Cíl práce: Cílem výzkumu je in vitro analýza bakteriálního biofilmu na různých typech ortodontických zámků s různým typem ligatur v čase 71 a 72. Bylo zkoumáno množství aerobních a anaerobních bakterií a rod Lactobacillus. Materiál a metodika: Soubor tvořilo 120 ortodontických zámků (40 kovových samoligovacích, 20 kovových elastickou ligaturou, 20 kovových s kovovou ligaturou, 20 keramických s elastickou ligaturou a 20 keramických s kovovou ligaturou), které byly fixovány na skleněné ploténky a vloženy do média obsahujícího sliny pacientů léčených fixním aparátem. Po 5 dnech (71) byla vyjmuta první polovina zámků, po 14 dnech (72) od začátku experimentu druhá polovina zámků. Následné proběhla mikrobiologická analýza spočívající v kultivaci jednotlivých vzorků na živných půdách. Výsledky byly vyhodnoceny na základe počtu kolonií na miskách, pro každý vzorek byla vypočítána hodnota CFU/ml (počet kolonie tvoncích jednotek na 1 ml vzorku) vyjadřující míru výskytu biofilmu tvořeného adhezí mikroorganismů Výsledky: Největší množství aerobů, anaerobů a laktobacilů se v obou časech nacházelo na kovových zámcích s elastickou ligaturou. Kovové samoligovací zámky vykazovaly nejnižší bakteriální adhezi. Závěr: Materiál ortodontického zámku, případně druh ligatury má vliv na bakteriální adhezi. U pacientů se sknem k demineralizacím je vhodné se vyvarovat kombinace kovový zámek a elastická ligatura, naopak s výhodou lze používat zámky samoligovací.
Aims: In vitro analysis of bacterial biofilm on different types of orthodontic brackets with various types of ligatares at time T1 and T2. Numbers of aerobic and anaerobic bacteria and Lactobacillus spp. were examined. Material and method: The sample included 120 orthocfont/c brackets (40 self-ligating metal, 20 metal with elastic ligature, 20 metal with metal ligature, 20 ceramic with elastic ligature, 20 ceramic with metal ligature), bonded on glass plates and put into an agent containing saliva of patients treated with fixed appliance. After 5 days (T1) the first half of brackets was removed, after 14 days (T2) the rest. Microbiological analysis was carried out involving cultivation of individual samples in culture media. Results were assessed according to the number of colonies in dishes; for each sample the value of CfUlml was calculated (number of units forming colonies in 1 ml of the sample). The value gives the occurrence of biofilm formed by adhesion of microorganisms. Results: The highest number of aerobes, anaerobes and lactobacilli at both T1 and T2 was found on metal brackets with elastic ligature. The lowest bacterial adhesion was found in metal self-ligating brackets. Conclusion: Material of orthodontic bracket and type of ligature influence bacterial adhesion. In patients susceptible to demineralizations it is recommended to avoid the combination of metal bracket and elastic ligature. On the contrary, metal self-ligating brackets are a good choice.
In this study we examined the extent of biofilm formation in field strains of Salmonella enterica serovar Typhimurium (S. Typhimurium), an important foodborne pathogen. Ninety-four field strains of S. Typhimurium were tested for their ability to form biofilm and components contributing to its formation. Most S. Typhimurium strains were highly capable of biofilm formation except for strains of phage type DT2 originating from pigeons. The most efficient biofilm forming strains were those of phage type DT104 positive for Salmonella genomic island 1 (SGI1). A comparison of SGI1 positive and negative strains indicated that the increased biofilm formation of SGI1 positive strains was associated with the presence of this genomic island. Finally, in five strains we found an alternative strategy of biofilm formation independent of curli fimbriae and cellulose production but solely dependent on an overproduction of capsular polysaccharide. Due to a mucoid and brown appearance on Congo Red agar we designated these strains as belonging to the SBAM (smooth brown and mucoid) morphotype.
- MeSH
- Analysis of Variance MeSH
- Polysaccharides, Bacterial metabolism MeSH
- Bacterial Proteins genetics metabolism MeSH
- Biofilms growth & development MeSH
- Cellulose genetics metabolism MeSH
- Bacteriophage Typing MeSH
- Phenotype MeSH
- Financing, Organized MeSH
- Genomic Islands MeSH
- Microscopy, Electron, Scanning veterinary MeSH
- Gene Expression Regulation, Bacterial MeSH
- Salmonella typhimurium MeSH
- Salmonella Infections, Animal microbiology MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
Multicellular structures formed by yeasts and other microbes are valuable models for investigating the processes of cell-cell interaction and pattern formation, as well as cell signaling and differentiation. These processes are essential for the organization and development of diverse microbial communities that are important in everyday life. Two major types of multicellular structures are formed by yeast Saccharomyces cerevisiae on semisolid agar. These are colonies formed by laboratory or domesticated strains and structured colony biofilms formed by wild strains. These structures differ in spatiotemporal organization and cellular differentiation. Using state-of-the-art microscopy and mutant analysis, we investigated the distribution of cells within colonies and colony biofilms and the involvement of specific processes therein. We show that prominent differences between colony and biofilm structure are determined during early stages of development and are associated with the different distribution of growing cells. Two distinct cell distribution patterns were identified-the zebra-type and the leopard-type, which are genetically determined. The role of Flo11p in cell adhesion and extracellular matrix production is essential for leopard-type distribution, because FLO11 deletion triggers the switch to zebra-type cell distribution. However, both types of cell organization are independent of cell budding polarity and cell separation as determined using respective mutants.
Nanostructured TiO2nanotubes (NTs) of diameters from 15 to 100nm were fabricated by an electrochemical anodization process. Biofilm-positive strains of Bacillus cereus and Pseudomonas aeruginosa behaved similarly on all TiO2NTs as well as on native titanium (Ti) foil. The adhesion and growth of mesenchymal stem cells (MSc), embryonic stem cells (ESc), and pure cardiomyocytes derived from ESc exhibited significant differences. MSc as well as ESc were, in contrast to cardiomyocytes, able to adhere, and grow on TiO2NTs. A correlation between NTs diameter and cell behaviour was however observed in the case of MSc and ESc. MSc were not in a physiological state in the case of 100nm TiO2NTs, while ESc were not able to grow on 15nm TiO2NTs. It can be stated that these differences can be assigned to different diameters of the NTs but not to the chemistry of the surface. This is the first study describing the comprehensive behaviour of both eukaryotic and prokaryotic cells on TiO2NTs. On the basis of obtained results, it can be concluded that new generation of medical devices providing selective cell behaviour can be fabricated by optimizing the nanoscale morphology of TiO2.
Nanofiber scaffolds provide numerous advantages over common carriers engineered for microorganisms. The most important advantage is an increased speed of primary surface colonization (up to four times faster), which shortens the time required for the areal biofilm formation and optimum performance of attached microorganisms (higher efficiency of biological activity of up to twice as fast). Image analysis predicts early formation of biofilm even in beginning stages; analysis of biofilm reveals the different structures of bacterial colonies on both scaffolds (higher porosity, size, and number of bacterial colonies on nanofiber's surface). The image analysis correlates well with determinations of dry matter (linear correlation of 0.96) and proteins (linear correlation of 0.89).
- MeSH
- Biofilms * MeSH
- Culture Media * MeSH
- Nanofibers * MeSH
- Polyurethanes MeSH
- Porosity MeSH
- Rhodococcus MeSH
- Publication type
- Journal Article MeSH
- Evaluation Study MeSH
The lifestyle of wild and laboratory yeast strains significantly differs. In contrast to the smooth colonies of laboratory strains, wild Saccharomyces cerevisiae strains form biofilm-like, strikingly structured colonies possessing distinctive traits enabling them to better survive in hostile environments in the wild. Here, comparing three sets of strains forming differently structured colonies (fluffy, semi-fluffy and smooth), each derived from ancestors with distinct genetic backgrounds isolated from natural settings (BR-88, BR-99 and BR-103), we specified the factors essential for the formation of structured colonies, i.e. for the lifestyle most likely to be preferred in the wild. The ability to form an abundant extracellular matrix (ECM) is one of the features typical for structured colonies. ECM influences colony architecture and many other physiological properties, such as the capability to retain water in a 2-fold surplus to wet cell biomass. ECM composition, however, differs among distinct strains, depending on their particular genetic background. We further show that the expression of certain genes (AQY1, FLO11) is also strictly related to the particular colony morphology, being highest in the most structured colonies. Flo11p adhesin, important for cell-cell and cell-surface adhesion, is essential for the formation of fluffy colonies and thus significantly contributes to the phenotype variability of wild yeast strains. On the other hand, surprisingly, neither the cell shape nor budding pattern nor the ability to form pseudohyphae directly influences the formation of three-dimensional fluffy colony architecture.
- MeSH
- Biofilms MeSH
- Hyphae genetics growth & development metabolism MeSH
- Gene Expression Regulation, Fungal MeSH
- Saccharomyces cerevisiae Proteins genetics metabolism MeSH
- Saccharomyces cerevisiae genetics growth & development physiology MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Colonies of Candida parapsilosis on culture plates were probed directly in situ using Raman spectroscopy for rapid identification of specific strains separated by a given time intervals (up to months apart). To classify the Raman spectra, data analysis was performed using the approach of principal component analysis (PCA). The analysis of the data sets generated during the scans of individual colonies reveals that despite the inhomogeneity of the biological samples unambiguous associations to individual strains (two biofilm-positive and two biofilm-negative) could be made.
Tvorba malých kolonií (SCV) se specifickými biochemickými vlastnostmi byla zjištěna u celé řady bakteriálních druhů. Bakterie s SCV fenotypem mají vyřazeny metabolické dráhy, které zajišťují aerobní respíraci, a chovají se proto jako striktní anaeroby. To je sice znevýhodňuje při kompetici o zdroje živin, ale na druhé straně jim umožňuie odolávat účinku některých antibiotik a přežívat uvnitř eukaryotických buněk. Infekce způsobené SCV mají proto často chronický a/nebo rekurentní průběh. Vyléčení obvykle není možné bez chirurgického zásahu. Zdá se, že vznik SCV fenotypu je široce rozšířenou životní strategií bakteriálních buněk, svým výskytem i klinickým významem srovnatelnou s tvorbou biofilmu.
Small-colony variants (SCV) associated with specific biochemical features were described in many bacterial species. Bacteria with SCV phenotype have knocked out metabolic pathways for aerobic respiration, thus they behave like strict anaerobes. They are handicaped in competition for nutrients with other microbes but on the other hand they are able to resist some antibiotics and survive inside eucaryotic cells. Therefore they use to cause chronic and/or recurrent infections. Recovery of these infections is not possible without surgery. SCV phenotype seems to be a common life strategy for many bacteria. Its occurrence and clinical importance is similar to that of biofilm formation.
- MeSH
- Bacteria * metabolism pathogenicity growth & development MeSH
- Bacterial Infections microbiology MeSH
- Drug Resistance, Bacterial MeSH
- Cell Respiration MeSH
- Chronic Disease MeSH
- Phenotype * MeSH
- Bacterial Physiological Phenomena MeSH
- Clinical Laboratory Techniques MeSH
- Humans MeSH
- Endocarditis, Non-Infective microbiology MeSH
- Recurrence MeSH
- Secondary Prevention MeSH
- Check Tag
- Humans MeSH
- Publication type
- Research Support, Non-U.S. Gov't MeSH
- Review MeSH
Microorganisms are not commonly found in the planktonic state but predominantly form dual- and multispecies biofilms in almost all natural environments. Bacteria in multispecies biofilms cooperate, compete or have neutral interactions according to the involved species. Here, the development of mono- and dual-species biofilms formed by Staphylococcus aureus and other foodborne pathogens such as Salmonella enterica subsp. enterica serovar Enteritidis, potentially pathogenic Raoultella planticola and non-pathogenic Escherichia coli over the course of 24, 48 and 72 h was studied. Biofilm formation was evaluated by the crystal violet assay (CV), enumeration of colony-forming units (CFU cm-2) and visualization using confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). In general, Gram-negative bacterial species and S. aureus interacted in a competitive manner. The tested Gram-negative bacteria grew better in mixed dual-species biofilms than in their mono-species biofilms as determined using the CV assay, CFU ml-2enumeration, and CLSM and SEM visualization. In contrast, the growth of S. aureus biofilms was reduced when cultured in dual-species biofilms. CLSM images revealed grape-like clusters of S. aureus and monolayers of Gram-negative bacteria in both mono- and dual-species biofilms. S. aureus clusters in dual-species biofilms were significantly smaller than clusters in S. aureus mono-species biofilms.
- MeSH
- Staining and Labeling MeSH
- Biofilms growth & development MeSH
- Enterobacteriaceae growth & development physiology MeSH
- Gentian Violet analysis MeSH
- Microscopy, Confocal MeSH
- Microbial Interactions * MeSH
- Microscopy, Electron, Scanning MeSH
- Colony Count, Microbial MeSH
- Staphylococcus aureus growth & development physiology MeSH
- Publication type
- Journal Article MeSH
Yeast biofilms are complex multicellular structures, in which the cells are well protected against drugs and other treatments and thus highly resistant to antifungal therapies. Colony biofilms represent an ideal system for studying molecular mechanisms and regulations involved in development and internal organization of biofilm structure as well as those that are involved in fungal domestication. We have identified here antagonistic functional interactions between transcriptional regulators Cyc8p and Tup1p that modulate the life-style of natural S. cerevisiae strains between biofilm and domesticated mode. Herein, strains with different levels of Cyc8p and Tup1p regulators were constructed, analyzed for processes involved in colony biofilm development and used in the identification of modes of regulation of Flo11p, a key adhesin in biofilm formation. Our data show that Tup1p and Cyc8p regulate biofilm formation in the opposite manner, being positive and negative regulators of colony complexity, cell-cell interaction and adhesion to surfaces. Notably, in-depth analysis of regulation of expression of Flo11p adhesin revealed that Cyc8p itself is the key repressor of FLO11 expression, whereas Tup1p counteracts Cyc8p's repressive function and, in addition, counters Flo11p degradation by an extracellular protease. Interestingly, the opposing actions of Tup1p and Cyc8p concern processes crucial to the biofilm mode of yeast multicellularity, whereas other multicellular processes such as cell flocculation are co-repressed by both regulators. This study provides insight into the mechanisms regulating complexity of the biofilm lifestyle of yeast grown on semisolid surfaces.
- MeSH
- Biofilms * MeSH
- Cell Adhesion physiology MeSH
- Nuclear Proteins genetics metabolism MeSH
- Membrane Glycoproteins genetics metabolism MeSH
- Cell Communication physiology MeSH
- Gene Expression Regulation, Fungal * MeSH
- Repressor Proteins genetics metabolism MeSH
- Saccharomyces cerevisiae Proteins genetics metabolism MeSH
- Saccharomyces cerevisiae physiology MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
