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PubMed1989

Dynamics of elimination of the eggs of Fasciola hepatica (Trematoda, Digenea) in the faeces of cattle in the Porma Basin, Spain.

In order to contribute to the knowledge of the epizootiological conditions in which fasciolosis develops in the León mountains, the elimination of Fasciola hepatica eggs in 10% of the total number of cattle (1301 samples) at five locations in the Porma river basin was recorded at monthly intervals between March 1986 and March 1987. The parasite was found in cattle [29.5% prevalence, average of 51.6 +/- 4.5 eggs g-1 (e.p.g.) faeces] throughout the year. The main egg elimination period was winter-spring, with maximum prevalence in January and maximum e.p.g. in February-March. Prevalence of infection in cattle generally increased with the host's age, whilst the average e.p.g. varied between different age groups.

Age Factors↗
PubMed1996

Paramphistomum daubneyi and Fasciola hepatica: the effect of dual infection on prevalence and cercarial shedding in preadult Lymnaea glabra.

Preadult Lymnaea glabra measuring 4-6 mm in height were each exposed to 1 Paramphistomum daubneyi miracidium before being exposed to 1 miracidium of Fasciola hepatica. Total prevalence of infection in the snail groups from 3 different populations ranged from 33% to 39%. In each group, snails harboring larval forms of P. daubneyi, F. hepatica, or both, were noted. If the results from the 3 snail populations are pooled, the total prevalence of snail infection was 13.6% in snails harboring only F. hepatica larvae, 13% in those harboring only P. daubneyi larvae, and 10% in those with both trematodes. Cercarial shedding was obtained from snails harboring F. hepatica larval forms; in the case of snails infected with both trematodes, the mean number of metacercariae ranged from 13 to 21 for F. hepatica, and from 8 to 14 for P. daubneyi. No infected snails were found in snail groups exposed only to 1 trematode miracidia.

Animals↗
PubMed1985

Diagnosis of Fasciola hepatica infection in beef calves by plasma enzyme analysis.

Plasma analysis for albumin, total bilirubin, and total protein values and aspartate aminotransferase (AST), arginase, and gamma-glutamyl transpeptidase (GGT) activities was used for the early and quantitative diagnosis of experimental Fasciola hepatica infections in beef calves. Calves were infected on 3 occasions with 1,000 (n = 5), 100 (n = 5), or 10 (n = 4) metacercariae for a total infective dose of 3,000, 300, or 30, respectively. Albendazole (15 mg/kg of body weight) was administered to 7 infected calves on postinfection (initial) week (PIW) 13. All calves were euthanatized and necropsied on PIW 16 for the determination of fluke infections. Plasma constituents were determined weekly. Significant (P less than 0.05) increases in AST activity occurred as early as PIW 4 and GGT activity at PIW 9, as compared with that in noninfected controls. Fluke burden-related differences were observed in GGT activity from PIW 9 onward. Increases in AST activity reflected parenchymal liver damage, whereas increases in GGT reflected hepatobiliary damage; therefore, differentiation could be made between the migratory and ductal phases of the infection. There was no correlation between arginase activity and fluke infection. As compared with fecal examination results, plasma enzyme analysis gave an earlier and semiquantitative indication of F hepatica infection in experimentally infected calves. Although increases in these plasma constituents were not definitely diagnostic of fascioliasis, useful information on the size of the fluke burden and progress of the disease process could be obtained by these methods. Plasma enzyme analyses of AST and GGT were not indicative of chemotherapeutic success or failure when calves with mature F hepatica (14 weeks old) infections were treated.

Animals↗
PubMed2006

Evaluation of relationship between repeat breeding and Fasciola hepatica and hydatid cyst infections in cows in Elazig district of eastern Turkey.

Sera samples from 89 dairy cows with repeat breeding and 111 healthy pregnant dairy cows (controls) from Elazig province of eastern Turkey were tested for presence of Fasciola hepatica and Hydatid cyst antibodies by use of an indirect enzyme linked immunosorbent assay (indirect-ELISA). One hundred and twenty one (60.5%) and 93 (46.5%) cows were found to be positive to F. hepatica and Hydatid cyst antibodies, respectively. Fifty two of 89 cows (58.4%) with a history of repeat breeding were seropositive to F. hepatica, and 43 of 89 (48.3%) were seropositive to Hydatid cyst antibodies. Whereas, seropositivity rates were 62.1% (69/11) for F. hepatica and 45% (50/111) for Hydatid cyst in healthy pregnant cows (control group). There were no statistically relationship between infected and control group (P>0.05). In conclusion, we could not detect any relationship between repeat breeding and F. hepatica and Hydatid cyst infections in cattle.

Animals↗
PubMed2001

Fasciola hepatica: the characteristics of experimental infections in Lymnaea truncatula subjected to miracidia differing in their mammalian origin.

Experimental infections of Lymaea truncatula, using two susceptible snail populations (Berneuil, or Migné, central France) and four isolates of Fasciola hepatica miracidia differing in their mammalian host of origin (cattle, nutrias, rabbits, or sheep), were performed under laboratory conditions to determine whether the host of origin had an effect on the daily production of cercariae. Snails were each subjected to bimiracidial exposures and were then reared under semi-natural conditions (a constant temperature of 20 degrees C and natural photoperiod). Significantly lower values were noted in the rabbit groups for survival rates at day 30 post-exposure, as well as for prevalences of infection, snail growth. duration of shedding period, and the total numbers of cercariae these snails shed. The total number of cercariae shed by both nutria groups was significantly higher than those recorded in the six other infected groups. In the cattle, rabbit, and sheep (Berneuil only) groups, the peaks in the daily distribution of cercariae occurred between day 2 and day 4 after the first shedding, and the number of cercaria-shedding snails decreased with increasing number of shedding waves. In contrast, in the three other groups, the peaks were only observed between days 20 and 45. Snails shedding their cercariae during nine or more waves were numerous in these last groups. No infradian-type rhythm in the daily distribution of cercarial numbers over the shedding period was noted for any snail group. The highest production of F. hepatica cercariae in both nutria groups would be a consequence of a higher success rate of miracidia when they infected an allopatric population of snails. The absence of an infradian-type rhythm in the distribution of daily cercarial numbers in the eight groups suggests that this rhythm, if it occurs, would only be influenced by temperature and thus be limited to periods with optimal conditions for cercarial shedding.

Animals↗
PubMed1981

Anthelmintic efficacy of albendazole in calves with naturally acquired Fasciola hepatica infections.

The anthelmintic efficacy of albendazole was evaluated as an oral drench at dosages of 15.0, 10.0, and 7.5 mg/kg of body weight in 3 groups crossbred Brahman calves (n = 12 group) infected with Fasciola hepatica. Although posttreatment fluke ova counts for the 3 albendazole treatment groups were significantly (P less than 0.01) lower (av 82%) than were counts in nontreated calves, there were no significant differences in the responses to the different albendazole treatments. At necropsy, adult fluke counts in treated calves were lower (P less than 0.05) than were counts in nontreated calves, but as with ova counts, a dose-related trend was not noticed. Efficacy against adult flukes was 63.4%, 50.0%, and 56.6% for 15.0, 10.0, and 7.5 mg/kg, respectively. Activity against immature flukes was not observed in calves given the 10.0 and 7.5 mg/kg, but there was a 36% decrease of flukes in those calves given 15.0 mg/kg. Significant decreases (P less than 0.05) in fluke ova viability were observed for the 3 treatment groups in which 12.9% of ova collected at necropsy failed to embryonate (control group av 6.7%). Posttreatment weight changes were not significantly different, although gains were greater within albendazole treatment groups. Decreases in gastrointestinal parasite ova counts after treatment were 98%, 93%, and 93% for groups given 15.0, 10.0, and 7.5 mg/kg, respectively. Ova counts in nontreated calves increased 26.2% during the same period.

Albendazole↗
PubMed2000

Comparison of hepatic and renal drug-metabolising enzyme activities in sheep given single or two-fold challenge infections with Fasciola hepatica.

The activity of drug-metabolising enzymes was compared in liver and kidneys of adult sheep given single or two-fold fluke infection. Fascioliasis was induced by oral administration of 200 metacercariae of Fasciola hepatica to female sheep either 10 or 20 weeks (mono-infections) or 10 and 20 weeks (bi-infection) before killing. The parasitic pathology was ascertained at autopsy and by clinical observation of animals. In the liver of both mono- and bi-infected animals, significant decreases (P<0.05) (17-44%) were observed in the microsomal content of cytochrome P450 and in the two measured P450-dependent monooxygenase activities, benzphetamine and ethylmorphine N-demethylations. Moreover, Western blot analysis of microsomes demonstrated a decrease in the expression of cytochrome P4503A subfamily correlative with that of its presumed corresponding activity ethylmorphine N-demethylase. By contrast, the conjugation of chloro-dinitrobenzene to glutathione remained unchanged in liver cytosolic fractions prepared from all these animals. In kidneys, a significant decrease (P<0.05) (30%) in microsomal cytochrome P450 level of 10-week mono-infected sheep was observed whereas there was no change in the other groups of animals. The inflammatory origin and the consequences in terms of pathology and animal productivity of the fascioliasis-induced decreases in tissue-oxidative drug metabolism are discussed, particularly in the case of adult sheep suffering repetitive infections.

Animals↗
PubMed1996

[The effect of emissions from a mercury-processing metallurgy plant on the intensity of experimental Fasciola hepatica infection in sheep].

A group of 14 improved Valashka lambs, aged 4 months, body weight 14-16 kg, were used in the experiment studying the effect of subchronic heavy metal intoxication on the course of experimental fasciolosis (Fasciola hepatica). The animals were divided into two groups, each of 7 lambs, 3 lambs--ewes and 4 lambs--rams. Each animal in group I was given orally for 27 days gelatinous capsules containing heavy metal emissions of the following composition: 4.5 mg Hg, 2.9 mg Pb, 147.8 mg Cu, 9.8 mg Zn, 0.9 mg Cr and 0.04 mg Cd per animal and day. Group II served as control. On Day 27, when the administration of heavy metals ceased, each animal in both groups received 250 F. hepatica metacercariae. The animals were sacrificed on Day 110 post infection, their liver necropsied and parenchymatous organs and muscles taken to examine the content of heavy metals. The heavy metal concentrations are presented in Tab. I. In the emission-intoxicated group, the maximum permissible reference level of mercury in the kidneys, liver and muscles was exceeded on the average by 1.94, 0.87 and 0.020 mg Hg/kg, respectively. Cu exceeded the reference level only in the liver, with 261.3 mg Cu/kg. In the kidneys and muscles, Cu was below the reference levels. An analogous situation was with Zn, Cr, and Cd. The F. hepatica infection mean intensity in this animal group was 38.3 +/- 3.01 specimens (min. 34 - max. 46 specimens). In control group, the heavy metal levels were several times lower than the reference values and the infection mean intensity was 27 +/- 5.4 (min. 19 - max. 35 specimens). In subchronically intoxicated animals, the reference values for mercury were exceeded and so were partially those of copper in the parenchymatous organs and muscles. The F. hepatica infection mean intensity also increased, compared with control. The results have proved the negative effect of the metal emissions on the animal immune system, which was manifested by the increased infection intensity.

Animals↗
PubMed1980

Effect of detergents and acid buffer on the reactivity of Fasciola hepatica antigens.

The effect of glycine-HCl (acid) buffer on antigen extraction and of three commonly used detergents--sodium dodecyl sulphate (SDS), sodium deoxycholate (DOC), and Triton X-100--on the reactivity of a standard Fasciola hepatica adult-worm antigen preparation (FhWWE) was studied. Acid buffer destroyed most of the immunologic reactivity of FhWWE when tested with anti-F. hepatica serum, but apparently did not affect the antigens reactivity with an anti-S. mansoni serum. These studies suggest that elution with acid buffer should be used with caution when FhWWE is the antigenic extract used in antibody-affinity chromatography. Neither Triton X-100 nor DOC appreciably increased the reactivity of FhWWE antigens. In addition, DOC decreased the antigen-antibody interactions. Low concentrations of SDS increased the reactivity of FhWWE, but higher concentrations decreased the antigen-antibody interactions.

Animals↗
PubMed2006

Estimating the true prevalence of Fasciola hepatica in cattle slaughtered in Switzerland in the absence of an absolute diagnostic test.

A survey of 1,331 cattle presented for slaughter at two abattoirs in Switzerland was used to estimate the true prevalence of Fasciola hepatica infection and the diagnostic parameters of visual meat inspection, coproscopy after sedimentation technique, a commercial ELISA test for specific antibody detection in serum and the post mortem microscopic detection of eggs in bile. Faeces, blood and the gall bladder were taken from most cattle presented for slaughter. In addition, livers that were rejected by the meat inspectors were also dissected to examine for the presence of liver fluke. Bayesian techniques (Markov Chain-Monte Carlo) were used to estimate the diagnostic parameters of each of these procedures and the true prevalence of bovine fasciolosis. The true prevalence of F. hepatica infection was estimated at 18.0% (95% credible intervals 15.9-20.3%). The diagnostic sensitivity of coproscopy, bile examination, antibody ELISA and meat inspection were estimated at 69.0% (57.3-79.7%), 93.4% (88.0-97.5%), 91.7% (87.2-95.2%) and 63.2% (55.6-70.6%), respectively. The diagnostic specificity of the ELISA test was estimated at 93.7% (91.7-95.2%). These results demonstrate that the prevalence of bovine fasciolosis is higher than previously thought due to the low sensitivity of meat inspection. They also demonstrate that traditional coproscopy can be very efficient if there is repeated sampling, resulting in sensitivity of approximately 92%.

Abattoirs↗
PubMed2002

[RAPD variation in two trematode species (Fasciola hepatica and Dicrocoelium dendriticum) from a single cattle population].

The method of random DNA amplification by PCR with arbitrary primers (RAPD-PCR) was used for the description and estimation of genetic variation in two trematode species, Fasciola hepatica (n = 21) and Dicrocoelium dendriticum (n = 8). The studied trematodes were liver parasites of five cattle individuals belonging to the same herd. To study the F. hepatica population, five primers were selected, which revealed 320 RAPD markers in five samples of parasites isolated from five different host individuals. Using 87 RAPD markers, a comparison of variation was conducted between F. hepatica and D. dendriticum samples from the same host individual. Based on the estimates of RAPD variation for the individual samples of parasites collected from each of five host individuals and for the total F. hepatica population, standard indices of genetic similarity (S), diversity (H), polymorphism (P), and population subdivision (FST) were calculated. From the indices of similarity in pairs (S), dendrograms were constructed, which reflect genetic relationship between the representatives of two species and between F. hepatica individuals isolated from the same or different host individuals. It was revealed that polymorphism level (P) varied within a range of 35.5 to 83.2% in the studied F. hepatica population and reached 95.1% in the studied D. dendriticum population. Two different trematode species that simultaneously parasitize the same host animal were characterized by similar estimates of polymorphism and genetic diversity and by similar topology of genetic similarity dendrograms. The degree of genetic similarity between F. hepatica and D. dendriticum was significantly lower (20%) than between five F. hepatica samples (41.4%) that formed two unequal clusters. Each of these clusters represents a heterogeneous group consisting of parasites collected from three or four host individuals. In the individual samples of parasites related to each of the studied host individuals, the indices of genetic similarity (S) and diversity (H) varied within a range of 43.3 to 64.8% and 25.1 to 56.6%, respectively. In the total F. hepatica sample, the estimates of intraspecific variation, the topology of dendrograms, and the FST index (7.4%) indicate the absence of clear genetic differentiation between the samples of parasites isolated from different host individuals. Possible reasons for the high level of genetic variation in the studied trematode populations and the genetic consequences of host--parasite interaction are discussed.

Animals↗
PubMed1998

[Identification, by Western blot, of Fasciola hepatica immunogens recognized by the sera of experimentally infected rats].

This paper was aimed at identifying the main components present in the excretory-secretory antigens of adult parasite which are recognized by the sera of rats experimentally infected with metacercariae of Fasciola hepatica, by using the Western Blot technique. The cynetics of antibodies was also determined with and indirect ELISA. The results obtained allowed to find 31 components with approximate molecular weights from 11 to 136 kD. The predominant fractions were the following: 11-13 kD, 14-16 kD, 23-33 kD, 55-57 kD, 65-71 kD, and 86-136 kD. Antibodies were detected from the 2nd. week of infection in 80% of the animals and from the 3rd. week in 100% of them. There were no antibodies during the first week. The identification of these antibodies may contribute to a better understanding of the mechanisms of immunity linked with the infection by F. hepatica.

Animals↗
PubMed1987

Fasciola hepatica: action in vitro of triclabendazole on immature and adult stages.

Under in vitro conditions in a balanced salt solution, triclabendazole was found to accumulate in significant amounts in both immature (3 week old) and adult Fasciola hepatica. A viable parasite was needed to concentrate the drug, but a high percentage of the compound was also bound by the dead worm. The drug could penetrate into liver flukes even when the oral route had been closed off by ligation, indicating that the drug can be taken up by transtegumentary absorption. A 24 hr exposure to triclabendazole, at 10-25 microM concentrations, was found to result in a strong inhibition of the parasite's motility. This effect was paralleled by dramatic changes in the worm's resting tegumental membrane potential. The onset of these actions was found to develop very slowly, and high drug levels had to accumulate within the parasite to initiate its immobilization. In addition to drug concentration and incubation time, physiological alterations observed were also dependent on other culture conditions, such as the presence or absence of serum albumin and the drug tissue/medium ratio. Biochemical examinations showed that triclabendazole significantly stimulated glucose derived acetate and propionate formation by adult liver flukes. Adenosine triphosphate levels were not changed even in the presence of high triclabendazole concentrations (25 microM). Likewise, the activities of various membrane associated adenosine triphosphatases were not altered by the drug. However, the ability of the drug to inhibit colchicine binding to microtubular protein purified from adult liver flukes suggested an interference of the drug with microtubular structure and function.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetates↗
PubMed1977

Interference with Fasciola hepatica snail finding by various aquatic organisms.

Previous studies using radioactive miracidia have shown that a number of non-host snails and bivalves, interposed as 'decoys' in linear test channels, may interfere with the capacity of Fasciola hepatica miracidia to infect Lymnaea truncatula. Applying similar experimental principles, the role of several other potential interferents have been analysed in the present study. Daphnia pulex (Cladocera) and larvae of Corethra sp. (Diptera) exercised significant interfering effects by protecting 'target' snails from infection. Evidence suggested that this effect was a result of their normal predatory behaviour. Other organisms including Herpobdella testacea and Helobdella stagnalis (Hirudinea), Acellus aquaticus (Isopoda), Planaria lugubris (Turbellaria) and L. truncatula egg clusters failed to interfere with miracidial host-finding. Nor did P. lugubris and L. truncatula 'conditioned water' interfere with the capacity of the miracidia to infect their host snail.

Animals↗
PubMed2006

The populations of Galba truncatula, known for their natural infections with Haplometra cylindracea (Digenea, Plagiorchioidea), are better intermediate hosts for metacercarial production of Fasciola hepatica.

Laboratory investigations on Galba truncatula were carried out to determine if snails coming from four populations known to be natural intermediate hosts of Haplometra cylindracea, a digenean species of frogs, would not be better hosts for experimental infections with Fasciola hepatica than those originating from two communities in which H. cylindracea was never found in the past years. Uninfected G. truncatula were used to constitute six groups of snails (one per population) before being subjected to individual monomiracidial exposures with F. hepatica. Insignificant differences between mean values were noted for snail survival at day 30 post-exposure, prevalence of snail infection with F. hepatica, and prepatent period. In contrast, the duration of cercarial shedding and the number of F. hepatica cercariae in the four groups known for natural infections with H. cylindracea were significantly greater. The use of these last lymnaeid populations for experimental infections with F. hepatica allows to have high numbers of cercariae because of long patent periods and, as a consequence, strongly reduces the cost price of these larvae for scientific purposes and/or commercial production.

Animals↗