SEARCH · PubMed Health

Results for “FASCIOLA HEPATICA”

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 433 records · Page 24Linked to original sources

PubMed1985

Suppression of Babesia microti infection in mice concurrently infected with Fasciola hepatica.

Blood cell parasitaemia of Babesia microti and the associated haematological changes were examined in mice harbouring patent Fasciola hepatica infections and in fluke-free control mice. B. microti parasitaemia was markedly suppressed in mice harbouring primary 7-week F. hepatica infections, as reflected in a reduction in the percentage of erythrocytes parasitised and in the incidence of multiple B. microti infections in the red cells. This suppression was accompanied by an annulment of B. microti induced reductions in haemoglobin and haematocrit levels in F. hepatica infected mice. In naive recipient mice, inoculated with blood from mice concurrently infected with F. hepatica and B. microti, the course of B. microti infection was characterised by a prolonged pre-parasitaemia period, a reduced peak parasitaemia and a delayed fall in haematocrit levels as compared to those inoculated with blood from mice infected with B. microti only. This feature may presumably be dose-related. The present study does not reveal the actual mechanism(s) involved in the suppression of the blood protozoan by F. hepatica. However, since B. microti has a preference for mature erythrocytes, the suppression may be a result of the altered erythrocyte kinetic state induced by the removal of erythrocytes by the blood-sucking fluke resulting in high levels of reticulocytes.

Animals↗

PubMed2001

Characterisation of a beta-tubulin gene from the liver fluke, Fasciola hepatica.

This study represents the first beta-tubulin sequence from a trematode parasite, namely, the liver fluke, Fasciola hepatica. PCR of genomic DNA showed that at least one beta-tubulin gene from F. hepatica contains no introns. A number of amino acids in the primary sequence of fluke tubulin are different from those described previously in various nematode species and the cestode, Echinococcus multilocularis. beta-Tubulin is an important target for benzimidazole anthelmintics, although (with the exception of triclabendazole) they show limited activity against F. hepatica. The amino acid differences in fluke beta-tubulin are discussed in relation to the selective toxicity of benzimidazoles against helminths and the mechanism of drug resistance.

Amino Acid Sequence↗

PubMed1999

Biochemical characterization and localization of Fasciola hepatica 26-28 kDa diagnostic coproantigen.

We have previously reported the usefulness of a 26-28 kDa coproantigen of Fasciola hepatica for diagnosis of infection. In this study, the 26-28 kDa coproantigen was biochemically characterized with the aid of monoclonal antibodies (MoAb) in an effort to better understand the biology of the antigen. Differential staining of chromatographically-purified 26-28 kDa coproantigen on SDS-PAGE, under reducing and non-reducing conditions, indicated that the coproantigen was a monomeric, highly glycosylated glycoprotein. Alkaline treatment of the purified coproantigen resulted in an 8 kDa protein core which still contained the epitope recognized by the MoAb. No protease activity was associated with the 26-28 kDa coproantigen. The coproantigen could be cleaved by trypsin without altering the reactive epitope recognized by the MoAb, but was resistant to pepsin digestion. Further, the coproantigen was stable under several different storage conditions. Indirect immunofluorescence on tissue sections of adult flukes indicated that the coproantigen was present in gut cells and tegument. Taken together these results confirm the stability of the 26-28 kDa coproantigen and its usefulness in diagnostic tests for F. hepatica infections.

Animals↗

PubMedDate not supplied

Infection of Lymnaea truncatula and Lymnaea glabra by Fasciola hepatica and Paramphistomum daubneyi in farms of central France.

Natural infection of Lymnaea glabra and Lymnaea truncatula by Fasciola hepatica and/or Paramphistomum daubneyi was studied at two periods of risk (June-July and September-October) in 11 French farms known for their high prevalences of F. hepatica infection in ruminants. A total of 1,778 L. truncatula and 2,396 L. glabra measuring 6 mm or more in height were collected to determine the prevalence of natural infection with F. hepatica and P. daubneyi. The role of four factors, i.e. season, snail co-infection (F. hepatica-P. daubneyi), ruminant host and the existence of single or mixed intermediate host communities, was investigated. There were no differences in prevalences between the two risk periods. Co-infections in L. glabra were more frequent than expected. The prevalences of infection with F. hepatica or P. daubneyi in L. glabra were higher in farms rearing sheep than in farms rearing cattle. A similar finding was also noted for L. truncatula infected with P. daubneyi only. L. glabra was a much better intermediate host for F. hepatica and P. daubneyi when it was the only available snail, possibly indicating an adaptation of parasites to their less usual host in local conditions. The two trematodes preferably developed in L. truncatula rather than in L. glabra when both host species lived in the same places.

Animals↗

PubMed1984

Efficacy of triclabendazole against Fasciola hepatica and Fascioloides magna in naturally infected calves.

Twenty calves (8 to 12 months old), naturally infected with Fasciola hepatica and Fascioloides magna, were obtained from Brazoria, Tex. They were randomly allotted to 3 treatment groups. One group (6 calves) was given the carrier without drug, the 2nd group (7 calves) was treated with triclabendazole at 6 mg/kg of body weight, and the 3rd group (7 calves) was treated with triclabendazole at 12 mg/kg. All treatments were administered as a drench. Calves given triclabendazole (either dosage level) had a 100% reduction in F hepatica burden as compared with the untreated controls. Both treatment doses also appeared to have detrimental effect on F magna infections. Viability of all flukes was determined on the basis of movement, color, and tegumental integrity. Clinical toxic reactions were not observed in the treated calves.

Animals↗

PubMed2004

Fasciola hepatica and Paramphistomum daubneyi: vertical distribution of metacercariae on plants under natural conditions.

Four experiments on the metacercariae of Fasciola hepatica and Paramphistomum daubneyi were carried out under natural conditions in order to study their vertical location on submerged plants and to determine whether simultaneous cercarial shedding of both digenea causes changes in the distributions of the metacercariae. These experiments were performed in experimental boxes, each containing six tufts of rushes. Most metacercariae (73.0%) of F. hepatica were found along the walls of boxes, while 81.5% of P. daubneyi metacercariae were found on rush stems. In the case of snails infected by either of the two digenea, 80.1% of F. hepatica cercariae encysted on submerged parts of rushes and of the box walls near the water surface (to a depth of 1 cm), whereas 73.0% of P. daubneyi metacercariae were found in the lower sections (from -4 to -7 cm). If snails dually infected with P. daubneyi and F. hepatica were used, the vertical distributions of the metacercariae were significantly different from those found for snails infected by either of the two digenea. If snails having 42-day old infections with F. hepatica and other snails with 70-day old infections with P. daubneyi were simultaneously introduced into the boxes, the frequency of F. hepatica cysts was significantly lower in the section located under the water surface (29% only), while the frequencies of metacercariae in the lower sections (from -1 to -5 cm) were increased. Some significant changes were also observed for the metacercariae of P. daubneyi. The disturbance noted in the vertical distributions of F. hepatica and P. daubneyi metacercariae suggest that the encystment of F. hepatica cercariae can be disturbed by the simultaneous encystment of P. daubneyi cercariae, or conversely.

Animals↗

PubMed1996

Efficacy of closantel against Fasciola hepatica in Korean native goats.

Closantel (Flukiver), a salicylanilide antiparasitic compound, was tested in Korean native goats infected with Fasciola hepatica. The goats were administered closantel once orally at a dose of 10 mg/kg body weight. Efficacy was monitored weekly by fecal examination of all infected animals starting the second week post-treatment and continuing for 3 weeks. Closantel elicited 80.3, 97.8 and 92.7% efficacy in goats with naturally-acquired fasciolosis at the second, third and fourth week post-treatment, respectively. It elicited a 100% efficacy in goats experimentally infected with F. hepatica metacercariae and treated at 18 weeks post-infection.

Animals↗

PubMed1990

Potential for the spread of Fasciola hepatica in cattle in Oklahoma.

In 29 central and western Oklahoma counties, 42 ranches were investigated for indigenous Fasciola hepatica infections and their suitability for the transmission of liver fluke. A 10-year retrospective study of Oklahoma cattle based on samples submitted to the Oklahoma Animal Disease Diagnostic Laboratory also was done. Indigenous fascioliasis was found in cattle in 12 counties (9 central and western counties identified in the combined field and retrospective studies and 3 additional eastern counties identified on the basis of the retrospective study). Factors essential for survival of free-living stages of F hepatica and for snail species necessary for propagation of the fluke existed in much of Oklahoma. Snails capable of serving as intermediate hosts for transmission of the fluke reportedly have been found in 41 of the 77 Oklahoma counties. Lymnaeid snails were detected in 4 counties in the field study.

Animals↗

PubMed1989

In vivo regulation of phosphorylation level and activity of phosphofructokinase by serotonin in Fasciola hepatica.

The level of phosphorylation and activation of phosphofructokinase by serotonin (5-hydroxytryptamine) was studied in intact liver flukes Fasciola hepatica. The enzyme was immunoprecipitated with antiserum prepared against pure enzyme from the liver flukes. The resuspended immunoprecipitated enzyme retained most of its original activity and its kinetic properties. The level of phosphorylation was determined by a "back phosphorylation" technique. According to this technique, the immunoprecipitated phosphofructokinase was phosphorylated with the catalytic subunit of pure cAMP-dependent protein kinase. Incubation of intact liver flukes with serotonin caused an increase in the level of enzyme phosphorylation which was concomitant with an increase in enzyme activity. The level of phosphorylation was increased by 0.08 mol per protomer as a result of maximal activation by serotonin. It is proposed that phosphorylation plays, at least in part, a functional role in the regulation of phosphofructokinase from the liver fluke F. hepatica under in vivo conditions.

Adenosine Triphosphate↗

PubMed1977

Contribution to the knowledge of infectivity of Fasciola hepatica adolescariae after their passage through the digestive tract of white mice.

The study of infective elements of Fasciola hepatica which passed through the digestive tract of white mice revealed that those adolescariae (transitive adolescariae) (Table 1), which were not visibly damaged or possessed a more or less digested outer cyst wall, remained infective. The mice infected with transitive adolescariae harboured higher number of trematodes in the livers than those infected with infective elements which had not previously passed through the digestive tract of the definitive host.

Animals↗

PubMed1983

Fasciola hepatica: carbohydrate metabolism of the adult.

Glycogen (or exogenous glucose) was the only energy source utilized by adult Fasciola hepatica under a number of different incubation conditions. When exogenous glucose was present in the incubation medium, significant amounts of lactate were excreted. Anaerobically, in the presence of glucose, lactate accounted for 20% of the total end products measured. In the absence of glucose, organic acid production accounted for approximately 60% of glycogen carbon utilized; this value was reduced to 40% in the presence of exogenous glucose. There was no appreciable Pasteur effect.

Acetates↗

PubMed1978

Concurrent daily infection of calves with Fasciola hepatica and Ostertagia ostertagi.

Three groups of calves were infected daily with either 1500 Ostertagia ostertagi larvae, 20 Fasciola hepatica metacercariae, or 1500 O ostertagi plus 20 F hepatica metacercariae. Weekly measurements were taken of calf weight, faecal egg output, plasma concentrations of albumin, plasma activities of sorbitol dehydrogenase, gamma glutamyl transpeptidase and pepsinogen and standard haematological indices. Calves were killed either 10 or 21 weeks after daily infections began. F hepatica infection had little influence on the size and structure of the O ostertagi worm population or vice versa. Mean worm burdens found at 20 weeks in those animals infected with both F hepatica and O ostertagi were 293 flukes and 20,641 nematodes. While this level of infection is similar to that seen in the disease complex in the field, there was no evidence of clinical disease or any difference in weight gain between the groups in this experiment. Factors other than additive worm burdens are obviously important for the expression of disease under field conditions.

Abomasum↗

PubMedDate not supplied

Lymphocyte and cytokine responses of young cattle during primary infection with Fasciola hepatica.

An experiment was designed to characterise the early immune responses of cattle given a trickle infection of the trematode Fasciola hepatica. Lymphocyte responses and IFNgamma production following stimulation with Fasciola antigens were measured. Animals were sequentially slaughtered at weeks 5, 7, 9 and 11 post-infection. Results demonstrated responses to fluke antigens and cytokine production (IFNgamma) from weeks 2-5 post-infection. These findings may suggest an early stimulation of IFNgamma production by peripheral blood lymphocytes following infection with F hepatica in cattle.

Animals↗

PubMed1989

Comparison of different Fasciola hepatica antigens and their use to detect infection in sheep by an enzyme immunoassay.

Soluble antigens of adult Fasciola hepatica were extracted from homogenized parasites and purified with gel chromatography on Sephadex G-200. Six peaks were obtained, and the second highest in molecular weight showed highest correspondence in a microplate enzyme immuno assay with parasite metabolite antigens. Optimal coating antigen concentration was 5 micrograms/ml and sample dilution 1:20. Total running time of assay was 3 hours. Positive and negative sheep sera was obtained from a group of experimentally infected tracer lambs.

Animals↗

PubMed1980

Resistance of Fasciola hepatica in rats and rabbits following sensitising infection and treatment.

Whereas one mature or two immature infections with Fasciola hepatica, which had been eliminated by anthelmintic treatment, conferred resistance to reinfection in rats, this did not occur with rabbits. The differences between the hosts were shown by the numbers of flukes which developed following challenge ands by the changes in peripheral eosinophil counts and serum glutamic dehydrogenase levels. In contrast, rabbits gave a stronger serological response (ELISA) than rats but this was not affected by treatment or challenge in either host.

Animals↗

PubMed1983

The activity of triclabendazole against immature and adult Fasciola hepatica infections in sheep.

The efficiency of a new benzimidazole anthelmintic, triclabendazole, was tested against cumulative infections with Fasciola hepatica aged 1 to 12 weeks in sheep and compared with that of rafoxanide. At 10 mg/kg, triclabendazole was 99% effective in eliminating both immature and adult flukes. At a lower dose rate of 5 mg/kg, triclabendazole was highly effective against adults and significantly reduced the number of early immature flukes with an 87% overall reduction of fluke burden. Rafoxanide at 7.5 mg/kg showed high efficiency against adult fluke, but its effect on immatures was not significant, and overall efficiency was 64%.

Animals↗

PubMed2004

First report of Lymnaea columella Say, 1817 (Pulmonata: Lymnaeidae) naturally infected with Fasciola hepatica (Linnaeus,1758) (Trematoda: Digenea) in Argentina.

We report the first evidence of natural infection of Lymnaea columella with Fasciola hepatica in Argentina. A sample of 601 snails was collected in May 2003 in northeastern Corrientes, a province bounded on the north by Paraguay, on the east by Brazil and on the southeast by Uruguay. Among 500 examined snails, 44 (8.8%) were exclusively infected with F. hepatica. Parasite identification was based on morphological features of cercariae from snails, and of eggs and adult flukes from Wistar rats. We discuss the events suggesting that an enzootic transmission cycle of F. hepatica has been recently established in northeastern Corrientes.

Animals↗

PubMed1991

[Fasciola hepatica antigens. Use in the diagnosis of human fascioliasis].

The ELISA technique was standardized for detecting antibodies against Fasciola in 25 serum samples from patients-infected with Fasciola hepatica using excretion-secretion antigens (ESA), tegument antigen and somatic antigen. A study was made of serum samples from 46 patients with other parasites such as Ascaris lumbricoides, Trichuris trichiura, Entamoeba histolytica, Schistosoma mansoni and Giardia lamblia. The cohort value for each trial was established after studying 100 serum samples from healthy people as negative controls taking as criterion the mean optical density plus 2 standard deviations from the mean. Regarding this group and using ESA, we obtained specificity and sensitivity.

Animals↗