its-2 rdna sequencing of gnathostoma species (nematoda) and elucidation of the species causing human gnathostomiasis in the americas.from several gnathostome species the complete internal transcribed spacer its-2 ribosomal dna (rdna) repeat sequence and a fragment of the 5.8s rdna were obtained by direct polymerase chain reaction cycle-sequencing and silver-staining methods. the size of the complete its-1 sequence in agarose gel electrophoresis was also obtained. the its-2 enabled the differentiation of gnathostoma spinigerum from thailand and gnathostoma binucleatum from mexico and ecuador and confirmed the validity of the l ...200010864252
a new species of gnathostoma (nematoda: gnathostomatidae) in procyon lotor hernandezii from mexico.gnathostoma lamothei n. sp., inhabiting the stomach of procyon lotor hernandezii wagler, 1831, in tlacotalpan, veracruz state, and rio sapo, oaxaca, mexico, is described. this new species differs from all other congeners by having the posterior half of the body surface covered by rows of tiny round bosses instead of spines, or lacking ornamentations. sequences of the its2 of the ribosomal dna of g. lamothei n. sp. are compared with sequences of other species of the genus recorded in mexico; they ...200516419762
discovery of an endemic area of gnathostoma turgidum infection among opossums, didelphis virginiana, in mexico.gnathostomosis, caused by gnathostoma binucleatum, is a serious public health issue in mexico. although 2 other gnathostoma spp., g. turgidum and g. lamothei, have been found in wild animals, their natural life cycle or their relation to human disease remains unclear. while we were conducting an epidemiological survey on gnathostoma spp. in sinaloa state, mexico, we found an endemic area for g. turgidum in common opossums, didelphis virginiana, located in tecualilla, sinaloa. the species identif ...200918989999
finding advanced third-stage larvae of gnathostoma turgidum stossich, 1902 in mexico from natural and experimental host and contributions to the life cycle order to clarify the role of gnathostoma turgidum as an etiological agent involved in human gnathostomiasis in mexico, establish the taxonomic identity of the advanced third-stage larvae (advl(3)), and contribute to the knowledge of its life cycle, experimental host infections, examination of potential natural hosts, and morphological comparisons were carried out. examination of ten species of potential hosts at san pedro las playas and tres palos lagoon in guerrero state, mexico revealed tha ...200919130085
is gnathostoma turgidum an annual parasite of opossums? drastic seasonal changes of infection in didelphis virginiana in mexico.gnathostoma turgidum is a nematode that parasitizes the stomach of opossums, didelphis virginiana. despite its wide distribution in the americas, its natural life cycle is poorly understood. recently, we found an endemic area for g. turgidum infection in sinaloa, mexico (diaz-camacho et al., 2009). based on sporadic surveys for several years, the prevalence was apparently high in summer and extremely low in winter. to confirm that this is really a seasonal variance, we conducted a longitudinal s ...200919281297
precocity of gnathostoma turgidum in naturally infected four-eyed opossum philander opossum pallidus from temascal, oaxaca, mexico.two female advanced third-stage larvae of gnathostoma turgidum recovered from the liver of one naturally infected four-eyed opossum philander opossum pallidus collected in oaxaca, mexico, were morphologically examined. because of some characteristics, the larvae do not fit into the typical advanced third-stage. the body shows a size at least three times larger than expected and rows of spines only in the anterior part of the body surface. consequently, in this research, we document for the first ...201019936791
description and development of the early third-stage larva of gnathostoma turgidum stossich, 1902 (nematoda: gnathostomatidae) and contributions to its life cycle.the egg and larval stages of gnathostoma turgidum were examined using light microscopy. fertilized uterine eggs are 65.97 long and 32.28 wide, oval, brownish, with two cap-like thickenings. the eggshell surface is covered with numerous irregularly shaped pits of various sizes and depths. a sheathed second-stage larva emerges from the egg, measures 178 x 9; the sheath measures 243 x 21. development to early third-stage larva in the coelomic cavity of cyclopoid copepods is similar to that describe ...201020232083
intrahepatic growth and maturation of gnathostoma turgidum in the natural definitive opossum host, didelphis virginiana.gnathostoma turgidum is a gastric nematode parasite of opossums found in the americas. we recently found that g. turgidum juveniles appear in the liver of the opossums where they become mature adults and almost synchronously move to the stomach during certain months of the year, suggesting the importance of the liver for the growth and maturation of this species in the final hosts. in this study we attempted to detect g. turgidum larvae in the liver of opossums, didelphis virginiana that are the ...201020447468
spontaneous cure after natural infection with gnathostoma turgidum (nematoda) in virginia opossums (didelphis virginiana).seasonality of the nematode gnathostoma turgidum in virginia opossums (didelphis virginiana) in the wild has been reported; however, the mechanisms involved in deworming are unknown. we monitored the parasitologic and biologic changes in four virginia opossums naturally infected with g. turgidum by coproparasitologic examination and abdominal ultrasonography. eggs became detectable in the feces of opossums in may, peaked in july and august, and suddenly decreased in october. adults of g. turgidu ...201424506422
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