scholarly journals Continuous Drip Flow System to Develop Biofilm ofE. faecalisunder Anaerobic Conditions

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Ana Maria Gonzalez ◽  
Erika Corpus ◽  
Amaury Pozos-Guillen ◽  
Daniel Silva-Herzog ◽  
Antonio Aragon-Piña ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Flow System ◽  
System Model ◽  
Bacterial Cells ◽  
Anaerobic Conditions ◽  
Gram Staining ◽  
Fresh Growth Medium ◽  
Scanning Electron ◽  
Continuous Drip

Purpose.To evaluate a structurally matureE. faecalisbiofilm developed under anaerobic/dynamic conditions in anin vitrosystem.Methods.An experimental device was developed using a continuous drip flow system designed to develop biofilm under anaerobic conditions. The inoculum was replaced every 24 hours with a fresh growth medium for up to 10 days to feed the system. Gram staining was done every 24 hours to control the microorganism purity. Biofilms developed under the system were evaluated under the scanning electron microscope (SEM).Results.SEM micrographs demonstrated mushroom-shaped structures, corresponding to a matureE. faecalisbiofilm. In the mature biofilm bacterial cells are totally encased in a polymeric extracellular matrix.Conclusions.The proposedin vitrosystem model provides an additional useful tool to study the biofilm concept in endodontic microbiology, allowing for a better understanding of persistent root canal infections.

Scanning electron microscopy of mouse ciliated oviduct and tracheal epithelium infected in vitro with Bordetella pertussis

1983 ◽  
Vol 29 (4) ◽  
pp. 415-420 ◽  
Author(s):  
Lauren B. Opremcak ◽  
Melvin S. Rheins
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Organ Culture ◽  
Bordetella Pertussis ◽  
Tracheal Ring ◽  
Fixation Method ◽  
Bacterial Cells ◽  
Ciliated Cells ◽  
Scanning Electron

Infection of mouse tracheal organ culture with Bordetella pertussis resulted in ciliostasis within 36 h. Scanning electron microscopy revealed that B. pertussis attached exclusively to ciliated cells but did not induce expulsion of this cell type at a test interval of 48 h. Mouse oviduct organ culture infected with B. pertussis demonstrated the same strict tropism for ciliated cells as in the tracheal ring system. Only ciliated cells were parasitized, becoming heavily colonized 48 h postinfection. Infected ciliated oviduct cells were not extruded. A fixation method which enhances fine structure was used in the scanning electron microscope studies. Bacterial fimbriae were not observed as the method of attachment of B. pertussis to cilia but fine fibers were seen extending between cilia and bacterial cells.

scholarly journals Lysostaphin Disrupts Staphylococcus aureus and Staphylococcus epidermidis Biofilms on Artificial Surfaces

2003 ◽  
Vol 47 (11) ◽  
pp. 3407-3414 ◽  
Author(s):  
Julie A. Wu ◽  
Caroline Kusuma ◽  
James J. Mond ◽  
John F. Kokai-Kun
Keyword(s):  
Staphylococcus Aureus ◽  
Extracellular Matrix ◽  
Staphylococcus Epidermidis ◽  
Artificial Surfaces ◽  
High Concentrations ◽  
Cross Bridges ◽  
Glass Surfaces ◽  
Sessile Cells ◽  
Scanning Electron

ABSTRACT Staphylococci often form biofilms, sessile communities of microcolonies encased in an extracellular matrix that adhere to biomedical implants or damaged tissue. Infections associated with biofilms are difficult to treat, and it is estimated that sessile bacteria in biofilms are 1,000 to 1,500 times more resistant to antibiotics than their planktonic counterparts. This antibiotic resistance of biofilms often leads to the failure of conventional antibiotic therapy and necessitates the removal of infected devices. Lysostaphin is a glycylglycine endopeptidase which specifically cleaves the pentaglycine cross bridges found in the staphylococcal peptidoglycan. Lysostaphin kills Staphylococcus aureus within minutes (MIC at which 90% of the strains are inhibited [MIC90], 0.001 to 0.064 μg/ml) and is also effective against Staphylococcus epidermidis at higher concentrations (MIC90, 12.5 to 64 μg/ml). The activity of lysostaphin against staphylococci present in biofilms compared to those of other antibiotics was, however, never explored. Surprisingly, lysostaphin not only killed S. aureus in biofilms but also disrupted the extracellular matrix of S. aureus biofilms in vitro on plastic and glass surfaces at concentrations as low as 1 μg/ml. Scanning electron microscopy confirmed that lysostaphin eradicated both the sessile cells and the extracellular matrix of the biofilm. This disruption of S. aureus biofilms was specific for lysostaphin-sensitive S. aureus, as biofilms of lysostaphin-resistant S. aureus were not affected. High concentrations of oxacillin (400 μg/ml), vancomycin (800 μg/ml), and clindamycin (800 μg/ml) had no effect on the established S. aureus biofilms in this system, even after 24 h. Higher concentrations of lysostaphin also disrupted S. epidermidis biofilms.

scholarly journals Equine lung decellularization: a potential approach for in vitro modeling the role of the extracellular matrix in asthma

2018 ◽  
Vol 9 ◽  
pp. 204173141881016 ◽  
Author(s):  
Renata Kelly da Palma ◽  
Paula Fratini ◽  
Gustavo Sá Schiavo Matias ◽  
Andressa Daronco Cereta ◽  
Leticia Lopes Guimarães ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Extracellular Matrix ◽  
Sodium Dodecyl ◽  
Treatment Strategies ◽  
Lung Compliance ◽  
Collagen I ◽  
The Future ◽  
Scanning Electron

Contrary to conventional research animals, horses naturally develop asthma, a disease in which the extracellular matrix of the lung plays a significant role. Hence, the horse lung extracellular matrix appears to be an ideal candidate model for in vitro studying the mechanisms and potential treatments for asthma. However, so far, such model to study cell–extracellular matrix interactions in asthma has not been developed. The aim of this study was to establish a protocol for equine lung decellularization that maintains the architecture of the extracellular matrix and could be used in the future as an in vitro model for therapeutic treatment in asthma. For this the equine lungs were decellularized by sodium dodecyl sulfate detergent perfusion at constant gravitational pressure of 30 cmH2O. Lung scaffolds were assessed by immunohistochemistry (collagen I, III, IV, laminin, and fibronectin), scanning electron microscopy, and DNA quantification. Their mechanical property was assessed by measuring lung compliance using the super-syringe technique. The optimized protocol of lung equine decellularization was effective to remove cells (19.8 ng/mg) and to preserve collagen I, III, IV, laminin, and fibronectin. Moreover, scanning electron microscopy analysis demonstrated maintained microscopic lung structures. The decellularized lungs presented lower compliance compared to native lung. In conclusion we described a reproducible decellularization protocol that can produce an acellular equine lung feasible for the future development of novel treatment strategies in asthma.

scholarly journals Combined Staining Techniques for Demonstration of Staphylococcus aureus Biofilm in Routine Histopathology

2018 ◽  
Vol 3 (1) ◽  
pp. 27-36 ◽  
Author(s):  
Louise Kruse Jensen ◽  
Nicole Lind Henriksen ◽  
Thomas Bjarnsholt ◽  
Kasper Nørskov Kragh ◽  
Henrik Elvang Jensen
Keyword(s):  
Staphylococcus Aureus ◽  
Extracellular Matrix ◽  
Bone Tissue ◽  
Human Case ◽  
Histochemical Staining ◽  
Aureus Strain ◽  
Bacterial Cells ◽  
Routine Basis ◽  
Bacterial Aggregates

Abstract. Aim: Visualization of Staphylococcus aureus biofilm using histochemical staining and combined histochemistry (HC) and immunohistochemistry (IHC).Methods: The ability of S. aureus S54F9 to form biofilm was tested in vitro. Hereafter, infected bone tissue was collected from two different porcine models of osteomyelitis inoculated with S. aureus strain S54F9. The infection time was five and fifteen days, respectively. Twenty-five different histochemical staining protocols were tested in order to find the stains that could identify extracellular biofilm matrix. Protocols with an optimal visualization of biofilm extracellular matrix were combined with an immunohistochemical protocol based on a specific antibody against S. aureus. The combined protocols were applied to the tissue from the porcine models and to infected bone tissue from a child suffering from chronic staphylococcal osteomyelitis for more than a year.Results: S. aureus S54F9 showed an ability to form biofilm in vitro. Visualization of biofilm, i.e. bacterial cells and extracellular matrix in different colours, was seen when the immunohistochemical protocol was combined with Alcian Blue pH3, Luna and Methyl-pyronin green. The bacterial cells were red to light brown and the extracellular matrix either light blue, blue or orange depending on the histochemical stain. In the porcine models and the human case 10 and 90 percent, respectively, of the bacterial aggregates in a 100x magnification field displayed both the extracellular matrix and the bacterial cells simultaneously in two different colours.Conclusions: A combination of HC and IHC can be used to diagnose and characterise biofilm infections on a routine basis.

Fabrication of Ti14Nb4Sn Alloys for Bone Tissue Engineering Applications

2012 ◽  
Vol 520 ◽  
pp. 214-219 ◽  
Author(s):  
Kun Mediaswanti ◽  
Vi Khanh Truong ◽  
Jafar Hasan ◽  
Yun Cang Li ◽  
Cui'e Wen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
In Vitro Test ◽  
Bacterial Cells ◽  
Bone Implant ◽  
Natural Bone ◽  
Vitro Test ◽  
Sintering Method ◽  
Scanning Electron ◽  
Sem Analyses

In this paper, porous Ti14Nb4Sn alloys were fabricated using a space holder sintering method, resulting in a porosity of ~70%. Scanning electron microscopy (SEM) analyses revealed a combination of both macropore and micropore structures. The fabricated titanium alloy scaffolds exhibited a similar structure to that of natural bone, which is expected to improve bone implant longevity. Bacterial cells of Pseudomonas aeruginosa ATCC 9027 were employed for the in vitro test.

Sem Studies of Co-Cr-Mo Surgical Implant Alloy Corrosion Behavior

1982 ◽  
Vol 40 ◽  
pp. 520-521
Author(s):  
Ann Chidester Van Orden ◽  
John L. Chidester ◽  
Anna C. Fraker ◽  
Pei Sung
Keyword(s):  
Electron Microscopy ◽  
Corrosion Behavior ◽  
Anodic Polarization ◽  
Saline Solution ◽  
Saturated Calomel Electrode ◽  
Physiological Saline ◽  
X Ray ◽  
Physiological Saline Solution ◽  
Scanning Electron

The influence of small variations in the composition on the corrosion behavior of Co-Cr-Mo alloys has been studied using scanning electron microscopy (SEM), energy dispersive x-ray analysis (EDX), and electrochemical measurements. SEM and EDX data were correlated with data from in vitro corrosion measurements involving repassivation and also potentiostatic anodic polarization measurements. Specimens studied included the four alloys shown in Table 1. Corrosion tests were conducted in Hanks' physiological saline solution which has a pH of 7.4 and was held at a temperature of 37°C. Specimens were mechanically polished to a surface finish with 0.05 µm A1203, then exposed to the solution and anodically polarized at a rate of 0.006 v/min. All voltages were measured vs. the saturated calomel electrode (s.c.e.).. Specimens had breakdown potentials near 0.47V vs. s.c.e.

Neutrophil migration through in vitro interstitial matrix

1992 ◽  
Vol 50 (1) ◽  
pp. 894-895
Author(s):  
J. Roemer ◽  
S.R. Simon
Keyword(s):  
Extracellular Matrix ◽  
Smooth Muscle ◽  
Cell Migration ◽  
Smooth Muscle Cells ◽  
Inflammatory Cell ◽  
Neutrophil Migration ◽  
Culture Conditions ◽  
Aortic Smooth Muscle ◽  
Specific Culture

We are developing an in vitro interstitial extracellular matrix (ECM) system for study of inflammatory cell migration. Falcon brand Cyclopore membrane inserts of various pore sizes are used as a support substrate for production of ECM by R22 rat aortic smooth muscle cells. Under specific culture conditions these cells produce a highly insoluble matrix consisting of typical interstitial ECM components, i.e.: types I and III collagen, elastin, proteoglycans and fibronectin.

Scanning Electron Microscopy of Staphylococcus Epidermidis Adherence to Continuous Ambulatory Peritoneal Dialysis Catheters

1985 ◽  
Vol 43 ◽  
pp. 520-521
Author(s):  
William J. Lamoreaux ◽  
David L. Smalley ◽  
Larry M. Baddour ◽  
Alfred P. Kraus
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Peritoneal Dialysis ◽  
Continuous Ambulatory Peritoneal Dialysis ◽  
Staphylococcus Epidermidis ◽  
Sterile Saline ◽  
Intravascular Devices ◽  
Capd Patient ◽  
Scanning Electron

Infections associated with the use of intravascular devices have been documented and have been reported to be related to duration of catheter usage. Recently, Eaton et al. reported that Staphylococcus epidermidis may attach to silastic catheters used in continuous ambulatory peritoneal dialysis (CAPD) treatment. The following study presents findings using scanning electron microscopy (SEM) of S. epidermidis adherence to silastic catheters in an in vitro model. In addition, sections of polyvinyl chloride (PVC) dialysis bags were also evaluated by SEM.The S. epidermidis strain RP62A which had been obtained in a previous outbreak of coagulase-negative staphylococcal sepsis at local hospitals was used in these experiments. The strain produced surface slime on exposure to glucose, whereas a nonadherent variant RP62A-NA, which was also used in these studies, failed to produce slime. Strains were grown overnight on blood agar plates at 37°C, harvested from the surface and resuspended in sterile saline (0.85%), centrifuged (3,000 rpm for 10 minutes) and then washed twice in 0.1 M phosphate-buffered saline at pH 7.0. Organisms were resuspended at a concentration of ca. 106 CFU/ml in: a) sterile unused dianeal at 4.25% dextrose, b) sterile unused dianeal at 1.5% dextrose, c) sterile used dialysate previously containing 4.25% dextrose taken from a CAPD patient, and d) sterile used dialysate previously containing 1.5% dextrose taken from a CAPD patient.

Application of Transmission Electron Microscope and Scanning Electron Microscope in experimental tumor studies

1990 ◽  
Vol 48 (3) ◽  
pp. 306-307
Author(s):  
Gao Fengming
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Malignant Transformation ◽  
Transmission Electron Microscope ◽  
Experimental Tumor ◽  
Transmission Electron ◽  
Embryo Cells ◽  
Tumor Studies ◽  
Scanning Electron

Transmission electron microscope(TEM) and scanning electron microscope(SEM) were widely used in experimental tumor studies. They are useful for evaluation of cellular transformation in vitro, classification of histological types of tumors and treating effect of tumors. We have obtained some results as follows:1. Studies on the malignant transformation of mammalian cells in vitro. Syrian golden hamster embryo cells(SGHEC) were transformed in vitro by ThO2 and/or ore dust. In a few days after dust added into medium, some dust crystals were phagocytized. Two weeks later, malignant transformation took place. These cells were of different size, nuclear pleomorphism, numerous ribosomes, increasing of microvilli on cell surface with various length and thickness, and blebs and ruffles(Figs. 1,2). Myelomonocytic leukemic transformation of mouse embryo cells(MEC) was induced in vitro by 3H-TdR. Transformed cells were become round from fusiform. The number of mitochondria and endoplasmic reticulum was reduced, ribosomes and nucleoli increased, shape of nuclei irregular, microvilli increased, and blebs and ruffles appeared(Fig. 3).

Development of an in vitro Model for the Study of the Response of Equine Tendon Fibroblasts to Injury and Medication

1997 ◽  
Vol 10 (01) ◽  
pp. 6-11 ◽  
Author(s):  
R. F. Rosenbusch ◽  
L. C. Booth ◽  
L. A. Dahlgren
Keyword(s):  
Electron Microscopy ◽  
Extracellular Matrix ◽  
Light Microscopy ◽  
Light And Electron Microscopy ◽  
Tendon Healing ◽  
Matrix Proteins ◽  
Isolated Cells ◽  
Superficial Digital Flexor Tendon ◽  
Vitro Model

SummaryEquine tendon fibroblasts were isolated from explants of superficial digital flexor tendon, subcultured and maintained in monolayers. The cells were characterized by light microscopy, electron microscopy and radiolabel studies for proteoglycan production. Two predominant cell morphologies were identified. The cells dedifferentiated toward a more spindle shape with repeated subcultures. Equine tendon fibroblasts were successfully cryopreserved and subsequently subcultured. The ability to produce proteoglycan was preserved.The isolated cells were identified as fibroblasts, based on their characteristic shape by light microscopy and ultrastructure and the active production of extracellular matrix proteins. Abundant rough endoplasmic reticulum and the production of extracellular matrix products demonstrated active protein production and export. Proteoglycans were measurable via liquid scintillation counting in both the cell-associated fraction and free in the supernatant. This model is currently being utilized to study the effects of polysulfated glycosaminoglycan on tendon healing. Future uses include studying the effects of other pharmaceuticals, such as hyaluronic acid, on tendon healing.A model was developed for in vitro investigations into tendon healing. Fibroblasts were isolated from equine superficial digital flexor tendons and maintained in monolayer culture. The tenocytes were characterized via light and electron microscopy. Proteoglycan production was measured, using radio-label techniques. The fibroblasts were cryopreserved and subsequently subcultured. The cells maintained their capacity for proteoglycan production, following repeated subculturing and cryopreservation.

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