minimal variation over a period of time. Understanding biofilm community dynamics in continuous culture, and whether they maintain distinct signatures of health and disease, is necessary to determine the reliability and applicability of such models to broader studies. To this end, we performed next-generation sequencing on biofilms grown from healthy and disease-site subgingival plaque for 80 days to assess stability and reliability of continuous oral biofilm growth.Results: Biofilms were grown from subgingival plaque collected from periodontitis-affected sites and healthy individuals for ten eight-day long generations, using hydroxyapatite disks. The bacterial community in each generation was determined using Human Oral Microbe Identification by Next-Generation Sequencing (HOMINGS) technology, and analyzed in QIIME. Profiles were steady through the ten generations, as determined by species abundance and prevalence, Spearman’s correlation coefficient, and Faith’s phylogenetic distance, with slight variation predominantly in low abundance species. Community profiles were distinct between healthy and disease site-derived biofilms as demonstrated by weighted UniFrac distance throughout the ten generations. Differentially abundant species between healthy and disease site-derived biofilms were consistent throughout the generations.Conclusions: Healthy and disease site-derived biofilms can reliably maintain consistent communities through ten generations of in vitro growth. These communities maintain signatures of health and disease and of individual donors despite culture in identical environments. This subgingival oral biofilm growth and perpetuation model may prove useful to studies involving oral infection or cell stimulation, or those measuring microbial interactions, which require the same biofilms over a period of time.


2021 ◽  
Vol 2 ◽  
Author(s):  
Shurooq Zakariya Albaghdadi ◽  
Jenan Bader Altaher ◽  
Hana Drobiova ◽  
Radhika G. Bhardwaj ◽  
Maribasappa Karched

Background: Periodontitis, a chronic inflammatory oral infection is the outcome of disturbances in the homeostasis of the oral biofilm microbiota. A number of studies have found the occurrence of Prevotella species in elevated levels in periodontitis compared to healthy subjects. Even though different aspects of Prevotella as part of oral biofilm have been studied, in vitro biofilms formed by these species have not been characterized systematically. The objective of this study was to characterize biofilms formed by several Prevotella species and further to assess biofilm inhibition and detachment of preformed biofilms.Methods: Biofilms were grown in 24-well plates containing brucella broth in anaerobic conditions for 3 days, and were quantified using crystal violet staining. Images of SYTO 9 Green fluorescent stained biofilms were captured using confocal microscopy. Biofilm inhibition and detachment by proteinase and DNase I was tested. The biochemical characterization included quantification of proteins and DNA in the biofilms and biofilm-supernatants.Results:Prevotella loescheii, Prevotella oralis and Prevotella nigrescens showed highest biofilm formation. P. nigrescens formed significantly higher amounts of biofilms than P. loescheii (P = 0.005) and P. oralis (P = 0.0013). Inhibition of biofilm formation was significant only in the case of P. oralis when treated with proteinase (P = 0.037), whereas with DNase I treatment, the inhibition was not significant (P = 0.531). Overall, proteinase was more effective in biofilm detachment than DNase I. Protein and DNA content were higher in biofilm than the supernatant with the highest amounts found in P. nigrescens biofilm and supernatants. P. oralis biofilms appeared to secrete large amounts of proteins extracellularly into the biofilm-supernatants.Conclusion: Significant differences among Prevotella species to form biofilms may imply their variable abilities to get integrated into oral biofilm communities. Of the species that were able to grow as biofilms, DNase I and proteinase inhibited the biofilm growth or were able to cause biofilm detachment.


1994 ◽  
Vol 72 (06) ◽  
pp. 906-911 ◽  
Author(s):  
D C Rijken ◽  
E Groeneveld ◽  
M M Barrett-Bergshoeff

SummaryBM 06.022 is a non-glycosylated mutant of human tissue-type plasminogen activator (t-PA) comprising only the kringle-2 and proteinase domains. The in vivo half-life of BM 06.022 antigen is 4- to 5-fold longer than that of t-PA antigen. The in vitro half-life of the activity of BM 06.022 at therapeutic concentrations in plasma is shorter than that of t-PA. In this study the inactivation of BM 06.022 in plasma was further investigated.Varying concentrations of BM 06.022 were incubated in plasma for 0-150 min. Activity assays on serial samples showed a dose-dependent decline of BM 06.022 activity with a half-life from 72 min at 0.3 μg/ml to 38 min at 10 μg/ml. SDS-polyacrylamide gel electrophoresis (SDS-PAGE) followed by fibrin autography showed the generation of several BM 06.022-complexes. These complexes could be completely precipitated with antibodies against Cl-inactivator, α2-antiplasmin and α1-antitrypsin.During the incubation of BM 06.022 in plasma, plasmin was generated dose-dependently as revealed by varying degrees of a2-anti-plasmin consumption and fibrinogen degradation. SDS-PAGE and immunoblotting showed that single-chain BM 06.022 was rapidly (i. e. within 45 min) converted into its two-chain form at concentrations of 5 μg/ml BM 06.022 and higher.In conclusion, BM 06.022 at therapeutic concentrations in plasma was inactivated by Cl-inactivator, a2-antiplasmin and a j-antitrypsin. The half-life of the activity decreased at increasing BM 06.022 concentrations, probably as a result of the generation of two-chain BM 06.022 which may be inactivated faster than the single-chain form.


1979 ◽  
Vol 42 (05) ◽  
pp. 1630-1633 ◽  
Author(s):  
A G Castle ◽  
N Crawford

SummaryBlood platelets contain microtubule proteins (tubulin and HMWs) which can be polymerised “in vitro” to form structures which resemble the microtubules seen in the intact platelet. Platelet tubulin is composed of two non-identical subunits a and p tubulin which have molecular weights around 55,000 but can be resolved in alkaline SDS-polyacrylamide gel electrophoresis. These subunits associate as dimers with sedimentation coefficients of about 5.7 S although it is not known whether the dimer protein is a homo- or hetero-dimer. The dimer tubulin binds the anti-mitotic drug colchicine and the kinetics of this binding are similar to those reported for neurotubulins. Platelet microtubules also contain two HMW proteins which appear to be essential and integral components of the fully assembled microtubule. These proteins have molecular weights greater than 200,000 daltons. Fluorescent labelled antibodies to platelet and brain tubulins stain long filamentous microtubular structures in bovine lens epithelial cells and this pattern of staining is prevented by exposing the cells to conditions known to cause depolymerisation of cell microtubules.


Author(s):  
Ting L. Luo ◽  
Michael E. Vanek ◽  
Carlos Gonzalez‐Cabezas ◽  
Carl F. Marrs ◽  
Betsy Foxman ◽  
...  

2021 ◽  
Vol 16 (1) ◽  
pp. 1934578X2098774
Author(s):  
Jinpeng Zou ◽  
Yang Liu ◽  
Ruiwei Guo ◽  
Yu Tang ◽  
Zhengrong Shi ◽  
...  

The drug resistance of Pseudomonas aeruginosa is a worldwide problem due to its great threat to human health. A crude extract of Angelica dahurica has been proved to have antibacterial properties, which suggested that it may be able to inhibit the biofilm formation of P. aeruginosa; initial exploration had shown that the crude extract could inhibit the growth of P. aeruginosa effectively. After the adaptive dose of coumarin was confirmed to be a potential treatment for the bacteria’s drug resistance, “coumarin-antibiotic combination treatments” (3 coumarins—simple coumarin, imperatorin, and isoimperatorin—combined with 2 antibiotics—ampicillin and ceftazidime) were examined to determine their capability to inhibit P. aeruginosa. The final results showed that (1) coumarin with either ampicillin or ceftazidime significantly inhibited the biofilm formation of P. aeruginosa; (2) coumarin could directly destroy mature biofilms; and (3) the combination treatment can synergistically enhance the inhibition of biofilm formation, which could significantly reduce the usage of antibiotics and bacterial resistance. To sum up, a coumarin-antibiotic combination treatment may be a potential way to inhibit the biofilm growth of P. aeruginosa and provides a reference for antibiotic resistance treatment.


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