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1.
A survey of whipworms was conducted in llamas and vicu?as in northwestern Argentina. Fecal examinations of a group of 14 llamas (April 1995-March 1996) and 69 vicu?as (November 1996) indicated a high prevalence (usually >50%) of Trichuris sp. in these hosts. Prevalence was highest during July-November 1995 that also coincided with the highest mean fecal egg count. During postmortem examinations of 1 llama and 1 vicu?a, specimens of Trichuris tenuis were recovered from the cecum/large intestine of each camelid. This is the first report of T. tenuis in South America, and the first report in the vicu?a. It is suggested that T. tenuis is the typical whipworm of aboriginal camelids.  相似文献   

2.
A new species of Trichuris from the cecum of white-tailed deer, Odocoileus virginianus, from the southeastern United States, is characterized herein. Males had spicules 2.20 to 3.05 mm long with bluntly rounded tips, an ejaculatory duct equal to or slightly longer than the vas deferens, and a spinous spicular sheath with an expansion near its center. Females had a spinous vulva, usually not everted, a loop in the oviduct just before it opened into the uterus, and a slightly curved posterior portion. Trichuris odocoileus was differentiated from T. lani , a species described in Russia which is most like T. odocoileus, by 1) possessing a spicular sheath with a central expansion, 2) greater size with longer ejaculatory duct and vas deferens, 3) slightly larger eggs, and 4) the unique loop in the oviduct. Trichuris odocoileus constitutes the 6th species of Trichuris recovered from North American ruminants. A key is provided to facilitate differentiation of the six species.  相似文献   

3.
Species of Trichuris (Nematoda:Trichuridae) parasitize a broad range of mammalian hosts. To date, 21 Trichuris species infecting nine families of rodents have been found in North and South America. Trichuris navonae n. sp. is described on the basis of specimens recovered from a species of forest-dwelling mice, Akodon montensis (Cricetidae: Sigmodontinae), from nine localities of Misiones Province, Argentina. A comparison with all the species of Trichuris from North and South American rodents is given. The separation of the new species of Trichuris is based on morphologic and morphometrica features, such as the absence of a spicular tube, the presence of a cylindrical spicular sheath with sharp spines, a non-protrusive vulva, a long anterior-posterior portion of the body, a lengthy spicule, and a proximal and distal cloacal tube. This is the third record of this genus in rodents of the Sigmodontinae from Argentina and the fifth record from South American rodents. Despite the large number of potential host species, only about 1.9% of sigmodontine rodent species have been reported as hosts of Trichuris spp. It is suggested that this number represents but a small fraction of Trichuris spp. that occur in sigmodontine rodents, and that additional survey of this group should yield additional species.  相似文献   

4.
Meningeal worm (Parelaphostrongylus tenuis), a common nematode parasite in white-tailed deer (Odocoileus virginianus) and pathogenic for several species of ungulates in eastern North America, is not known to occur in the west. Heads of 1,902 white-tailed deer were examined for adult meningeal worm to determine geographic distribution of the parasite in Saskatchewan and Manitoba (Canada) and North Dakota (USA). Finding the parasite in a deer in eastern Saskatchewan near the Manitoba border established the current northern and western limits in Canada. Prevalence of infection was < 1, 18.6, and 8.2% in Saskatchewan, Manitoba, and North Dakota, respectively. Infected deer occurred throughout southern Manitoba and eastern North Dakota. Distribution appears to have changed little since the last published survey for P. tenuis in the region in 1972. We examined precipitation, temperature, deer density, and forest cover as likely correlates to prevalence and distribution of P. tenuis. Deer management units used for hunting purposes were the scale of analysis in the three jurisdictions. Presence of P. tenuis was positively correlated with precipitation during frost-free periods and deer density, and it was negatively correlated with winter and spring temperatures. Landscapes with > 25 and < 75% forest cover were most likely to have infected deer. Low rainfall and low density of white-tailed deer likely influence the westernmost limit of P. tenuis.  相似文献   

5.
We present a human infection with the canine whipworm, Trichuris vulpis, in a child suffering from rhinitis with a diagnosis of rhinitis. T. vulpis eggs resemble those of T. trichiura but they can be differentiated based on their morphological features and egg size, using micrometry with an ocular micrometer. T. vulpis eggs measured an average of 90 μm by 44 μm (range 86-99 μm by 38-47 μm). Prevalence of hookworms (28.1%), Toxocara canis (11.8%), and Trichuris vulpis (3.5%) was found in 292 fecal samples of dogs collected at the peri-domicile, which showed that the risk of infection was not only fortuitous. The treatment of canine whipworm infections is similar to that of T. trichiura infection. We recommend differentiation of the 2 species for their epidemiological and prevention implications.  相似文献   

6.
以采自广东不同地区的猪鞭虫(Trichuris suis)和斯氏鞭虫(Trichuris skrjabini)为研究对象,扩增线粒体基因组的pnad4和pcox1基因,将扩增产物纯化后克隆至pMD18-T载体,对阳性菌落进行测序和序列分析。结果表明,来源于不同地区的鞭虫上述两个基因种内相对保守,差异性不大,但种间差异较大。猪鞭虫和斯氏鞭虫的pnad4长度均为468 bp,相互间有162个种间遗传标记位点;猪鞭虫和斯氏鞭虫的pcox1长度分别为600 bp与438 bp,相互间有156个种间遗传标记位点。两种鞭虫之间的pnad4基因差异率为45.1%-45.9%,pcox1基因差异率为44.1%-45.4%。上述线粒体两个基因均可作为区分两种线虫的种间遗传标记。  相似文献   

7.
中国块菌属多样性   总被引:3,自引:1,他引:2  
在中国特别是西南地区块菌属Tuber资源调查的基础上,本文综合形态特征、生态特征以及分子系统学分析,对比研究了欧洲和北美的部分块菌属标本,对中国块菌属已知种类进行了分类订正和系统的总结.研究确认我国分布有17种块菌,其中3/4的种类分布于西南地区.尚有6种因未观察到可靠的标本而存疑,3种排除在我国分布.文中对该属在我国...  相似文献   

8.
Genetic and morphological variability of whipworms Trichuris Roederer, 1761 (Nematoda: Trichuridae), parasites of small rodents in southwestern Europe, was studied. Isozyme patterns of natural populations of nematodes parasitizing rodent species of the Muridae (Apodemus sylvaticus, Apodemus flavicollis, Mus musculus) and Arvicolidae (Clethrionomys glareolus, Microtus agrestis, Microtus arvalis) were analyzed at 6 putative loci. Two diagnostic loci were found in T. muris from Muridae and from Arvicolidae. Thus, the existence of 2 species of Trichuris restricted to different host families was indicated. They included Trichuris muris Schrank, 1788, originally described as being from mice, and Trichuris arvicolae n. sp., parasitizing the above species of Arvicolidae. The morphological variability of both species was compared. Although ranges of all morphological characters of the new species overlapped with those of T. muris, stepwise discriminant analysis yielded a 100% accurate classification of females when using vagina length and egg size. Males of T. muris and T. arvicolae cannot be separated entirely. A set of 6 variables yielded 95.7% discrimination; the most discriminating variables were spicule size and body width.  相似文献   

9.
10.
Although there has been extensive debate about whether Trichuris suis and Trichuris trichiura are separate species, only one species of the whipworm T. trichiura has been considered to infect humans and non-human primates. In order to investigate potential cross infection of Trichuris sp. between baboons and humans in the Cape Peninsula, South Africa, we sequenced the ITS1-5.8S-ITS2 region of adult Trichuris sp. worms isolated from five baboons from three different troops, namely the Cape Peninsula troop, Groot Olifantsbos troop and Da Gama Park troop. This region was also sequenced from T. trichiura isolated from a human patient from central Africa (Cameroon) for comparison. By combining this dataset with Genbank records for Trichuris isolated from other humans, non-human primates and pigs from several different countries in Europe, Asia, and Africa, we confirmed the identification of two distinct Trichuris genotypes that infect primates. Trichuris sp. isolated from the Peninsula baboons fell into two distinct clades that were found to also infect human patients from Cameroon, Uganda and Jamaica (named the CP-GOB clade) and China, Thailand, the Czech Republic, and Uganda (named the DG clade), respectively. The divergence of these Trichuris clades is ancient and precedes the diversification of T. suis which clustered closely to the CP-GOB clade. The identification of two distinct Trichuris genotypes infecting both humans and non-human primates is important for the ongoing treatment of Trichuris which is estimated to infect 600 million people worldwide. Currently baboons in the Cape Peninsula, which visit urban areas, provide a constant risk of infection to local communities. A reduction in spatial overlap between humans and baboons is thus an important measure to reduce both cross-transmission and zoonoses of helminthes in Southern Africa.  相似文献   

11.
The whipworm, Trichuris trichiura, causes trichuriasis in ~600 million people worldwide, mainly in developing countries. Whipworms also infect other animal hosts, including pigs (T. suis), dogs (T. vulpis) and non-human primates, and cause disease in these hosts, which is similar to trichuriasis of humans. Although Trichuris species are considered to be host specific, there has been considerable controversy, over the years, as to whether T. trichiura and T. suis are the same or distinct species. Here, we characterised the entire mitochondrial genomes of human-derived Trichuris and pig-derived Trichuris, compared them and then tested the hypothesis that the parasites from these two host species are genetically distinct in a phylogenetic analysis of the sequence data. Taken together, the findings support the proposal that T. trichiura and T. suis are separate species, consistent with previous data for nuclear ribosomal DNA. Using molecular analytical tools, employing genetic markers defined herein, future work should conduct large-scale studies to establish whether T. trichiura is found in pigs and T. suis in humans in endemic regions.  相似文献   

12.
The whipworm Trichuris muris is known to be associated with various rodent species in the northern hemisphere, but the species identity of whipworm infecting rodents in the Oriental region remains largely unknown. We collected Trichuris of Muridae rodents in mainland and insular Southeast Asia between 2008 and 2015 and used molecular and morphological approaches to identify the systematic position of new specimens. We discovered two new species that were clearly distinct from T. muris, both in terms of molecular phylogenetic clustering and morphological features, with one species found in Thailand and another one in Borneo. We named the new species from Thailand as Trichuris cossoni and the species from Borneo as Trichuris arrizabalagai. Molecular phylogeny using internal transcribed spacer region (ITS1-5.8S-ITS2) showed a divergence between T. arrizabalagai n. sp., T. cossoni n. sp. and T. muris. Our findings of phylogeographically distinct Trichuris species despite some globally distributed host species requires further research into the distribution of different species, previously assumed to belong to T. muris, which has particular relevance for using these species as laboratory model organisms.  相似文献   

13.
14.
Populations of Trichuris spp. isolated from six species of sigmodontine rodents from Argentina were analyzed based on morphological characteristics and ITS2 (rDNA) region sequences. Molecular data provided an opportunity to discuss the phylogenetic relationships among the Trichuris spp. from Noth and South America (mainly from Argentina). Trichuris specimens were identified morphologically as Trichuris pardinasi, T. navonae, Trichuris sp. and Trichuris new species, described in this paper. Sequences analyzed by Maximum Parsimony, Maximum Likelihood and Bayesian inference methods showed four main clades corresponding with the four different species regardless of geographical origin and host species. These four species from sigmodontine rodents clustered together and separated from Trichuris species isolated from murine and arvicoline rodents (outgroup). Different genetic lineages observed among Trichuris species from sigmodontine rodents which supported the proposal of a new species. Moreover, host distribution showed correspondence with the different tribes within the subfamily Sigmodontinae.  相似文献   

15.
Sangmi Lee 《Journal of Asia》2011,14(3):299-303
The eight species of Pseudotelphusa (Gelechiidae: Litini) are known to occur in North America. Three new species of the genus from North America are described and illustrated.  相似文献   

16.
Trichuris eggs were found in Kerodon rupestris (Rodentia, Caviidae) coprolites collected in archaeological layers dated from 30,000 yr BP (before present) to 8,450 yr BP. Adult worms and eggs of this genus were not found in a search of living mammals of the region. Results indicate that K. rupestris was a host for an unknown Trichuris species not found in this rodent presently. Climate changes that occurred by 10,000 yr ago in the region could be the cause of its disappearance. The finding of parasites in archaeological material can show the antiquity of host-parasite relationships and parasite losses through time.  相似文献   

17.
Brunke AJ  Majka CG 《ZooKeys》2010,(65):51-61
New distributional and bionomic data are provided for species of the genus Xantholinus in North America. Xantholinus elegans (Olivier 1795) (= X. jarrigei Coiffait 1956)is recorded from North America for the first time, based on specimens collected in Ontario, Canada from 2007-2010. The armature of the internal sac of the aedeagus in situ is illustrated to aid in identification. Xantholinus linearis (Olivier 1795), known previously from the Maritime Provinces of Canada and the eastern United States, is newly recorded from Ontario. Xantholinus longiventris Heer 1839 is still only known from western North America. A key is provided to allow recognition of all three species.  相似文献   

18.
In the present communication we have studied the isoenzymatic pattern activity of the glucose 6-phosphate dehydrogenase (G6PD) in Oesophagostomum venulosum, Trichuris ovis and T. suis, parasites of Capra hircus (goat), Ovis aries (sheep) and Sus scrofa domestica (pig) respectively, by polyacrylamide gel electrophoresis. Different phenotypes have been observed in the G6PD isoenzymatic pattern activity in males and females of Oesophagostomum venulosum. Furthermore, G6PD activity has been assayed in Trichuris ovis collected from Ovis aries and Capra hircus. No differences have been observed in the isoenzymatic patterns attending to the different hosts. All the individuals exhibited one single band or two bands; this suggests a monomeric condition for G6PD in T. ovis. In T. suis the enzyme G6PD appeared as a single electrophoretic band in about 85.7% of the individuals.  相似文献   

19.
Trichuridae family has a genetic and morphological variability between species affecting rodents, but it is considerably hard to morphologically diagnose species within the genus of Trichuris and the individuals of these species are identified according to their host, as it is known that Trichuris spp. is strictly host-specific. However, some species lack host specificity. So, it is necessary to use molecular data in order to well identify the Trichuris spp. in Egyptian rodents. The host examined in the current research is Psammomys obesus and the molecularly identified species from its cecum is Trichuris arvicolae. In addition, Trichuris arvicolae was subjected to in vitro treatment with Androctonus crassicauda Crude Venom as a model of natural alternative treatment for gastrointestinal nematodes that increasingly develop anthelmintic drug resistance. The changes in Trichuris arvicolae were monitored using scanning electron microscopy, Androctonus crassicauda Crude Venom made a significant ultrastructural surface changes in Trichuris arvicolae, including marked cuticular sloughing, disintegrated bacillary glands, bursting of vulva and edema of anal region. This study was done for closer identification of Trichuris spp. infecting rodents in Egypt and evaluating the efficacy of Androctonus crassicauda Crude Venom in vitro.  相似文献   

20.
Hexabathynella is the only cosmopolitan genus of the order Bathynellacea (Crustacea). The known species number 18, found in Europe (9), Africa (1), South America (2), North America (3) and Australia and New Zealand (3). Phylogenetic analysis suggests that the least derived species are those from South America and the most derived those from the Iberian Peninsula, North America and Australia. The five species with the most plesiomorphic characters occur in salt or brackish water, which supports a marine origin for the genus. Phylogenetic and biogeographical analyses suggest that the distribution of the genus can be explained by dispersion and a double vicariant biogeographical model based on plate tectonics and the evolution of the Tethys during the Mesozoic and Cenozoic.  © 2003 The Linnean Society of London . Biological Journal of the Linnean Society , 2003, 78 , 457–466.  相似文献   

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