Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “TREMATODE INFECTIONS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

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

At least 1,549 records · Page 86Linked to original sources
PubMed2005

Multiple cathepsin B isoforms in schistosomula of Trichobilharzia regenti: identification, characterisation and putative role in migration and nutrition.

Among schistosomatids, Trichobilharzia regenti, displays an unusual migration through the peripheral and central nervous system prior to residence in the nasal cavity of the definitive avian host. Migration causes tissue degradation and neuromotor dysfunction both in birds and experimentally infected mice. Although schistosomula have a well-developed gut, the peptidases elaborated that might facilitate nutrition and migration are unknown. This is, in large part, due to the difficulty in isolating large numbers of migrating larvae. We have identified and characterised the major 33 kDa cathepsin B-like cysteine endopeptidase in extracts of migrating schistosomula using fluorogenic peptidyl substrates with high extinction coefficients and irreversible affinity-labels. From first strand schistosomula cDNA, degenerate PCR and Rapid Amplification of cDNA End protocols were used to identify peptidase isoforms termed TrCB1.1-TrCB1.6. Highest sequence homology is to the described Schistosoma mansoni and Schistosoma japonicum cathepsins B1. Two isoforms (TrCB1.5 and 1.6) encode putatively inactive enzymes as the catalytic cysteine is substituted by glycine. Two other isoforms, TrCB1.1 and 1.4, were functionally expressed as zymogens in Pichia pastoris. Specific polyclonal antibodies localised the peptidases exclusively in the gut of schistosomula and reacted with a 33kDa protein in worm extracts. TrCB1.1 zymogen was unable to catalyse its own activation, but was trans-processed and activated by S. mansoni asparaginyl endopeptidase (SmAE aka. S. mansoni legumain). In contrast, TrCB1.4 zymogen auto-activated, but was resistant to the action of SmAE. Both activated isoforms displayed different pH-dependent specificity profiles with peptidyl substrates. Also, both isoforms degraded myelin basic protein, the major protein component of nervous tissue, but were inefficient against hemoglobin, thus supporting the adaptation of T. regenti gut peptidases to parasitism of host nervous tissue.

Animals↗
PubMed1989

Studies on cardiovascular fluke (Digenea: Spirorchiidae) infections in sea turtles from the Great Barrier Reef, Queensland, Australia.

Twenty-seven sea turtles (23 Chelonia mydas and four Eretmochelys imbricata) from northeast Queensland were found to be infected with cardiovascular flukes and/or their eggs. Five had originated from turtle farms in the Torres Strait, five from an oceanarium on Magnetic Island (146 degrees 56'E, 19 degrees S) and the remainder from coral reefs in the Torres Strait or near Townsville. The incidence of flukes and/or eggs in the groups was 4.8 per cent (5 of 104), 33.3 per cent (5 of 15) and 72.2 per cent (17 of 22), respectively. Affected animals ranged in size from 18 to 108 cm (curved carapace length) and weighed between 0.5 and 77 kg. The average number of flukes per host was 47. Flukes were recovered from the three chambers of the heart and major vessels (right aortic arch and brachiocephalic artery), where they were attached to the walls or free in the lumen. They were subsequently identified as Haplotrema spp. and/or Learedius spp. In 59.2 per cent (16 of 27) of turtles, flukes were not found, although their eggs were detected microscopically. Gross pathological changes associated with the presence of flukes included thickening and hardening of arterial walls (four turtles), thrombus formation (three), chronic pneumonia (two) and an excess of pericardial or peritoneal fluid (four). Microscopically, the essential changes was that of chronic inflammation, as evidenced by the proliferation of epithelial cells, reticulo-endothelial cells and fibroblasts in areas accessible to flukes and/or eggs. Multiple diffuse egg granulomas were a prominent feature of most organs, the spleen and lungs being predilection sites. Proliferative changes had occurred in the endocardium and in the endothelium of vessels supplying the spleen, stomach, intestine and pancreas (18 turtles). The walls of major arteries, lungs, liver, brain, crop and stomach were also acutely inflamed (eight turtles). Haemorrhage was recorded in the lungs and/or brain of eight turtles with heavy fluke infestations. Other vascular changes, viz. congestion, oedema and hypertrophy of arterial/arteriolar walls, resulted from the inhibition of blood flow by parasitic emboli.

Animals↗
PubMedDate not supplied

[Distribution of trematodes of the family Prosthogonimidae in river and lake ecological systems in the south of the Western Siberia].

The results of long-term investigations (1994-2003) of an infection rate of trematodes of the family Prosthogonimidae in the first intermediate hosts (snails of the family Bithyniidae) and in the final hosts (birds) from a basin of the Chany Lake (Western Siberia) are discussed. A total of 1824 specimens of Bithynia tentaculata (L., 1758) and 7166 specimens of Opisthorchophorus troscheli (Paasch, 1842) have been collected from eight rivers and two lakes in the south of the Western Siberia. Data of incomplete helminthological dissection of 225 young water-fowl of 18 species were analyzed. Birds were obtained in July, August and September, 1996-2003 from the Chany lake basin. Maritas of the trematode family Prosthogonimidae were revealed in bursa Fabricii (26.12%) of seven bird species of two orders (Anseriformes and Gruiformes): Grey Lag-Goose Anser anser (L.) (Infection rate-28.6% +/- 12.1), Mallard Anas platyrhynchos L. (27.5% +/- 6.2), Shoveler--A. clypeata L. (22.2% +/- 13.9), Pochard Aythya ferina (L.) (51.7% +/- 9.3), Coot Fulica atra L. (28.6% +/- 5.6), Tufted Duck A. fuligula (L.) (1 case), Wigeon A. penelope L. (1 case). Average intensity of invasion is 5.8 marita specimens per infected bird. The maximal number of parasites (37 maritas), and also the highest average intensity of invasion are recorded for the Coot. The 342 maritas of the family Prosthogonimidae belong to three species: Prosthogonimus ovatus (Rud., 1803) (49.7%), P. cuneatus (Rud., 1809) (32.8%) and Schistogonimus rarus (Braun, 1901) (14.6%); these trematode species have been recorded in 35, 12 and 8 bird species, respectively. Grey Lag-Goose, Shoveler, Pochard and Tufted Duck are new host records for P. cuneatus in for Western Siberia. Parthenitae of trematodes (Prosthogonimidae) were revealed from eight populations of bithyniid snails. The infection rate of the trematodes (parthenitae and cercariae) in population of bithyniid snails from lake ecological system varied 6.55-54.4%, and in river ecological systems in was 0.6-4.2 %. The infection rate of trematodes (parthenitae and cercariae) of the first intermediate hosts was 2.64% that is significantly lower than that of the final hosts from the Chany Lake basin. Both O. troscheli and B. tentaculata were noted as the first intermediate hosts of prosthogonimid trematodes of three species: P. ovatus, P. cuneatus and S. rarus. All three species of trematode were found in three water reservoirs: Ob River (B. tentaculata), Kargat River (O. troscheli) and Chany Lake (O. troscheli). Thus it is found out that 39 bird species can be the final hosts of prosthogonimid trematodes. About a quarter of nestlings is infected with these trematodes. The infection rate of parthenitae in snails from the lake ecosystems is significantly higher than in the river ecosystems.

Animals↗
PubMed2002

Antigenicity of Pseudodactylogyrus anguillae and P. bini (Monogenea) in the European eel (Anguilla anguilla, L.) under different oxygenation conditions.

The antibody response of European eels (Anguilla anguilla, L.) to the branchial parasites Pseudodactylogyrus anguillae and P. bini under hyperoxygenation conditions was studied. The antigenic fractions of parasites were detected by means of electrophoretic techniques (SDS-PAGE) and by Western blot analysis. The results obtained demonstrate that under hyperoxygenation conditions, the eels responded to a greater number of proteins, and this was correlated with a decrease in the level of infestation.

Anguilla↗