Expression and characterization of glutathione peroxidase of the liver fluke, Fasciola gigantica.

Glutathione peroxidase (GPx) is a key member of the family of antioxidant enzymes in trematode parasites including Fasciola spp. Because of its abundance and central role as an anti-oxidant that helps to protect parasites from damage by free radicals released from the host immune cells, it has both diagnostic as well as vaccine potential against fasciolosis. In this study, we have cloned, characterized, and detected the expression of the GPx protein in Fasciola gigantica (Fg). FgGPx (582 bp) was cloned by polymerase chain reaction (PCR) from complementary DNA (cDNA) from an adult fluke. Its putative peptide has no signal sequence and is composed of 168 amino acids, with a molecular weight of 19.1 kDa, and conserved sequences at NVACKUG, FPCNQFGGQ, and WNF. Phylogenetic analysis showed that GPx is present from protozoa to mammals and FgGPx was closely related to Fasciola hepatica GPx. A recombinant FgGPx (rFgGPx) was expressed in Escherichia coli BL21 (DE3) and used for immunizing mice to obtain polyclonal antibodies (anti-rFgGPx) for immunoblotting and immunolocalization. In immunoblotting analysis, the FgGPx was expressed in all stages of F. gigantica (eggs, metacercariae, newly excysted juveniles (NEJ), 4-week-old juveniles, and adults). This mouse anti-rFgGPx reacted with the native FgGPx at a molecular weight of 19.1 kDa in adult whole body (WB) and tegumental antigens (TA) as detected by immunoblotting. The FgGPx protein was expressed at a high level in the tegument, vitelline glands, and eggs of the parasite. Anti-rFgGPx exhibited no cross-reactivity with the other parasite antigens, including Eurytrema pancreaticum, Cotylophoron cotylophorum, Fischoederius cobboldi, Gastrothylax crumenifer, Paramphistomum cervi, and Setaria labiato papillosa. The possibility of using rFgGPx for immunodiagnosis and/or as a vaccine for fasciolosis in animals of economic importance will be explored in the future.

Fungus-benzimidazole interactions: a prerequisite to deploying egg-parasitic fungi Paecilomyces lilacinus and Verticillium chlamydosporium as biocontrol agents against fascioliasis and amphistomiasis in ruminant livestock.

In vitro trials investigating the effects of albendazole and triclabendazole anthelmintics on the growth profiles of the egg-parasitic fungi Paecilomyces lilacinus and Verticillium chlamydosporium were undertaken. In addition, in vivo trials were conducted in goats fed on millet grain cultures of each fungus and administered albendazole and triclabendazole anthelmintics. In vitro growth revealed V. chlamydosporium to be more sensitive to albendazole compared to P. lilacinus. In contrast, triclabendazole had the least inhibitory effect on in vitro growth of both P. lilacinus and V. chlamydosporium. Similar to albendazole, growth of P. lilacinus was more vigorous at 0.5 ppm concentration of triclabendazole. Efforts to re-isolate these egg-parasitic fungi from faeces of goats fed on fungal millet grain cultures before and following single intraruminal administration of albendazole and triclabendazole showed that P. lilacinus was not able to be re-isolated from the faeces at any sampling period. In contrast, V. chlamydosporium was able to be re-isolated from the faeces at all of the sampling periods except for the samples taken at 8-18 h and 18-24 h after administration of albendazole and triclabendazole, respectively. Lack of fungal activity at these times coincided with peak plasma availability of anthelmintics and suggests faecal levels of drugs were also high at these times and impacted negatively on fungal viability.

The silencing of cysteine proteases in Fasciola hepatica newly excysted juveniles using RNA interference reduces gut penetration.

Probing protein function in parasitic flatworms is hampered by the difficulties associated with the development of transgenic approaches. Although RNA interference (RNAi) in schistosomes shows much promise, it has not been reported in other trematodes. Here, we show the successful silencing of the cysteine proteases cathepsin B and L in the infective stage of Fasciola hepatica newly excysted juveniles (NEJs). Silencing resulted in marked reductions in target transcript levels and significant diminution in the encoded proteins in the gut. RNAi of either enzyme in NEJs induced transient, abnormal locomotory phenotypes, and significantly reduced penetration of the rat intestinal wall.

Liver Fluke-Associated Biliary Tract Cancer.

Cholangiocarcinoma (CCA) is an aggressive cancer arising from epithelial cells of the bile duct. Most patients with CCA have an unresectable tumor at the time of diagnosis. In Western countries, the risk of CCA increases in patients with primary sclerosing cholangitis, whereas liver fluke infection appears to be the major risk factor for CCA in Asian countries. A diagnosis of liver fluke infection often relies on stool samples, including microscopic examination, polymerase chain reaction-based assays, and fluke antigen detection. Tests of serum, saliva and urine samples are also potentially diagnostic. The presence of liver fluke along with exogenous carcinogens magnifies the risk of CCA in people living in endemic areas. The "liver fluke-cholangiocarcinoma" carcinogenesis pathways consist of mechanical damage to the bile duct epithelium, immunopathologic and cellular reactions to the liver fluke's antigens and excretory/secretory products, liver fluke-induced changes in the biliary tract microbiome and the effects of repeated treatment for liver fluke. A vaccine and novel biomarkers are needed for the primary and secondary prevention of CCA in endemic areas. Importantly, climate change exerts an effect on vector-borne parasitic diseases, and awareness of liver fluke should be enhanced in potentially migrated habitat areas.

Hepatic fascioliasis presenting with bile duct obstruction: a case report.

Fascioliasis is a zoonotic infection caused by a liver trematode: fasciola hepatica; which commonly affects cattle and sheep, humans are accidental hosts. Several cases have been reported in the literature worldwide with a large geographical distribution. We present a case of bile duct obstruction due to a hepatic fascioliasis, successfully treated with both a combined surgical and medical approaches. A high index of suspicion should be kept in mind for all cases of obstructive jaundice, especially in areas in which human fascioliasis infection is repeatedly reported.

Human and livestock trematode infections in a mobile pastoralist setting at Lake Chad: added value of a One Health approach beyond zoonotic diseases research.

Background: At Lake Chad in Central Africa, mobile pastoralists face economic losses due to livestock trematodiases. Fasciola gigantica and Schistosoma bovis-trematodes that affect livestock-share transmission ecology traits with Schistosoma haematobium and S. mansoni that cause human schistosomiasis. This project aimed at assessing treatment strategies and elucidating the predictive potential of human and livestock trematode infections. Methods: Schistosomiasis and fascioliasis were investigated concurrently in humans and cattle by repeated cross-sectional surveys. Urine and stool samples from humans and faecal samples from cattle were examined for trematode eggs. Treatment strategies were assessed by means of focus group discussions and in-depth interviews. Results: Mobile pastoralists of four ethnic groups participated. Prevalence of human schistosomiasis and livestock trematodiases showed considerable heterogeneity from one ethnic group to another, but correlated within ethnic groups. Effective trematocidal drugs were not available in the study area. Conclusions: Mutual predictive potential of human schistosomiasis and livestock fascioliasis relates to distinct livestock husbandry practices. Introducing efficacious strategic treatment against human schistosomiasis and livestock fascioliasis might improve human and animal health and well-being. Our research provides evidence for the benefits of a One Health approach targeting diseases that share specific ecological traits.

Hepatic fascioliasis due to Fasciola hepatica: a two-case report.

Two cases of hepatic fascioliasis due to Fasciola hepatica were retrieved from our surgical-pathology file since the hospital's foundation in 1969 up to 2005. The diagnosis of hepatic fascioliasis was based on detection of one live fluke in a large cystic lesion in the lobectomized liver specimen in one case and of deposited eggs in the large liver specimen obtained from open biopsy in the other Hepatic fascioliasis is rather rare and almost worldwide in distribution including Thailand. The diagnosis should be considered in the patient from endemic areas consisting of the northern, northeastern and upper-central regions of the country, with a history of ingesting fresh water plants or drinking untreated water and having fever right-upper-quadrant pain or intrahepatic cystic lesion(s) together with absolute peripheral blood eosinophilia.

Fascioliasis in developed countries: a review of classic and aberrant forms of the disease.

Cases of human infestation by Fasciola hepatica are not uncommon in Spain and other European countries. We report our experience with 20 patients diagnosed from 1982 to 1991 and present a critical review of published cases from western countries. Because F. hepatica has a special tropism for the liver, abdominal pain, hepatomegaly, and constitutional symptoms are among the most common manifestations of acute-stage fascioliasis. However, in the chronic stage, biliary colic and cholangitis are the predominant manifestations. The clinical spectrum of fascioliasis is variable, and patients may present with extrahepatic abnormalities, such as pulmonary infiltrates, pleuropericarditis, meningitis, or lymphadenopathy. Therefore, a high index of suspicion is required to establish a correct diagnosis. Eosinophilia is the most frequent laboratory abnormality. The CT scan has become a useful technique in the diagnostic work-up. A definitive diagnosis may be established by the observation of parasite ova in the feces, but most cases may be diagnosed by serologic methods. Triclabendazole and bithionol are the most effective drugs against F. hepatica. The efficacy of praziquantel is controversial.

Parasitic causes of pancreatic and biliary tract disease: a growing concern in a highly mobile population.

A leading cause of biliary tract disease and pancreatitis worldwide is parasitic disease. In the United States, increased global travel and the AIDS epidemic has led to a rise in the frequency of parasitic disease. Biliary disease and pancreatic disease secondary to parasitic infestation is relatively new in this country, with the first case being described in 1977. These diseases are no longer the exclusive realm of infectious disease specialists and require general practitioners and gastroenterologists to be well versed in the spectrum of parasitic pancreatic and biliary disease.

[Fasciola hepatica. study of a series of 37 patients]. / Fasciolasis hepatobiliar. Estudio de una serie de 37 pacientes.

BACKGROUND: To analyze the clinical, bacteriologic, diagnostic and therapeutic features of patients with Fasciola hepatica (FH) in our hospital. PATIENTS AND METHOD: We reviewed all the patients with a diagnosis of fascioliasis from 1975 to 1999 in the Aranzazu Hospital in San Sebastián (Guipúzcoa, Spain). Diagnosis was made by direct vision of adult parasites during surgery and/or the presence of ova in stool examinations and/or positive serologic tests in patients with symptoms consistent with parasitosis. RESULTS: Thirty-seven patients were included (23 men and 14 women), aged 19 to 71 years. Ingestion of watercress was confirmed in 27. Seven cases occurred as part of familiar outbreaks. Thirty-two were in the liver invasive stage and in 5 the biliary tree was invaded. The most common features were eosinophilia (91.8%), malaise and weight loss (75.6%), elevated alkaline phosphatase (74.2%), and abdominal pain (72.9%). Adult worms in the biliary ducts were observed in 3 patients and ova in feces were observed in 6. In 13 of 27 patients indirect hemagglutination test was ( 1/1,280. Data significant to confirmation of liver involvement were provided by laparoscopy in 12 of 13 patients and by imaging techniques in 13 of 31 patients. Four patients had cholelithiasis and of these, 2 also showed adult parasites in the common bile duct. Three patients underwent surgery. Therapy with dehydroemetine and/or bithionol was followed by complete remission in 30 patients, although 6 required repeat treatment cycles. The remaining 4 patients were cured by praziquantel. CONCLUSIONS: Most of the patients in these series reported consumption of watercress and all patients showed the symptoms typical of parasite disease. Imaging techniques proved to be of great utility in confirming the diagnosis of hepato-biliary disease. In most of the patients therapy with dehydroemetine and/or bithionol (in one or several cycles) was followed by complete remission.

Endoscopic extraction of living fasciola hepatica: case report and literature review.

Fasciola hepatica infestation is known to cause bile duct inflammation and biliary obstruction. Endoscopic retrograde cholangiopancreatography shows distinct features in some patients with fascioliasis, but the condition may be overlooked in chronic cases. The endoscopic retrograde cholangiopancreatograpy images must be carefully examined to rule out other possible causes of irregularity and thickening of the common bile duct wall. Parasite removal during endoscopic retrograde cholangiopancreatograpy is one therapeutic option in patients with acute obstructive cholangitis due to F. hepatica. We present a case of fascioliasis-induced acute cholangitis that was diagnosed and treated via endoscopy. A review of the literature on extraction of living parasites is also included.

[Fascioliasis: diagnosis, epidemiology and treatment]. / Fascioliasis. Diagnóstico, epidemiología y tratamientos.

Fascioliasis is a trematode, disease of liver and bile ducts of sheep, cattle, and other ruminants throughout the world that is caused by the fluke, Fasciola hepatica. Human infection has been reported in Mexico, Cuba, Puerto Rico, Chile, Peru, Uruguay, Brazil, Argentina, the US, Europe, eastern Africa, Japan and Australia. The parasite's miracidium invades one of the various Lymnaea water snail hosts. Infection results from ingestion of encysted metacercariae attached to raw watercress (Nasturtium officinale). Symptoms recorded from human cases included irregular fever, epigastric pain and abdominal tenderness, obstructive jaundice and leucocytosis with eosinophilea up to 60%. Specific diagnosis is based on recovery of the eggs in the patient's stool or from biliary tract drainage. Treatment is with emetine hydrochloride given intramusculary. Bithionol is given orally at a dosage of 30-50 mg/kg but on alternate days from 10 to 15 doses. Praziquantel is probably effective. Preventive measures include education of the public on mode of transmission of life cycle of the parasite, and dipping fresh watercress into boiling water for a few sec, or drying suspected watercress.

Biliary colic with dilated common bile duct: simple "sheepish" problem?

A 40-year-old man, resident of a rural area of Rajasthan state of India presented with recurrent biliary colic and fever since last 2 years. Examination was normal and investigations revealed a dilated common bile duct with elevated alkaline phosphatase. Magnetic resonance cholangiopancreatography revealed a dilated biliary system without any evident cause. Patient was subjected to endoscopic retrograde cholangioancreatography and it demonstrated biliary dilatation with a linear filling defect in lower common bile duct, further sphinicterotomy was done and a live Fasciola hepatica was extracted using a biliary basket.

Direct and indirect affection of the central nervous system by Fasciola infection.

Fascioliasis is a worldwide, zoonotic disease caused by the liver trematodes Fasciola hepatica and Fasciola gigantica. Neurological fascioliasis has been widely reported in all continents, affecting both sexes and all ages. Two types of records related to two physiopathogenic mechanisms may be distinguished: cases in which the neurological symptoms are due to direct effects of a migrating juvenile present in the brain or neighboring organ and with cerebral lesions suggesting migration through the brain; and cases with neurological symptoms due to indirect immuno-allergic and toxic effects at distance from flukes in the liver. Neurological manifestations include minor symptoms, mainly cephalalgias, and major symptoms which are nonspecific, extremely diverse, varying from one patient to another and even within the same patient, and comprising meningeal manifestations and impressive neurological manifestations. The puzzling neurological polymorphism leads to confusion with cerebral tumors, multiple sclerosis, lesions of the brainstem, or cerebro-meningeal hemorrhages. Only blood eosinophilia and information on infection source guide toward correct diagnosis by appropriate coprological and/or serological techniques. Although neurological patients usually recover after fasciolicide treatment or surgical worm extraction, sequelae, which are sometimes important, remain in several patients. The need to include possible neurological complications within the general frame of fascioliasis becomes evident.

Biliary fascioliasis--an uncommon cause of recurrent biliary colics: report of a case and brief review.

Biliary parasitosis is one of the important causes of biliary obstruction in endemic areas, however due to migration and travel the disease is known to occur in non endemic zones as well. The spectrum of biliary fascioliasis ranges from recurrent biliary colics to acute cholangitis. The long term complications are gall stones, sclerosing cholangitis and biliary cirrhosis. We describe fascioliasis as a cause of recurrent biliary colics in a young male necessitating multiple hospitalizations over a period of four years. Investigative profile had been non-contributory every time he was hospitalized for his abdominal pain prior to the current presentation. He never had cholangitis due to the worm in the common bile duct. It was only at endoscopic retrograde cholangiopancreatography (ERCP) biliary fascioliasis was discovered to be the cause of his recurrent biliary colics. After removal of the live Fasciola hepatica from the common bile duct he became symptom free and is attending our clinic for last 11 months now. Clinical spectrum of biliary fascioliasis is discussed in this report.