first record of ascogregarina taiwanensis (apicomplexa: lecudinidae) in north american aedes albopictus.aedes albopictus collected in the east st. louis, illinois, area were found infected with the gregarine protozoan, ascogregarina taiwanensis. infection rates varied from 67 to 95% at 4 sites and 0 to 10% at 2 others. lower infection levels were found in ae. epactius (42%) and culex restuans (one larva). four mosquito species were cross-infected in the laboratory with gregarines isolated from field-collected hosts. aedes atropalpus was 90% susceptible to a. taiwanensis (100% in ae. albopictus), w ...19902370530
parasites of the asian tiger mosquito and other container-inhabiting mosquitoes (diptera:culicidae) in northcentral microorganisms including 4 protozoans, 2 fungi, and a bacterium infected aedes albopictus (skuse) larvae collected from 12 counties in northecentral florida. ae albopictus and 14 other species of mosquitoes were collected from tires, flower-holding vases in cemeteries, other types of artificial containers, and treeholes. ascogregarina taiwanensis (lien & levine) was the most common parasite of ae. albopictus throughout the year. the microsporidium vavraia culicis (weiser) infected aedes ae ...19979103767
effect of nutrient levels and ascogregarina taiwanensis (apicomplexa: lecudinidae) infections on the vector competence of aedes albopictus (diptera: culicidae) for dirofilaria immitis (filarioidea: onchocercidae).the effect of habitat nutrients and ascogregarina taiwanensis (lein & levine) infection on the vector competence of a new orleans strain of aedes albopictus (skuse) for dirofilaria immitis (leidy) were evaluated. larvae were infected with a. taiwanensis oocysts and reared under high and deficient nutrient conditions using leaf litter as a food source. ascogregarine-infected and uninfected females were fed on d. immitis-infected blood and examined after 15 d for filariae. susceptibility to infect ...199910071493
aedes albopictus (diptera: culicidae): an experimental and natural host of dirofilaria immitis (filarioidea: onchocercidae) in florida, u.s.a.females of an aedes albopictus (skuse) colony from southeastern florida, u.s.a., ingested low (22.9 +/- 3.2 mg/female) and high (243.2 +/- 37.6 mf/female) numbers of microfilariae from a dog infected with dirofilaria immitis (leidy). high mortality of females occurred during the first 4 d after infection regardless of the number of microfilariae ingested; daily mortality was almost negligible during 5-15 d after infection. percentage of survival 15 d after infection was higher (63%) in females t ...199910467770
role of gregarine parasite ascogregarina culicis (apicomplexa: lecudinidae) in the maintenance of chikungunya virus in vector mosquito.ascogregarina culicis and ascogregarina taiwanensis are common gregarine parasites of aedes aegypti and aedes albopictus mosquitoes, respectively. these mosquito species are also known to transmit dengue and chikungunya viruses. the sporozoites of these parasites invade the midgut epithelial cells and develop intracellularly and extracellularly in the gut to complete their life cycles. the midgut is also the primary site for virus replication in the vector mosquitoes. therefore, studies were car ...200314563178
oviposition by aedes aegypti (diptera: culicidae) in relation to conspecific larvae infected with internal symbiotes.female mosquitoes use abiotic and biotic factors, such as the presence of heavy metals or parasites, to determine the acceptability of oviposition sites. some biotic factors can originate from mosquito larvae. when mosquito larvae are starved or infected with trematode metacercaria, they render associated water unacceptable to ovipositioning females. internal symbiotes are common in wild mosquito populations, and i tested whether or not larvae of aedes aegypti infected with a gregarine (ascogreg ...200415266753
intestinal expression of h+ v-atpase in the mosquito aedes albopictus is tightly associated with gregarine infection.vacuolar atpase (v-atpase) is a family of atp-dependent proton pumps expressed on the plasma membrane and endomembranes of eukaryotic cells. acidification of intracellular compartments, such as lysosomes, endosomes, and parasitophorous vacuoles, mediated by v-atpase is essential for the entry by many enveloped viruses and invasion into or escape from host cells by intracellular parasites. in mosquito larvae, v-atpase plays a role in regulating alkalization of the anterior midgut. we extracted rn ...200616579815
cloning, purification, and nucleotide-binding traits of the catalytic subunit a of the v1vo atpase from aedes albopictus.the asian tiger mosquito, aedes albopictus, is commonly infected by the gregarine parasite ascogregarina taiwanensis, which develops extracellularly in the midgut of infected larvae. the intracellular trophozoites are usually confined within a parasitophorous vacuole, whose acidification is generated and controlled by the v(1)v(o) atpase. this proton pump is driven by atp hydrolysis, catalyzed inside the major subunit a. the subunit a encoding gene of the aedes albopictus v(1)v(o) atpase was clo ...200717321148
parasitism of ascogregarina taiwanensis and ascogregarina culicis (apicomplexa: lecudinidae) in larvae of aedes albopictus and aedes aegypti (diptera: culicidae) from manaus, amazon region, brazil.the aim of the study was to determine the existence of ascogregarina spp. in larvae of aedes albopictus and aedes aegypti collected in urban and suburban areas of manaus, amazon region, brazil. between may 2004 and july 2005, the mid-gut of 3rd and 4th instar larvae, collected in tire traps in six neighborhoods of manaus, was examined for the presence of trophozoites of ascogregarina. coexistence of ae. albopictus larvae infected by a. taiwanensis, and ae. aegypti larvae by a. culicis, was detec ...200818028941
escape from gregarine parasites affects the competitive interactions of an invasive mosquito.when a species is introduced into a new location, it may escape, at least temporarily, from its natural enemies. in field surveys, we found that when the exotic, invasive mosquito, aedes albopictus, invades new sites, it initially experiences reduced infection by its gut parasite, ascogregarina taiwanensis. to determine the effect of this escape from parasitism on the competitive ability of a. albopictus, we performed a laboratory competition experiment in which infected and uninfected a. albopi ...019777120
a genome-sequence survey for ascogregarina taiwanensis supports evolutionary affiliation but metabolic diversity between a gregarine and cryptosporidium.we have performed a whole-genome-sequence survey for the gregarine, ascogregarina taiwanensis and herein describe both features unique to this early diverging apicomplexan and properties that unite it with cryptosporidium, the coccidia, and the apicomplexa. phylogenetic trees inferred from a concatenated protein sequence comprised of 10,750 amino acid positions, as well as the large subunit rrna genes, robustly support phylogenetic affinity of ascogregarina with cryptosporidium at the base of th ...200919778951
[ecology of aedes aegypti and aedes albopictus in the americas and disease transmission].the recent range expansion of the mosquito aedes albopictus has been associated in some areas by declines in abundance or local elimination of aedes aegypti, but the two species still coexist in large regions of the americas. we offer a summary of the possible mechanisms responsible for the abundance and displacement pattern observed and of their significance in terms of disease transmission. among these mechanisms we may mention the competition for limiting resources, the differences in the abi ...201526535539
aedes albopictus in northeast mexico: an update on adult distribution and first report of parasitism by ascogregarina taiwanensis.aedes albopictus has been known as efficient vector of dengue in asian countries and its wide displacement of ae. aegypti has been documented in many parts of the world. the present survey was carried out to update the distribution of ae. albopictus in northeast mexico and to report the first record of parasitism of mosquitoes by ascogregarina taiwanensis in mexico.201324220079
life cycle completion of parasite ascogregarina taiwanensis (apicomplexa: lecudinidae) in non-native host ochlerotatus japonicus (diptera: culicidae).ascogregarina taiwanensis (lien and levine), a protist gut parasite of aedes albopictus (skuse), is not known to complete its life cycle within the potential competitor species, ochlerotatus japonicus (theobald). in a laboratory cross infection study we demonstrated that a. taiwanensis completed its life cycle within oc. japonicus and remained infectious. we also sampled cohabitating mosquito larvae in mercer county, nj, and based on ribosomal dna sequence data, we determined that oc. japonicus ...201223025193
apoptosis of ascogregarina taiwanensis (apicomplexa: lecudinidae), which failed to migrate within its natural host.sexual reproduction of ascogregarina taiwanensis (apicomplexa: lecudinidae), a parasite specific to the mosquito aedes albopictus, in malpighian tubules is initiated by the entry of the trophotozoites developed in the midgut shortly after pupation (usually <5 h). however, only a low proportion of trophozoites are able to migrate; others end up dying. in this study, we demonstrated that those trophozoites that failed to migrate eventually died of apoptosis. morphological changes such as shrinkage ...201322996442
new findings on the developmental process of ascogregarina taiwanensis and ascogregarina culicis in aedes albopictus and aedes aegypti.infection in different stages of larvae of aedes aegypti and ae. albopictus with ascogregarina taiwanensis and a. culicis, respectively, revealed that the oocysts of ascogregarina spp. are able to infect any instar and can complete their life cycle within 9.5 +/- 1 days. when early instars ingested oocysts, parasite development was synchronized to larval-pupal ecdysis and oocyst dissemination occurred at the time of adult emergence, oviposition, or both. the parasites also developed normally whe ...200616646318
susceptibility of aedes aegypti and aedes albopictus larvae to ascogregarina culicis and ascogregarina taiwanensis (apicomplexa: lecudinidae) from florida.the susceptibility of aedes aegypti to ascogregarina culicis and aedes albopictus to ascogregarina taiwanensis was examined with mosquito and parasite strains from tampa, fl. when each host was bioassayed with its natural gregarine, the infection intensity indicated that ae. aegypti was 59% more susceptible to a. culicis (87 gamonts/larva) than ae. albopictus to a. taiwanensis (47 gamonts/larva). infections in single and mixed host populations exposed to 100 oocysts/larva of one and both parasit ...200313678712
laboratory susceptibility of wyeomyia smithii (diptera: culicidae) to ascogregarina taiwanensis (apicomplexa: lecudinidae).gregarines in the genus ascogregarina are not known to develop in sabethine mosquitoes, but we successfully infected larvae of wyeomyia smithii with ascogregarina taiwanensis in the laboratory. ascogregarina taiwanensis is a natural parasite of the exotic asian tiger mosquito, aedes albopictus. only 18% to 70% of the w. smithii larvae had visible trophozoites, with a range of 1-92 per larva. trophozoites persisted in the midgut for more than 37 d, and one adult female w. smithii had gametocysts ...200712425526
directed migration of ascogregarina taiwanensis (apicomplexa: lecudinidae) in its natural host aedes albopictus (diptera: culicidae).directed migration of trophozoites from the midgut toward the malpighian tubules is essential for ascogregarina taiwanensis (apicomplexa: lecudinidae) to complete its developmental cycle within the natural host aedes albopictus. we have obtained a 275-bp actin cdna fragment amplified from extracted mrnas of migrating trophozoites, suggesting the involvement of actin in trophozoite motility. down-regulation on the migration of the trophozoite was seen in mosquito larvae fed with cytochalasin d, m ...200711596918
morphological traits for distinguishing extracellular gamonts of ascogregarina culicis and ascogregarina taiwanensis in aedes aegypti and aedes albopictus. 200111356058
role of habitat components on the dynamics of aedes albopictus (diptera: culicidae) from new orleans.monthly sampling of tire pile populations of aedes albopictus (skuse) in orleans parish, new orleans, la, was done in 1995 to determine prevalence of ascogregarine parasites and changes in wing length. prevalence of ascogregarina taiwanensis (lien & levine) infection was 100% in midsummer and decreased in the fall and spring (60-70%). wing lengths were longest in the spring and fall and shortest in midsummer. we evaluated the effect of a. taiwanensis infections under high and deficient levels of ...199910337101
the life cycle of ascogregarina taiwanensis (apicomplexa:lecudinidae).a number of features, including large size of the trophozoite, host-specificity, developmental synchrony and evident migration behavior, of ascogregarina taiwanensis make it suitable as a model for studies of parasite-host relationships. in this article, wei june chen describes the life cycle of as. taiwanensis; and raises some areas for future work, including the interaction between the parasite and its host, inhibition of sexual reproduction by non-natural hosts and their mutual effects during ...199910322337
ultrastructure of infection, development and gametocyst formation of ascogregarina taiwanensis (apicomplexa: lecudinidae) in its mosquito host, aedes albopictus (diptera: culicidae).the life history of the protozoan parasite ascogregarina taiwanensis in mosquito larvae (aedes albopictus, collected in southern taiwan) was shown to consist of two consecutive stages--intracellular and extracellular. light microscopy showed that most trophozoites moved into the malpighian tubules and developed into giant trophozoites during the first day pupa. the locomotion may be associated with bristle-like ridges of the trophozoite. the stage for sexual reproduction, i.e., the gamete, was t ...20079190261
developmental synchrony of ascogregarina taiwanensis (apicomplexa: lecudinidae) within aedes albopictus (diptera: cuclicidae).development of ascogregarina taiwanensis lien & levine was synchronized with its host, the asian tiger mosquito, aedes albopictus (skuse). trophozoites of the parasite migrate to the malpighian tubules where the gamonts fuse to form gametocysts and later mature oocysts. in this study, we observed that water temperature, which alters the development time of mosquito larvae, also affected parasite development. a. taiwanensis developed in a shorter time at 29 degrees c, whereas at 14 degrees c, the ...19968742523
parasitism of aedes aegypti and ae. albopictus (diptera: culicidae) by ascogregarina spp. (apicomplexa: lecudinidae) in florida.aedes aegypti (l.) and ae. albopictus (skuse) from 40 sites in 17 counties of florida were surveyed for gregarine parasites during the spring and autumn of 1993 and in july 1994. larvae collected from containers (mainly tires) were dissected to determine the number of gregarine trophozoites present. ascogregarina spp. were found at 70% of the sites and occurred as frequently in ae. aegypti populations as in ae. albopictus. within sites, parasite distributions were highly variable and aggregated ...19958551508
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, ...19947807086
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