Ultrastructural changes in the oocyst wall during excystation of Cryptosporidium parvum (Apicomplexa; Eucoccidiorida)

1985 ◽  
Vol 63 (8) ◽  
pp. 1892-1896 ◽  
Author(s):  
David W. Reduker ◽  
C. A. Speer ◽  
John A. Blixt

Cryptosporidium parvum oocysts were obtained from the feces of naturally infected calves and the oocyst wall was examined ultrastructurally. The oocyst wall averaged 49.7 nm thick and was composed of two layers. The outer layer was irregular in thickness, averaging 10 nm. A thin, electron-lucent space (2.5 nm) was interposed between the outer and inner layers. The inner layer had an outer (11.6 nm) and an inner (25.8 nm) zone. A suture that extended partway around the oocyst was observed within the inner layer of the oocyst wall. The suture underwent dissolution during excystation.


Parasitology ◽  
1991 ◽  
Vol 103 (2) ◽  
pp. 171-177 ◽  
Author(s):  
A. Bonnin ◽  
J. F. Dubremetz ◽  
P. Camerlynck

A monoclonal antibody (OW-IGO) raised against purified excysted oocysts ofCryptosporidium parvumreacted in an immunofluorescence assay with the oocyst wall. The corresponding antigen was localized by immunoelectron microscopy in fibrillous material present in the parasitophorous vacuole of developing macrogametes and in the wall of both single and double layered sporulating oocysts. Gold particles were also detected over electron-lucent vesicles of the macrogametes by immunoelectron microscopy. On Western blotting ofC. parvumoocyst extracts, major bands at 250 and 40 kDa and several minor components were recognized by Mab OW-IGO. Almost complete abolition of Western blot reactivity occurred after periodate oxidation of oocyst antigen, suggesting that monoclonal antibody OW-IGO reacts with a carbohydrate epitope. Taken together, our results suggest that a fibrillous glycoproteinic material is released in the parasitophorous vacuole from electron-lucent vesicles during gametogenesis, and later condensed in the oocyst wall.



Parasitology ◽  
1981 ◽  
Vol 83 (2) ◽  
pp. 285-291 ◽  
Author(s):  
R. M. Pittilo ◽  
S. J. Ball ◽  
L. P. Joyner ◽  
C. C. Norton

SUMMARYThe ultrastructure of the macrogamete and developing oocyst of Eimeria maxima (Weybridge strain) was examined in the intestinal cells of chicks fed 3 different anticoccidial drugs. Amprolium at 125 p.p.m., arprinocid at 35 p.p.m. and dinitolmide at 250 p.p.m. caused considerable morphological abnormality and incomplete development of the wall-forming bodies of Type 2 (WFB II), which did not appear able to participate in oocyst wall formation. The wall-forming bodies of Type 1 (WFB I) were able in each case to participate in oocyst wall formation although amprolium and dinitolmide produced morphological abnormalities in them. In birds medicated with dinitolmide, the outer layer of the oocyst wall was formed initially at opposite poles of the macrogame tes rather than as a uniform layer. Other abnormalities resulting from drug treatment are reported and some evidence that intravacuolar tubules may be formed by the parasite pellicle is presented.





2002 ◽  
Vol 2 (3) ◽  
pp. 159-168 ◽  
Author(s):  
V. Gitis ◽  
R.C. Haught ◽  
R.M. Clark ◽  
E. Radha Krishnan

Pilot-scale experiments were conducted to investigate removal of Cryptosporidium parvum by contact granular filtration. The research demonstrated enhanced removal of Cryptosporidium parvum in the presence of kaolin particles. This is believed to be due electrostatic adhesion of Cryptosporidium parvum oocysts to the kaolin clay particles. The elementary physico-chemical interactions between filter granules and suspension particles will be discussed. This innovative concept was successfully implemented to reduce the ripening sequence of subsequent filtration experimental test runs by the addition of large surface area particles to slurry of kaolin and Cryptosporidium parvum in surface water.



1997 ◽  
Vol 35 (11-12) ◽  
pp. 261-268 ◽  
Author(s):  
D. C. Johnson ◽  
C. E. Enriquez ◽  
I. L. Pepper ◽  
T. L. Davis ◽  
C. P. Gerba ◽  
...  

Discharge of sewage into the ocean is still a common method of disposal worldwide. Both treated and untreated sewage may contain significant concentrations of waterborne pathogens, such as Giardia, Cryptosporidium, poliovirus and Salmonella. Limited studies exist on the survival of poliovirus and Salmonella in marine waters; however, almost no information exists on the survival of protozoan parasites in marine waters. This study examined the survival of Giardia muris cysts, Cryptosporidium parvum oocysts, poliovirus-1 and Salmonella typhimurium in marine waters. The survival of the microorganisms varied according to the presence of light, salinity and water quality (as determined by quantity of enterococci). All microorganisms survived longer in the dark than in sunlight, the order of survival in sunlight being: Cryptosporidium > poliovirus > Giardia > Salmonella.



2005 ◽  
Vol 68 (5) ◽  
pp. 1093-1096 ◽  
Author(s):  
K. E. KNIEL ◽  
M. C. JENKINS

The purpose of this study was to determine if the viral symbiont of Cryptosporidium parvum (CPV) sporozoites could be used as a target for sensitive detection of the parasite in food samples. Polyclonal sera specific to the recombinant viral capsid protein (rCPV40) was used in a dot blot hybridization assay to detect oocysts recovered from green onions and cilantro. Small batches of chopped green onions and cilantro leaves were artificially contaminated with three different concentrations of oocysts: 106, 102, and 101. rCPV40 was superior in detecting oocysts compared with other antibodies directed toward total oocyst protein and oocyst surface antigens. This study provides evidence that CPV is an excellent target for sensitive detection of C. parvum oocysts in foods.



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