Animal Models to Evaluate Bacterial Biofilm Development

2014 ◽  
pp. 127-139
Author(s):  
Kim Thomsen ◽  
Hannah Trøstrup ◽  
Claus Moser
Keyword(s):  
Animal Models ◽  
Bacterial Biofilm ◽  
Biofilm Development

Bifunctional Composites for Biofilms Modulation on Cervical Restorations

2021 ◽  
pp. 002203452110181
Author(s):  
A.A. Balhaddad ◽  
I.M. Garcia ◽  
L. Mokeem ◽  
M.S. Ibrahim ◽  
F.M. Collares ◽  
...  
Keyword(s):  
Free Energy ◽  
Surface Free Energy ◽  
Contact Angles ◽  
Bacterial Biofilm ◽  
Dental Composite ◽  
Log P ◽  
Rrna Gene ◽  
Cervical Lesions ◽  
Biofilm Growth ◽  
Biofilm Development

Cervical composites treating root carious and noncarious cervical lesions usually extend subgingivally. The subgingival margins of composites present poor plaque control, enhanced biofilm accumulation, and cause gingival irritation. A potential material to restore such lesions should combine agents that interfere with bacterial biofilm development and respond to acidic conditions. Here, we explore the use of new bioresponsive bifunctional dental composites against mature microcosm biofilms derived from subgingival plaque samples. The designed formulations contain 2 bioactive agents: dimethylaminohexadecyl methacrylate (DMAHDM) at 3 to 5 wt.% and 20 wt.% nanosized amorphous calcium phosphate (NACP) in a base resin. Composites with no DMAHDM and NACP were used as controls. The newly formulated 5% DMAHDM–20% NACP composite was analyzed by micro-Raman spectroscopy and transmission electron microscopy. The wettability and surface-free energy were also assessed. The inhibitory effect on the in vitro biofilm growth and the 16S rRNA gene sequencing of survival bacterial colonies derived from the composites were analyzed. Whole-biofilm metabolic activity, polysaccharide production, and live/dead images of the biofilm grown over the composites complement the microbiological assays. Overall, the designed formulations had higher contact angles with water and lower surface-free energy compared to the commercial control. The DMAHDM-NACP composites significantly inhibited the growth of total microorganisms, Porphyromonas gingivalis, Prevotella intermedia/nigrescens, Aggregatibacter actinomycetemcomitans, and Fusobacterium nucleatum by 3 to 5-log ( P < 0.001). For the colony isolates from control composites, the composition was typically dominated by the genera Veillonella, Fusobacterium, Streptococcus, Eikenella, and Leptotrichia, while Fusobacterium and Veillonella dominated the 5% DMAHDM–20% NACP composites. The DMAHDM-NACP composites contributed to over 80% of reduction in metabolic and polysaccharide activity. The suppression effect on plaque biofilms suggested that DMAHDM-NACP composites might be used as a bioactive material for cervical restorations. These results may propose an exciting path to prevent biofilm growth and improve dental composite restorations’ life span.

scholarly journals Options and Limitations in Clinical Investigation of Bacterial Biofilms

2018 ◽  
Vol 31 (3) ◽  
Author(s):  
Maria Magana ◽  
Christina Sereti ◽  
Anastasios Ioannidis ◽  
Courtney A. Mitchell ◽  
Anthony R. Ball ◽  
...  
Keyword(s):  
Clinical Investigation ◽  
Bacterial Biofilm ◽  
Clinical Settings ◽  
Microbial Composition ◽  
The Past ◽  
Methodological Research ◽  
Current Trends ◽  
Literature Searches ◽  
Biofilm Development ◽  
Multispecies Biofilms

SUMMARYBacteria can form single- and multispecies biofilms exhibiting diverse features based upon the microbial composition of their community and microenvironment. The study of bacterial biofilm development has received great interest in the past 20 years and is motivated by the elegant complexity characteristic of these multicellular communities and their role in infectious diseases. Biofilms can thrive on virtually any surface and can be beneficial or detrimental based upon the community's interplay and the surface. Advances in the understanding of structural and functional variations and the roles that biofilms play in disease and host-pathogen interactions have been addressed through comprehensive literature searches. In this review article, a synopsis of the methodological landscape of biofilm analysis is provided, including an evaluation of the current trends in methodological research. We deem this worthwhile because a keyword-oriented bibliographical search reveals that less than 5% of the biofilm literature is devoted to methodology. In this report, we (i) summarize current methodologies for biofilm characterization, monitoring, and quantification; (ii) discuss advances in the discovery of effective imaging and sensing tools and modalities; (iii) provide an overview of tailored animal models that assess features of biofilm infections; and (iv) make recommendations defining the most appropriate methodological tools for clinical settings.

scholarly journals The Histidine Kinase BinK Is a Negative Regulator of Biofilm Formation and Squid Colonization

2016 ◽  
Vol 198 (19) ◽  
pp. 2596-2607 ◽  
Author(s):  
John F. Brooks ◽  
Mark J. Mandel
Keyword(s):  
Histidine Kinase ◽  
Biofilm Formation ◽  
Bacterial Biofilm ◽  
Negative Regulator ◽  
Epithelial Tissue ◽  
Temperature Modulation ◽  
Content Type ◽  
Animal Hosts ◽  
Biofilm Development

ABSTRACTBacterial colonization of animal epithelial tissue is a dynamic process that relies on precise molecular communication. Colonization ofEuprymna scolopesbobtail squid byVibrio fischeribacteria requires bacterial aggregation in host mucus as the symbiont transitions from a planktonic lifestyle in seawater to a biofilm-associated state in the host. We have identified a gene,binK(biofilm inhibitor kinase; VF_A0360), which encodes an orphan hybrid histidine kinase that negatively regulates theV. fischerisymbiotic biofilm (Syp)in vivoandin vitro. We identifiedbinKmutants as exhibiting a colonization advantage in a global genetic screen, a phenotype that we confirmed in controlled competition experiments. Bacterial biofilm aggregates in the host are larger in strains lacking BinK, whereas overexpression of BinK suppresses biofilm formation and squid colonization. Signaling through BinK is required for temperature modulation of biofilm formation at 28°C. Furthermore, we present evidence that BinK acts upstream of SypG, the σ54-dependent transcriptional regulator of thesypbiofilm locus. The BinK effects are dependent on intact signaling in the RscS-Syp biofilm pathway. Therefore, we propose that BinK antagonizes the signal from RscS and serves as an integral component inV. fischeribiofilm regulation.IMPORTANCEBacterial lifestyle transitions underlie the colonization of animal hosts from environmental reservoirs. Formation of matrix-enclosed, surface-associated aggregates (biofilms) is common in beneficial and pathogenic associations, but investigating the genetic basis of biofilm development in live animal hosts remains a significant challenge. Using the bobtail squid light organ as a model, we analyzed putative colonization factors and identified a histidine kinase that negatively regulates biofilm formation at the host interface. This work reveals a novelin vivobiofilm regulator that influences the transition of bacteria from their planktonic state in seawater to tight aggregates of cells in the host. The study enriches our understanding of biofilm regulation and beneficial colonization by an animal's microbiome.

scholarly journals Extracellular DNA and Type IV Pilus Expression Regulate the Structure and Kinetics of Biofilm Formation by Nontypeable Haemophilus influenzae

mBio ◽  
2017 ◽  
Vol 8 (6) ◽  
Author(s):  
Jayajit Das ◽  
Elaine Mokrzan ◽  
Vinal Lakhani ◽  
Lucia Rosas ◽  
Joseph A. Jurcisek ◽  
...  
Keyword(s):  
Middle Ear ◽  
In Silico ◽  
Biofilm Formation ◽  
Rational Design ◽  
Bacterial Biofilm ◽  
Confocal Imaging ◽  
Extracellular Dna ◽  
Fractal Structures ◽  
Biofilm Development

ABSTRACT Biofilms formed in the middle ear by nontypeable Haemophilus influenzae (NTHI) are central to the chronicity, recurrence, and refractive nature of otitis media (OM). However, mechanisms that underlie the emergence of specific NTHI biofilm structures are unclear. We combined computational analysis tools and in silico modeling rooted in statistical physics with confocal imaging of NTHI biofilms formed in vitro during static culture in order to identify mechanisms that give rise to distinguishing morphological features. Our analysis of confocal images of biofilms formed by NTHI strain 86-028NP using pair correlations of local bacterial densities within sequential planes parallel to the substrate showed the presence of fractal structures of short length scales (≤10 μm). The in silico modeling revealed that extracellular DNA (eDNA) and type IV pilus (Tfp) expression played important roles in giving rise to the fractal structures and allowed us to predict a substantial reduction of these structures for an isogenic mutant (ΔcomE) that was significantly compromised in its ability to release eDNA into the biofilm matrix and had impaired Tfp function. This prediction was confirmed by analysis of confocal images of in vitro ΔcomE strain biofilms. The fractal structures potentially generate niches for NTHI survival in the hostile middle ear microenvironment by dramatically increasing the contact area of the biofilm with the surrounding environment, facilitating nutrient exchange, and by generating spatial positive feedback to quorum signaling. IMPORTANCE NTHI is a major bacterial pathogen for OM, which is a common ear infection in children worldwide. Chronic OM is associated with bacterial biofilm formation in the middle ear; therefore, knowledge of the mechanisms that underlie NTHI biofilm formation is important for the development of therapeutic strategies for NTHI-associated OM. Our combined approach using confocal imaging of NTHI biofilms formed in vitro and mathematical tools for analysis of pairwise density correlations and agent-based modeling revealed that eDNA and Tfp expression were important factors in the development of fractal structures in NTHI biofilms. These structures may help NTHI survive in hostile environments, such as the middle ear. Our in silico model can be used in combination with laboratory or animal modeling studies to further define the mechanisms that underlie NTHI biofilm development during OM and thereby guide the rational design of, and optimize time and cost for, benchwork and preclinical studies. IMPORTANCE NTHI is a major bacterial pathogen for OM, which is a common ear infection in children worldwide. Chronic OM is associated with bacterial biofilm formation in the middle ear; therefore, knowledge of the mechanisms that underlie NTHI biofilm formation is important for the development of therapeutic strategies for NTHI-associated OM. Our combined approach using confocal imaging of NTHI biofilms formed in vitro and mathematical tools for analysis of pairwise density correlations and agent-based modeling revealed that eDNA and Tfp expression were important factors in the development of fractal structures in NTHI biofilms. These structures may help NTHI survive in hostile environments, such as the middle ear. Our in silico model can be used in combination with laboratory or animal modeling studies to further define the mechanisms that underlie NTHI biofilm development during OM and thereby guide the rational design of, and optimize time and cost for, benchwork and preclinical studies.

scholarly journals Phenazine-1-Carboxylic Acid Promotes Bacterial Biofilm Development via Ferrous Iron Acquisition

2011 ◽  
Vol 193 (14) ◽  
pp. 3606-3617 ◽  
Author(s):  
Y. Wang ◽  
J. C. Wilks ◽  
T. Danhorn ◽  
I. Ramos ◽  
L. Croal ◽  
...  
Keyword(s):  
Carboxylic Acid ◽  
Ferrous Iron ◽  
Iron Acquisition ◽  
Bacterial Biofilm ◽  
Biofilm Development

Characterization of bacterial biofilm communities in tertiary treatment processes for wastewater reclamation and reuse

2008 ◽  
Vol 58 (5) ◽  
pp. 1023-1030 ◽  
Author(s):  
Tadashi Shoji ◽  
Shuichi Ochi ◽  
Masaaki Ozaki
Keyword(s):  
Urban Areas ◽  
Heterotrophic Bacteria ◽  
Bacterial Biofilm ◽  
Nitrifying Bacteria ◽  
Water Supply Systems ◽  
Ammonia Oxidizing Bacteria ◽  
Tertiary Treatment ◽  
Treatment Processes ◽  
Related Group ◽  
Biofilm Development

The concern with wastewater reuse as a sustainable water resource in urban areas has been growing. For the reclamation and distribution of wastewater, biofilm development deserves careful attention from the point of view of its promotion (e.g. biofiltration) and inhibition (e.g. clogging and hygiene problems). As the first step to control biofilm development, bacterial biofilm communities in tertiary treatment processes were characterized by using molecular biological methods. The result of clone library analysis showed that Nitrospirae-related (nitrite-oxydizing bacteria) and Acidobacteria-related (probably oligotrophic bacteria) groups were dominant. The ratio of the Nitrospirae-related group to the Acidobacteria-related group was associated with ammonia load, whereas other operational conditions (process, media, temperature, salt) did not clearly affect the phylum-level community or the dominant sequence of nitrifying bacteria. The result of real-time PCR also indicated that high ammonia load promotes the proliferation of nitrite- and ammonia-oxidizing bacteria. Regarding water supply systems, some researchers also have suggested the dominance of Nitrospirae- and Acidobacteria-related groups in biofilm formed on water distribution pipes. In tertiary wastewater treatment, therefore, it is concluded that oligotrophic and autotrophic bacteria are the dominant groups in biofilm samples because assimilable organic carbon is too poor to proliferate various heterotrophic bacteria.

scholarly journals Take my breath away

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Vinai C Thomas ◽  
Paul D Fey
Keyword(s):  
Cell Wall ◽  
Bacterial Cell ◽  
Bacterial Cell Wall ◽  
Bacterial Biofilm ◽  
Biofilm Development

A lack of oxygen activates a pathway that causes the bacterial cell wall to break down, which, in turn, aids bacterial biofilm development.

scholarly journals Novel Antibacterial Modification of Polycarbonate for Increment Prototyping in Medicine

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4725
Author(s):  
Tomasz Flak ◽  
Ewa Trejnowska ◽  
Szymon Skoczyński ◽  
Jadwiga Gabor ◽  
Beata Swinarew ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Antibacterial Properties ◽  
Antimicrobial Properties ◽  
Modern Medicine ◽  
Bacterial Biofilm ◽  
Polymer Materials ◽  
Resistant Bacteria ◽  
Entire Volume ◽  
Increased Risk ◽  
Biofilm Development

In the era of modern medicine, the number of invasive treatments increases. Artificial devices used in medicine are associated with an increased risk of secondary infections. Bacterial biofilm development observed on the implanted surface is challenging to treat, primarily due to low antibiotics penetration. In our study, the preparation of a new polycarbonate composite, filled with nanosilver, nanosilica and rhodamine B derivative, suitable for three-dimensional printing, is described. Polymer materials with antimicrobial properties are known. However, in most cases, protection is limited to the outer layers only. The newly developed materials are protected in their entire volume. Moreover, the antibacterial properties are retained after multiple high-temperature processing were performed, allowing them to be used in 3D printing. Bacterial population reduction was observed, which gives an assumption for those materials to be clinically tested in the production of various medical devices and for the reduction of morbidity and mortality caused by multidrug-resistant bacteria.

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