ANOMALIES OF ONCOTAXY IN TWO SPECIES OF ECHINOCOCCUS FROM NORTH AMERICA

1959 ◽  
Vol 37 (5) ◽  
pp. 793-801 ◽  
Author(s):  
G. Lubinsky
Keyword(s):  
North America ◽  
Echinococcus Multilocularis ◽  
Probable Origin

Anomalies of oncotaxy of adult and larval scoleces of Echinococcus multilocularis and E. aff. granulosus from North America are described. It is pointed out that some of these anomalies affect characters usually believed to be characteristic of species. Abnormal oncospheres of E. multilocularis with 2, 7, and 12 hooks are described and the probable origin of the giant oncospheres is discussed.

scholarly journals Asian Admixture in European Echinococcus multilocularis Populations: New Data From Poland Comparing EmsB Microsatellite Analyses and Mitochondrial Sequencing

2021 ◽  
Vol 7 ◽  
Author(s):  
Gérald Umhang ◽  
Jenny Knapp ◽  
Marion Wassermann ◽  
Vanessa Bastid ◽  
Carine Peytavin de Garam ◽  
...  
Keyword(s):  
North America ◽  
Echinococcus Multilocularis ◽  
Nuclear Genome ◽  
Microsatellite Analysis ◽  
Northern Eurasia ◽  
Mitochondrial Haplotype ◽  
Red Foxes ◽  
Asian Origin ◽  
Eastern European Countries ◽  
The Impact

The cestode Echinococcus multilocularis is the causative agent of a severe zoonotic disease: alveolar echinococcosis (AE). The parasite is distributed over a vast area in northern Eurasia and North America, but the impact of AE on human health is highly uneven between different regions. One hypothetical reason for this difference in virulence may be the genetic structure of E. multilocularis which—based on mitochondrial sequences and EmsB microsatellite profiles—forms four distinct clades. These clades correspond approximately to their continents of origin: Asia, Europe, and North America, with a fourth clade apparently restricted to Mongolia and neighboring regions, even though this clade has not yet been described by EmsB genotyping. However, there are various records of genetic variants from the “wrong” region, e.g., “European” haplotypes in Western Canada, which may be the result of introduction or natural migration of host animals. One such example, prompting this study, is the recent record of an “Asian” mitochondrial haplotype in worms from foxes in Poland. At the time, this could not be confirmed by EmsB microsatellite analysis, a method that has proven to possess greater discriminatory power with the E. multilocularis nuclear genome than sequencing of mitochondrial markers. Therefore, worms collected from foxes in Poland were examined both by EmsB analysis and sequencing of the full mitochondrial cox1 gene in order to allocate the samples to the European or Asian cluster. Based on EmsB analyses of 349 worms from 97 Polish red foxes, 92% of the worms clearly showed “European-type” EmsB profiles, but 27 worms (8%) from seven foxes showed profiles that clustered with samples of Asian origin. According to cox1 sequences, a total of 18 worms from 8 foxes belonged to the Asian cluster of haplotypes. The two methods did not fully agree: only 13 worms from three foxes belonged to Asian clusters by both EmsB and cox1, whereas 18 worms from nine foxes belonged to different clusters, according to each marker. Cross-fertilization between worms of Asian origin and those from the European Polish population may explain these conflicting results. The presence of clearly Asian elements in the Polish E. multilocularis population could be the result of introduction of E. multilocularis with host animals (e.g., domestic dogs), or the migration of foxes. In the absence of genetic data from eastern European countries, especially those bordering Poland, it cannot be concluded whether this Asian admixture is typical for a larger area toward central/eastern Europe, or the Polish parasite population is the western extreme of a gradient where both European and Asian elements mingle. Further studies are needed on this subject, preferably using both mitochondrial sequencing and EmsB microsatellite analysis.

scholarly journals A comparison of Species Distribution Modeling approaches for an under-sampled parasite of public health importance, Echinococcus multilocularis

2016 ◽  
Author(s):  
Heather M. Williams ◽  
Brian Egan ◽  
Katharina Dittmar
Keyword(s):  
Public Health ◽  
High Resolution ◽  
North America ◽  
Species Distribution ◽  
Echinococcus Multilocularis ◽  
Research Effort ◽  
The United States ◽  
Distribution Models ◽  
Public Health Importance ◽  
Occurrence Data

AbstractBackgroundSpecies distribution models (SDMs) have an important role in predicting the range of emerging and understudied pathogens and parasites. Their use, however, is often limited by the lack of high-resolution unbiased occurrence records. Echinococcus multilocularis is a parasitic cestode of public health importance which is widely distributed throughout Eu rasia and is considered an emerging threat in North America. In common with many parasite species, available data for E. multilocularis occurrence are spatially biased and often poorly geo-referenced.ResultsHere we produce three separate SDMs using MaxEnt for E. multilocularis using varying complexities of sampling schemes and environmental predictors, designed to make the best possible use of non-ideal occurrence data. The most realistic model utilized both derived and basic climatic predictors; an occurrence sampling scheme which relied primarily on high resolution occurrences from the literature and a bias grid to compensate for an apparently uneven research effort. All models predicted extensive regions of high suitability for E. multilocularis in North America, where the parasite is poorly studied and not currently under coordinated surveillance.ConclusionsThrough a pragmatic approach to non-ideal occurrence data we were able to produce a statistically well supported SDM for an under-studied species of public health importance. Although the final model was only trained on data from Eurasia, the global model projection encompassed all known occurrences in the United States. The approach defined here may be applicable to many other such species and could provide useful information to direct resources for future field based surveillance programs for E. multilocularis in North America.

scholarly journals The ecological niche of Echinococcus multilocularis in North America: understanding biotic and abiotic determinants of parasite distribution with new records in New Mexico and Maryland, United States

Therya ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 91-102
Author(s):  
Sebastian Botero-Cañola ◽  
Altangerel T. Dursahinhan ◽  
Sara E. Racz ◽  
Parker V. Lowe ◽  
John E. Ubelaker ◽  
...  
Keyword(s):  
United States ◽  
New Mexico ◽  
North America ◽  
Echinococcus Multilocularis ◽  
Ecological Niche ◽  
New Records ◽  
Parasite Distribution

The occurrence of Echinococcus multilocularis Leuckart, 1863 in Alberta

1971 ◽  
Vol 49 (4) ◽  
pp. 575-576 ◽  
Author(s):  
John C. Holmes ◽  
Jerome L. Mahrt ◽  
William M. Samuel
Keyword(s):  
North America ◽  
Echinococcus Multilocularis ◽  
Peromyscus Maniculatus ◽  
Aspen Parkland

Echinococcus multilocularis Leuckart, 1863 has been recovered from 63 of 283 Peromyscus maniculatus trapped near Edmonton, Alberta. This record extends the known distribution of Echinococcus multilocularis in central North America to the northwestern edge of the prairie and into the aspen parkland zone.

BIOGEOGRAPHY OF JACK PINE

1967 ◽  
Vol 45 (11) ◽  
pp. 2201-2211 ◽  
Author(s):  
C. W. Yeatman
Keyword(s):  
North America ◽  
Pinus Banksiana ◽  
Pinus Contorta ◽  
Geographic Origin ◽  
Glacial Refugia ◽  
Jack Pine ◽  
Hybrid Swarms ◽  
Late Tertiary ◽  
History Of ◽  
Probable Origin

Interpretation of genetic variation associated with geographic origin must take into account the evolution and migratory history of the species being-studied. A literature survey was made to determine the probable origin of jack pine (pinus banksiana) and its migration from glacial refugia following the Wisconsin glacial maximum. Jack pine and contorta pine (Pinus contorta) became differentiated following cooling of the climate and crustal uplift in western North America in the late Tertiary. Modern hybrid swarms and introgression of jack pine and lodgepole pine (Pinus contorta var. lalifolia) east of the Rocky Mountains are of recent origin, dating from late post-glacial migration from the east and west respectively. Geological and paleobotanical evidence, particularly from fossil pollen depositions, indicate that jack pine survived glaciation in an extensive refugium centered on the Appalachian Highlands of eastern North America, and not in additional refugia south or west of the Great Lakes. This conclusion is consistent with the clinal pattern of geographic variation evident from genecological studies of the species.

scholarly journals Deep amplicon sequencing highlights low intra-host genetic variability of Echinococcus multilocularis and high prevalence of the European-type haplotypes in coyotes and red foxes in Alberta, Canada

2021 ◽  
Vol 15 (5) ◽  
pp. e0009428
Author(s):  
Maria A. Santa ◽  
Andrew M. Rezansoff ◽  
Rebecca Chen ◽  
John S. Gilleard ◽  
Marco Musiani ◽  
...  
Keyword(s):  
North America ◽  
Relative Abundance ◽  
Echinococcus Multilocularis ◽  
Population Expansion ◽  
Amplicon Sequencing ◽  
Intraspecific Diversity ◽  
Mixed Infections ◽  
Western Canada ◽  
Red Foxes ◽  
The North

Echinococcus multilocularis (Em) is a zoonotic parasite considered a global emergent pathogen. Recent findings indicate that the parasite is expanding its range in North America and that European-type haplotypes are circulating in western Canada. However, genetic analyses are usually conducted only on a few parasites out of thousands of individuals within each definitive host, likely underestimating the prevalence of less common haplotypes. Moreover, mixed infections with several mtDNA haplotypes in the same host have been reported, but their relative abundance within the host was never estimated. We aimed to 1) estimate the frequency of co-infections of different Em haplotypes in coyotes (Canis latrans) and red foxes (Vulpes vulpes) from western Canada and their relative abundance within the definitive hosts, 2) detect less prevalent haplotypes by sampling a larger proportion of the parasite subpopulation per host, and 3) investigate differences in the distribution of Em haplotypes in these main definitive hosts; foxes and coyotes. We extracted DNA from ~10% of the worm subpopulation per host (20 foxes and 47 coyotes) and used deep amplicon sequencing (NGS technology) on four loci, targeting the most polymorphic regions from the mitochondrial genes cox1 (814 bp), nad1 (344 bp), and cob (387 bp). We detected the presence of mixed infections with multiple Em haplotypes and with different Echinococcus species including Em and E. granulosus s.l. genotypes G8/G10, low intraspecific diversity of Em, and a higher abundance of the European-type haplotypes in both hosts. Our results suggest a population expansion of the European over the North American strain in Alberta and a limited distribution of some European-type haplotypes. Our findings indicate that deep amplicon sequencing represents a valuable tool to characterize Em in multiple hosts, to assess the current distribution and possible origins of the European strain in North America. The potential use of next-generation sequencing technologies is particularly important to understand the patterns of geographic expansion of this parasite.

Echinococcus multilocularis and Echinococcus canadensis in wolves from western Canada

Parasitology ◽  
2013 ◽  
Vol 141 (2) ◽  
pp. 159-163 ◽  
Author(s):  
JANNA M. SCHURER ◽  
KAREN M. GESY ◽  
BRETT T. ELKIN ◽  
EMILY J. JENKINS
Keyword(s):  
North America ◽  
Echinococcus Multilocularis ◽  
Wildlife Conservation ◽  
Parasite Species ◽  
Mixed Infections ◽  
Western Canada ◽  
Echinococcus Canadensis ◽  
Sampling Locations ◽  
Multiple Species ◽  
Canadian Wildlife

SUMMARYEchinococcus species are important parasites of wildlife, domestic animals and people worldwide; however, little is known about the prevalence, intensity and genetic diversity of Echinococcus tapeworms in Canadian wildlife. Echinococcus tapeworms were harvested from the intestines of 42% of 93 wolves (Canis lupus) from five sampling regions in the Northwest Territories, Manitoba and Saskatchewan, and visually identified to genus level by microscopic examination. Genetic characterization was successful for tapeworms from 30 wolves, and identified both Echinococcus canadensis and Echinococcus multilocularis in all sampling locations. Mixed infections of E. canadensis/E. multilocularis, as well as the G8/G10 genotypes of E. canadensis were observed. These findings suggest that wolves may be an important definitive host for both parasite species in western Canada. This represents the first report of wolves naturally infected with E. multilocularis in North America, and of wolves harbouring mixed infections with multiple species and genotypes of Echinococcus. These observations provide important information regarding the distribution and diversity of zoonotic species of Echinococcus in western North America, and may be of interest from public health and wildlife conservation perspectives.

Sign in / Sign up

Export Citation Format

Share Document