A unique group of scabies mite pseudoproteases promotes cutaneous blood coagulation and delays plasmin-induced fibrinolysis

Background Scabies, a highly contagious skin disease affecting more than 200 million people worldwide at any time, is caused by the parasitic mite Sarcoptes scabiei. In the absence of molecular markers, diagnosis requires experience making surveillance and control challenging. Superficial microthrombi in the absence of vasculitis in scabies-affected skin are a recognised, yet unexplained histopathological differential of scabies infection. This study demonstrates that a family of Scabies Mite Inactivated Cysteine Protease Paralogues (SMIPP-Cs) excreted by the mites plays a role in formation of scabies-induced superficial microthrombi. Methodology/Principal findings A series of in vitro and ex vivo experiments involving two representative recombinant SMIPP-Cs was carried out. In the presence of SMIPP-Cs, the thrombin clotting time (TCT), fibrin formation and plasmin induced fibrinolysis were monitored in vitro. The ultrastructure of the SMIPP-C—modulated fibrin was analysed by Scanning Electron Microscopy (SEM). Immuno-histological analyses were performed ex vivo, to localise the SMIPP-C proteins within scabies infected skin biopsies. SMIPP-Cs displayed pro-coagulant properties. They bound calcium ions, reduced the thrombin clotting time, enhanced the fibrin formation rate and delayed plasmin-induced fibrinolysis. The SMIPP-Cs associated with fibrin clots during fibrinogen polymerisation and did not bind to preformed fibrin. Scanning electron microscopy revealed that the fibrin clots formed in the presence of SMIPP-Cs were aberrant and denser than normal fibrin clots. SMIPP-Cs were detected in microthrombi which are commonly seen in scabietic skin. Conclusions/Significance The SMIPP-Cs are the first scabies mite proteins found in sub-epidermal skin layers and their pro-coagulant properties promote superficial microthrombi formation in scabetic skin. Further research is needed to evaluate their potential as diagnostic or therapeutic target.

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Specific Disruption of EstablishedP. aeruginosaBiofilms Using Polymer-Attacking Enzymes

10.1101/598979 ◽

2019 ◽

Cited By ~ 1

Author(s):

Kristin N. Kovach ◽

Derek Fleming ◽

Kendra P. Rumbaugh ◽

Vernita D. Gordon

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Ex Vivo ◽

Enzymatic Treatment ◽

Glycoside Hydrolases ◽

Extracellular Dna ◽

Extracellular Polysaccharides ◽

The Matrix ◽

Scanning Electron

AbstractBiofilms are communities of bacteria embedded in an extracellular matrix of self-produced polymeric substances. This polymer matrix lends the bacteria protection against a wide array of chemical and mechanical stresses that they may experience in their environment, which might be a location in the human body in the case of a biofilm infection, or a surface immersed in fluid in an industrial setting. Breaking down the matrix network renders biofilms more susceptible to physical disruption and to treatments. Different species of bacteria, and different strains within the same species, produce different types of matrix polymers – this suggests that targeting specific polymers for disruption may be more effective than non-specific approaches to disrupting biofilm matrices. In this study, we treatedPseudomonas aeruginosabiofilms with enzymes that are specific to different matrix polymers. We used bulk rheology to measure the resulting alteration in biofilm mechanics, and scanning electron microscopy to visualize the alteration in the matrix network upon treatment. Different lab strains ofP. aeruginosaform biofilms that can be dominated by one of three main extracellular polysaccharides: Psl, alginate, and Pel, which binds electrostatically to extracellular DNA in the matrix. We applied enzymes to biofilms dominated by different extracellular polysaccharides and found that, for biofilms grownin vitro, the effect of enzymatic treatment is maximized when the enzyme is specific to a dominant matrix polymer – for such a case, specifically-matched enzymatic treatment tends to: reduce yield strain and yield stress; reduce or eliminate long-range structure and shorten or eliminate connecting network fibers in the biofilm as seen under scanning electron microscopy; and increase the rate of biofilm drying, most likely due to increased diffusivity as a result of network compromise. However, forex vivobiofilms grown in murine wounds, we find that generic glycoside hydrolases have more profound disruptive effects than specifically-matched enzymes, even though they had no measurable effect for biofilms grownin vitro. This highlights the importance of the environment in which the biofilms are grown, the need to take this into account when developing treatments for biofilms, and the possibility that effective approaches to eradicating biofilms in environmental or industrial settings may need to be very different from effective treatments of infection.

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EX VIVO MODEL OF RABBIT INTESTINAL EPITHELIUM APPLIED TO THE STUDY OF COLONIZATION BY ENTEROAGGREGATIVE ESCHERICHIA COLI

Arquivos de Gastroenterologia ◽

10.1590/s0004-2803.201700000-12 ◽

2017 ◽

Vol 54 (2) ◽

pp. 130-134 ◽

Cited By ~ 3

Author(s):

Ricardo Luís Lopes BRAGA ◽

Ana Claudia Machado PEREIRA ◽

Paula Azevedo dos SANTOS ◽

Angela Corrêa FREITAS-ALMEIDA ◽

Ana Cláudia de Paula ROSA

Keyword(s):

Electron Microscopy ◽

Escherichia Coli ◽

Scanning Electron Microscopy ◽

Organ Culture ◽

Colonic Mucosa ◽

Ex Vivo ◽

Gastrointestinal Infections ◽

In Vitro Organ Culture ◽

Scanning Electron

ABSTRACT BACKGROUND The diarrheal syndrome is considered a serious public health problem all over the world and is considered a major cause of morbidity and mortality in developing countries. The high incidence of enteroaggregative Escherichia coli in diarrheal syndromes classified as an emerging pathogen of gastrointestinal infections. After decades of study, your pathogenesis remains uncertain and has been investigated mainly using in vitro models of adhesion in cellular lines. OBJECTIVE The present study investigated the interaction of enteroaggregative Escherichia coli strains isolated from childhood diarrhea with rabbit ileal and colonic mucosa ex vivo, using the in vitro organ culture model. METHODS The in vitro adhesion assays using cultured tissue were performed with the strains co-incubated with intestinal fragments of ileum and colon over a period of 6 hours. Each strain was tested with three intestinal fragments for each region. The fragments were analysed by scanning electron microscopy. RESULTS Through scanning electron microscopy we observed that all strains adhered to rabbit ileal and colonic mucosa, with the typical aggregative adherence pattern of “stacked bricks” on the epithelium. However, the highest degree of adherence was observed on colonic mucosa. Threadlike structures were found in greater numbers in the ileum compared to the colon. CONCLUSION These data showed that enteroaggregative Escherichia coli may have a high tropism for the human colon, which was ratified by the higher degree of adherence on the rabbit colonic mucosa. Finally, data indicated that in vitro organ culture of intestinal mucosa from rabbit may be used to elucidate the enteroaggregative Escherichia coli pathogenesis.

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

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100119429 ◽

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.

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The Mesothelial Cell as a Non-Thrombogenic Surface

Thrombosis and Haemostasis ◽

10.1055/s-0038-1661149 ◽

1984 ◽

Vol 52 (02) ◽

pp. 102-104 ◽

Cited By ~ 25

Author(s):

L J Nicholson ◽

J M F Clarke ◽

R M Pittilo ◽

S J Machin ◽

N Woolf

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Blood Flow ◽

Cell Surface ◽

Mesothelial Cell ◽

Mesothelial Cells ◽

Plastic Film ◽

In Vitro System ◽

Scanning Electron

SummaryA technique for harvesting mesothelial cells is described. This entails collagenase digestion of omentum after which the cells can be cultured. The technique has been developed using the rat, but has also been successfully applied to human tissue. Cultured rat mesothelial cells obtained in this way have been examined by scanning electron microscopy. Rat mesothelial cells grown on plastic film have been exposed to blood in an in vitro system using a Baumgartner chamber and have been demonstrated to support blood flow. No adhering platelets were observed on the mesothelial cell surface. Fibroblasts similarily exposed to blood as a control were washed off the plastic.

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Study of Phosphocalcic Glasses from SiO2-CaO-P2O5 System with and Without Silver II. The bioactivity analysis by FTIR, SEM methods and microbiological study of silver-doped glasses

Revista de Chimie ◽

10.37358/rc.17.6.5639 ◽

2017 ◽

Vol 68 (6) ◽

pp. 1188-1192

Author(s):

Daniela Avram ◽

Nicolae Angelescu ◽

Dan Nicolae Ungureanu ◽

Ionica Ionita ◽

Iulian Bancuta ◽

...

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Body Fluid ◽

Pathogenic Bacteria ◽

De Novo ◽

Microbiological Examination ◽

Doped Glasses ◽

P2o5 System ◽

Scanning Electron

The study in vitro of the glass powders bioactivity was performed by soaking them in simulated body fluid for 3 to 21 days at a temperature of 37�C and pH = 7.20. The synthesis de novo of hydroxyapatite, post soaking was confirmed by Fourier Transform Infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The study of the antimicrobial activity was performed by microbiological examination on two strains of pathogenic bacteria involved in postoperative nosocomial infections.

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Synthesis and Evaluation of AlgNa-g-poly(QCL-co-HEMA) Hydrogels as Platform for Chondrocyte Proliferation and Controlled Release of Betamethasone

International Journal of Molecular Sciences ◽

10.3390/ijms22115730 ◽

2021 ◽

Vol 22 (11) ◽

pp. 5730

Author(s):

Jomarien García-Couce ◽

Marioly Vernhes ◽

Nancy Bada ◽

Lissette Agüero ◽

Oscar Valdés ◽

...

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Controlled Release ◽

Biomedical Applications ◽

Release Kinetics ◽

Cell Types ◽

Tissue Engineering Scaffolds ◽

Almost All ◽

Scanning Electron

Hydrogels obtained from combining different polymers are an interesting strategy for developing controlled release system platforms and tissue engineering scaffolds. In this study, the applicability of sodium alginate-g-(QCL-co-HEMA) hydrogels for these biomedical applications was evaluated. Hydrogels were synthesized by free-radical polymerization using a different concentration of the components. The hydrogels were characterized by Fourier transform-infrared spectroscopy, scanning electron microscopy, and a swelling degree. Betamethasone release as well as the in vitro cytocompatibility with chondrocytes and fibroblast cells were also evaluated. Scanning electron microscopy confirmed the porous surface morphology of the hydrogels in all cases. The swelling percent was determined at a different pH and was observed to be pH-sensitive. The controlled release behavior of betamethasone from the matrices was investigated in PBS media (pH = 7.4) and the drug was released in a controlled manner for up to 8 h. Human chondrocytes and fibroblasts were cultured on the hydrogels. The MTS assay showed that almost all hydrogels are cytocompatibles and an increase of proliferation in both cell types after one week of incubation was observed by the Live/Dead® assay. These results demonstrate that these hydrogels are attractive materials for pharmaceutical and biomedical applications due to their characteristics, their release kinetics, and biocompatibility.

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