scholarly journals Characterization of a Novel Megalocytivirus Isolated from European Chub (Squalius cephalus)

Viruses ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 440 ◽  
Author(s):  
Maya A. Halaly ◽  
Kuttichantran Subramaniam ◽  
Samantha A. Koda ◽  
Vsevolod L. Popov ◽  
David Stone ◽  
...  
Keyword(s):  
Sequence Data ◽  
Phylogenetic Analyses ◽  
Electron Microscopic Examination ◽  
Illumina Miseq ◽  
Open Reading Frames ◽  
Electron Microscopic ◽  
Cytoplasmic Inclusions ◽  
European Chub ◽  
Transmission Electron ◽  
Squalius Cephalus

A novel virus from moribund European chub (Squalius cephalus) was isolated on epithelioma papulosum cyprini (EPC) cells. Transmission electron microscopic examination revealed abundant non-enveloped, hexagonal virus particles in the cytoplasm of infected EPC cells consistent with an iridovirus. Illumina MiSeq sequence data enabled the assembly and annotation of the full genome (128,216 bp encoding 108 open reading frames) of the suspected iridovirus. Maximum Likelihood phylogenetic analyses based on 25 iridovirus core genes supported the European chub iridovirus (ECIV) as being the sister species to the recently-discovered scale drop disease virus (SDDV), which together form the most basal megalocytivirus clade. Genetic analyses of the ECIV major capsid protein and ATPase genes revealed the greatest nucleotide identity to members of the genus Megalocytivirus including SDDV. These data support ECIV as a novel member within the genus Megalocytivirus. Experimental challenge studies are needed to fulfill River’s postulates and determine whether ECIV induces the pathognomonic microscopic lesions (i.e., megalocytes with basophilic cytoplasmic inclusions) observed in megalocytivirus infections.

scholarly journals Systemic Iridovirus Infection in the Banggai Cardinalfish (Pterapogon Kauderni Koumans 1933)

2009 ◽  
Vol 21 (3) ◽  
pp. 306-320 ◽  
Author(s):  
E. Scott Weber ◽  
Thomas B. Waltzek ◽  
Devon A. Young ◽  
Erica L. Twitchell ◽  
Amy E. Gates ◽  
...  
Keyword(s):  
Genomic Sequence ◽  
Sequence Data ◽  
Molecular Diagnostic ◽  
Molecular Testing ◽  
Electron Microscopic ◽  
Cytoplasmic Inclusions ◽  
Marine Habitats ◽  
Transmission Electron ◽  
Atpase Gene ◽  
Wide Range

Iridoviruses infect food and ornamental fish species from a wide range of freshwater to marine habitats across the globe. The objective of the current study was to characterize an iridovirus causing systemic infection of wild-caught Pterapogon kauderni Koumans 1933 (Banggai cardinalfish). Freshly frozen and fixed specimens were processed for histopathologic evaluation, transmission electron microscopic examination, virus culture, molecular virologic testing, microbiology, and in situ hybridization (ISH) using riboprobes. Basophilic granular cytoplasmic inclusions were identified in cytomegalic cells often found beneath endothelium, and hexagonal virus particles typical of iridovirus were identified in the cytoplasm of enlarged cells by transmission electron microscopy. Attempts at virus isolation in cell culture were unsuccessful; however, polymerase chain reaction (PCR)-based molecular testing resulted in amplification and sequencing of regions of the DNA polymerase and major capsid protein genes, along with the full-length ATPase gene of the putative iridovirus. Virus gene sequences were then used to infer phylogenetic relationships of the P. kauderni agent to other known systemic iridoviruses from fishes. Riboprobes, which were transcribed from a cloned PCR amplification product from the viral genome generated hybridization signals from inclusions within cytomegalic cells in histologic sections tested in ISH experiments. To the authors' knowledge, this is the first report of a systemic iridovirus from P. kauderni. The pathologic changes induced and the genomic sequence data confirm placement of the Banggai cardinalfish iridovirus in the genus Megalocytivirus family Iridoviridae. The ISH provides an additional molecular diagnostic technique for confirmation of presumptive infections detected in histologic sections from infected fish.

A Comparative Study of Fractographic Replicas

1974 ◽  
Vol 32 ◽  
pp. 566-567
Author(s):  
Loren Anderson ◽  
Pat Pizzo ◽  
Glen Haydon
Keyword(s):  
Electron Microscopy ◽  
Electron Microscopic Examination ◽  
Direct Examination ◽  
Electron Microscopic ◽  
Reliable Technique ◽  
Service Failures ◽  
Transmission Electron ◽  
Mode Of Failure ◽  
Scanning Electron Microscopic ◽  
Scanning Electron

Transmission electron microscopy of replicas has long been used to study the fracture surfaces of components which fail in service. Recently, the scanning electron microscope (SEM) has gained popularity because it allows direct examination of the fracture surface. However, the somewhat lower resolution of the SEM coupled with a restriction on the sample size has served to limit the use of this instrument in investigating in-service failures. It is the intent of this paper to show that scanning electron microscopic examination of conventional negative replicas can be a convenient and reliable technique for determining mode of failure.

scholarly journals Taxonomic Re-Examination of Nine Rosellinia Types (Ascomycota, Xylariales) Stored in the Saccardo Mycological Collection

2021 ◽  
Vol 9 (3) ◽  
pp. 666
Author(s):  
Niccolò Forin ◽  
Alfredo Vizzini ◽  
Federico Fainelli ◽  
Enrico Ercole ◽  
Barbara Baldan
Keyword(s):  
Sequence Data ◽  
Phylogenetic Analyses ◽  
Illumina Miseq ◽  
Botanical Garden ◽  
Molecular Study ◽  
Its2 Sequence ◽  
Type Specimens ◽  
Its1 Sequence ◽  
Dna Sequence Data ◽  
Nomen Novum

In a recent monograph on the genus Rosellinia, type specimens worldwide were revised and re-classified using a morphological approach. Among them, some came from Pier Andrea Saccardo’s fungarium stored in the Herbarium of the Padova Botanical Garden. In this work, we taxonomically re-examine via a morphological and molecular approach nine different Roselliniasensu Saccardo types. ITS1 and/or ITS2 sequences were successfully obtained applying Illumina MiSeq technology and phylogenetic analyses were carried out in order to elucidate their current taxonomic position. Only the ITS1 sequence was recovered for Rosellinia areolata, while for R. geophila, only the ITS2 sequence was recovered. We proposed here new combinations for Rosellinia chordicola, R. geophila and R. horridula, while for R. ambigua, R. areolata, R. australis, R. romana and R. somala, we did not suggest taxonomic changes compared to the current ones. The name Rosellinia subsimilis Sacc. is invalid, as it is a later homonym of R. subsimilis P. Karst. & Starbäck. Therefore, we introduced Coniochaeta dakotensis as a nomen novum for R. subsimilis Sacc. This is the first time that these types have been subjected to a molecular study. Our results demonstrate that old types are an important source of DNA sequence data for taxonomic re-examinations.

scholarly journals Chromate Reduction in Serratia marcescens Isolated from Tannery Effluent and Potential Application for Bioremediation of Chromate Pollution

2002 ◽  
Vol 2 ◽  
pp. 972-977 ◽  
Author(s):  
M.A. Mondaca ◽  
V. Campos ◽  
R. Moraga ◽  
C.A. Zaror
Keyword(s):  
Natural Waters ◽  
Waste Treatment ◽  
Environmental Concern ◽  
Electron Microscopic Examination ◽  
Tannery Effluent ◽  
Chromate Reduction ◽  
Bacterial Cells ◽  
Electron Microscopic ◽  
Treatment Processes ◽  
Transmission Electron

Pollution of aquatic systems by heavy metals has resulted in increasing environmental concern because they cannot be biodegraded. One metal that gives reason for concern due to its toxicity is chromium. Cr(VI) and Cr(III) are the principal forms of chromium found in natural waters. A chromate-resistant strain of the bacterium S. marcescens was isolated from tannery effluent. The strain was able to reduce Cr(VI) to Cr(III), and about 80% of chromate was removed from the medium. The reduction seems to occur on the cell surface. Transmission electron microscopic examination of cells revealed that particles were deposited on the outside of bacterial cells. A stable biofilm was formed in less than 10 h, reaching around 1010cfu attached per milligram of activated carbon. These findings demonstrate that immobilizedS. marcescensmight be used in industrial waste treatment processes.

Electrophoretic and electron microscopic examination of the adductor and diductor muscles of an articulate brachiopod, Terebratalia transversa

1982 ◽  
Vol 60 (4) ◽  
pp. 550-559 ◽  
Author(s):  
William P. Eshleman ◽  
Jerrel L. Wilkens ◽  
Michael J. Cavey
Keyword(s):  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Electron Microscopic Examination ◽  
Light Chains ◽  
Electron Microscopic ◽  
Electrophoretic Patterns ◽  
Transmission Electron ◽  
Adductor Muscles ◽  
Regulation Of Contraction

The proteins of the striated adductor muscles, smooth adductor muscles, and diductor muscles of the articulate brachiopod Terebratalia transversa have been examined by sodium dodecyl sulfate – polyacrylamide gel electrophoresis. Electrophoretic patterns indicate the presence of paramyosin in all of these valve muscles. Tentative identification has also been made of the proteins responsible for actin and for myosin regulation of contraction (troponin–tropomyosin and myosin light chains, respectively). The myofilaments of the striated adductor cells, smooth adductor cells, and diductor cells have been characterized by transmission electron microscopy. The smooth adductor cells and the diductor cells exhibit very thick myofilaments which are fusiform in shape, exceptionally long, and axially banded. Morphological features of these thick myofilaments are consistent with those of paramyosin filaments found in other muscles and myoepithelia. Although the striated adductor cells contain paramyosin, it is not manifest in the thick myofilaments.

scholarly journals Internalization of Staphylococcus aureusby Endothelial Cells Induces Apoptosis

1998 ◽  
Vol 66 (12) ◽  
pp. 5994-5998 ◽  
Author(s):  
Barbara E. Menzies ◽  
Iordanka Kourteva
Keyword(s):  
Endothelial Cells ◽  
Umbilical Vein ◽  
Electron Microscopic Examination ◽  
Cytochalasin D ◽  
Nuclear Morphology ◽  
Electron Microscopic ◽  
Transmission Electron ◽  
Transmission Electron Microscopic ◽  
Endothelial Cell Death ◽  
Umbilical Vein Endothelial Cells

ABSTRACT The ability of Staphylococcus aureus to invade and survive within endothelial cells is believed to contribute to its propensity to cause persistent endovascular infection with endothelial destruction. In the present study, we show that following invasion of human umbilical vein endothelial cells, intracellular S. aureus organisms remain viable over a 72-h period and, as determined by transmission electron microscopic examination, that the bacteria exist within vacuoles and free within the cytoplasm. We also demonstrate that endothelial cell death following S. aureusinvasion occurs at least in part by apoptosis as shown by DNA fragmentation and changes in nuclear morphology. Apoptotic changes were evident as early as 1 h after infection of endothelial cells. Internalization of S. aureus rather than adherence appears to be necessary, since use of the phagocytosis inhibitor cytochalasin D prevented apoptosis. UV-killed staphylococci, although retaining the capacity to be internalized, were not capable of inducing apoptosis, suggesting that apoptosis is dependent upon a factor associated with viable organisms. The studies demonstrate that viable intracellularS. aureus induces apoptosis of endothelial cells and that internalized staphylococci can exist free within the cytoplasm.

Ultrastructural studies of cartilage in genetic disorders of skeletal growth

1978 ◽  
Vol 36 (2) ◽  
pp. 668-669
Author(s):  
D. O. Sillence ◽  
D. L. Rimoin ◽  
Ruth Silberberg
Keyword(s):  
Genetic Disorders ◽  
Electron Microscopic Examination ◽  
Uranyl Acetate ◽  
Osmic Acid ◽  
Electron Microscopic ◽  
Skeletal Dysplasias ◽  
Ultrastructural Studies ◽  
Low Viscosity ◽  
Transmission Electron ◽  
Cacodylate Buffer

The human skeletal dysplasias are an heterogeneous group of heritable connective tissue disorders associated with abnormalities in the size and shape of the limbs, trunk and/or skull which frequently result in disproportionate short stature. In recent years it has become apparent that these comprise over 50 distinct conditions with a variety of subtypes distinguished on clinical and radiological grounds. We have investigated the pathogenesis of these conditions in over 100 patients by direct transmission electron microscopic examination of chondro-osseous tissue. Some of the ultrastructural studies have been previously reported.Small biopsies of chondro-osseous junction were collected for electron microscopy from the rib or iliac crest of patients with skeletal dysplasias or from normal controls at the time of surgery. These were cut into small blocks and fixed for one hour in either 5% glutaraldehyde in white's buffer or directly in 1% osmic acid in White's buffer or a modified Karnovsky's fixative, (2. 5% paraformaldehyde, 2. 5% glutaraldehyde, 2. 5mM calcium in cacodylate buffer). Subsequent processing included osmium fixation, block staining with uranyl acetate and embedding in Araldite or Spurr's low viscosity resin (firm composition). Sections were cut with glass knives or diamond knives. The latter produced sections which were much more even in thickness, permitting more consistent appraisal of matrix features.

A Rapid Method for Electron Microscopic Examination of Biological Specimens

1971 ◽  
Vol 29 ◽  
pp. 486-487
Author(s):  
Glenn Stoner
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Simple Procedure ◽  
Contact Point ◽  
Electron Microscopic Examination ◽  
Test Solution ◽  
Biological Applications ◽  
Electron Microscopic ◽  
Preparation Time ◽  
Transmission Electron

The purpose of this paper is to demonstrate the use of a method which reduces the sample preparation time for transmission electron microscopy studies to about one minute.The relatively simple procedure is as follows: When a sample is desired, place 1 mℓ test solution in a 2-5 mℓ container, add 0.1 mℓ of a solution of 0.3 mg/mℓ fibrinogen, immediately insert a 400 mesh E.M. grid held by forceps, withdraw immediately, blot (at the tweezer tip-grid contact point) with filter paper, blow dry with a lab drier, add one drop of stain (2% urinal acetate), blot and blow dry in the above manner. Then immediately insert in the pre-pump chamber of the E.M.The above process has been used by the author in a variety of biological applications, from studies of fibrin growth from fibrinogen to identification of unknown viruses. The accompaning figures for T4, bacteriophage are given simply to demonstrate the method.

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