Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “FASCIOLIASIS”

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 1,495 records · Page 83Linked to original sources
PubMed2004

Expression of interleukin 4, interleukin 4 splice variants and interferon gamma mRNA in calves experimentally infected with Fasciola hepatica.

Interleukin 4 (IL-4) is expected to play a dominant role in the development of T helper (Th) 2 cells. Th2 immune responses with expression of relatively large amounts of interleukin 4 (IL-4) but little interferon gamma (IFN-gamma) are characteristic for chronic helminth infections. But no information is available about IL4 expression during early Fasciola hepatica (F. hepatica) infections in cattle. Therefore, we investigated F. hepatica specific IL-4 and IFN-gamma mRNA expression in peripheral blood mononuclear cells (PBMCs) from calves experimentally infected with F. hepatica. Cells were collected prior to infection and on post-inoculation days (PIDs) 10, 28 and 70. Interestingly, PBMCs responded to stimulation with F. hepatica secretory-excretory products (FhSEP) already on PID 10 and expressed high amounts of IL-4 but not of IFN-gamma mRNA suggesting that F. hepatica induced a Th2 biased early immune response which was not restricted to the site of infection. Later in infection IL-4 mRNA expression decreased whereas IFN-gamma mRNA expression increased slightly. Isolated lymph node cells (LNCs) stimulated with FhSEP and, even more importantly, non-stimulated LN tissue samples indicated highly polarized Th2 type immune responses in the draining (hepatic) lymph node, but not in the retropharyngeal lymph node. During preliminary experiments, two splice variants of bovine IL-4 mRNA, boIL-4delta2 and boIL-4delta3, were detected. Since a human IL-4delta2 was assumed to act as competitive inhibitor of IL-4, it was important to know whether expression of these splice variants of bovine IL-4 have a regulatory function during an immune response to infection with F. hepatica. Indeed, IL-4 splice variants could be detected in a number of samples, but quantitative analysis did not yield any clue to their function. Therefore, the significance of bovine IL-4 splice variants remains to be determined.

Alternative Splicing↗
PubMed2004

Immunization of rats against Fasciola hepatica using crude antigens conjugated with Freund's adjuvant or oligodeoxynucleotides.

Chronic Fasciola hepatica infection is correlated with the development of a T helper (Th2)-predominant immune response. To determine whether immunostimulatory CpG-containing oligodeoxynucleotides (CpG-ODN) or Freund's complete adjuvant (FCA), known to promote a Th1 (T helper 1) immune responses, could provide protection from F. hepatica infection, total homogenate (TH) of F. hepatica mixed with CpG-ODN or FCA were injected subcutaneously (s.c.) into Wistar rats. A F. hepatica-specific Th1-predominant immune response was induced with CpG-ODN or FCA in lymph nodes of immunized animals. Lymph node cells from TH-CpG-ODN or TH-FCA immunized rats showed increased antigen-specific proliferation with high levels of INFgamma, compared to lymphocytes from rats injected with TH alone. In contrast, these two groups of immunized animals did not modify IL-4 release by draining lymph node cells, when they were subsequently stimulated with TH in vitro. However, a significant reduction in the burden of flukes (76.7%) was only observed in rats immunized with TH-FCA. Conversely, immunization of rats with TH-CpG-ODN did not promote protection against the parasite. Therefore, even though CpG-ODNs and FCA induced Th1 type responses, only FCA provided a significant protection to rats infected with F. hepatica.

Adjuvants, Immunologic↗
PubMed2005

Characterization of the humoral immune response in alpacas (Lama pacos) experimentally infected with Fasciola hepatica against cysteine proteinases Fas1 and Fas2 and histopathological findings.

A characterization of the humoral immune response of alpacas to Fasciola hepatica Fas1 and Fas2 antigens, two abundant cysteine proteinases in the excretory/secretory (E/S) products, was performed over the course of 6 months of experimental infection. Six adult alpacas aged 1-2 years old received a single dose of 200 F. hepatica metacercariae; two non-infected alpacas were kept as control group. All infected animals shed eggs 8 weeks post-infection (PI) and the number of flukes recovered at necropsy averaged 41+/-4. The livers of infected animals showed regions with chronic inflammation, granuloma containing parasite eggs, necrosis and cirrhosis. Peripheral eosinophilia in infected animals was greatly enhanced 6 weeks post-infection and later. A single peak of serum glutamic piruvic transaminase (SGPT) was observed 4 weeks PI and serum glutamic oxalacetic transaminase (SGOT) elevated 3 weeks PI and later. Circulating IgG Abs against Fas1 and Fas2 were measured by enzyme-linked immunosorbent assay (ELISA). Fas2-ELISA detected the infection 10 days PI reaching to highest titer on 7-8 weeks PI and kept elevated, until the end of infection. Fas1-ELISA detected the infection 2 weeks PI and followed the same pattern as Fas2-ELISA. Anti Fas2 IgG Abs were in higher titers and showed stronger avidity than anti Fas1 IgG Abs. In addition, rabbit IgG antibodies raised against cysteine proteinase Fas2 showed infiltration of this parasite antigen associated to the degradation of bile ducts and liver parenchyma of infected alpacas. In the present study we have established a F. hepatica experimental infection of alpacas, Fas2 appears to have a role in the pathogenesis of the liver damage in alpacas caused by the liver fluke. Infected alpacas elicited a strong humoral immune response against fluke cysteine proteinases Fas1 and Fas2, which might be considered as candidates for immunodiagnosis and vaccine development against fasciolosis in alpacas.

Animals↗
PubMed2004

Detection of circulating 54 kDa antigen in sera of bovine calves experimentally infected with F. gigantica.

The antibody response and circulating antigen levels in bovine calves, infected experimentally with Fasciola gigantica, were monitored using enzyme-linked immunoelectrotransfer blot (EITB) and sandwich ELISA, respectively. By EITB, the infected calves' sera recognized the polypeptides in the range of 54-58 kDa as early as 2 weeks post-infection. By 12th week post-infection, the lower two polypeptides of 12 and 8 kDa had disappeared. In sandwich ELISA, the circulating 54 kDa and whole worm antigen of F. gigantica were detected in the sera samples of infected calves as early as 2 weeks post-infection and persisted until the end of experiment (26th week PI). The 54 kDa antigen of F. gigantica appears to be specific and possesses promising immunodiagnostic potential for early prepatent diagnosis of bovine fasciolosis.

Animals↗
PubMed2004

Detection of Fasciola gigantica infection in snails by polymerase chain reaction.

Polymerase chain reaction (PCR) was used to detect Fasciola gigantica infection in the snail intermediate host. Fasciola specific primers amplified a 124 bp fragment in PCR when the genomic DNA isolated from F. gigantica infected Lymnaea auricularia snails was used as template. In addition to the 124 bp amplicon, a ladder of DNA fragments representing amplification of the 124 bp repetitive sequences was observed. Genomic DNA of the parasite was used as a positive control, which also gave an amplification of the 124 bp fragment. DNA isolated from non-infected snails was used as a negative control and no amplification of this sequence was observed. This technique is highly specific and sensitive and possesses fairly good prospects of its utility as an epidemiological tool for ascertaining the infectivity status in ubiquitous snail populations.

Animals↗
PubMed2004

Determination of the effective dose of an experimental fasciolicide in naturally and experimentally infected cattle.

The aim of the present study was to determine the effective dose of an experimental fasciolicide called compound alpha or 5-chloro-2-methylthio-6-(1-napthyloxy)1H-benzimidazole in experimentally and naturally infected cattle. In the first experiment, 24 fluke-free heifers were each infected with 800 metacercariae of Fasciola hepatica and re-infected on day 45 with other 600 cysts per animal. On day 75, when the animals had 4- and 10-week-old flukes respectively, they were divided into four groups (G) of six animals each according to fluke egg counts. Groups 1-3 received compound alpha at 10, 12 and 14 mg/kg/p.o., respectively. G4 remained as an untreated control. Twenty days after treatment, the animals were sacrificed for the recovery of flukes. Efficacy was assessed as a percentage of egg or fluke reduction relative to the untreated control. In the second experiment (naturally infected cattle), 24-year-old steers positive to F. hepatica eggs were blocked into four groups of five animals each. Groups 1-3 received compound alpha at 10, 12 and 14 mg/kg/p.o., respectively. Group 4 served as a non-treated control. All procedures to determine efficacy were carried out as mentioned in the first experiment. The results in the first study showed a percentage on egg reduction of 97.3, 100 and 100 and overall fluke reduction of 94.3, 100 and 100 for Groups 1-3, respectively. In the second study, the percentage of egg reduction was of 87.5, 99.1 and 100 and overall efficacy regarding fluke reduction was of 84.2, 99.6, and 100 for Groups 1-3, respectively. It is concluded that the effective dose selected for compound alpha was of 12 mg/kg/p.o. in cattle having an induced or natural F. hepatica infection.

Administration, Oral↗
PubMed2004

Characterisation of Fasciola species from Mainland China by ITS-2 ribosomal DNA sequence.

Isolates of Fasciola (Platyhelminthes: Trematoda: Digenea) from different host species and geographical locations in Mainland China were characterised genetically. The second internal transcribed spacer (ITS-2) of nuclear ribosomal DNA (rDNA) was amplified from individual trematodes by polymerase chain reaction (PCR), and the representative amplicons were cloned and sequenced. The length of the ITS-2 sequences was 361-362bp for all Chinese Fasciola specimens sequenced. While there was no variation in length or composition of the ITS-2 sequences among multiple specimens from France, Sichuan and Guangxi, sequence difference of 1.7% (6/362) was detected between specimens from France and Sichuan, and those from Guangxi. Based on ITS-2 sequence data, it was concluded that the Fasciola from Sichuan represented Fasciola hepatica, the one from Guangxi represented Fasciola gigantica and the one from sheep from Heilongjiang may represent an "intermediate genotype", as its ITS-2 sequences were unique in that two different ITS-2 sequences exist in the rDNA array within a single Fasciola worm. One of the sequences is identical to that of F. hepatica, and the other is almost identical to that of F. gigantica in that nucleotides at five of the six polymorphic positions represent F. gigantica. This microheterogeneity is possibly due to sequence polymorphism among copies of the ITS-2 array within the same worm. Based on the sequence differences, a PCR-linked restriction fragment length polymorphism (PCR-RFLP) assay was established for the unequivocal delineation of the Fasciola spp. from Mainland China using restriction endonuclease Hsp92II or RcaI. This assay should provide a valuable tool for the molecular identification and for studying the ecology and population genetic structures of Fasciola spp. from Mainland China and elsewhere.

Animals↗
PubMed2004

A geographic information systems model for mapping risk of fasciolosis in cattle and buffaloes in Cambodia.

A geographic information systems (GIS) model for mapping the risk of fasciolosis in cattle and buffaloes was developed for the Kingdom of Cambodia using determinants of inundation, proximity to rivers, land use, slope, elevation, and the density of cattle and buffaloes. Determinants were subjectively weighted according to their perceived relative importance before combining them to produce a risk-map of fasciolosis. The model estimates that 28% of Cambodia is potentially at risk of fasciolosis with areas of high and moderate risk concentrated in southern and central Cambodia. The estimates of risk reflect the actual prevalence of fasciolosis in most districts surveyed, suggesting that the epidemiological determinants and weightings used to produce the model were appropriate. These results will be progressively refined as more detailed field surveys are completed to fully validate the model.

Animals↗
PubMed2004

Herd-level seroprevalence of fasciolosis in cattle in north central Portugal.

An epidemiological study of Fasciola hepatica in cattle was implemented in the north central region of Portugal. Both an enzyme-linked immunosorbent assay and an egg shedding quantification technique were used in the follow-up of seven herds. Two of these herds were negative and the other five were positive for F. hepatica. A herd cut-off of value of 0.425 optical density was calculated and herd sensitivity (HSe) and herd specificity (HSp) were defined. Three seroprevalence studies were also implemented in the region with stratification by county sub-regions for a period of 18 months. Overall mean herd prevalence in Vagos of 11, 23 and 48% was progressively found for the three studies, respectively.

Animals↗
PubMed2004

Humoral immune response against Fasciola gigantica fatty acid binding protein.

Recombinant fatty acid binding protein of Fasciola gigantica was expressed in Escherichia coli and purified by nickel chelating affinity chromatography. The recombinant protein along with native fatty acid binding protein (FABP) isolated from the parasite were evaluated for their potential in the diagnosis of F. gigantica infection in sheep, cattle and buffaloes, both by ELISA and western blotting. Results of this study indicate that there is no humoral immune response generated against this protein in the experimental infection of these ruminants with F. gigantica, thereby limiting the usefulness of this antigen in the early diagnosis of fasciolosis in these animals. Also, the paper discusses the probable reasons for the failure of this protein in detecting humoral response in these animals by ELISA and immunoblotting.

Animals↗
PubMed2004

Vaccination of mice and sheep with Fh12 FABP from Fasciola hepatica using the new adjuvant/immunomodulator system ADAD.

We evaluate the ability of a Fasciola hepatica FABP native antigen (Fh12) with a new vaccination system called ADAD to protect mice and sheep against an experimental F. hepatica infection. The vaccination protocol consists of a set of two injections. The first injection contains a micelle in which two components are included, saponin from Quillaja saponaria (Qs) and/or Anapsos (A) a Polypodium leucotomos hydroalcoholic extract, both emulsified in a non-mineral oil (Montanide) in a water/oil emulsion (30/70). This is subcutaneously injected to achieve the "adaptation" of the immune system to subsequent stimuli. The second injection contains in addition the Fh12 antigen. Two different experiments were carried out using two mouse strains (BALB/c and CD-1). Mice vaccinated with Qs+A+Fh12 presented a survival rate of 40%, when compared with control groups. Furthermore, we evaluated the efficiency of the vaccination in sheep against an experimental F. hepatica challenge. The vaccinated sheep presented lower fluke recovery (24.5%), number of eggs in bile fluid (58.1%) and faeces (40.3%) than control groups. The recovered flukes were shorter (32.7%), immature (34.0%) and with lower body mass (31.6%) than non-complete vaccinated sheep. Thus, the new ADAD system could be a good alternative for future vaccination experiments against fasciolosis.

Adjuvants, Immunologic↗
PubMed2005

Performance characteristics of an enzyme-linked immunosorbent assay performed in milk for the detection of liver fluke (Fasciola hepatica) infection in cattle.

AIM: To determine the performance characteristics of an enzyme-linked immunosorbent assay (ELISA) for the detection of antibodies against liver fluke (Fasciola hepatica) in bovine milk. METHODS: Serum and milk from liver fluke infected and non-infected cattle was assayed in a commercially available enzyme-linked immunosorbent assay. Serum test results were used to determine the "gold standard" infection status of cattle and milk ELISA results assessed by ROC analysis. RESULTS: ROC analysis suggested changes to the ELISA protocol, arriving at milk dilutions assayed considerably higher than those suggested by the manufacturer. With those changes, the ELISA performed with high sensitivity and specificity, 95 and 98.2%, respectively, for individual bovine milks (relative to sera). For bovine tank milks, sensitivity was lower, with bulk milks only testing positive if 60% or more of cattle milking in the herd were infected. CONCLUSIONS: The analysis of the ELISA's performance when used on individual bovine milks demonstrated high sensitivity and specificity. ROC analyses optimised the assay conditions and cut-off point suggested by the manufacturer for this commercial diagnostic assay. This would help with the identification and control of fasciolosis, enabling simpler sample collection.

Animals↗
PubMed2005

Evaluation of a commercially available enzyme-linked immunosorbent assay for detecting antibodies to Fasciola hepatica and Fasciola gigantica in cattle, sheep and buffaloes in Australia.

A commercially available ELISA for detecting antibodies to liver fluke was evaluated for use in Australia. Milk and serum samples from cattle and sheep in which infection with Fasciola hepatica was confirmed by detection of eggs in faeces were used to estimate sensitivity. Similar samples collected from cattle and sheep outside the F. hepatica-endemic area were used to estimate specificity. The ELISA was also evaluated for detecting antibodies to F. hepatica in milk from sheep and antibodies to Fasciola gigantica in sera from cattle and buffaloes, but with small numbers of samples. In cattle, the sensitivity and specificity of the ELISA were 98.2% and 98.3% using serum and 97.7% and 99.3% using milk. In infected herds, 41.4% and 41.5% of animals were positive in the serum and milk ELISAs, respectively, whereas F. hepatica eggs were found in faecal samples from 26.5% of animals. In sheep, the sensitivity of the ELISA was 96.9% and the specificity was 99.4%. In infected flocks, 60.2% of animals were positive in the serum ELISA and F. hepatica eggs were found in faecal samples 52.2% of animals. There was perfect agreement in the ELISA between paired serum and milk samples collected from ewes. The assay detected antibodies in sera from cattle and buffaloes with natural and experimental F. gigantica infections. In the experimentally infected animals, antibodies were detected 2 weeks post-infection. We conclude that the ELISA will be a valuable tool for diagnosing F. hepatica infections in cattle and sheep. The assay may also be useful for diagnosing F. gigantica infections but further studies are required to establish sensitivity and specificity.

Animals↗
PubMed2005

Cellular and humoral responses in liver of cattle and buffaloes infected with a single dose of Fasciola gigantica.

The cellular components of the hepatic inflammatory infiltrate in cattle and buffaloes infected with a single dose of 1000 Fasciola gigantica were analysed by immunohistochemistry and histology. T and B lymphocytes, plasma cells, eosinophils and mast cells were present in the hepatic lesions. It is proposed that both cellular and humoral immune responses were induced in the liver of cattle and buffaloes during infection with F. gigantica probably by antigens released by the developing flukes and by damage caused by the flukes during their migration in the liver. The local T cell response differed between these animals, with the response decreasing after 3 weeks post-infection in cattle in contrast to a gradually increasing response in buffaloes. Difference in the T cell response between cattle and buffaloes may be related to their differences in resistance and resilience to infection with F. gigantica.

Animals↗
PubMed2005

Serological changes in goats experimentally infected with Fasciola gigantica in Buea sub-division of S.W.P. Cameroon.

Based on the recent increase in the rearing of West African Dwarf (WAD) goats in this environment, a study of biochemical parameters was carried out in healthy and infected goats to obtain baseline data for monitoring the health and productive indices in breeding programmes for the goats. The results revealed variations in some of the parameters studied. The serum minerals potassium, chlorine and bicarbonate did not show any significant differences (P>0.05) between the infected and control groups of goats, but there was a significant difference (P<0.0001) in sodium, calcium and urea levels. For serum lipids cholesterol and triglyceride, there were significant (P<0.0001) differences between the infected and control group. This goes same for serum proteins, albumin and total proteins. However, serum enzymes, serum glutamic oxaloacetic transaminase (SGOT) and gamma glutamyl transferase (GGT) were not significantly different (P>0.05) between the infected and control groups. There was a significant difference (P<0.0001) in alkaline phosphatase (ALP) and serum glutamic pyruvic transaminase (SGPT) between the infected and control groups.

Alanine Transaminase↗
PubMed2005

Seasonal pattern of bovine fasciolosis in the Kafue and Zambezi catchment areas of Zambia.

In order to establish seasonality of bovine fasciolosis in the Southern province of Zambia, 288 cattle were examined at slaughter at Turnpike slaughter slab for 1 year. The examination involved liver inspection and coprological examination. Liver condemnation rates were relatively high at the beginning of both the cold dry season and the rainy season (May/June and December, respectively). All cattle, regardless of age, had higher fluke abundances in the post-rainy season (39.1% young and 42.1% adult) while the lowest rates were in the hot dry season (13.3% young and 14.3% adult). On coprological examination, the highest abundance was in the post-rainy season (45.0%) and the lowest in the cold dry season (24.9%). From November (end of dry season) to February/March (end of rains), more fluke eggs were found than in any other period. The distribution of fluke eggs was significantly different (p<0.001) among the four seasons. Identified associations were: egg counts were highest in post-rainy (mean abundance=146) and lowest in cold dry season (mean abundance=118) at 95% confidence (CI 0.64-1.25). Differences in abundance observed according to origin, sex and age of cattle were not significant on both methods. Based on these results, it may be concluded that Fasciola gigantica was present throughout the year in cattle in Zambia but the abundance was highest in the post-rainy season and lowest in the cold dry season.

Age Factors↗
PubMed2005

Field trial on comparative efficacy of four fasciolicides against natural liver fluke infection in cattle.

A controlled trial was conducted to evaluate the current efficacy of albendazole (ABZ), rafoxanide (RFX), triclabendazole (TRC) or clorsulon (CLS) against Fasciola hepatica in naturally infected cattle. This trial was conducted in Turkey during the spring, the time of year when liver fluke infection is endemic. Fifty crossbred cattle were selected for inclusion in the trial based on finding eggs of F. hepatica in the feces. The cattle were weighed and randomly allotted into five groups of 10 cattle and treatments were as follows: Group 1 served as non-treated control (CONT), Group 2 was treated orally with ABZ at 12 mg/kg, Group 3 was treated orally with RFX at 10 mg/kg, Group 4 received TRC orally at 12 mg/kg and Group 5 received CLS administered subcutaneously (s.c.) at 2 mg/kg. On day 0 (inclusion day), individual fecal samples were collected on days 0 (inclusion day), 7, 14, 28 and 56, after treatment. The drug efficacy was assessed as a percentage of the egg or fluke reduction and body weight gain relative to the untreated control. The results in the study showed a mean reduction of egg counts by 66.7%, 68.2%, 78% and 84.2% in Groups 2-5, respectively. In conclusion, our results indicate that CLS is a highly effective compound for the treatment of F. hepatica in cattle under these field conditions.

Albendazole↗