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Robertsson, CarolinaORCID iD iconorcid.org/0000-0001-9545-9161
Publications (7 of 7) Show all publications
Neilands, J., Svensäter, G., Boisen, G., Robertsson, C., Wickström, C. & Davies, J. R. (2023). Formation and Analysis of Mono-species and Polymicrobial Oral Biofilms in Flow-Cell Models. In: Bacterial Pathogenesis: Methods and Protocols, (pp. 33-52). Springer
Open this publication in new window or tab >>Formation and Analysis of Mono-species and Polymicrobial Oral Biofilms in Flow-Cell Models
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2023 (English)In: Bacterial Pathogenesis: Methods and Protocols,, Springer, 2023, p. 33-52Chapter in book (Refereed)
Abstract [en]

The oral microbiota, which is known to include at least 600 different bacterial species, is found on the teethand mucosal surfaces as multi-species communities or biofilms. The oral surfaces are covered with a pellicleof proteins absorbed from saliva, and biofilm formation is initiated when primary colonizers, which expresssurface adhesins that bind to specific salivary components, attach to the oral tissues. Further developmentthen proceeds through co-aggregation of additional species. Over time, the composition of oral biofilms,which varies between different sites throughout the oral cavity, is determined by a combination ofenvironmental factors such as the properties of the underlying surface, nutrient availability and oxygenlevels, and bacterial interactions within the community. A complex equilibrium between biofilm communities and the host is responsible for the maintenance of a healthy biofilm phenotype (eubiosis). In the faceof sustained environmental perturbation, however, biofilm homeostasis can break down giving rise todysbiosis, which is associated with the development of oral diseases such as caries and periodontitis.In vitro models have an important part to play in increasing our understanding of the complex processesinvolved in biofilm development in oral health and disease, and the requirements for experimental system,microbial complexity, and analysis techniques will necessarily vary depending on the question posed. In thischapter we describe some current and well-established methods used in our laboratory for studying oralbacteria in biofilm models which can be adapted to suit the needs of individual users. 

Place, publisher, year, edition, pages
Springer, 2023
Series
Methods in Molecular Biology, E-ISSN 1940-6029 ; 2674
National Category
Cell and Molecular Biology
Identifiers
urn:nbn:se:mau:diva-62874 (URN)10.1007/978-1-0716-3243-7_2 (DOI)37258958 (PubMedID)2-s2.0-85160680476 (Scopus ID)978-1-0716-3242-0 (ISBN)978-1-0716-3243-7 (ISBN)
Available from: 2023-09-29 Created: 2023-09-29 Last updated: 2023-10-06Bibliographically approved
Robertsson, C. (2023). Responses to External Cues in Oral Bacteria. (Doctoral dissertation). Malmö: Malmö University Press
Open this publication in new window or tab >>Responses to External Cues in Oral Bacteria
2023 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

This thesis investigates responses to external cues in oral bacteria on a molecular level. Paper I maps Ser/Thr/Tyr phosphorylated proteins in relation to the general proteome in an oral commensal streptococcus (Streptococcus gordonii DL1). The identified phosphoproteins were involved in various bacterial processes, several associated to dysbiosis and development of biofilm-induced disease. Comparison against phosphoproteomes of other bacteria showed many similarities. This is of interest for the identification of shared phosphorylation profiles. 

Paper II studies differences between the S. gordonii DL1 general proteomes in planktonic and biofilm growth phases, and the regulatory effects of salivary mucin MUC5B on protein expression in the biofilm cells. Regulations in protein expression between the different growth conditions provides insights in bacterial mechanisms for adaptation to the biofilm lifestyle. 

Paper III examines the regulatory roles of salivary MUC5B on biofilm attachment and metabolic output in two clinical isolates of oral commensals, S. gordonii CW and Actinomyces naeslundii CW. S. gordonii facilitated adhesion of A. naeslundii to MUC5B during early attachment. Both bacteria were also able to utilize MUC5B as a sole nutrient source during early biofilm formation, individually and synergistically in a dual species biofilm. The specific responses elicited by MUC5B in paper II-III seem to promote commensal colonization while down-regulating dysbiosis-related biofilm activities. 

Microbiological studies are often focused on dysbiosis and development of disease. However, mechanisms that promote eubiosis are equally important to understand how health can be maintained. Findings associated with responses to external cues in oral bacteria may contribute to future development of novel preventative strategies and identification of predictive biomarkers for oral health. 

Abstract [sv]

Avhandlingen undersöker orala bakteriers svar till utifrån kommande signaler på en molekylärbiologisk nivå. I delarbete I kartläggs proteiner med serin/treonin/ tyrosin fosforylering i relation till det generella proteomet hos en oral streptokock (Streptococcus gordonii DL1). De identifierade fosfoproteinerna kunde kopplas till olika bakteriella processer, varav flera av intresse ur kariessynpunkt. Jämförelse mot andra bakteriers fosfoproteom visade många likheter, vilket är av intresse för identifiering av delade fosforyleringsprofiler. 

I delarbete II undersöks skillnader i det generella proteomet hos S. gordonii DL1 mellan tillväxtfaserna planktonisk och biofilm, samt reglerande effekter av salivmucinet MUC5B på biofilmscellerna proteinuttryck. Skillnaderna i proteinuttryck mellan tillväxtfaser ger ledtrådar om bakteriernas mekanismer för anpassning till biofilmstillväxt. 

Delarbete III studeras salivmucinet MUC5Bs reglerande roll på vidhäftning och metabolism i biofilmer med kliniska isolat av S. gordonii CW samt Actinomyces naeslundii CW. S. gordonii ökade vidhäftningen av A. naeslundii till MUC5B. Båda arterna kunde också använda MUC5B som enda näringskälla under tidig biofilmsbildning, både enskilt och tillsammans. Responserna som MUC5B framkallade i biofilmerna (paper II och III) verkar främja kolonisering av kommensaler och samtidigt nedreglera kariesrelaterade aktiviteter. 

Mikrobiologiska studier fokuserar ofta på dysbiosis och sjukdomsutveckling, men mekanismer som bibehåller eubiosis är minst lika viktiga för att förstå hur oral hälsa kan främjas. Resultat kopplade till orala bakteriers svar på utifrån kommande signaler kan bidra till framtida utveckling av nya strategier för prevention och identifiering av prediktiva biomarkörer för oral hälsa. 

Place, publisher, year, edition, pages
Malmö: Malmö University Press, 2023. p. 105
Series
Malmö University Odontological Dissertations, ISSN 1650-6065
Keywords
Oral Microbiology, Oral Biofilms, Saliva, Salivary mucin MUC5B, Streptococcus, Actinomyces
National Category
Microbiology Biochemistry and Molecular Biology Cell and Molecular Biology Dentistry
Identifiers
urn:nbn:se:mau:diva-62571 (URN)10.24834/isbn.9789178774180 (DOI)978-91-7877-417-3 (ISBN)978-91-7877-418-0 (ISBN)
Public defence
2023-12-08, KL:2370, Carl Gustafs väg 34, Malmö, 09:00 (English)
Opponent
Supervisors
Projects
Foresight
Funder
Swedish Research Council, 201601994NIH (National Institutes of Health), P005403501
Available from: 2023-10-27 Created: 2023-10-26 Last updated: 2024-02-23Bibliographically approved
Robertsson, C., Svensäter, G., Davies, J. R., Bay Nord, A., Malmodin, D. & Wickström, C. (2023). Synergistic metabolism of salivary MUC5B in oral commensal bacteria during early biofilm formation. Microbiology Spectrum, 11(6)
Open this publication in new window or tab >>Synergistic metabolism of salivary MUC5B in oral commensal bacteria during early biofilm formation
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2023 (English)In: Microbiology Spectrum, E-ISSN 2165-0497, Vol. 11, no 6Article in journal (Refereed) Published
Abstract [en]

Bacterial metabolism in oral biofilms is comprised of complex networks of nutritional chains and biochemical regulations. These processes involve both intraspecies and interspecies networks as well as interactions with components from host saliva, gingival crevicular fluid, and dietary intake. In a previous paper, a large salivary glycoprotein, mucin MUC5B, was suggested to promote a dental health-related phenotype in the oral type strain of Streptococcus gordonii DL1, by regulating bacterial adhesion and protein expression. In this study, nuclear magnetic resonance-based metabolomics was used to examine the effects on the metabolic output of monospecies compared to dual species early biofilms of two clinical strains of oral commensal bacteria, S. gordonii and Actinomyces naeslundii, in the presence of MUC5B. The presence of S. gordonii increased colonization of A. naeslundii on salivary MUC5B, and both commensals were able to utilize MUC5B as a sole nutrient source during early biofilm formation. The metabolomes suggested that the bacteria were able to release mucin carbohydrates from oligosaccharide side chains as well as amino acids from the protein core. Synergistic effects were also seen in the dual species biofilm metabolome compared to the monospecies, indicating that A. naeslundii and S. gordonii cooperated in the degradation of salivary MUC5B. A better understanding of bacterial interactions and salivary-mediated regulation of early dental biofilm activity is meaningful for understanding oral biofilm physiology and may contribute to the development of future prevention strategies for biofilm-induced oral disease.

IMPORTANCE: The study of bacterial interactions and salivary-mediated regulation of early dental biofilm activity is of interest for understanding oral microbial adaptation to environmental cues and biofilm maturation. Findings in oral commensals can prove useful from the perspectives of both oral and systemic health of the host, as well as the understanding of general microbial biofilm physiology. The knowledge may provide a basis for the development of prognostic biomarkers, or development of new treatment strategies, related to oral health and disease and possibly also to other biofilm-induced conditions. The study is also an important step toward developing the methodology for similar studies in other species and/or growth conditions.

Place, publisher, year, edition, pages
ASM International, 2023
Keywords
MUC5B, NMR, actinomyces, bacterial metabolism, biofilm physiology, dental biofilm, metabolomics, oral microbiology, saliva, streptococci
National Category
Dentistry
Identifiers
urn:nbn:se:mau:diva-63213 (URN)10.1128/spectrum.02704-23 (DOI)001085549500001 ()37855449 (PubMedID)2-s2.0-85180007534 (Scopus ID)
Available from: 2023-10-23 Created: 2023-10-23 Last updated: 2024-01-10Bibliographically approved
Gonzalez-Martinez, J. F., Boyd, H., Gutfreund, P., Welbourn, R. J., Robertsson, C., Wickström, C., . . . Sotres, J. (2022). MUC5B mucin films under mechanical confinement: A combined neutron reflectometry and atomic force microscopy study.. Journal of Colloid and Interface Science, 614, 120-129, Article ID S0021-9797(22)00109-6.
Open this publication in new window or tab >>MUC5B mucin films under mechanical confinement: A combined neutron reflectometry and atomic force microscopy study.
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2022 (English)In: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 614, p. 120-129, article id S0021-9797(22)00109-6Article in journal (Refereed) Published
Abstract [en]

HYPOTHESIS: Among other functions, mucins hydrate and protect biological interfaces from mechanical challenges. Mucins also attract interest as biocompatible coatings with excellent lubrication performance. Therefore, it is of high interest to understand the structural response of mucin films to mechanical challenges. We hypothesized that this could be done with Neutron Reflectometry using a novel sample environment where mechanical confinement is achieved by inflating a membrane against the films.

EXPERIMENTS: Oral MUC5B mucin films were investigated by Force Microscopy/Spectroscopy and Neutron Reflectometry both at solid-liquid interfaces and under mechanical confinement.

FINDINGS: NR indicated that MUC5B films were almost completely compressed and dehydrated when confined at 1 bar. This was supported by Force Microscopy/Spectroscopy investigations. Force Spectroscopy also indicated that MUC5B films could withstand mechanical confinement by means of steric interactions for pressures lower than ∼ 0.5 bar i.e., mucins could protect interfaces from mechanical challenges of this magnitude while keeping them hydrated. To investigate mucin films under these pressures by means of the employed sample environment for NR, further technological developments are needed. The most critical would be identifying or developing more flexible membranes that would still meet certain requirements like chemical homogeneity and very low roughness.

Place, publisher, year, edition, pages
Elsevier, 2022
Keywords
Atomic force microscopy, Force spectroscopy, Mechanical confinement, Mucins, Neutron reflectometry
National Category
Physical Chemistry
Identifiers
urn:nbn:se:mau:diva-50061 (URN)10.1016/j.jcis.2022.01.096 (DOI)000750672100013 ()35091141 (PubMedID)2-s2.0-85123366668 (Scopus ID)
Available from: 2022-02-09 Created: 2022-02-09 Last updated: 2024-02-05Bibliographically approved
Boyd, H., Gonzalez-Martinez, J. F., Welbourn, R. J., Gutfreund, P., Klechikov, A., Robertsson, C., . . . Sotres, J. (2021). A comparison between the structures of reconstituted salivary pellicles and oral mucin (MUC5B) films.. Journal of Colloid and Interface Science, 584, 660-668, Article ID S0021-9797(20)31464-8.
Open this publication in new window or tab >>A comparison between the structures of reconstituted salivary pellicles and oral mucin (MUC5B) films.
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2021 (English)In: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 584, p. 660-668, article id S0021-9797(20)31464-8Article in journal (Refereed) Published
Abstract [en]

HYPOTHESIS: Salivary pellicles i.e., thin films formed upon selective adsorption of saliva, protect oral surfaces against chemical and mechanical insults. Pellicles are also excellent aqueous lubricants. It is generally accepted that reconstituted pellicles have a two-layer structure, where the outer layer is mainly composed of MUC5B mucins. We hypothesized that by comparing the effect of ionic strength on reconstituted pellicles and MUC5B films we could gain further insight into the pellicle structure.

EXPERIMENTS: Salivary pellicles and MUC5B films reconstituted on solid surfaces were investigated at different ionic strengths by Force Spectroscopy, Quartz Crystal Microbalance with Dissipation, Null Ellipsometry and Neutron Reflectometry.

FINDINGS: Our results support the two-layer structure for reconstituted salivary pellicles. The outer layer swelled when ionic strength decreased, indicating a weak polyelectrolyte behavior. While initially the MUC5B films exhibited a similar tendency, this was followed by a drastic collapse indicating an interaction between exposed hydrophobic domains. This suggests that mucins in the pellicle outer layer form complexes with other salivary components that prevent this interaction. Lowering ionic strength below physiological values also led to a partial removal of the pellicle inner layer. Overall, our results highlight the importance that the interactions of mucins with other pellicle components play on their structure.

Place, publisher, year, edition, pages
Elsevier, 2021
Keywords
Ionic strength, MUC5B, Mucin, Salivary pellicle, Steric forces
National Category
Dentistry
Identifiers
urn:nbn:se:mau:diva-37667 (URN)10.1016/j.jcis.2020.10.124 (DOI)000600220000006 ()33198975 (PubMedID)2-s2.0-85096107333 (Scopus ID)
Available from: 2020-12-21 Created: 2020-12-21 Last updated: 2023-10-30Bibliographically approved
Robertsson, C., Svensäter, G., Blum, Z., Jakobsson, M. E. & Wickström, C. (2021). Proteomic response in Streptococcus gordonii DL1 biofilm cells during attachment to salivary MUC5B. Journal of Oral Microbiology, 13(1), Article ID 1967636.
Open this publication in new window or tab >>Proteomic response in Streptococcus gordonii DL1 biofilm cells during attachment to salivary MUC5B
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2021 (English)In: Journal of Oral Microbiology, ISSN 2000-2297, E-ISSN 2000-2297, Vol. 13, no 1, article id 1967636Article in journal (Refereed) Published
Abstract [en]

Background Salivary mucin MUC5B seems to promote biodiversity in dental biofilms, and thereby oral health, for example, by inducing synergistic 'mucolytic' activities in a variety of microbial species that need to cooperate for the release of nutrients from the complex glycoprotein. Knowledge of how early colonizers interact with host salivary proteins is integral to better understand the maturation of putatively harmful oral biofilms and could provide key insights into biofilm physiology. Methods The early oral colonizer Streptococcus gordonii DL1 was grown planktonically and in biofilm flow cell systems with uncoated, MUC5B or low-density salivary protein (LDP) coated surfaces. Bacterial cell proteins were extracted and analyzed using a quantitative mass spectrometry-based workflow, and differentially expressed proteins were identified. Results and conclusions Overall, the proteomic profiles of S. gordonii DL1 were similar across conditions. Six novel biofilm cell proteins and three planktonic proteins absent in all biofilm cultures were identified. These differences may provide insights into mechanisms for adaptation to biofilm growth in this species. Salivary MUC5B also elicited specific responses in the biofilm cell proteome. These regulations may represent mechanisms by which this mucin could promote colonization of the commensal S. gordonii in oral biofilms.

Place, publisher, year, edition, pages
Taylor & Francis, 2021
Keywords
Salivary mucin, MUC5B, oral streptococci, Streptococcus gordonii, oral biofilm, saliva, mass spectrometry, protein expression, proteomics
National Category
Dentistry
Identifiers
urn:nbn:se:mau:diva-45857 (URN)10.1080/20002297.2021.1967636 (DOI)000687414300001 ()34447490 (PubMedID)2-s2.0-85120853173 (Scopus ID)
Available from: 2021-09-14 Created: 2021-09-14 Last updated: 2024-02-05Bibliographically approved
Robertsson, C., Svensäter, G., Blum, Z. & Wickström, C. (2020). Intracellular Ser/Thr/Tyr phosphoproteome of the oral commensal Streptococcus gordonii DL1. BMC Microbiology, 20(1), Article ID 280.
Open this publication in new window or tab >>Intracellular Ser/Thr/Tyr phosphoproteome of the oral commensal Streptococcus gordonii DL1
2020 (English)In: BMC Microbiology, E-ISSN 1471-2180, Vol. 20, no 1, article id 280Article in journal (Refereed) Published
Abstract [en]

BACKGROUND: To respond and adapt to environmental challenges, prokaryotes regulate cellular processes rapidly and reversibly through protein phosphorylation and dephosphorylation. This study investigates the intracellular proteome and Ser/Thr/Tyr phosphoproteome of the oral commensal Streptococcus gordonii. Intracellular proteins from planktonic cells of S. gordonii DL1 were extracted and subjected to 2D-gel electrophoresis. Proteins in general were visualized using Coomassie Brilliant Blue and T-Rex staining. Phosphorylated proteins were visualized with Pro-Q Diamond Phosphoprotein Gel Stain. Proteins were identified by LC-MS/MS and sequence analysis.

RESULTS: In total, sixty-one intracellular proteins were identified in S. gordonii DL1, many of which occurred at multiple isoelectric points. Nineteen of these proteins were present as one or more Ser/Thr/Tyr phosphorylated form. The identified phosphoproteins turned out to be involved in a variety of cellular processes.

CONCLUSION: Nineteen phosphoproteins involved in various cellular functions were identified in S. gordonii. This is the first time the global intracellular Ser/Thr/Tyr phosphorylation profile has been analysed in an oral streptococcus. Comparison with phosphoproteomes of other species from previous studies showed many similarities. Proteins that are consistently found in a phosphorylated state across several species and growth conditions may represent a core phosphoproteome profile shared by many bacteria.

Place, publisher, year, edition, pages
BioMed Central, 2020
Keywords
2DE, Oral bacteria, Phosphoproteome, Pro-Q diamond, Streptococci, Streptococcus gordonii
National Category
Dentistry
Identifiers
urn:nbn:se:mau:diva-18388 (URN)10.1186/s12866-020-01944-y (DOI)000573079700001 ()32928109 (PubMedID)2-s2.0-85091053882 (Scopus ID)
Available from: 2020-09-24 Created: 2020-09-24 Last updated: 2024-02-05Bibliographically approved
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ORCID iD: ORCID iD iconorcid.org/0000-0001-9545-9161

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