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PubMed1989

In vitro development of Neospora caninum (Protozoa: Apicomplexa) from dogs.

The development of Neospora caninum isolated from naturally infected dogs was examined in mammalian cell cultures. Tachyzoites developed by endodyogeny when inoculated onto bovine monocyte or bovine cardiopulmonary artery endothelial cell cultures. Tachyzoites were 5.0 by 2.0 microns and had a posteriorly located nucleus. Cytopathogenic effects of parasite development consisted of the formation of holes in the cell monolayer associated with the rupture of infected host cells. Serial passage of tachyzoites was achieved by subinoculation of tachyzoites onto non-infected bovine monocyte cell cultures. It appears that N. caninum can be continuously grown in cell cultures.

Animals↗
PubMed1989

Phylogenetic analysis of the class Sporozoea (phylum Apicomplexa Levine, 1970): evidence for the independent evolution of heteroxenous life cycles.

A phylogenetic analysis of representative genera in the class Sporozoea was undertaken using biological and morphological features to infer evolutionary relationships among the widely recognized groups in the class. Gregarines were used as a functional outgroup to the remaining sporozoa (adeleids, eimeriorins, haemosporinids, and piroplasms). The piroplasms were shown to be closely related to the adeleid parasites. Species of Babesia and Theileria were shown not to form a sister group to the haemosporinids as has been frequently suggested. The data indicate that the biologically diverse family Haemogregarinidae should be divided into at least 3 families (Haemogregarinidae Neveu-Lemaire, 1901, containing the genera Haemogregarina and Cyrilia; Karyolysidae Wenyon, 1926, containing the genus Karyolysus; Hepatozoidae Wenyon, 1926, containing the genus Hepatozoon) because the 4 genera currently within the family do not form a monophyletic group. Correlation between parasite phylogeny and taxonomic affinities of their definitive hosts suggests that the definitive hosts of heteroxenous sporozoa are their ancestral hosts. Heteroxenous sporozoan life cycles apparently have evolved independently to adapt to changes in the feeding behaviors of their definitive hosts.

Animals↗
PubMed1994

Seasonality, prevalence and pathogenicity of the gregarine Ascogregarina taiwanensis (Apicomplexa: Lecudinidae) in mosquitoes from Florida.

Aedes albopictus larvae collected in Gainesville, FL, were infected with the gregarine Ascogregarina taiwanensis. Natural prevalence varied from 68 to 100%. Eight mosquito species were tested in the laboratory for susceptibility to A. taiwanensis isolated from field-collected Ae. albopictus. Aedes aegypti, Aedes albopictus, and Aedes taeniorhynchus became 100% infected in the larval stage, whereas Aedes triseriatus was less susceptible; Culex quinquefasciatus, Culex nigripalpus, Culex territans, and Anopheles quadrimaculatus were not susceptible. Viable A. taiwanensis oocysts from adults were recovered from Ae. taeniorhynchus (30%) and Ae. albopictus (100%); no oocysts were produced in the other exposed hosts. Mortality induced by A. taiwanensis infection was low in all mosquitoes except Ae. taeniorhynchus. We conclude that A. taiwanensis has little short-term impact on the mortality of the 3 most common container-inhabiting mosquito species in Florida; however, the long-term impact on overall host population regulation has yet to be determined.

Aedes↗
PubMed1993

Experimental transmission of Caryospora bigenetica Wacha et Christiansen, 1982 (Apicomplexa: Eimeriidae) from a rattlesnake, Crotalus atrox, to rodents and pigs.

Caryosporan oocysts were found in the feces of a diamond rattlesnake, Crotalus atrox, kept in ZOO Ustí nad Labem, Czech Republic. Comparison of oocyst structure with hitherto described Caryospora species from snakes revealed that they were Caryospora bigenetica Wacha et Christiansen, 1982. The rattlesnake, Crotalus atrox, represents a new host for C. bigenetica. The common vole (Microtus arvalis) and gerbil (Meriones unguiculatus) were successfully infected with a mixture of C. bigenetica oocysts and sporocysts following oral inoculation. All experimentally infected animals displayed clinical signs of dermal coccidiosis, including swellings of the face, ears, footpads, and scrota or vagina. Gerbils developed more severe clinical signs of infection and had a higher mortality than voles. Developmental stages of C. bigenetica were found in connective tissue of the nose, cheeks, ears, scrotum or vagina. Transmission of C. bigenetica caryocysts between common voles and mice, between mice and common voles, common voles and gerbils, and common voles and pigs was demonstrated. This study demonstrates that C. bigenetica can be transmitted by predation or cannibalism between different species of rodents and pigs.

Animals↗
PubMed1995

Country-wide prevalence of Ascogregarina culicis (apicomplexa: lecudinidae), a protozoan parasite of Aedes aegypti in Trinidad, West Indies.

The prevalence of the gregarine parasite Ascogregarina culicis was determined for Aedes aegypti populations in Trinidad, West Indies. Over 5 months, a total of 5,651 Ae. aegypti larvae were collected and identified from 419 sites throughout Trinidad as part of a national dengue surveillance program. Ascogregarina culicis infections were detected in 13.4% of 1,986 Ae. aegypti larvae dissected. In 7 of 8 counties or major subdivisions where this parasite was detected in Trinidad, the prevalence per locality ranged from 9.6 to 17.1% with an associated parasite density of 19.1-51.9 trophozoites/larva. Confirming that Ae. aegypti populations in Trinidad are highly susceptible to infection with A. culicis parasites, experimental studies showed that a strain of A. culicis from Florida readily infected 3 strains of Ae. aegypti from Trinidad with essentially no associated mortality. This report extends the known geographic range of A. culicis in Ae. aegypti populations and represents one of the first country-wide surveys for this gregarine parasite.

Aedes↗
PubMed1998

Life cycle, host restriction and longevity of Babesiosoma mariae HOARE, 1930 (Apicomplexa: Dactylosomatidae).

Morphometric and morphological observations on B. mariae in an experimentally infected fish (using the leech vector Batracobdeloides tricarinata for the first time) revealed that three successive types of merogonic cycles occurred within the fish erythrocytes. The third cycle produced merozoites destined to become gamonts. The gamonts were somewhat larger than merogonic stages and comprised the majority of the parasitic stages during parasitaemia for up to 7 months. In the leech crop gamonts released from the fish blood became associated in syzygy and fused. The formed zygote underwent sporogony within the gut tissues and up to 8 sporozoites budded simultaneously from the periphery of an irregularly shaped oocyst. The sporozoites underwent merogony typical as that of erythrocytic merogony mainly in the salivary tissues. The merozoites either initiated a further cycle of merogony or moved towards the proboscis. The babesiosomes survived in the leech over a period of 9 months involving 7 meals after the initial meal provided the fasting period did not exceed 60-90 days. Survival was attributed to residual stages in the salivary glands. Cross transmission experiments between fishes via B. tricarinata revealed that the fish babesiosomes were not host specific. Previously described African fresh water fish dactylosomatids were indistinguishable from each other and on the basis of the current results, they are regarded as a single species Babesiosoma mariae.

Animals↗
PubMed1996

Host Specificity of Gregarina blattarum von Siebold, 1839 (Apicomplexa: Eugregarinida) among Five Species of Domiciliary Cockroaches

The host specificity of Gregarina blattarum was evaluated among five species of domiciliary cockroaches: Blatella germanica, Supella longipalpa, Blatta orientalis, Periplaneta americana, and Periplaneta fuliginosa. Third- and fourth-instar nymphs were allowed to feed on crushed dog kibble contaminated with G. blattarum oocysts. Cockroaches were killed 8 days postinfection and examined for parasites. Gregarina blattarum infections were observed in all experimentally infected replications of B. germanica. No infection was observed in an experimentally infected replication of S. longipalpa, B. orientalis, P. americana, or P. fuliginosa, nor was an infection observed in a time zero or ending time control group. In vitro excystation assays using extracts of host gut homogenates demonstrate that G. blattarum sporozoites successfully excyst and begin the life cycle in all five cockroach species tested. No excystation was observed in neutral buffered saline controls. These data suggest that G. blattarum comprises a complex of cryptic species marked by narrow host utilization rather than a single species parasitizing a broad array of cockroach taxa.

Journal Article↗
PubMed1997

Occurrence of Merogony of Aggregata Frenzel 1885 (Apicomplexa) in Pleoticus muelleri and Artemesia longinaris (Crustacea: Natantia) from Patagonian Waters (Argentina)

The aim of this paper is to describe the merogonic phases of the coccidian Aggregata sp. in the natantians Pleoticus muelleri and Artemesia longinaris from Argentina. Ninety-seven specimens of P. muelleri (from San Jorge Gulf) and 49 of A. longinaris (from Rawson) were examined for intestinal parasites. Intestines were processed under standard histological conditions. The distribution of the octopuses (where gamogony and sporogony of Aggregata spp. take place) in the area considered and the importance of finding these protistans in crustaceans other than brachyurans are also explored. High prevalence values for both hosts indicate that shrimps are the primary hosts for these parasites in Argentinean waters. Copyright 1997 Academic Press. Copyright 1997 Academic Press

Journal Article↗
PubMed1989

Haemogregarina sp. (Apicomplexa: Adeleorina) from the gecko Tarentola annularis in the Sudan: fine structure and life-cycle trials.

The ubiquitous gecko Tarentola annularis in the area around Khartoum, Sudan, was found to be infected with Haemogregarina sp., with merogonic stages in its pulmonary endothelial cells and gamonts in its erythrocytes. The fine structure of Haemogregarina meronts, merozoites and gamonts revealed great conformity with the micromorphology of similar stages of other apicomplexan parasites. The unsuccessful transmission of Haemogregarina gamonts to the mosquitoes Aedes aegypti, Culex quinquefasciatus and Anopheles stephensi is also reported.

Aedes↗
PubMed1989

Characterization of a surface antigen of Eimeria nieschulzi (Apicomplexa, Eimeriidae) sporozoites.

A monoclonal antibody (McAb 3C3) reacting with a pellicular antigen of Eimeria nieschulzi sporozoites has been selected among hybridomas produced against this organism by immunofluorescence assay. This antigen has been shown to be located on the zoite surface by immunofluorescence on living organisms. Capping and shedding of antigen-monoclonal antibody immune complexes was observed upon incubation at 37 degrees C. On western immunoblotting, two polypeptides at 22 and 26 kDa were recognized by McAb 3C3, whereas only one polypeptide of 22 kDa was immunoprecipitated by the same antibody after lactoperoxidase surface radio-iodination of sporozoites.

Animals↗