scholarly journals Effect of household bleach on the structure of the sporocyst wall of Toxoplasma gondii

Parasite ◽  
2021 ◽  
Vol 28 ◽  
pp. 68
Author(s):  
Aurélien Dumètre ◽  
Jitender P. Dubey ◽  
David J.P. Ferguson
Keyword(s):  
Toxoplasma Gondii ◽  
Outer Layer ◽  
Wall Layer ◽  
Cross Link ◽  
Oocyst Wall ◽  
Maclura Pomifera ◽  
Transmission Electron ◽  
Household Bleach ◽  
Sporocyst Wall ◽  
Molecular Nature

Toxoplasma gondii oocysts are responsible for food- and water-borne infections in humans worldwide. They are resistant to common chemical disinfectants, including chlorinated products, presumably due to the structure and molecular nature of the oocyst wall but also the sporocyst wall. In this study, we used fluorescence microscopy and transmission electron microscopy to characterise the structure of both the oocyst and sporocyst walls, exposed to household bleach. Bleach removed the outer layer of the oocyst wall and the outer layer of the wall of sporocysts exposed due to rupture of the oocyst wall. The loss of the outer sporocyst wall layer was associated with a decrease in its autofluorescence, which can be linked to the degradation of dityrosine cross-link proteins, and loss of Maclura pomifera lectin-reactive glycoproteins. This study suggests that the inner layers of the oocyst and sporocyst walls are the main structures responsible for the resistance of the parasite to household bleach.

Description of Eimeria bubonis sp.n. (Protozoa: Eimeriidae) and Caryospora bubonis sp.n. (Protozoa: Eimeriidae) in the great horned owl, Bubo virginianus (Gmelin), of Saskatchewan

1981 ◽  
Vol 59 (2) ◽  
pp. 170-173 ◽  
Author(s):  
Richard J. Cawthorn ◽  
P. H. G. Stockdale
Keyword(s):  
New Species ◽  
Outer Layer ◽  
Polar Granule ◽  
Oocyst Wall ◽  
Bubo Virginianus ◽  
Sporocyst Residuum ◽  
Two New Species ◽  
Sporocyst Wall ◽  
Oocyst Residuum

Two new species of Eimeriidae are described from the great horned owl, Bubo virginianus (Gmelin), of Saskatchewan. The subspherical oocysts of Eimeria bubonis sp.n. are 22.8 ± 2.7 μm (18–30) long and 21.7 ± 2.4 μm (16–29) wide. The spindle-shaped sporocysts are 12.7 ± 1.1 μm (9.5–15.0) long and 7.8 ± 0.7 μm (5.8–10.0) wide. The polar granule, Steida body, and sporocyst residuum are present; the micropyle and oocyst residuum are absent. The oocyst wall is 0.8 μm thick, with a thick, clear outer layer and a thin, dark inner layer. Sporozoites, with a prominent conoid at the anterior end, are 13.1 ± 1.5 μm (10.0–16.3) long and 2.6 ± 0.3 μm (2.0–4.8) wide.The subspherical oocysts of Caryospora bubonis sp.n. are 43.9 ± 3.4 μm (38–52) long and 40.2 ± 2.8 μm (33–47) wide. The subspherical sporocysts are 26.6 ± 3.4 μm (20–33) long and 25.6 ± 2.4 μm (20–32) wide. The sporocyst residuum is present; the polar granule, Steida body, and oocyst residuum are absent. The oocyst wall is 1.1 μm thick, with a thick, clear outer layer and a thin, dark inner layer. The sporocyst wall is 0.8 μm thick with a thick, clear outer layer and a thin, dark inner layer. Sporozoites, with a prominent conoid at the anterior end, are 15.5 ± 1.9 μm (13.0–20.8) long and 2.5 ± 0.2 μm (2.3–3.0) wide.In both species, sporulation is complete in 96 h at 21 ± 2 °C.

Coccidians in the liver and testis of the herring Clupea harengus L.

1984 ◽  
Vol 62 (3) ◽  
pp. 480-493 ◽  
Author(s):  
Carol M. Morrison ◽  
William E. Hawkins
Keyword(s):  
Outer Layer ◽  
Parasitophorous Vacuole ◽  
Light And Electron Microscopy ◽  
Testicular Tissue ◽  
Clupea Harengus ◽  
Hepatic Tissue ◽  
Oocyst Wall ◽  
Sporocyst Wall ◽  
Mature Fish ◽  
Host Parasite

The coccidians Goussia clupearum from liver and Eimeria sardinae from testis of herring caught in waters near Nova Scotia were studied by light and electron microscopy. Unsporulated and sporulatcd oocysts were the most frequently encountered stages. Oocyst walls of both species were thin and closely apposed to the host cell. At least a part of the oocyst wall appeared to serve also as the boundary of the parasitophorous vacuole. In G. clupearum, membranes lining parasitophorous vacuoles of various stages seemed to be involved in host–parasite nutrient transfer. Wall-forming bodies were found in the sporont of E. sardinae, and presumptive wall-forming bodies were found in the sporont of G. clupearum. The sporocyst wall of G. clupearum appeared to consist of two valves. The wall had a thick transversely striated inner layer and a thin outer layer consisting of several closely apposed membranes. The lamellated membranes extended from the outer layer. The sporocyst wall of E. sardinae was thin and consisted of three loosely organized membranes. The sporocysts of neither species had a Stieda body. Goussia clupearum, which often elicited an intense host reaction, infected 85% of mature fish whereas E. sardinae infected 90–100%. Replacement of hepatic tissue by G. clupearum could stress fish and replacement of testicular tissue by E. sardinae could reduce sperm production, thus detrimentally affecting herring stocks.

Haustorial development of Peronospora tabacina infecting Nicotiana tabacum

1983 ◽  
Vol 61 (12) ◽  
pp. 3444-3453 ◽  
Author(s):  
R. N. Trigiano ◽  
C. G. Van Dyke ◽  
H. W. Spurr Jr.
Keyword(s):  
Cell Wall ◽  
Toluidine Blue ◽  
Mesophyll Cell ◽  
Wall Layer ◽  
Peronospora Tabacina ◽  
Host Cytoplasm ◽  
Transmission Electron ◽  
Mold Fungus ◽  
Host Cell Wall ◽  
Hyphal Wall

The development of haustoria in tobacco by the blue-mold fungus Peronospora tabacina was examined using light, scanning, and transmission electron microscopy. Electron-lucent, callose-like appositions were observed between the host plasmalemma and the host mesophyll cell wall prior to haustorial penetration. An electron-opaque penetration matrix was present between the apposition and the host cell wall. The intercellular hyphal wall consisted of two layers which differed in staining quality. The haustorial wall was also two layered, but was primarily composed of and continuous with the inner wall layer of the intercellular hypha. Haustoria were either finger-like or branched and were encased with callose-like material. Most encasements were thickened at the proximal regions of haustoria but were thinner along the distal portions. Vesicles were present in host cytoplasm and were occasionally attached to the invaginated host plasmalemma. These vesicles might contribute to the deposition of the encasement material. The encasement stained positively for callose using aniline blue; calcofluor and toluidine blue O tests for cellulose were inconclusive, and lignin was not detected using toluidine blue O or phloroglucinol–HCl.

scholarly journals In VitroEffects of Novel Ruthenium Complexes in Neospora caninum and Toxoplasma gondii Tachyzoites

2013 ◽  
Vol 57 (11) ◽  
pp. 5747-5754 ◽  
Author(s):  
Fabienne Barna ◽  
Karim Debache ◽  
Carsten A. Vock ◽  
Tatiana Küster ◽  
Andrew Hemphill
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Toxoplasma Gondii ◽  
Neospora Caninum ◽  
Ruthenium Complexes ◽  
Term Treatment ◽  
Content Type ◽  
Transmission Electron ◽  
Long Term Treatment

ABSTRACTUpon the screening of 16 antiproliferative compounds againstToxoplasma gondiiandNeospora caninum, two hydrolytically stable ruthenium complexes (compounds 16 and 18) exhibited 50% inhibitory concentrations of 18.7 and 41.1 nM (T. gondii) and 6.7 and 11.3 nM (N. caninum). To achieve parasiticidal activity with compound 16, long-term treatment (22 to 27 days at 80 to 160 nM) was required. Transmission electron microscopy demonstrated the rapid impact on and ultrastructural alterations in both parasites. These preliminary findings suggest that the potential of ruthenium-based compounds should thus be further exploited.

A transmission electron microscopical study of the tegument of Maritrema feliui (Digenea: Microphallidae)

2013 ◽  
Vol 58 (4) ◽  
Author(s):  
Zdzisław Świderski ◽  
Isabel Montoliu ◽  
Carlos Feliu ◽  
David Gibson ◽  
Jordi Miquel
Keyword(s):  
Surface Layer ◽  
Plasma Membrane ◽  
Outer Layer ◽  
Microscopical Study ◽  
The Other ◽  
Cytoplasmic Region ◽  
Transmission Electron ◽  
Basal Plasma Membrane ◽  
Basal Plasma ◽  
Electron Microscopical

AbstractThe tegument of the microphallid digenean Maritrema feliui, examined by means of TEM, is described as a syncytial epithelium organised into two layers. The outer layer is an external anucleate, cytoplasmic region connected to a second region composed of nucleate perikarya (cytons) deeply embedded in the surrounding cortical parenchyma. The surface layer of the tegument is covered by a plasma membrane with many deep invaginations, which are apparently pinocytotic. This layer also bears numerous large, electron-dense spines of two types, which are intracellular and attached to the basal plasma membrane. Its cytoplasm is rich in free ribosomes, contains numerous mitochondria, disc-shaped granules frequently arranged in a rouleau, and several large, moderately electron-dense, membranous bodies. The subtegumentary perikarya and their nuclei, which are both flattened, are described in detail, as are their connections with the surface tegument. These perikarya appear to be the source of the disc-shaped granules and some of the other inclusions present in the surface layer. The main characteristics of the tegumental structure of M. feliui are commented upon in relation to the findings of previous publications and their suggested functions.

scholarly journals Ultrastructure of phagocytes and oocysts of Nematopsis sp. (Apicomplexa, Porosporidae) infecting Crassostrea rhizophorae in Northeastern Brazil

2019 ◽  
Vol 28 (1) ◽  
pp. 97-104
Author(s):  
Themis Jesus Silva ◽  
Emerson Carlos Soares ◽  
Graça Casal ◽  
Sónia Rocha ◽  
Elton Lima Santos ◽  
...  
Keyword(s):  
Parasitophorous Vacuole ◽  
Adductor Muscle ◽  
Systematic Position ◽  
Variable Number ◽  
Northeastern Brazil ◽  
Ultrastructural Organization ◽  
Oocyst Wall ◽  
Transmission Electron ◽  
Adductor Muscles ◽  
Crassostrea Rhizophorae

Abstract This work describes the detailed ultrastructural morphology of the phagocyte imprisoning an oyster of Nematopsis (Apicomplexa) found in Crassostrea rhizophorae, in the city of Maceió (AL), Brazil. The highly infected hosts had half-open leaflets with weak, slow retraction of the adductor muscles. Variable number of ellipsoid oocytes, either isolated and or clustered, was found between myofibrils of the adductor muscle. Each oocyst was incarcerated in a parasitophorous vacuole of host uninucleated phagocyte. The oocysts were composed of a dense wall containing a uninucleate vermiform sporozoite. The wall of the fine oocysts was composed of homogeneous electron-lucent material formed by three layers of equal thickness, having a circular orifice-micropyle obstructed by the operculum. The oocysts presented ellipsoid morphology with their wall was surrounded by a complex network of numerous microfibrils. Important details of the taxonomic value were visualized such as the ultrastructural organization of the oocyst wall and the organization of the micropyle and operculum, beyond the microfibrils that protrude from the oocyst wall only observed by transmission electron microscopy (TEM) and that may aid in the identification of the species. However, in order to clarify the systematic position of the species reported of the genus Nematopsis, it is important to proceed with genetic analyses.

scholarly journals Toxoplasma gondii Inside LLCMK2 Cells. A Study by Field Emission Scanning and Transmission Electron Microscopy

2003 ◽  
Vol 9 (S02) ◽  
pp. 232-233
Author(s):  
Rodrigo Cardoso Magno ◽  
Lorian Cobra Straker ◽  
Wanderley de Souza ◽  
Marcia Attias
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Toxoplasma Gondii ◽  
Field Emission ◽  
Transmission Electron

The ultrastructural development of the oocyst wall of Eimeria maxima

Parasitology ◽  
1980 ◽  
Vol 81 (1) ◽  
pp. 115-122 ◽  
Author(s):  
R. M. Pittilo ◽  
S. J. Ball
Keyword(s):  
Outer Wall ◽  
Amorphous Region ◽  
Wall Layer ◽  
Intestinal Cells ◽  
Type I ◽  
Type Ii ◽  
Oocyst Wall ◽  
Outer Membranes ◽  
Eimeria Maxima ◽  
Intracellular Process

SUMMARYOocyst wall formation in Eimeria maxima was studied during the macrogamete stage in intestinal cells of the chick and in unsporulated oocysts isolated from faeces. The outer of the 2 membranes bounding the mature macrogamete separated from the surface but remained as a veil surrounding the developing oocyst throughout the whole intracellular process. Wall-forming bodies Type I were initially applied to the limiting membrane of the zygote cytoplasm; a layer of material similar to their contents was then formed around the zygote. As this occurred a new double membrane was formed surrounding the oocyst cytoplasm. The outer wall layer was initially homogenous in appearance but later developed into 2 zones, an outer amorphous region and an inner osmiophilic region. The inner layer of the oocyst wall was formed from the contents of the wallforming bodies Type II which dispersed between the outer wall and the limiting membranes of the oocyst cytoplasm. There was evidence of an additional membrane formed external to the outer wall. The outer membranes were not present around the wall of oocysts passed in the faeces of chicks, but the same wall zonation was evident, although the inner osmiophilic zone of the outer wall layer was markedly thinner in comparison with the same zone seen in the tissues.

scholarly journals The inner–outer layer interface in large-eddy simulations with wall-layer models

2003 ◽  
Vol 24 (4) ◽  
pp. 538-550 ◽  
Author(s):  
Ugo Piomelli ◽  
Elias Balaras ◽  
Hugo Pasinato ◽  
Kyle D. Squires ◽  
Philippe R. Spalart
Keyword(s):  
Outer Layer ◽  
Wall Layer ◽  
Large Eddy Simulations ◽  
Layer Interface ◽  
Large Eddy

Small-scale characteristics of a turbulent boundary layer over a rough wall

1997 ◽  
Vol 342 ◽  
pp. 263-293 ◽  
Author(s):  
H. S. SHAFI ◽  
R. A. ANTONIA
Keyword(s):  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
Outer Layer ◽  
Large Scale ◽  
Energy Dissipation Rate ◽  
Wall Layer ◽  
Rough Wall ◽  
Small Scale ◽  
Smooth Wall ◽  
Velocity Derivative

Measurements of the spanwise and wall-normal components of vorticity and their constituent velocity derivative fluctuations have been made in a turbulent boundary layer over a mesh-screen rough wall using a four-hot-wire vorticity probe. The measured spectra and variances of vorticity and velocity derivatives have been corrected for the effect of spatial resolution. The high-wavenumber behaviour of the spectra conforms closely with isotropy. Over most of the outer layer, the normalized magnitudes of the velocity derivative variances differ significantly from those over a smooth wall layer. The differences are such that the variances are much more nearly isotropic over the rough wall than on the smooth wall. This behaviour is consistent with earlier observations that the large-scale structure in this rough wall layer is more isotropic than that in a smooth wall layer. Isotropy-based approximations for the mean energy dissipation rate and mean enstrophy are consequently more reliable in this rough wall layer than in a smooth wall layer. In the outer layer, the vorticity variances are slightly larger than those over a smooth wall; reflecting structural differences between the two flows.

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