Identification of isolate-specific sporozoite proteins of Cryptosporidium parvum by two-dimensional gel electrophoresis.

Five isolates of Cryptosporidium parvum collected from human, horse, and calf sources were compared for differences in sporozoite protein patterns by using two-dimensional gel electrophoresis. Silver-stained two-dimensional gels contained over 300 protein spots from detergent-solubilized sporozoites. A distinguishing 106-kilodalton peptide that shifted in isoelectric point was detected in four of the five isolates. Computerized two-dimensional gel analysis was performed to obtain objective quantitation of the pI shift. Three of these four isolates could be differentiated from one other by the pI shift in this peptide. The fifth isolate was distinguished by the absence of the 106-kilodalton peptide and the presence of a 40-kilodalton peptide that was not observed in any other isolate.

Identification of outer oocyst wall proteins of three Cryptosporidium (Apicomplexa: Cryptosporidiidae) species by 125I surface labeling.

Autoradiography of oocyst wall surface proteins of three Cryptosporidium spp. revealed common bands at 285 to 290, 145 to 148, 120, 57, and 32 kilodaltons (kDa). Cryptosporidium baileyi and C. muris share proteins at 180, 100, 80 to 81, 29, and 18 to 19 kDa; C. baileyi and C. parvum share one protein at 46 to 47 kDa; and C. muris and C. parvum share a protein at 67 to 69 kDa. Additional protein bands, each unique to one species, were also observed.

Electrophoretic and immunoblot analysis of Cryptosporidium oocysts.

Cryptosporidium oocysts were recovered by density gradient centrifugation from diarrhoeal faeces of four human patients and one goat kid. Goat-derived oocysts were further treated with excystation medium and the excysted oocyst walls purified by isopycnic ultracentrifugation. Soluble extracts from intact oocysts and the oocyst wall preparation were analysed by SDS-PAGE. Fifty-one polypeptide bands were detected in intact oocyst preparations: 48 were in the range 14,000-200,000 molecular weight (MW), two bands were less than 14,000 MW and one band was above 200,000 MW. Twenty-one bands were detected in the oocyst wall preparation, all within the range 14,000-200,000 MW. Immunoblot analysis of Cryptosporidium polypeptides using acute or convalescent human and goat sera revealed a large number of reactive bands. Varying degrees of heterogeneity were observed within and between the two serum groups. Nine of the 10 human sera and all of the goat kid sera reacted with a 23,000 MW and 32,000 MW antigen. A 15,500 MW antigen was also detected by all the goat and four of the 10 human sera. Both serum groups reacted with various antigens above 40,000 MW. Surface labelling of three human isolates of Cryptosporidium oocysts with 125I was performed using the Bolton and Hunter reagent. The solubilized preparations were separated by SDS-PAGE on 12% and 18% slab gels and autoradiographed. Common bands were seen at 15,500, 32,000, 47,500, 79,000 and 96,000 MW. Some variation in the molecular weight of polypeptides labelled with 125I was observed among the three isolates.(ABSTRACT TRUNCATED AT 250 WORDS)

[Amino acid makeup of the oocyst proteins of some species of coccidia of hens]. / Aminokislotnyi sostav belkov ootsist nekotorykh vidov koktsidii kur

The composition of amino acids of sporocysts, membranes of oocysts and oocysts of four species of Coccidia from hens is reported. A considerable figgerence was found to exist in the quantitative composition of amino acids in oocysts of different Coccidia species and in different structures of oocysts. It is necessary to carry out a search of preparations breaking the inclusions of some amino acids into the protein molecule of oocysts of Coccidia from hens.

Observations on a feline coccidium with some characteristics of Toxoplasma and Sarcocystis.

Two morphologically different cysts were found in skeletal muscles of mice inoculated with fecal material from a stray cat containing Isopora-type oocysts. The most common cyst contained bradyzoites resembling those of Toxoplasma and resulted from an oocyst measuring 11 times 13 mum which appeared to be identical to that of Toxoplasma. The other cyst, observed in only a few mice, contained bradyzoites resembling those of Sarcocystis, but the oocyst or sporocyst that gave rise to it was overlooked and apparently lost. Two more strains of the parasite resembling Toxoplasma were found in feces of stray cats. When inoculated into mice, the oocyst of this parasite routinely produced chronic infection and formed cysts similar to Toxoplasma in skeletal muscles and occasionally in the central nervous system. The majority of infected mice developed Toxoplasma antibody, but only to low titers. Cats fed carcasses of infected mice remained healthy and shed nonsporulated oocysts following a prepatent period of about 5 days. Cats did not develop Toxoplasma antibody. There was little or no cross immunity between the parasite and T. gondii in cats or mice. Transmission of the parasite between mice by the cyst stage normally was not possible; however, mice inoculated with cortisone acetate did become infected when inoculated with cysts. In other laboratory animals inoculated orally with the oocyst asymptomatic infection was detected in 3 species of rats, in guinea pigs and in dogs, but not in monkeys, pigeons or Japanese qualis. Fluorescent antibody tests on human sera failed to provide evidence of natural human infection with the parasite.

Hammondia hammondi gen. nov., sp.nov., from domestic cats, a new coccidian related to Toxoplasma and Sarcocystis.

Hammondia hammondi gen.nov.,sp.nov (Eimeriorina:Sarcocystidae) is described as an obligate heteroxenous protozoon of domestic cats (final host) and laboratory mice (experimental intermediate host). Oocysts from the final host are infectious only for the intermediate host; and cysts from the intermediate host are infectious only for the final host. Intracellular cysts develop principally in striated muscle of mice that ingest oocysts, with a few cysts in the brain and perhaps elsewhere. Cysts are without septa or radial spines; bradyzoites are slender, there is no evidence of metrocytes. Cysts are not infectious for mice. After the ingestion of cysts by cats, a multiplicative cycle precedes the development of gametocytes in the epithelium of the samll intestine. Oocysts are shed unsporulated, sporogony is outside of the host, resulting in two sporocysts with four sporozoites each. Oocysts of the species average 11 x 13 mum. The prepatent period i 5s 5 to 8 days, and oocyst shedding persists for 10 to 28 days followed by immunity. Cysts in skeletal muscle measured between 100 and 340 mum in length and 40 and 95 mu-m in width. Experimental intermediate hosts are laboratory mice, rats, hamsters, guinea pigs, Peromyscus and Mastomys. Some of the intermediate hosts develop low levels of antibody and some cross-immunity against Toxoplasma; however, this has not been observed in cats.