Unikaryon slaptonleyi sp.nov. (Microspora: Unikaryonidae) isolated from echinostome and strigeid larvae from Lymnaea peregra: observations on its morphology, transmission and pathogenicity

Parasitology ◽  
1983 ◽  
Vol 87 (2) ◽  
pp. 175-184 ◽  
Author(s):  
Elizabeth U. Canning ◽  
Rosalind J. Barker ◽  
Jill C. Hammond ◽  
J. P. Nicholas
Keyword(s):  
Host Cell ◽  
Fasciola Hepatica ◽  
Polar Filament ◽  
Pieris Brassicae ◽  
Cell Cytoplasm ◽  
Terrestrial Arthropods ◽  
Host Cell Cytoplasm ◽  
Lymnaea Peregra ◽  
High Doses ◽  
Germinal Tissue

SUMMARYA microsporidium, isolated from echinostome and strigeid larval trematodes in Lymnaea peregra, is described as a new species Unikaryon slaptonleyi sp.nov. The nuclei isolated at all stages of development, the disporoblastic sporogony and development in contact with host cell cytoplasm are used to assign the species to the genus Unikaryon. The absence of a vacuolar membrane to isolate the meronts and stages of sporulation from the host cell cytoplasm differentiates this genus from Encephalitozoon. Spores are uninucleate, have 17–21 turns of the polar filament coil and measure 5·0 × 2·8/μm fresh. U. slaptonleyi was isolated from rediae and metacercariae of Echinoparyphium recurvatum and sporo-cysts and cercariae of an unidentified strigeid trematode in L. peregra. It was transmitted in the laboratory to unidentified echinostomes in L. peregra and to unidentified strigeids in Planorbis planorbis by feeding the spores to field-collected snails from which cercariae were already emerging. In these natural and experimental hyperinfections the snail tissues were lightly infected but, in the helminths, much of the parenchyma and germinal tissue was destroyed, so that few cercariae were released and most of those were distorted. Similar heavy infections were produced in Fasciola hepatica in Lymnaea truncatula, when spores were fed to the snails 14 days after miracidial penetration, but even high doses (106 spores/snail) produced only light infections in Schistosoma mansoni in Biomphalaria glabrata, in only 2 out of 9 snails. No infections were obtained in larvae producing xiphidiocercariae in P. planorbis although echinostomes became infected under the same conditions. Of a number of aquatic and terrestrial arthropods tested for susceptibility by feeding or by inoculation of spores into the haemocoele, only Pieris brassicae became infected. In a small proportion of pupae surviving from larvae which had been inoculated with spores at 3rd or 4th instar, there was clear evidence of spore replication.

The RhopH complex is transferred to the host cell cytoplasm following red blood cell invasion by Plasmodium falciparum

2008 ◽  
Vol 160 (2) ◽  
pp. 81-89 ◽  
Author(s):  
Laetitia Vincensini ◽  
Gamou Fall ◽  
Laurence Berry ◽  
Thierry Blisnick ◽  
Catherine Braun Breton
Keyword(s):  
Plasmodium Falciparum ◽  
Blood Cell ◽  
Host Cell ◽  
Cell Invasion ◽  
Red Blood Cell ◽  
Cell Cytoplasm ◽  
Host Cell Cytoplasm

scholarly journals Brefeldin A inhibits transport of the glycophorin-binding protein from Plasmodium falciparum into the host erythrocyte

1994 ◽  
Vol 300 (3) ◽  
pp. 821-826 ◽  
Author(s):  
J Benting ◽  
D Mattei ◽  
K Lingelbach
Keyword(s):  
Plasmodium Falciparum ◽  
Golgi Apparatus ◽  
Host Cell ◽  
Protein Secretion ◽  
Secretory Pathway ◽  
Binding Protein ◽  
Brefeldin A ◽  
Cell Cytoplasm ◽  
Parasite Cell ◽  
Host Cell Cytoplasm

Plasmodium falciparum, a protozoan parasite of the human erythrocyte, causes the most severe form of malaria. During its intraerythrocytic development, the parasite synthesizes proteins which are exported into the host cell. The compartments involved in the secretory pathway of P. falciparum are still poorly characterized. A Golgi apparatus has not been identified, owing to the lack of specific protein markers and Golgi-specific post-translational modifications in the parasite. The fungal metabolite brefeldin A (BFA) is known to inhibit protein secretion in higher eukaryotes by disrupting the integrity of the Golgi apparatus. We have used the parasite-encoded glycophorin-binding protein (GBP), a soluble protein found in the host cell cytoplasm, as a marker to investigate the effects of BFA on protein secretion in the intracellular parasite. In the presence of BFA, GBP was not transported into the erythrocyte, but remained inside the parasite cell. The effect caused by BFA was reversible, and the protein could be chased into the host cell cytoplasm within 30 min. Transport of GBP from the BFA-sensitive site into the host cell did not require protein synthesis. Similar observations were made when infected erythrocytes were incubated at 15 degrees C. Incubation at 20 degrees C resulted in a reduction rather than a complete block of protein export. The relevance of our findings to the identification of compartments involved in protein secretion from the parasite cell is discussed.

scholarly journals Localization of Chlamydia trachomatis hypothetical protein CT311 in host cell cytoplasm

2011 ◽  
Vol 51 (3) ◽  
pp. 101-109 ◽  
Author(s):  
Lei Lei ◽  
Manli Qi ◽  
Nicole Budrys ◽  
Robert Schenken ◽  
Guangming Zhong
Keyword(s):  
Chlamydia Trachomatis ◽  
Host Cell ◽  
Hypothetical Protein ◽  
Cell Cytoplasm ◽  
Host Cell Cytoplasm

Eimeria canadensis (Protozoa, Sporozoea): ultrastructure of the host–parasite interface during development of first-generation schizonts in vitro

1980 ◽  
Vol 58 (11) ◽  
pp. 2018-2025 ◽  
Author(s):  
Bodo E. G. Mueller
Keyword(s):  
Host Cell ◽  
Parasitophorous Vacuole ◽  
Eimeria Species ◽  
Outer Zone ◽  
Ultrastructural Observation ◽  
Cell Cytoplasm ◽  
Cell Organelles ◽  
Host Cell Cytoplasm ◽  
Host Parasite

Eimeria canadensis sporozoites were inoculated into monolayer cultures of Madin–Darby bovine kidney and primary bovine embryonic kidney cells. Sporozoites retained their shape for at least 9 days. At that time, the nucleus was enlarged and contained a prominent nucleolus, and amylopectin granules were no longer apparent. The width of the parasitophorous vacuole (pv) between host cell cytoplasm and parasite pellicle widened during transformation of sporozoites into multinucleate schizonts. Areas of altered host cell cytoplasm immediately adjacent to the pv membrane increased in size and became confluent, resulting in the formation of two distinct layers of cytoplasm. The outer zone contained the host cell nucleus, mitochondria, Golgi stacks, and ER, whereas the inner layer appeared granular and was void of all cell organelles except structures resembling ribosomes. Microfilaments were abundant at the border between inner and outer zone. In the most advanced stages observed, host cell organelles persisted only in the perinuclear region. The remaining, attenuated cytoplasm resembled the former inner zone.The novel ultrastructural observation of a bilayered cytoplasm of cells harbouring E. canadensis schizonts is compared with light microscope reports of similar effects caused by other Eimeria species of ruminants and with electron microscope findings of altered intestinal and abomasal cells of sheep harbouring "globidial" schizonts.

scholarly journals Chlamydia trachomatis GlgA Is Secreted into Host Cell Cytoplasm

PLoS ONE ◽  
2013 ◽  
Vol 8 (7) ◽  
pp. e68764 ◽  
Author(s):  
Chunxue Lu ◽  
Lei Lei ◽  
Bo Peng ◽  
Lingli Tang ◽  
Honglei Ding ◽  
...  
Keyword(s):  
Chlamydia Trachomatis ◽  
Host Cell ◽  
Cell Cytoplasm ◽  
Host Cell Cytoplasm

scholarly journals Characterization of CPAF Critical Residues and Secretion during Chlamydia trachomatis Infection

2015 ◽  
Vol 83 (6) ◽  
pp. 2234-2241 ◽  
Author(s):  
Zhangsheng Yang ◽  
Lingli Tang ◽  
Xin Sun ◽  
Jijie Chai ◽  
Guangming Zhong
Keyword(s):  
Host Cell ◽  
Sample Treatment ◽  
Cell Cytoplasm ◽  
Inhibitory Peptide ◽  
Lower Efficiency ◽  
Content Type ◽  
Chlamydia Trachomatis Infection ◽  
Host Cell Cytoplasm ◽  
Treatment Conditions ◽  
Critical Residues

CPAF (chlamydial protease-like activity factor), aChlamydiaserine protease, is activated via proximity-induced intermolecular dimerization that triggers processing and removal of an inhibitory peptide occupying the CPAF substrate-binding groove. An active CPAF is a homodimer of two identical intramolecular heterodimers, each consisting of 29-kDa N-terminal and 35-kDa C-terminal fragments. However, critical residues for CPAF intermolecular dimerization, catalytic activity, and processing were defined in cell-free systems. Complementation of a CPAF-deficient chlamydial organism with a plasmid-encoded CPAF has enabled us to characterize CPAF during infection. The transformants expressing CPAF mutated at intermolecular dimerization, catalytic, or cleavage residues still produced active CPAF, although at a lower efficiency, indicating that CPAF can tolerate more mutations insideChlamydia-infected cells than in cell-free systems. Only by simultaneously mutating both intermolecular dimerization and catalytic residues was CPAF activation completely blocked during infection, both indicating the importance of the critical residues identified in the cell-free systems and exploring the limit of CPAF's tolerance for mutations in the intracellular environment. We further found that active CPAF was always detected in the host cell cytoplasm while nonactive CPAF was restricted to within the chlamydial inclusions, regardless of how the infected cell samples were treated. Thus, CPAF translocation into the host cell cytoplasm correlates with CPAF enzymatic activity and is not altered by sample treatment conditions. These observations have provided new evidence for CPAF activation and translocation, which should encourage continued investigation of CPAF in chlamydial pathogenesis.

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