Mortalities and wasting in Indonesian sheep associated with the trematode Eurytrema pancreaticum

Dicrocoeliidae Family: Major Species Causing Veterinary Diseases

This chapter analyses the taxonomic position of the Dicrocoeliidae family and several of its genera and species. The chapter reviews the biology of major veterinary disease-causing species, including Dicrocoelium dendriticum, Dicrocoelium hospes, Dicrocoelium chinensis, Eurytrema pancreaticum and Platynosomum fastosum. All these species have indirect life cycles with two intermediate hosts: molluscs as the first host and ants, grasshoppers and lizards as the second host. Dicrocoelium dendriticum is a widespread liver fluke found in ruminants across Europe, Asia, North Africa and North America. It can also infect humans. Dicrocoelium hospes is widely distributed in the savanna areas of Africa south of the Sahara, while D. chinensis is mainly found in ruminants in East Asia and some European countries (probably imported from Asia). Eurytrema pancreaticum is a common parasite that lives in the bile ducts, gall bladder, pancreatic ducts and intestines of ruminants. It is found in Europe, Madagascar, Asia and South America. Adults of P. fastosum live in the liver, gall bladder and pancreas of birds and mammals in Europe, Africa, Asia, North, Central and South America. Information on the epidemiology, pathology, clinical aspects, diagnosis, treatment, control, prevention and economic impact of Dicrocoeliosis caused by D. dendriticum, Eurytrematodosis and Platynosomiosis have been included.

Morphological and molecular characterization of Eurytrema spp. Looss, 1907 detected in domestic water buffaloes and cattle in northern Vietnam

Eurytrema spp. are pancreatic flukes belonging to the Dicrocoeliidae family. They are the cause of neglected diseases in Vietnam and are responsible for economic losses in ruminant production, particularly in water buffaloes and cattle. Eurytrema spp. have been widely reported in several Asian countries. Recently, morphological and molecular analyses to discriminate Eurytrema spp. have been conducted in Brazil, China, Bangladesh, Nepal, and Indonesia; however, similar analyses have not been performed in Vietnam. In the present study, we identified Eurytrema flukes collected from water buffaloes and cattle in northern Vietnam based on their morphology. Morphometric analyses were conducted on 15 samples each of Eurytrema cladorchis and Eurytrema coelomaticum. Representative samples from both species were selected for molecular analyses, and the nucleotide sequences of the 18S ribosomal RNA (18S rRNA) gene and internal transcribed spacer 2 (ITS2) were determined. Phylogenetic analyses based on 18S rRNA sequences revealed that E. cladorchis from Vietnam belongs to the same clade as that from Bangladesh. Similarly, E. coelomaticum isolates from Vietnam and China belonged to the same clade. Both clades were isolated from E. pancreaticum. This is the first study to describe the coexistence of E. cladorchis and E. coelomaticum in Vietnam and the first report of the ITS2 nucleotide sequence for E. coelomaticum, which can be used for molecular species discrimination.

Pancreatic eurytrematosis in small ruminants: A forgotten disease or an untold history?

Trematodiosis are among the most neglected parasitic diseases worldwide. The pancreatic eurytrematosis (PE) is a chronic parasitic infection mostly reported in cattle but has been unnoticed in small ruminants for many decades. Our review showed PE has been recorded as scattered regional reports in goats and sheep, mainly in Asia and Eastern Europe. Eurytrema coelomaticum, Eurytrema cladorchis, and Eurytrema pancreaticum have been the main pathogenic species infecting pancreatic ducts of small ruminants. Climatic, environmental, and regional conditions in both hemispheres may support the survival and feasibility of intermediate hosts and parasitic forms, enabling the emergence and spread of PE in small ruminants. As a primarily asymptomatic condition, PE in goats and sheep flocks may also have a high prevalence, causing severe parasitic pancreatitis, production losses, and death. There is little information on anthelmintic therapeutics for PE in small ruminants, and most used anti-fluke drugs are ineffective. PE is likely more unnoticed than a neglected trematodiosis in goats and sheep, or both from a global perspective.

Eurytrema coelomaticum natural infection in small ruminants: a neglected condition

Pancreatic eurytrematosis (PE) is an under diagnosed and neglected parasitosis in goats and sheep in the Americas. Clinical and pathological features of PE are not well defined in small ruminants worldwide. Natural cases of PE in small ruminants were detected in the Federal District, Brazil. A survey of necropsy records, including epidemiological and clinicopathological data, in goats and sheep was conducted. Most cases of PE occurred during the rainy season in adult females, with an incidence of 12.9% in goats and 0.8% in sheep. Clinical signs varied from asymptomatic infections to anorexia, lethargy, weakness, marked weight loss and death in some goats. Overall, most cases of PE in goats and sheep were incidental necropsy findings with minor pancreatic lesions. Three goats, however, showed severe chronic pancreatitis, dilation of major pancreatic ducts with numerous trematodes present and marked abdominal fat necrosis. Morphological and molecular characterization of flukes detected Eurytrema coelomaticum. Our findings shed light on the prevalence of E. coelomaticum infections in small ruminants in the region and highlight the possibility of severe and lethal cases in goats. PE must be further investigated in small ruminant populations in relevant livestock production regions of the Americas.

Dicrocoeliidae Family: Major Species Causing Veterinary Diseases

This chapter analyses the taxonomic position of Dicrocoeliidae family and several of its genus and species. The biology of the major species causing veterinary diseases such Dicrocoelium dendriticum, Dicrocoelium hospes, Dicrocoelium chinensis, Eurytrema pancreaticum and Platynosomum fastosum, has been reviewed. All these species have an indirect life cycle, involving two intermediate hosts (molluscs as first and ants, grasshoppers and lizards as second). Dicrocoelium dendriticum is a very widespread hepatic trematode in the ruminants of many countries in Europe, Asia, North Africa and North America, even affecting humans. Dicrocoelium hospes is widely distributed in the savanna areas of Africa south of the Sahara, whilst D. chinensis has mainly been found in ruminants in East Asia and some European countries (probably imported from Asia). Eurytrema pancreaticum is a common parasite whose adults live in ruminant bile ducts, gall bladder, pancreatic ducts and intestines in Europe, Madagascar, Asia and South America. Adult P. fastosum live in the liver, gall bladder and pancreas of birds and mammals in Europe, Africa, Asia, North, Central and South America. Information about the epidemiology, pathology, clinical aspect, diagnosis, treatment, control, prevention and economic impact mainly of Dicrocoeliosis produced by D. dendriticum, as well as of Eurytrematodosis and Platynosomiosis, has been included.

Characterization of the complete nuclear ribosomal DNA sequences of Eurytrema pancreaticum

Eurytrema pancreaticum is one of the most common trematodes of cattle and sheep, and also infects humans occasionally, causing great economic losses and medical costs. In this study, the sequences of the complete nuclear ribosomal DNA (rDNA) repeat units of five E. pancreaticum individuals were determined for the first time. They were 8306–8310 bp in length, including the small subunit (18S) rDNA, internal transcribed spacer 1 (ITS1), 5.8S rDNA, internal transcribed spacer 2 (ITS2), large subunit (28S) rDNA and intergenic spacer (IGS). There were no length variations in any of the investigated 18S (1996 bp), ITS1 (1103 bp), 5.8S (160 bp), ITS2 (231 bp) or 28S (3669 bp) rDNA sequences, whereas the IGS rDNA sequences of E. pancreaticum had a 4-bp length variation, ranging from 1147 to 1151 bp. The intraspecific variations within E. pancreaticum were 0–0.2% for 18S rDNA, 0–0.5% for ITS1, 0% for 5.8S rDNA and ITS2, 0–0.2% for 28S rDNA and 2.9–20.2% for IGS. There were nine types of repeat sequences in ITS1, two types in 28S rDNA, but none in IGS. A phylogenetic analysis based on the 18S rDNA sequences classified E. pancreaticum in the family Dicrocoeliidae of Plagiorchiata, closely related to the suborder Opisthorchiata. These results provide useful information for the further study of Dicrocoeliidae trematodes.

Identification and characterization of microRNAs in the pancreatic fluke Eurytrema pancreaticum

Background

Eurytrema pancreaticum is one of the most common flukes, which mainly infects ruminants globally and infects human beings accidentally; causing eurytremiasis that has high veterinary and economic importance. MicroRNAs (miRNAs) are small non-coding RNAs and are now considered as a key mechanism of gene regulation at the post-transcription level.

Methods

We investigated the global miRNA expression profile of E. pancreaticum adults using next-generation sequencing technology combined with real-time quantitative PCR.

Results

By using the genome of the closely-related species Schistosoma japonicum as reference, we obtained 27 miRNA candidates out of 16.45 million raw sequencing reads, with 13 of them found as known miRNAs in S. japonicum and/or S. mansoni, and the remaining 14 miRNAs were considered as novel. Five out of the 13 known miRNAs coming from one family named as sja-miR-2, including family members from miR-2a to miR-2e. Targets of 19 miRNAs were successfully predicated out of the 17401 mRNA and EST non-redundant sequences of S. japonicum. It was found that a significant high number of targets were related to “chch domain-containing protein mitochondrial precursor” (n = 29), “small subunit ribosomal protein s30e” (n = 21), and “insulin-induced gene 1 protein” (n = 9). Besides, “egg protein cp3842” (n = 2), “fumarate hydratase” (n = 2), “ubiquitin-conjugating enzyme” (n = 2), and “sperm-associated antigen 6” (n = 1) were also found as targets of the miRNAs of E. pancreaticum.

Conclusions

The present study represents the first global characterization of E. pancreaticum miRNAs, which provides novel resources for a better understanding of the parasite, which, in turn, has implications for the effective control of the disease it causes.

Wasting and mortality in beef cattle parasitized by Eurytrema coelomaticum in the State of Paraná, southern Brazil

A sporadic wasting syndrome affecting beef cattle herds parasitized by Eurytrema coelomaticum is described in the State of Paraná, southern Brazil. The disease was characterized by progressive weight loss, poor body condition despite plenty of good quality forage available, and death. Annual losses ranged from 1 to 3%. The clinical course of the disease varied from 2 to 10 months after the onset of the first clinical signs. At necropsy, one of the three distinct following patterns of lesions were observed: the pancreas was of normal size and color; small, shrunken, white and markedly and diffusely firm (fibrosis); or slightly enlarged and dark with a shriveled capsular surface. Myriads of leaf-shaped trematodes of the genus Eurytrema were packed inside multiple dilated ducts with thickened, whitish fibrous walls, or the flukes were embedded in the remaining pancreatic parenchyma. Microscopic findings included extensive loss of the pancreatic parenchyma with replacement fibrosis, intralesional flukes and eggs, and ductal hyperplasia. Inflammatory reaction varied from absent to severe with the presence of a granulomatous reaction around the trematode eggs. One affected animal had high plasma amylase concentration (1580U/L) suggesting exocrine pancreatic insufficiency. Glucose blood levels were not significantly increased. We suggest that diffuse and marked fibrosis of the pancreas induced by the presence of large amounts of pancreatic flukes is the cause of the sporadic cases of chronic wasting and death of cattle in this geographic area.

Helminth infections of sheep in North Sumatra, Indonesia

Gastrointestinal tracts of 73 indigenous sheep were obtained from the Medan abattoir in North Sumatra, Indonesia, and examined for the presence of helminths. A total of 13 species of helminths, eight nematodes, one cestode and four trematodes were encountered. All sheep were infected by more than one species of nematodes. Trichostrongylus colubriformis, T. axei and Haemonchus contortus were the most common species. The intensity of the nematode infections was very high: the average burden was over 7500 worms. Trichostrongylus spp. accounted, on average, for 81.5% of the total nematode burden. No influence of age on total nematode burden could be shown. Eurytrema pancreaticum and Schistosoma spindale were found in 23.3% and 4.1% of the examined sheep, respectively. The results are discussed in relation to common management and helminth control systems.