Effect of TrisEDTA and Chlorhexidine 0.12% on an In Vitro-Defined Biofilm Representing the Subgingival Plaque Biofilm of the Dog

This study was designed to investigate the effects of chlorhexidine 0.12%, TrisEDTA (tromethamine ethylenediamintetraacetic acid), and a combination of chlorhexidine 0.12% and TrisEDTA on an in vitro plaque biofilm model comprised of three bacterial species commonly found in canine subgingival plaque. Porphyromonas gulae, Actinomyces canis, and Neisseria canis were grown in a biofilm on polished hydroxyapatite coated titanium alloy pucks for 72 h prior to exposure to one of four test solutions: TrisEDTA, chlorhexidine 0.12%, a combination of TrisEDTA and chlorhexidine 0.12%, or sterile deionized water as a control. Following exposure to the test solution, a sample was collected of the biofilm either immediately or following 24 h of additional incubation in a broth medium. Lower numbers of CFU/mL of Porphyromonas gulae resulted when the biofilm was treated with a solution of chlorhexidine 0.12% and TrisEDTA compared to with chlorhexidine 0.12% alone, TrisEDTA alone, or the control and so this solution can be said to be synergistic against Porphyromonas gulae in this controlled in vitro model. Greater reductions in the numbers of CFU/mL of Actinomyces canis and Neisseria canis resulted from treatment with chlorhexidine 0.12% alone than if treated with the combination of TrisEDTA and chlorhexidine 0.12%. When treated biofilm samples were allowed 24 h of additional growth in fresh media, greater variance resulted and this variance highlights the complex dynamics involved in bacterial growth within a biofilm.

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Assessment of Inhibitory Effects of Fluoride-Coated Tubes on Biofilm Formation by Using the In Vitro Dental Unit Waterline Biofilm Model

Applied and Environmental Microbiology ◽

10.1128/aem.00610-08 ◽

2008 ◽

Vol 74 (19) ◽

pp. 5958-5964 ◽

Cited By ~ 15

Author(s):

Toshiaki Yabune ◽

Satoshi Imazato ◽

Shigeyuki Ebisu

Keyword(s):

Biofilm Formation ◽

Polyvinylidene Fluoride ◽

In Vitro Model ◽

Bacterial Species ◽

Biofilm Model ◽

Dental Unit Waterlines ◽

Vitro Model ◽

Methylobacterium Mesophilicum ◽

The One

ABSTRACT This study aimed to establish an in vitro model to simulate biofilms formed in dental unit waterlines (DUWLs) and to investigate the ability of polyvinylidene fluoride (PVDF)-coated tubes to inhibit biofilm formation using this model. The water and biofilm samples were obtained from DUWLs which had been clinically used for 2.5 years, and the predominant bacteria were identified. A conventional polyurethane tube was incubated for 24 to 96 h in the mixed flora of isolated bacteria, and the optimal incubation conditions to simulate a clinically formed biofilm were determined by observation with a scanning electron microscope. Biofilm formation on a PVDF-coated tube was observed using this in vitro model, and the adherence of different bacterial species to conventional and PVDF-coated tubes was assessed. Sphingomonas paucimobilis, Acinetobacter haemolytics, and Methylobacterium mesophilicum were predominantly isolated from contaminated DUWLs. Incubation of the polyurethane tube with the mixed flora containing these three species for 96 h resulted in the formation of a mature biofilm similar to the one clinically observed. The PVDF-coated tube was significantly less adhesive to all three bacterial species than the polyurethane tube (P < 0.05 by the Mann-Whitney U test), and the attachment of small amounts of rods was observed even after incubation with the mixed flora for 96 h. In conclusion, an in vitro biofilm model was obtained by using a mixed flora of bacteria isolated from DUWLs, and the PVDF-coated tube was found to be effective in preventing biofilm formation using this model.

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Impact of bacterial species and baseline resistance on fosfomycin efficacy in urinary tract infections

Journal of Antimicrobial Chemotherapy ◽

10.1093/jac/dkz519 ◽

2019 ◽

Vol 75 (4) ◽

pp. 988-996 ◽

Cited By ~ 6

Author(s):

Iain J Abbott ◽

Jordy Dekker ◽

Elke van Gorp ◽

Rixt A Wijma ◽

Merel N Raaphorst ◽

...

Keyword(s):

In Vitro Model ◽

Bacterial Species ◽

Clinical Isolates ◽

Infection Model ◽

Limit Of Quantification ◽

E Coli ◽

Mutant Prevention Concentration ◽

Vitro Model ◽

Tract Infections

Abstract Objectives To assess the antibacterial effects of a single 3 g oral fosfomycin dose on Escherichia coli and Klebsiella pneumoniae clinical isolates within a dynamic bladder infection model. Methods An in vitro model simulating dynamic urinary fosfomycin concentrations was used. Target fosfomycin exposure (Cmax = 1984 mg/L and Tmax = 7.5 h) was validated by LC-MS/MS. Pharmacodynamic responses of 24 E. coli and 20 K. pneumoniae clinical isolates were examined (fosfomycin MIC ≤0.25–128 mg/L). Mutant prevention concentration (MPC), fosfomycin heteroresistance, fosfomycin resistance genes and fosA expression were examined. Pathogen kill and emergence of high-level resistance (HLR; MIC >1024 mg/L) were quantified. Results Following fosfomycin exposure, 20 of 24 E. coli exhibited reductions in bacterial counts below the lower limit of quantification without regrowth, despite baseline fosfomycin MICs up to 128 mg/L. Four E. coli regrew (MIC = 4–32 mg/L) with HLR population replacement. At baseline, these isolates had detectable HLR subpopulations and MPC >1024 mg/L. All E. coli isolates were fosA negative. In contrast, 17 of 20 K. pneumoniae regrew post exposure, 6 with emergence of HLR (proportion = 0.01%–100%). The three isolates without regrowth did not have a detectable HLR subpopulation after dynamic drug-free incubation. All K. pneumoniae had MPC >1024 mg/L and were fosA positive. WGS analysis and fosA expression failed to predict fosfomycin efficacy. Conclusions E. coli and K. pneumoniae isolates demonstrate discrepant responses to a single fosfomycin dose in a dynamic bladder infection in vitro model. Treatment failure against E. coli was related to an HLR subpopulation, not identified by standard MIC testing. Activity against K. pneumoniae appeared limited, regardless of MIC testing, due to universal baseline heteroresistance.

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Enteropathogenic Infections: Organoids Go Bacterial

Stem Cells International ◽

10.1155/2021/8847804 ◽

2021 ◽

Vol 2021 ◽

pp. 1-14

Author(s):

Viktoria Hentschel ◽

Frank Arnold ◽

Thomas Seufferlein ◽

Ninel Azoitei ◽

Alexander Kleger ◽

...

Keyword(s):

In Vitro Model ◽

Bacterial Species ◽

Personal Hygiene ◽

Considerable Proportion ◽

Oral Transmission ◽

Intestinal Organoids ◽

Enteric Infections ◽

Vitro Model

Enteric infections represent a major health care challenge which is particularly prevalent in countries with restricted access to clean water and sanitation and lacking personal hygiene precautions, altogether facilitating fecal-oral transmission of a heterogeneous spectrum of enteropathogenic microorganisms. Among these, bacterial species are responsible for a considerable proportion of illnesses, hospitalizations, and fatal cases, all of which have been continuously contributing to ignite researchers’ interest in further exploring their individual pathogenicity. Beyond the universally accepted animal models, intestinal organoids are increasingly valued for their ability to mimic key architectural and physiologic features of the native intestinal mucosa. As a consequence, they are regarded as the most versatile and naturalistic in vitro model of the gut, allowing monitoring of adherence, invasion, intracellular trafficking, and propagation as well as repurposing components of the host cell equipment. At the same time, infected intestinal organoids allow close characterization of the host epithelium’s immune response to enteropathogens. In this review, (i) we provide a profound update on intestinal organoid-based tissue engineering, (ii) we report the latest pathophysiological findings defining the infected intestinal organoids, and (iii) we discuss the advantages and limitations of this in vitro model.

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An in vitro model for investigation of vitamin A effects on wound healing

International Journal for Vitamin and Nutrition Research ◽

10.1024/0300-9831/a000692 ◽

2021 ◽

pp. 1-6

Author(s):

Hoda Keshmiri Neghab ◽

Mohammad Hasan Soheilifar ◽

Gholamreza Esmaeeli Djavid

Keyword(s):

Wound Healing ◽

Endothelial Cell ◽

Vitamin A ◽

In Vitro Model ◽

Cellular Proliferation ◽

Endothelial Cell Migration ◽

Normal Fibroblast ◽

Anti Inflammatory ◽

Vitro Model

Abstract. Wound healing consists of a series of highly orderly overlapping processes characterized by hemostasis, inflammation, proliferation, and remodeling. Prolongation or interruption in each phase can lead to delayed wound healing or a non-healing chronic wound. Vitamin A is a crucial nutrient that is most beneficial for the health of the skin. The present study was undertaken to determine the effect of vitamin A on regeneration, angiogenesis, and inflammation characteristics in an in vitro model system during wound healing. For this purpose, mouse skin normal fibroblast (L929), human umbilical vein endothelial cell (HUVEC), and monocyte/macrophage-like cell line (RAW 264.7) were considered to evaluate proliferation, angiogenesis, and anti-inﬂammatory responses, respectively. Vitamin A (0.1–5 μM) increased cellular proliferation of L929 and HUVEC (p < 0.05). Similarly, it stimulated angiogenesis by promoting endothelial cell migration up to approximately 4 fold and interestingly tube formation up to 8.5 fold (p < 0.01). Furthermore, vitamin A treatment was shown to decrease the level of nitric oxide production in a dose-dependent effect (p < 0.05), exhibiting the anti-inflammatory property of vitamin A in accelerating wound healing. These results may reveal the therapeutic potential of vitamin A in diabetic wound healing by stimulating regeneration, angiogenesis, and anti-inﬂammation responses.

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