Cryptosporidium parvum activates nuclear factor kappaB in biliary epithelia preventing epithelial cell apoptosis

BACKGROUND & AIMS

Our previous studies have shown that Cryptosporidium parvum induces biliary epithelial cell apoptosis in vivo and causes apoptosis in bystander uninfected biliary epithelia in vitro. We analyzed C. parvum-induced nuclear factor kappa B (NF-kappaB) activation in human biliary epithelial cells and assessed its relevance to epithelial cell apoptosis.

METHODS

In vitro models of cryptosporidial infection using a human biliary epithelial cell line were used to assay C. parvum- induced NF-kappaB activation and associated apoptosis.

RESULTS

Degradation of I(kappa)B and nuclear translocation of the NF-kappaB family of proteins (p65 and p50) were observed in the biliary epithelial cell cultures directly exposed to the parasite. Activation of NF-kappaB was found only in directly infected cells (but not in bystander uninfected cells). A time-dependent secretion of a known NF-kappaB gene product, interleukin 8, from infected cell cultures was detected. C. parvum-induced biliary epithelial cell apoptosis was limited to bystander uninfected cells. In contrast, inhibition of NF-kappaB activation resulted in apoptosis in directly infected cells and significantly enhanced C. parvum-induced apoptosis in bystander uninfected cells.

CONCLUSIONS

These observations support the concept that, while C. parvum triggers host cell apoptosis in bystander uninfected biliary epithelial cells, which may limit spread of the infection, it directly activates the NF-kappaB/I(kappa)B system in infected biliary epithelia thus protecting infected cells from death and facilitating parasite survival and propagation.

Microsporidial AIDS cholangiopathy due to Encephalitozoon intestinalis: case report and review

Microsporidia are increasingly recognized as opportunistic infections in immunodeficient patients, predominantly patients with AIDS. The two microsporidia most commonly associated with disease in AIDS patients are Enterocytozoon bieneusi and Encephalitozoon intestinalis (previously known as Septata intestinalis). The most common clinical presentation of microsporidiosis in AIDS patients is diarrhea, most commonly caused by the Enterocytozoon bieneusi species. Encephalitozoon intestinalis is a recently described species that has been reported to cause disseminated human infection including cholangitis. We report a case of AIDS cholangiopathy that presented with abdominal pain and cholestatic liver tests. Ultrasound examination and ERCP revealed a picture of sclerosing cholangitis. Bile samples obtained at ERCP were negative for microsporidia; stool studies for microsporidia and cryptosporidia were also negative. No organisms were identified on routine light microscopy of the biopsy specimens from the duodenum, ampulla, and bile duct. E. intestinalis spores were demonstrated in the bile duct biopsies, by methylene blue and azure 11 staining and confirmed by electron microscopy. Albendazole therapy was successful in eradicating E. intestinalis with clinical improvement and improvement in CD4 count. However, the cholangiographic picture did not improve and repeat cholangiography revealed progressive bile duct injury. Albendazole therapy was delayed and may have been too late to prevent bile duct damage; the drug had to be approved by the US Food and Drug Administration for compassionate use. This is an unusual case of sclerosing cholangitis caused by an unusual organism and requiring biliary sphincterotomy and stent placement for progressive stricturing despite eradication of the infection.

Detection of acetylcholinesterase activity and gamma-aminobutyric acid binding sites in Dicrocoelium dendriticum

In the present study we report the presence of acetylcholinesterase activity and gamma-aminobutyric acid binding sites in crude extracts of Dicrocoelium dendriticum. This indirectly demonstrates the presence of acetylcholine and GABA. The presence of these neurotransmitters could indicate the existence of two systems implicated in the neurotransmission of the Digenea.

Morphologic and biochemical changes caused by experimentally induced dicroceliosis in hamsters (Mesocricetus auratus)

BACKGROUND AND PURPOSE

The aim of the study reported here was to investigate the pathomorphologic changes caused by experimentally induced dicroceliosis and their correlation with hepatobiliary function.

METHODS

Studies were carried out at days 80 and 120 after oral inoculation of hamsters with 40 metacercariae of Dicrocoelium dendriticum.

RESULTS

The parasite-induced pathologic changes were assessed by presence of fluke eggs in feces, increased plasma alanine transaminase and aspartate transaminase activities and morphologic alterations. Dicroceliosis was characterized by bile ductular proliferation and enlargement of the bile duct surface area caused by hyperplastic cholangitis in septal bile ducts. The liver from infected animals contained portal tracts infiltrated with small to moderate numbers of lymphocytes, macrophages, and eosinophils. Simultaneously, there was an increase in portal tract collagen that extended to the interlobular septa and caused pressure atrophy of the hepatic parenchyma. The concentration of thiobarbituric acid-reactive substances and the ratio of oxidized to reduced glutathione, measured as markers of oxidative stress, were significantly increased.

CONCLUSIONS

The presence of oxidative alterations could be related to the morphologic evidence of chronic inflammatory response as well as to liver cellular injury indicated by cellular swelling, and increased presence of peroxisomes and lysosomes.

Mechanisms of attachment and internalization of Cryptosporidium parvum to biliary and intestinal epithelial cells

BACKGROUND & AIMS

Although infection of the intestinal and biliary tracts by Cryptosporidium parvum is a major problem in patients with the acquired immunodeficiency syndrome, the specific microbial and host molecules involved in C. parvum infection are unknown. We tested the hypothesis that lectin-carbohydrate interactions and cytoskeleton reorganization are involved in the infection of biliary and intestinal epithelia by C. parvum.

METHODS

In vitro models of cryptosporidial infection using human biliary and intestinal epithelial cell lines were used to assay C. parvum attachment and invasion.

RESULTS

Exposure of C. parvum sporozoites to the sugar, galactose-N-acetylgalactosamine (Gal/GalNAc), and to bovine mucin reduced C. parvum attachment to biliary and intestinal epithelia up to 70%. Preincubation of cell monolayers with either lectins specific to Gal/GalNAc, or glycosidases that specifically release Gal/GalNAc oligosaccharides from glycoproteins, decreased attachment up to 80%. Cytochalasin B and cytochalasin D, but not nocodazole, decreased invasion of cells by C. parvum up to 70% without affecting attachment. During cell invasion (but not attachment), confocal microscopy showed recruitment of actin (but not tubulin) in biliary and intestinal epithelia directly adjacent to C. parvum.

CONCLUSIONS

Gal/GalNAc epitopes of glycoproteins on the epithelial apical membrane and Gal/GalNAc-specific sporozoite surface lectins are involved in the mechanism(s) of C. parvum attachment to intestinal and biliary epithelial cells, and actin remodeling in host cells is required for C. parvum invasion.

Pathology of pyogenic liver abscess in children

Little is known about preexisting lesions in livers of children with pyogenic liver abscess (PLA). Study of these lesions may elucidate possible predisposing factors for the disease. In Vitória, state of Espirito Santo, Brazil, PLA in children is frequently associated with helminthic infections and eosinophilia. We hypothesize that nematode infection with larvae migrating through the liver is a predisposing factor for PLA, because the infection induces immunomodulation and likely trapping of bacteria in liver granulomas. In this report, we describe observations of 22 cases of PLA in children studied at autopsy (16 cases) or in surgical biopsies (6 cases), including 17 boys and 5 girls ranging in age from 1 to 13 years (mean 4.6 years, median 3.5 years). Multiple abscesses in both lobes were found in 13 cases and a single abscess was found in the right lobe in 10 cases. All cases showed histologically classical pyogenic inflammation without morphological evidence of amoebiasis. In six cases there were granulomas similar to those caused by larva migrans visceralis (from Toxocara or other nematodes) in liver tissue not affected by the abscess. Nematode antigens in central areas of necrosis of granuloma in all six cases and fragments of a larva, possibly of Toxocara, were found on samples immunohistochemically stained with polyclonal anti-Toxocara antibodies. There were numerous eosinophils in abscesses with Charcot-Leyden crystals. Eosinophils were found frequently in portal triads far from the abscess wall. In four cases, in which bile duct ascariasis was found, worms were noted in the bile ducts, and eggs were found in liver parenchyma surrounding the abscess in two cases. Foreign-body granulomas were found in one case in which penetrating trauma was the cause of abscess. In one case there was one histiocytic granuloma whose origin was not determined. The observation of six cases of granuloma similar to larva migrans visceralis (or produced by other nematode larva) in liver tissue not directly affected by the abscess supports the hypothesis that helminth infections with larva migrating through the liver are a predisposing factor for pyogenic hepatic abscess in children.

Cryptosporidium parvum induces apoptosis in biliary epithelia by a Fas/Fas ligand-dependent mechanism

Although the clinical features of sclerosing cholangitis from opportunistic infections of the biliary tree in patients with acquired immunodeficiency syndrome (AIDS) are well known, the mechanisms by which associated pathogens, such as Cryptosporidium parvum, cause disease are obscure. Using an in vitro model of biliary cryptosporidiosis, we observed that C. parvum induces apoptosis in cultured human biliary epithelia. Both caspase protease inhibitors and neutralizing antibodies to either Fas receptor (Fas) and Fas ligand (FasL) inhibited this process; neutralizing antibodies to other apoptotic cytokines [interleukin-1beta (IL-1beta), tumor necrosis factor-alpha (TNF-alpha), and transforming growth factor-beta (TGF-beta)] had no effect. C. parvum stimulated FasL membrane surface translocation, increased both FasL and Fas protein expression in infected biliary epithelia, and induced a marked increase of soluble FasL (but not IL-1beta, TNF-alpha, and TGF-beta) in supernatants from infected cells. When a coculture model is used in which infected and uninfected cell populations were physically separated by a semipermeable membrane, both uninfected biliary epithelia and uninfected Fas-sensitive Jurkat cells (but not a Fas-resistant Jurkat cell line) underwent apoptosis when cocultured with infected biliary epithelia. Moreover, both a neutralizing antibody to FasL and a metalloprotease inhibitor blocked the apoptosis in uninfected cocultured cells. Activation of caspase activity was also observed in uninfected cocultured biliary epithelia. The data suggest that C. parvum induces apoptosis in biliary epithelia by a Fas/FasL-dependent mechanism involving both autocrine and paracrine pathways. These observations may be relevant to both the pathogenesis and therapy of the cholangitis seen in AIDS patients with biliary cryptosporidiosis.

Primary experimental infection of riverine buffaloes with Fasciola gigantica

The clinical course of the primary experimental Fasciola gigantica infection was investigated in riverine buffalo calves of the Murrah breed. Nine male calves aged 12-15 months were randomly assigned to two groups of five (Group I) and four (Group II) animals. Each animal in Group I, was orally infected with 1000 metacercariae (mc) of F. gigantica, whereas Group II animals did not receive any infection dose and served as uninfected controls. No clinical signs of fasciolosis were observed until the sixth week post-infection (PI). Group I animals, however, developed recognised symptoms of acute fasciolosis, comprising apyrexic inappetance, anemia, poor weight gain, diarrhoea and sub-mandibular and facial oedema, respectively, from 5, 6, 8, 16 and 17 weeks PI. The signs were intermittent in nature and of variable duration. The prepatent period was of 92-97 days (mean 95.2 +/- 3.1). One of the five infected animals died on Day 147 PI. At necropsy, 36.8 +/- 11.0% of the infection dose was recovered as adult fluke population. The gross lesions were primarily biliary in nature. Group II, the uninfected controls, throughout the study period of 165 days PI, did not show any symptom and were negative for F. gigantica. The study demonstrated that the onset of adverse effects of F. gigantica on the growth and health of the infected host was mainly noted during late prepatency much before coprological prediction and diagnosis. The significance of preventive therapy against fasciolosis during prepatency has been stressed in endemic areas.

Enhanced bile formation induced by experimental dicrocoeliosis in the hamster

The purpose of this investigation was to determine the effects of experimental dicrocoeliosis on bile formation in the hamster. Studies were carried out at 120 days after infection with an oral dose of 40 metacercariae of Dicrocoelium dendriticum. A significant elevation in bile flow (+20%) and in the biliary output of glutathione (+34%), bile acid (+59%), cholesterol (+108%), phospholipids (+99%) and alkaline phosphatase (+36%) was observed in the infected animals. The bile-to-plasma [14C] mannitol ratio increased to values greater than 1 and there was a reduced contribution (-26%) of biliary tree to bile formation. Those data suggest that enhancement in choleresis had a canalicular origin. The presence of oxidative stress, evidenced by the increased oxidized/reduced glutathione ratio and TBARS concentrations, may contribute to the elevated glutathione efflux into bile. Enhancement in bile acid output was not due to qualitative or quantitative changes in bile acid metabolism, as indicated by the absence of significant modification in liver cholesterol 7alpha-hydroxylase activity and bile acid profile in bile. Increase in the ability of the canalicular membrane to export bile acids was not involved, since maximal secretion rate for exogenously administered taurocholate was decreased. When bile flow, bile acid and biliary lipid secretion was determined in colchicine-pretreated animals differences between control and infected animals were abolished, suggesting that stimulation of the transcytotic vesicle pathway plays an important role in the alteration of the biliary function caused by dicrocoeliosis.

Ultrasound diagnosis of biliary ascariasis

Two patients with right upper quadrant pain underwent real time ultrasound examination and biliary ascariasis was diagnosed. One case was confirmed by endoscopic retrograde cholangiopancreatography with removal of the parasites, and the other by intravenous cholangiography. Patients with ascariasis in the bile duct occasionally presenting with atypical right upper quadrant abdominal pain can be diagnosed accurately by real time ultrasound, which shows the movement of the worms.

Occurrence and morphological comparisons of Campula oblonga (Digenea: Campulidae), including a report from an atypical host, the thresher shark, Alopias vulpinus

New host records for Campula oblonga Cobbold, 1858 from the common dolphin, Delphinus delphis L., and from the thresher shark, Alopias vulpinus (Bonnaterre), are reported herein. Campulids have not been reported previously from a host that was not a marine mammal. The excellent condition and small size of the gravid specimen and the diet and natural history of the thresher shark lead us to conclude that the digene was acquired from the consumption of infected fish. Specimens of C. oblonga from these 2 hosts and from harbor porpoises, Phocoena phocoena (L.), and from Dall's porpoises, Phocoenoides dalli (True), are compared, and a wide variation in ranges and values for characters is noted. The synonymy of Campula folium Ozaki, 1935 with C. oblonga is further supported by the apparent effect of the host on the size of the trematodes. Due to the degree of variation in measurements and the numerous factors that may impact these values, we recommend the use of qualitative morphologic characters for the identification of C. oblonga.

A fatal Pegosomum sp. (Trematoda: Echinostomatidae) infection in a wild cattle egret (Bubulcus ibis) from Japan

An adult cattle egret (Bubulcus ibis) caught in Kobe of Hyogo Prefecture, Japan, in December 1995 died of a severe infection associated with the trematode parasite Pegosomum sp. At necropsy, 22 trematode parasites were found in the lumen of the bile duct, and the duct wall was markedly thickened. Histopathologically, severe cholangitis and cholecystitis were observed in close association with the parasites in the bile duct. Severe Pegosomum sp. infection may be one of the factors contributing to the mortality of wild cattle egrets. This is the first reported case of the genus Pegosomum infection in wild birds of Japan.

Fasciola hepatica infection in farmed emus (Dromaius novaehollandiae)

OBJECTIVE

To describe two cases of infection with Fasciola hepatica in young farmed emus, subacute and chronic fasciolosis and a response to treatment of the flock with albendazole.

PROCEDURE

Gross lesions were found at necropsy and hepatic lesions in microscopic examination. The parasite recovered from one emu was identified by its morphological characteristics and an egg count reduction test was carried out after treatment of the flock with albendazole.

RESULTS

Hepatic lesions resembling subacute and chronic fasciolosis of ruminants were identified. An adult fluke was recovered from the liver of one of the birds and was identified as F hepatica. The eggs of the fluke were irregular in shape and size. No fluke eggs were identifiable in faeces of live emus 10 days after treatment of the flock with albendazole at a dose of 10 mg/kg.

CONCLUSIONS

This is the first reported case of infection with F hepatica in farmed emus and the first report of the occurrence of Fasciola infection is the class Aves. The irregular shape and size of the eggs may be attributable to infection of an aberrant host. Treatment with albendazole eliminated eggs from the faeces of the flock.

Parasites in Italian sea turtles. I. The leatherback turtle Dermochelys coriacea (Linnaeus, 1766)

Three species of trematodes (Digenea) were collected from a leatherback turtle (Dermochelys coriacea) stranded on the coast of Lampedusa (Sicily Channel, Mediterranean Sea, Italy). One, Enodiotrema carettae, was found in the liver and two, Enodiotrema instar and Pyelosomum renicapite, in the intestine. E. carettae and E. instar are new host findings, E. carettae is a geographic novelty as well. A description of E. instar, previously reported and described by Looss (1902), is included.

Comparative evaluation of agar gel precipitation, counterimmunoelectrophoresis and passive haemagglutination tests for the diagnosis of Dicrocoelium dendriticum infection in sheep and goats

The sensitivity and specificity of the agar gel precipitation test (AGPT), counter immunoelectrophoresis (CIEP) and passive haemagglutination test (PHT) were evaluated for the diagnosis of Dicrocoelium dendriticum infection in naturally infected sheep and goats. Two hundred and forty five sheep and goat sera samples were tested using phosphate buffered saline, pH 7.2 extracted adult fluke antigen. CIEP detected 69.8% of the infected animals and was found to be the most sensitive, followed by PHT which detected 50.0% of the infected sheep and goats. AGPT was found to be the least sensitive, detecting only 23.8% of the infected animals. The specificity of

Hepatic coccidiosis associated with hepatic necrosis in a goat

Hepatic coccidiosis, usually caused by a member of the genus Eimeria, is common in rabbits but rare in other mammals. We describe the first reported case of naturally occurring hepatic coccidiosis in a goat. An approximately 6-month-old crossbred goat was presented with a history of diarrhea for 1 week and death. The liver had grossly visible, coalescing foci of necrosis measuring up to 6 cm in greatest dimension. Microscopically, areas of coagulative necrosis also had ectatic and hyperplastic bile ducts that contained coccidial meronts, macrogamonts, and microgamonts within the cytoplasm of epithelial cells. Bile duct lumina contained scattered oocysts. Fibrosis and aggregates of lymphocytes surrounded affected ducts. Microscopic and ultrastructural characteristics of coccidian stages were compatible with the genus Eimeria, but the species could not be determined. The small intestine also had coccidiosis; however, it was unclear whether or not the same coccidian species affected both the liver and the intestine.

[Fasciolinip-1: experimental fasciolicidal activity in sheep]

The aim of the present study was to evaluate the flukicide efficacy of the 2-amino-5(6)-chloro-1-methoxycarbonylbenzimidazole (II), named Fasciolinip-1, against eight and twelve-week old flukes in sheep. In a first experiment 35 young sheep were infected each with 300 metacercariae of Fasciola hepatica. Eight weeks postinfection five groups of seven animals each were treated as follows: Groups 1, 2 and 3 were given 2.5, 5 and 10 mg/kg of Fasciolinip-1. Groups 4 and 5 remained as non-treated and vehicle controls, respectively. In a second study, 32 sheep were infected each with 150 metacercariae. Twelve weeks postinfection, the animals were divided into 4 groups of 8 sheep each. Groups 1, 2 and 3 were treated orally with 5, 10 and 15 mg/kg of Fasciolinip-1, respectively. Group 4 remained as non-treated control. Fifteen days after treatment, all sheep from both experiments were killed to collect the flukes present in liver. Results indicated efficacies of 19.1%, 49.6% and 65.2% for groups 1, 2 and 3 of the first study and 48.3%, 64.8 and 90.6% for sheep of the second experiment, respectively. It was concluded that Fasciolinip-1 removed 8-week old flukes in limited numbers and 12-week old flukes in 90.6% when used at 15 mg/kg body weight.

Explanatum explanatum (Creplin, 1847) Fukui, 1929, in buffaloes in the Ahwaz area, southwest Iran

Explanatum explanatum (Creplin, 1847) Fukui 1929, was found in three indigenous buffaloes in the west Ahwaz area, southwest Iran for the first time. The presence of this amphistome in bile ducts caused remarkable fibrosis of submucosa ad hyperplasia of the endothelial layer, such that villus-like structures and protuberances were formed in large bile ducts of the infected livers.

Hepato-biliary coccidiosis in a dairy goat

Hepato-biliary coccidiosis is reported in a diary goat that died of liver failure. Two types of lesions were seen in the liver. In the biliary type, coccidial oocysts, schizonts, gametes and gametocytes were seen in the epithelium of the bile duct, the wall of which was highly fibrosed. The hepatic type was in the form of granuloma, composed of oocysts and macrophages encapsulated in a fibrous capsule. Hepatic lymph nodes were diffusely scattered with oocysts and macrophages. Liver coccidiosis was found to be unresponsive to oral sulphamethazine treatment.

Efficacy of albendazole and mebendazole against Hymenolepis microstoma and Hymenolepis diminuta

An investigation of the chemotherapeutic effects of 2 anthelmintics, albendazole (ABZ, methyl 5-[propylthio]benzimidazole-2- carbamate) and mebendazole (MBZ, methyl 5-[benzoyl]benzimidazole-2-carbamate), on Hymenolepis microstoma and Hymenolepis diminuta in experimentally infected mice and rats is reported. Single (50 mg/kg) or multiple daily oral doses (50 mg kg-1 day-1 for 3 consecutive days) of MBZ had no effect on H. microstoma; at necropsy, the drug treated mice harbored appreciable numbers of the parasite in the bile duct and biliary passages. ABZ was also inactive when given as a single oral 50 mg/kg dose on day 27 PI. Better results were obtained when ABZ was administered at a dosage of 50 mg kg-1 day-1 for 3 consecutive days; the reduction in worm burden obtained with this treatment regimen was 50%. These results are in marked contrast to those obtained with the same anthelmintics against enteral H. diminuta in rats which succumbed at lower dosages. A review was made of the published reports on the pharmacokinetic behavior of these benzimidazole carbamate anthelmintics and a hypothesis for the inactivity of MBZ against H. microstoma is proposed.

Comparative pathological study of hepatic changes induced by Fasciola gigantica and Gigantocotyle explanatum in Javanese thin-tailed sheep

Pathological changes in the liver induced by Fasciola gigantica and Gigantocotyle explanatum were readily distinguishable from each other. Lesions associated with the migration of immature flukes through the parenchyma were a prominent feature of infection with Fasciola gigantica, whereas lesions induced by Gigantocotyle explanatum were confined to the large bile ducts. The size of the hepatic lesions increased during the course of infection with Fasciola gigantica and was associated with the formation of progressively larger areas of scar tissue in the parenchymal migration tracts as the flukes grew. This was also as a result of the progressively increasing cellular infiltration, proliferation of bile ductules and fibrosis which occurred in adjacent portal triads and interlobular septa. The absence of signs of migration through the hepatic parenchyma by Gigantocotyle explanatum, was regarded as evidence that these flukes gain entry to the bile ducts from the intestine via the common bile duct. In bile ducts infected with Fasciola gigantica there was more extensive desquamation of the epithelium, more intense mucosal infiltration with lymphoid cells and fewer eosinophils, less severe glandular hyperplasia, more free blood in the lumen and a thicker duct wall than in bile ducts infected with Gigantocotyle explanatum.

Developmental stages of Cyclospora talpae in the liver and bile duct of the mole (Talpa europaea)

The completed life-cycle of Cyclospora talpae, an extra-intestinal coccidian (Apicomplexa) of the liver of the mole (Talpa europaea), is reported. Oocysts sporulated within 12-14 days at room temperature (20-22 degrees C). Both macro- and microgametocytes developed independently within the nucleus of epithelial cells lining the bile duct as demonstrated by both light and electron microscopy. Merogony was seen in the mononuclear cells in the capillary sinusoids of the liver. Merozoites showed the typical ultrastructural features of the Apicomplexa. The life-cycle of C. talpae and the ultrastructure of the gametogonic and merogonic stages are reported; the ultrastructure of the merozoites is reported as the first description of this stage for the genus Cyclospora.

Experimental biliary cryptosporidiosis in broiler chickens

Biliary cryptosporidiosis was studied by inoculation of 2 x 10(5) Cryptosporidium baileyi oocysts (AU-B1 isolate) into the gall bladders of ten 6-day-old broiler chickens. Clinical signs of disease were not seen. Three of the 10 chickens developed biliary tract infections, based on histologic examination of tissue sections. Lesions seen in the gall bladders of these birds included epithelial hyperplasia and infiltration of the underlying connective tissue with mononuclear leukocytes. One of these birds also had involvement of the hepatic bile ducts. The bile ducts were mildly dilated and contained lesions similar to those seen in the gall bladder. Few to many cryptosporidia were present in the gall bladders and bile ducts of infected birds. Chickens may be of use in the study of biliary cryptosporidiosis, a common sequel to enteric infection in humans with human immunodeficiency virus infection.

A risk-assessed evaluation of postmortem meat inspection procedures for ovine thysanosomiasis

A risk assessment model was used to evaluate 4 meat inspection procedures for routine detection of Thysanosoma actinioides, a tapeworm that commonly infests the bile duct system of adult sheep in the United States. The overall sensitivities of different procedures ranged from 11.96 to 58.70%, and the nondetection rates per 1,000 viscera sets that passed inspection ranged from 38 to 77. On the basis of performance attributes for each procedure produced by the risk assessment model, the consumer was exposed to an aesthetic defect that was in 9 to 17 of every 1,000 livers passed for human consumption. The amount of wastage was also identified (3 to 39 livers/1,000 passed). Viewing of the incision site of the common hepatic duct was the most preferable routine inspection procedure, and matched pair analysis revealed that there was no additional benefit in combining this procedure with routine expression of a portion of bile from the gallbladder.

Artificial infection by transplantation of juvenile Fasciola worms into the abdominal cavity of rats

Rats were successfully infected with Japanese Fasciola sp. by transplantation of juvenile worms (JW) or metacercariae (MC) into the abdominal cavity. Moreover, the rat was investigated on its suitability for different experiments with liver flukes. JWs or MCs transplanted intraperitoneally (IP) matured in the bile duct of rats. Moreover, more stable infections were established by inoculation of JWs than MCs. About 3 of 10-15 JWs transplanted into the abdominal cavity of a rat matured and laid eggs in the bile duct. The mean prepatent period was 63.5 days in the JW inoculated group. EPG values were kept constant at a level of 10(2)-10(3) about 100 to 230 days after the transplantation of JWs. The life span of Japanese liver flukes was estimated to be about 400 days in rats. From these results, it was concluded that the rat is suitable for various experiments with Fasciola sp.

Mast cell responses to Hymenolepis microstoma infection in mice

Murine mast cells (MC) responded strongly to Hymenolepis microstoma infection. Starting day 7 postinfection (PI) and continuing until the end of the experiment (35 days PI), significantly larger numbers of MC were present in both the duodenum and bile duct of infected mice than in uninfected controls. In animals challenged with 5 cysticercoids 2 wk after primary infection, the MC response in the duodenum, but not in the bile duct, was of even greater degree than in naive hosts. The majority of MC in the duodenum of infected and challenged mice were intraepithelial mucosal MC, whereas in the bile duct the majority were connective tissue MC. Hypertrophy of the duodenal submucosa and of the bile duct wall was noticeable in all infected and challenged hosts. Worms in primary infections were not affected by the host response, but none of the worms in the challenge dose became established. It is postulated that the type of MC involved in specific immune response of the host is the intraepithelial MC, whereas the cell type participating in general inflammatory events is the connective tissue MC.

Sonographic appearances in biliary ascariasis

Biliary ascariasis is as frequent a cause of adult biliary disease as gallstones in Kashmir Valley, India. In the present study, we prospectively evaluated the role of sonography in the diagnosis of biliary ascariasis and its utility in monitoring the exit of worms from the bile duct. Sonography was performed on 28 patients with biliary ascariasis proven by endoscopic retrograde cholangiopancreatography. The bile ducts were dilated on sonography in 26 patients. The characteristic sonographic features of worms in the bile duct were as follows: (a) a single, long, linear or curved echogenic structure without acoustic shadowing (2 patients); (b) multiple, long, linear, parallel echogenic strips, usually without acoustic shadowing (15 patients); (c) a thick, long, linear or curved, nonshadowing echogenic strip containing a central, longitudinal anechoic tube, probably representing the digestive tract of the worm (7 patients); and (d) characteristic movement of these long echogenic structures within the bile duct (8 patients). One patient with pancreatic ascariasis exhibited long, linear, nonshadowing echogenic strips in a dilated pancreatic duct. Other sonographic changes observed in these patients were (a) gallbladder distention (10 patients), edema of the gallbladder wall (8 patients), sludge within the gallbladder (11 patients), a coiled echogenic structure within the gallbladder (1 patient); (b) multiple liver abscesses (1 patient); and (c) edematous pancreatitis (4 patients). Sonography detected worms in the biliary tree in 24 of 28 patients (85.7%). Serial sonograms accurately demonstrated the spontaneous exit of worms in 18 patients and the persistence of worms in 3 patients. Sonography is a simple, rapid, and noninvasive method for diagnosis and follow-up of patients with biliary ascariasis.

[Oschmarinella mascomai sp. n. (Trematoda : Campulidae), a parasite of the bile ducts of Stenella coeruleoalba (Meyen, 1833) (Cetacea : Delphinidae) in the Mediterranean Sea]

Description of Oschmarinella mascomai n. sp. (Trematoda : Campulidae) a bile duct parasite of the striped dolphin, Stenella coeruleoalba (Meyen, 1833) (Cetacea : Delphinidae), from the Mediterranean Sea. Differential characters from the other species of this genus is described.

Cholangiocarcinoma associated with liver fluke infection: a preventable source of morbidity in Asian immigrants

In the Far East infection with the liver flukes Clonorchis sinensis and Opisthorchis viverrini is the most frequently documented cause of cholangiocarcinoma. Liver fluke infection in the United States remains a health problem for more than 500,000 Southeast Asian refugees who have immigrated to this country since 1975. Recent surveys have revealed that up to 26% of Asian immigrants have an active liver fluke infection. However, the common clinical manifestations of this condition, as well as the possibility of developing such long-term sequelae as cholangiocarcinoma, remain unknown to many physicians providing care for this population. This report describes a clinically unsuspected C. sinensis infection associated with cholangiocarcinoma in an elderly Chinese immigrant, and emphasizes the importance of early diagnosis and treatment of all liver fluke infections in the prevention of bile duct neoplasms in high risk populations.

Parasites of the Dall's porpoise (Phocoenoides dalli True)

The prevalences of three helminths, Campula oblonga, Halocercus dalli and Crassicauda sp., recovered from Dall's porpoises which were net-entrapped incidentally in the vicinity of the Western Aleutian Islands in the northwest Pacific are reported. Specimens of Campula oblonga were found within the bile ducts of 46% of 127 livers examined. The prevalence of hepatic trematodiasis increased with the age of the host. Pulmonary nodules associated with Halocercus dalli were noted in 71% of the Dall's porpoises. Adult H. dalli were recovered from the main stem bronchi of heavily infected lungs. Younger animals exhibited a relatively higher prevalence. Specimens of Crassicauda sp. were found within the main lactiferous canal of 69% of 29 mammary glands examined. The prevalence was highest in mature porpoises. Possible detrimental effects and the modes of transmission of the three species of parasites are also considered.

Worm recovery, haemagglutinating antibodies and IgE-levels after immunisation against Fasciola hepatica in rats

Female inbred Hooded Lister (HL) rats were each infected with 20 metacercariae (Mc) of Fasciola hepatica. Remarkable variations between the number of flukes established in the bile ducts suggest the presence of individual, perhaps genetically controlled, differences in immune responsiveness of HL rats to F. hepatica. Serum (4 ml) from HL rats infected with 20 Mc 6 weeks prior to transfer partially protected rats against a F. hepatica challenge infection. However, 1 X 10(6) lymphoid cells originating from rats of the same age and stage of infection did not show the same protective qualities. Furthermore, attempts to immunise HL rats i.p. with either juvenile or adult excretory/secretory (ES) products, or somatic tissue antigens and AlOH3-gel as adjuvant failed. When compared to other investigations, the present results further suggest that both the adjuvant and the route of administration are crucial for the stimulation of a protective immunity to F. hepatica. Low titers and low anamnestic responses of haemagglutinating antibodies after prior immunisation with juvenile ES antigens or both juvenile ES and somatic tissue antigen suggest the occurrence of an immunosuppressive effect caused by juvenile ES products. The total serum IgE-levels in immunised groups were generally lower when compared to the challenge control group, whereas the F. hepatica ES-specific IgE-levels rose after challenge, but immediately decreased again when compared to challenge controls. These findings support the hypothesis of an immunomodulatory effect caused by the vaccination scheme.

Opisthorchis viverrini infection: pathogenesis and clinical features

The pathological changes are more or less related to the intensity and the duration of the infection, and are commonly seen in older patients with a large number of flukes. The pathogenesis is due to the mechanical irritation by the flukes and some toxic substances produced by them. Lesions are mainly confined to the biliary system. There is hyperplasia of the epithelial cells lining the bile ducts. In heavy and severe infections there are obstruction of the biliary tract, bile retention, extensive hyperplasia of the biliary system, with glandular proliferation of papillomatous and adenomatous type, cholangitis, periductal infiltration with eosinophils, round cells and fibrosis in the portal areas, necrosis and atrophy of hepatic cells. The bile ducts are dilated and in late cases saccular or cystic formations may develop into large cysts. The gallbladder may enlarge and contain white bile. The liver profile is generally normal. The majority of cases are symptomless. Clinical features vary from mild to severe. The symptoms and signs are vague gastro-intestinal symptoms, flatulence, anorexia, lassitude, weight loss, dull pain at the right hypochondrium, hot cutaneous sensation of the abdomen, and enlargement of the liver with some tenderness. In few cases the manifestations are severe. There is relapsing cholangitis, the patient is seriously ill and may succumb to septic shock. Cholangiocarcinoma, gallstones and obstructive jaundice are not unusual associations.

Protection against Fasciola hepatica in rats with adult fluke antigen in Freund's adjuvant: influence of antigen batch, antigen dose and number of sensitising injections

Protection of rats against Fasciola hepatica infection induced by intraperitoneal injection of adult fluke antigen in Freund's adjuvant was dependent on the batch of antigen. Relatively modest protection of 41 per cent and 55 per cent provided by some batches at one dose could be improved to 65 to 84 per cent and 86 per cent respectively by increasing the amount of antigen used for sensitisation. Protection was found to require at least two sensitising injections. Subcutaneous sensitisation with adult fluke antigen in Freund's adjuvant did not protect, whereas when this was given in conjunction with intraperitoneal injections of saline in Freund's adjuvant protection was achieved.

Evolution of fascioliasis after eating wild watercress

Fascioliasis is rarely reported in humans although it is endemic in sheep and cattle. We describe the illness of a 60-year-old widow who ate wild watercress which is the usual source of infestation. Laparotomy for suspected liver abscesses revealed necrotic tracts on the surface of the liver left by the invasion of numerous flukes. Diagnosis was made during the latent phase by the detection of serum antibody to fasciola hepatica antigen obtained from a sheep. Symptoms returned during the cholestatic phase. Mature flukes were then present in the large bile ducts and ova appeared in the stools. Symptoms resolved twelve weeks after presentation.

Proline biosynthesis by Fasciola hepatica at different developmental stages in vivo and vitro

The ability of Fasciola hepatica to produce proline was assessed by measuring activity of the proline biosynthesis enzyme ornithine-delta-transaminase, and the arginine-dependent production of proline in vitro. This was related to the changes in bile proline of rats during the course of infection. It was found that the total production of proline and total enzyme activity per fluke increased as the fluke increased in size. However, while the specific enzyme activity remained constant throughout development, there was a preferential increase in proline production relative to protein content of the flukes just prior to their migration into the bile ducts. This early amplification of proline production could provide the stimulus to induce hyperplasia in the bile duct in preparation for fluke entry as proline production relative to protein content of fluke dropped markedly after migration into the bile ducts and never again reached the pre-migration level.

The anoplocephalid cestode parasites of the spectacled hare-wallaby Lagorchestes conspicillatus Gould, 1842 (Marsupialia: Macropodidae)

Progamotaenia gynandrolinearis sp. nov. is described from the small intestine of Lagorchestes conspicillatus Gould, 1842 from Barrow I., Western Australia. It is distinguished from other species by the small number of testes arranged in a single transverse row. Progamotaenia lagorchestis (Lewis, 1914) is redescribed. The name Progamotaenia thylogale sp. nov. is proposed for a second species described previously under the name P. lagorchestis. Progamotaenia zschokkei (Janicki, 1905), Progamotaenia festiva (Rudolphi, 1819) and Progamotaenia villosa (Lewis, 1914) were also found in L. conspicillatus.