PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Rhabditoidea”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1994

Synonymy of Longibucca eptesica with Longibucca lasiura (Nematoda: Rhabditoidea) and new host and geographic records.

The genus Longibucca Chitwood, 1933 (Nematoda: Rhabditoidea) is reviewed based on examination of museum and adult specimens collected from 4 species of bats (Myotis lucifugus, Myotis ciliolabrum, Eptesicus fuscus, and Lasionycteris noctivagans) in Alberta, Canada. Two species are considered valid, namely Longibucca vivipara Chitwood, 1933, and Longibucca lasiura McIntosh and Chitwood, 1934. Longibucca eptesica Elsea, 1953 is considered a synonym of L. lasiura. New hosts of Longibucca lasiura include Pipistrellus subflavus, Lasionycteris noctivagans, and Myotis ciliolabrum. New geographic ranges of Longibucca lasiura are Virginia, U.S.A., Canada, and western North America.

Alberta↗
PubMed1992

Cytochemical characterization of the cuticle of Caenorhabditis elegans (Nematoda: Rhabditoidea).

At the ultrastructural level, the Caenorhabditis elegans (Maupas, 1900; Doughert, 1953) cuticle shows the presence of six layers: epicuticle, external cortical, internal cortical, intermediate, fibrous and basal. Two techniques were used for carbohydrate localization: the periodic acid-thiosemicarbazide-silver proteinate (Thiéry) and gold-labelled lectins. No labelling was found on the nematode's cuticle. With the ethanolic phosphotungstic acid technique (E-PTA), that detects basic proteins, reaction product was observed in the outer cortical layer, in the cuticle struts and in the dense bodies of the muscle cell. Surface anionic sites of C. elegans were visualized by using cationized ferritin particles, at pH 7.2, and by using colloidal iron hydroxide particles at pH 1.8. Treatments with trypsin and neuraminidase (Vibrio cholerae) did not interfere with the binding of the cationic particles to the nematode's surface. In contrast, treatment with chondroitinase ABC, a specific enzyme for glycosaminoglycans, significantly reduced the binding.

Animals↗
PubMedDate not supplied

[Morphology and biometry of eggs and larvae of Strongyloides sp. Grassi, 1879 (Rhabditoidea: Strongyloididae), a gastrointestinal parasite of Hydrochaeris hydrochaeris (Linnaeus, 1766) (Rodentia: Hydrochaeridae), in the municipality of Juiz de Fora, Minas Gerais, Brazil].

An important method to diagnose and study the helminthofauna of wild animals is to examine the host's feces to find eggs and larvae, seeking to identify the parasites and study their morphobiology. The objective of the present work is to provide morphological and biometric data on the eggs and larvae of Strongyloides sp., a capybara gastrointestinal parasite. Using the technique of Gordon and Whitlock, simple flotation and the modified Baermann examination, capybara fecal samples were selected based on a criterion of the highest proportion of eggs and larvae in the initial development stages, for morphometric description of eggs, L1, L2 and L3 of Strongyloides sp. From past reports of parasitism in Hydrochaeris hydrochaeris, we suspect that the eggs and larvae in this study are of Strongyloides chapini Sandground, 1925, which constitutes the first description of these stages for this species of nematode. Nevertheless, the morphology and biometry data of these stages demonstrate that they are similar to those of other species of the Strongyloides genus.

Animals↗
PubMed1995

Morphology, homogonic development, and lack of a free-living generation in Strongyloides robustus (Nematoda, Rhabditoidea), a parasite of North American sciurids.

Adult females of Strongyloides robustus Chandler, 1942, a parasite of sciurids in North America, were found in the duodenal mucosa of 30 of 32 red squirrels (Tamiasciurus hudsonicus (Erxleben)) collected in Cape Breton Island, Nova Scotia, Canada. The parasitic female is illustrated and redescribed; characteristics include: body 3.8-8.0 mm long, cephalic extremity with X-shaped mouth and 8 circumoral lobes, ovaries spiralling around intestine, and tail bluntly rounded. Eggs in fresh feces contained tadpole-stage larvae. In fecal cultures, eggs hatched and larvae invariably developed to the filariform infective third stage; i.e. a free-living generation did not occur and is probably absent in S. robustus in Cape Breton and possibly other parts of North America. It is hypothesized that homogonically developing S. robustus might be more fecund or more efficiently transmitted than species of Strongyloides that exhibit both homogonic and heterogonic development. Larvae of S. robustus in fecal cultures, i.e. homogonic larvae, are described in detail. Intestinal walls of second- and third-stage larvae, as well as the lateral chords of young third-stage larvae, contained numerous round bodies, likely nutrient stores. Third-stage larvae were present within 2 days in cultures maintained at 30 degrees C, 4 days at 20 degrees C, and 7 days at 15 degrees C. They lived for at least 33 and 30 days at 15 degrees C and 20 degrees C, respectively. Third-stage larvae probably die when their nutrient stores are exhausted.

Animals↗
PubMed1998

Thermal response of Heterorhabditis bacteriophora transformed with the Caenorhabditis elegans hsp70 encoding gene.

A heat-shock response is induced when cells are exposed to temperatures slightly higher than their optimal physiological temperature. This response is based on the synthesis of heat-shock proteins encoded by the heat-shock genes. A correlation between the increased thermotolerance and production of 70-kDa heat-shock protein (hsp70) has been observed in many organisms. We tested this hypothesis by transferring a Caenorhabditis elegans heat-inducible hsp70 A-encoding gene into the entomopathogenic nematodes Heterorhabditis bacteriophora Hp88. Successful transformation of the gene was confirmed by Southern blot hybridization and polymerase chain reaction. Our blot studies showed that the transgenic nematodes contained five to ten copies per genome of the introduced hsp70 A gene. hsp70 mRNA transcripts were detected in both wild-type and transgenic nematodes. Transcripts increased severalfold in transgenic nematodes upon heat shock. Infective juveniles of both transgenic and wild-type nematodes that exposed to a sublethal heat treatment (35 degrees C) for 2 h followed by a normally lethal heat treatment (40 degrees C) for 1 h. More than 90% of transgenic nematodes survived heat treatment, compared to 2% to 3% of the wild-type strain. Our observations establish that overexpression of hsp70 A gene resulted an enhanced thermotolerance in the transgenic nematodes. The transgenic nematodes displayed normal growth and development.

Animals↗