An in vitro biofilm model system maintaining a highly reproducible species and metabolic diversity approaching that of the human oral microbiome

The aim of this study was to evaluate the potential anti-biofilm and antibacterial activities of Streptococcus downii sp. nov. To test anti-biofilm properties, Streptococcus mutans, Actinomyces naeslundii, Veillonella parvula, Fusobacterium nucleatum, Porphyromonas gingivalis, and Aggregatibacter actinomycetemcomitans were grown in a biofilm model in the presence or not of S. downii sp. nov. for up to 120 h. For the potential antibacterial activity, 24 h-biofilms were exposed to S. downii sp. nov for 24 and 48 h. Biofilms structures and bacterial viability were studied by microscopy, and the effect in bacterial load by quantitative polymerase chain reaction. A generalized linear model was constructed, and results were considered as statistically significant at p < 0.05. The presence of S. downii sp. nov. during biofilm development did not affect the structure of the community, but an anti-biofilm effect against S. mutans was observed (p < 0.001, after 96 and 120 h). For antibacterial activity, after 24 h of exposure to S. downii sp. nov., counts of S. mutans (p = 0.019) and A. actinomycetemcomitans (p = 0.020) were significantly reduced in well-structured biofilms. Although moderate, anti-biofilm and antibacterial activities of S. downii sp. nov. against oral bacteria, including some periodontal pathogens, were demonstrated in an in vitro biofilm model.

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EXPANSION OF HEMATOPOIETIC STEM CELLS IN VITRO AS A MODEL SYSTEM FOR HUMAN TISSUE ENGINEERING

Orthopedic Clinics of North America ◽

10.1016/s0030-5898(05)70167-x ◽

2000 ◽

Vol 31 (3) ◽

pp. 499-509 ◽

Cited By ~ 3

Author(s):

Joel S. Greenberger ◽

Julie P. Goff ◽

Jason Bush ◽

Alfred Bahnson ◽

Douglas Koebler ◽

...

Keyword(s):

Tissue Engineering ◽

Stem Cells ◽

Hematopoietic Stem Cells ◽

Human Tissue ◽

Model System ◽

Hematopoietic Stem

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Serotonin Binding Proteins: An In Vitro Model System for Monoamine-related Neurotoxicitya

Annals of the New York Academy of Sciences ◽

10.1111/j.1749-6632.1994.tb21830.x ◽

2006 ◽

Vol 738 (1) ◽

pp. 408-418 ◽

Cited By ~ 1

Author(s):

GEORGES VAUQUELIN ◽

MARLENE JIMENEZ RIO ◽

CARLOS VELEZ PARDO

Keyword(s):

Binding Proteins ◽

In Vitro Model ◽

Model System ◽

In Vitro Model System ◽

Vitro Model

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Exposure of ichnovirus particles to digitonin leads to enhanced infectivity and induces fusion from without in an in vitro model system

Journal of General Virology ◽

10.1099/vir.0.83118-0 ◽

2007 ◽

Vol 88 (11) ◽

pp. 2977-2984 ◽

Cited By ~ 4

Author(s):

Don Stoltz ◽

Renée Lapointe ◽

Andrea Makkay ◽

Michel Cusson

Keyword(s):

Outer Membrane ◽

In Vitro Model ◽

Model System ◽

Host Cells ◽

Fusion Event ◽

Susceptible Host ◽

In Vitro Model System ◽

Vitro Model

Unlike most viruses, the mature ichnovirus particle possesses two unit membrane envelopes. Following loss of the outer membrane in vivo, nucleocapsids are believed to gain entry into the cytosol via a membrane fusion event involving the inner membrane and the plasma membrane of susceptible host cells; accordingly, experimentally induced damage to the outer membrane might be expected to increase infectivity. Here, in an attempt to develop an in vitro model system for studying ichnovirus infection, we show that digitonin-induced disruption of the virion outer membrane not only increases infectivity, but also uncovers an activity not previously associated with any polydnavirus: fusion from without.

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Effect of Oxidized Myofibrils Protein Subjected to Mutiple Freeze-Thaw Cycles on N-Nitrosamine Formation in In Vitro Model System

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.550-553.1590 ◽

2012 ◽

Vol 550-553 ◽

pp. 1590-1594 ◽

Cited By ~ 1

Author(s):

Hua Yang ◽

Pei Pei Meng ◽

Rui Wang ◽

Pei Ran Li ◽

Peng Li ◽

...

Keyword(s):

Sodium Nitrite ◽

Protein Carbonyl ◽

Model System ◽

Model Systems ◽

Secondary Amines ◽

Freeze Thaw ◽

Heavy Chains ◽

Carcinogenic Substance ◽

The Times

N-nitrosamine is a kind of carcinogenic substance, which is possibly formed in the reaction of nitrites with amino acids or secondary amines. Two in vitro model systems were designed to evaluate the influence of oxidized myofibrils protein subjected to repeated freeze-thaw cycles (0, 1, 2, 3, 4, 7, 10 times) on N-nitrosamine formation. Model system I contains diethylamine and sodium nitrite, while model system II contains only sodium nitrite as reaction solution. Oxidized myofibrils protein were added to both systems. The results revealed that as the number of freeze-thaw cycles increased, cross-linking of myosin heavy chains and the content of protein carbonyl increased, but the content of protein sulfydryl decreased, which indicates oxidization of protein occurred. The concentration of N-nitrosodiethylamine increased as the number of freeze-thaw cycles increased, especially after four cycles. Oxidized myofibrils protein promoted the formation of N-nitrosodiethylamine. The more the times of freeze-thaw cycles were subjected, the more oxidization of myofibrils protein occurred and the higher yield of the N-nitrosodiethylamine.

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In VitroEfficacies and Resistance Profiles of Rifampin-Based Combination Regimens for Biofilm-Embedded Methicillin-Resistant Staphylococcus aureus

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01236-13 ◽

2013 ◽

Vol 57 (11) ◽

pp. 5717-5720 ◽

Cited By ~ 31

Author(s):

Hung-Jen Tang ◽

Chi-Chung Chen ◽

Kuo-Chen Cheng ◽

Kuan-Ying Wu ◽

Yi-Chung Lin ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Fusidic Acid ◽

Antibacterial Activities ◽

Methicillin Resistant ◽

Content Type ◽

Biofilm Model ◽

Rifampin Resistance ◽

Combination Regimens ◽

Resistant Mutation

ABSTRACTTo compare thein vitroantibacterial efficacies and resistance profiles of rifampin-based combinations against methicillin-resistantStaphylococcus aureus(MRSA) in a biofilm model, the antibacterial activities of vancomycin, teicoplanin, daptomycin, minocycline, linezolid, fusidic acid, fosfomycin, and tigecycline alone or in combination with rifampin against biofilm-embedded MRSA were measured. The rifampin-resistant mutation frequencies were evaluated. Of the rifampin-based combinations, rifampin enhances the antibacterial activities of and even synergizes with fusidic acid, tigecycline, and, to a lesser extent, linezolid, fosfomycin, and minocycline against biofilm-embedded MRSA. Such combinations with weaker rifampin resistance induction activities may provide a therapeutic advantage in MRSA biofilm-related infections.

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Relevance of Biofilm Models in Periodontal Research: From Static to Dynamic Systems

Microorganisms ◽

10.3390/microorganisms9020428 ◽

2021 ◽

Vol 9 (2) ◽

pp. 428

Author(s):

María Carmen Sánchez ◽

Andrea Alonso-Español ◽

Honorato Ribeiro-Vidal ◽

Bettina Alonso ◽

David Herrera ◽

...

Keyword(s):

Research Group ◽

Surface Composition ◽

Bacterial Colonization ◽

Implant Surface ◽

Biofilm Growth ◽

Biofilm Model ◽

Dental Implant Surface ◽

The Impact

Microbial biofilm modeling has improved in sophistication and scope, although only a limited number of standardized protocols are available. This review presents an example of a biofilm model, along with its evolution and application in studying periodontal and peri-implant diseases. In 2011, the ETEP (Etiology and Therapy of Periodontal and Peri-Implant Diseases) research group at the University Complutense of Madrid developed an in vitro biofilm static model using representative bacteria from the subgingival microbiota, demonstrating a pattern of bacterial colonization and maturation similar to in vivo subgingival biofilms. When the model and its methodology were standardized, the ETEP research group employed the validated in vitro biofilm model for testing in different applications. The evolution of this model is described in this manuscript, from the mere observation of biofilm growth and maturation on static models on hydroxyapatite or titanium discs, to the evaluation of the impact of dental implant surface composition and micro-structure using the dynamic biofilm model. This evolution was based on reproducing the ideal microenvironmental conditions for bacterial growth within a bioreactor and reaching the target surfaces using the fluid dynamics mimicking the salivary flow. The development of this relevant biofilm model has become a powerful tool to study the essential processes that regulate the formation and maturation of these important microbial communities, as well as their behavior when exposed to different antimicrobial compounds.

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