Metorchis Bilis Research Articles

АНАЛИЗ НЕКОТОРЫХ МОРФОМЕТРИЧЕСКИХ И БИОЛОГИЧЕСКИХ ПОКАЗАТЕЛЕЙ ПЛОТВЫ RUTILUSRUTILUS (LINNAEUS, 1758)

The common roach is a widespread and semi-anadromous fish inhabiting the waters of Europe, Siberia, the Aral Sea basin. Control catches contained roach with a commercial length 12.6-32.6 cm, with a total mass of 41-543 g, age varying within 1+ - 6+. Juvenile stage individuals made - 5.7%, females - 68.6%, males - 25.7%. The annual gain at the age 1+ - 2+ made 3.8 cm, from 2+ to 3+ = 0.6 cm, from 3+ to 4+ = 2.3 cm, from 4+ to 5+ = 2.5 cm, 5+ - 6+ = 2.3 cm. The rate of linear gain decreases from 2+ and equals 3.2%, from 3+ to 4+ = 11.8%, from 4+ to 5+ = 11.5%, from 5+ to 6 + = 9.5%. The annual gain in body weight of species aged from 1+ to 2+ was 50.8 g, from 3+ was 24.8 g, from 4+ = 79.5 g, from 5+ and 6 + = 112.2 and 23.3 g, respectively. From 2+ to 3+ the weight gain is 17.3%, compared to individuals from 1+ to 2+ (85.1%). In the age categories from 3+ to 4+ and 4+ to 5 +, the weight gain was 47.2% and 45.3%, from 5+ to 6+ = 6.5%. In this study, the roach was prevalent in the II and V stages of gonad maturity. Individuals with I and II degrees of fat content were found in all age groups. The study of roach muscles using the compression method revealed the invasion by Opisthorchis felineus (Rivolta, 1884) and Metorchis bilis (Braun, 1790). Invasion extensiveness of O pisthorchis felineus was 28.6%, of Metorchis bilis - 5.7%, combined infestation with two parasites - 2.8%. Invasion activity in opisthorchis was 15.1 specimens, in metorchis - 5.3 specimens, copiousness index made 4.7 and 0.5 copies, respectively.

ПОКАЗАТЕЛИ ИНВАЗИИ МАССОВЫХ ВИДОВ КАРПОВЫХ РЫБ НИЖНЕГО ИРТЫША МЕТАЦЕРКАРИЯМИ СЕМ. OPISTHORCHIIDAE

In the basin of the Lower Irtysh, the most common types of carp fish (Cyprinidae) are ide ( Leuciscus idus ), bream ( Abramis brama ) and roach ( Rutilus rutilus ). The fish caught in the summer 2017 (20 ide specimens of 3+…7+ years old and 61 roach specimens of 1+…6+ years old) were infested by two Opisthorchiidae representatives: opisthorchosis pathogen Opisthorchis felineus and methorhoz pathogen Metorchis bilis , for which they are an intermediate hosts (a definitive host are carnivorous animals and a human). The extent of invasion by metacercariae of O. felineus was 70%, the combined infection with M. bilis - 25%. Species infested only by methorchis were not detected. Bream is invaded only by an opisthorchiasis pathogen (46.1%). Minimal values were registered in roach: degree of invasion by opisthorchis is 31.1%, degree of invasion by methorchisis is 3.3%, combined invasion occurs in 1.6% of fish. Intensity of infestation with metacercariae of O. felineus (specimens per one fish) made in average: at the age of 3+ - 180.4 specimens per one fish; at the age of 4+ - 105; 5+ - 483.4; 6+ - 938; 7+ - 22. M. bilis was registered at the age of 5+ - 8.5 specimens; 6+ - 675; 7+ - 18. In roach, the intensity of invasion of O. felineus per fish was at the age of 3+ - 33.1 specimens; 4+ - 9.3; 5+ - 7.7; 6+ - 5.3. M. bilis in roach was registered since the age of 2+ and amounted to 2 specimens per a fish; 3+ - 25; 6+ - 6. In bream the intensity of infestation of O. felineus is not high and at the age of 3+ it made 2.7; 4+ - 3.3; 5+ - 13; 6+ - 1 per a fish. The maximum abundance index of O. felineus and M. bilis was found in the population of ide and made 316.5 and 35.5 specimens; in roach AI was 21.9 and 0.8, respectively. The population of bream was least affected by opisthorchis (2.3). The high number of parasites proves that the Lower Irtysh basin is a natural seat of opisthorchosis, that is why, in order to prevent opisthorchosis and methorchisis spreading, it is recommended to strengthen the veterinary and sanitary control in places where fish products are processed and sold, as well as to extend activities on publicizing sanitary rules and preventive norms against these infections.

Opisthorchiasis in Western Siberia: Epidemiology and distribution in human, fish, snail, and animal populations

Opisthorchiasis is a widespread helminth infection in Russia. The largest opisthorchiasis endemic focus in the world is the Ob river watershed in Western Siberia. The main causative agent of this condition is the liver fluke, Opisthorchis felineus. In addition, another liver fluke species in the Opisthorchiidae family, Metorchis bilis, causes a symptomatically similar disease, metorchiasis. Despite a long research history going back to 1927, opisthorchiasis remains a serious problem in Russia, and numerous questions related to the epidemiology of these liver fluke infections and their patterns of distribution in Western Siberia, the causes of high prevalence in different populations, and the prognosis of the epidemiological situation remain to be answered.In this review, we first briefly describe the life cycle of O. felineus and then summarize the available published data on the epidemiological aspects of O. felineus infection among populations in Western Siberia. Additionally, the geographical distribution and rates of infection with the two major small liver flukes, O. felineus and M. bilis, in the intermediate (Bithyniidae snails and cyprinid fish) and definitive (humans, wild and domestic carnivorous animals and birds) hosts are described to assess their role in the transmission cycle. Moreover, species in the genus Opisthorchis and the genus Metorchis that have been reported in carnivorous mammals and birds in Western Siberia are listed and their potential to serve as the agents of opisthorchiasis transmission is discussed.

Первое обнаружение Opisthorchis Felineus и Metorchis Bilis в первых промежуточных хозяевах битиниидах из бассейна озера Чаны (Новосибирская область)

Objective of research: to perform the analysis of long-term (15 annum) dynamics of Bithyniidae snails infected by trematode parthenites from the Chany Lake, the biggest lake in the south of Western Siberia.
 Materials and methods: The Bithyniidae snails examined in the lake-river systems Chany Lake in 1994-2013 (in the middle reaches and in the estuary of the Kargat River) and in the Zolotye Rossypi Bay and the Malye Chany Lake. The Bithyniidae snails were collected from May to September (twice in any ten days) by hand from 4–6 plots of 0.25 m2 at a depth of 0.1–0.7 m. In total, 8,316 Bithynia troscheli (Paasch, 1842) and 766 В. tentaculata (L., 1758) were examined. Identification of parthenitae trematode was based on observation when mature cercariae were capable of leaving the shell of the host snail on their own.
 Results and discussion: In Bithyniidae snails, we found parthenites from trematodes from 12 families Cyathocotylidae Mühling, 1898 Poche, 1925; Prosthоgonimidae Luhe, 1909; Pleurogenetidae Looss, 1898; Lecithodendriidae Odhner, 1911; Microphallidae (Ward, 1901) Travassos, 1920; Plagiorchiidae Lühe, 1901 Echinostomatidae (Looss 1899) Dietz, 1909 Odhner 1910); Psilostomidae (Looss 1900) Odhner 1913; Notocotylidae Luhe, 1909; Monorchiidae Odhner, 1911; Cyclocoelidae Kossack, 1911 и Opisthorchidae (Lass, 1899) Braun, 1901. 
 The prevalence of bithyniid snails infected by trematode parthenites varied from 1,6% to 24,1% in different years
 The double infection by trematode parthenites was found in 0,96% bithyniid snails from estuary of the Kargat River; 4,45% in the Malye Chany Lake, and 26,6%, in the Zolotye Rossypi Bay. The cercariae of Opisthorchidae family in four annum of the fifteen detected. The prevalence of bithyniid snails infected by trematode parthenites from Opisthorchis felineus (Rivolta, 1884) and Metorchis bilis (Braun, 1890) was observed in Chany Lake systems for the first time. Both species (O. felineus and M. bilis) of trematodes have danger to human health and causes very dangerous disease, opisthorchiasis and metorchiasis.

Chromosome morphometry in opisthorchiid species (Platyhelminthes, Trematoda)

Few existing studies have dealt with cytogenetics in trematodes, largely due to the attendant technical difficulty of chromosome preparation. We performed a comparative analysis of chromosomes in five opistorchiid species, including Opisthorchis felineus Rivolta, 1884, Opisthorchis viverrini Poirier, 1886, Clonorchis sinensis Cobbold, 1875, Metorchis xanthosomus Creplin 1846, and Metorchis bilis (Braun, 1790) Odening, 1962. For some of these species, no detailed morphometric description of their karyotypes has yet been published; for the karyotype of Metorchis bilis this is the first-ever description. We found that opisthorchiids, like other trematodes, are characterized by karyotypic conservatism (N=6–7) and karyotype asymmetry, although comparison of chromosome morphometric traits did reveal differences between the karyotypes of the species. Moreover, to address certain a methodological issue in trematode chromosome preparation, we analyzed how the source of chromosomal material (partenitae or mature flukes) and the chromosome preparation techniques used (air-drying and cell suspension methods) affected chromosome spreading and size, concluding that the most reliable comparative method involves comparing relative parameters (relative length, arm ratio, centromeric index) of chromosomes prepared using the same technique.

ЕКОЛОГО-БІОЛОГІЧНІ, ЕПІДЕМІОЛОГІЧНІ ТА КЛІНІЧНІ АСПЕКТИ ЕНДЕМІЧНОГО ОСЕРЕДКУ ОПІСТОРХОЗУ В СУМСЬКІЙ ОБЛАСТІ

<p class="1"><em>На території Сумської області зареєстровано 4 види опісторхід: Opisthorchis felineus, Pseudamphisto­mum truncatum, Metorchis bilis і Metorchis xanthosomus. Встановлено, що осередки опісторхідозів в умовах досліджуваної території прив’язані, в першу чергу, до малих річок. Марити опісторхід у природних екосистемах Сумської області зареєстровані у 5 видів м’ясоїдних ссавців. В антропогенних екосистемах Сумської області провідну роль у циркуляції опісторхід відіграють домашні коти. Проведена оцінка зараження коропових риб метацеркаріями опісторхід. Встановлено, що домінантними з точки зору зараження і накопичення метацеркарій опісторхід є 3 види коропових риб: плітка, краснопірка і уклейка. Опісторхоз переважно перебігає латентно. З маніфестних форм хвороби найчастіше виявляється холецистит (78,6 %). Вирішальну роль у діагностиці хронічного опісторхозу має копроовоскопія (100 %). Групу ризику складають рибалки та члени їх сімей (71,9 %). Основним фактором передавання є солена та в’ялена риба.</em></p>

Intestinal and liver flukes of birds of prey (Accipitriformes, Falconiformes, Strigiformes) from Slovakia: uniform or diverse compound?

During 2012-2014 up to 286 birds of the orders Falconiformes (5 species), Accipitriformes (11 species), and Strigiformes (7 species) were examined for trematodes and this represents the first detailed study in Slovakia. A total of 12 trematode species belonging to the families Diplostomidae, Cyathocotylidae, Strigeidae, and Opisthorchiidae were identified. Rare infections were found in falcons where only two species (40%) and three of 85 examined birds (3.5%) were infected with a low range of two to four worms of generalists Strigea falconis or Plagiorchis elegans. Contrary to that, ten accipitriformes species (90.9%) and 63 of 156 bird individuals (40.4%) were infected with nine flukes: Conodiplostomum perlatum, Conodiplostomum spathula, Neodiplostomum attenuatum, Neodiplostomum spathoides, Parastrigea flexilis, Strigea falconis, Strigea vandenbrokae, Paracoenogonimus ovatus, and Metorchis bilis. S. falconis and N. attenuatum were the most frequent, occurring in parallel in eight and four bird species, in numbers up to 575 and 224. The intensity of infection with other fluke species was low ranging from one to 13 worms. Three owl (Strigiformes) representatives (42.9%) were exclusive hosts for Neodiplostomum canaliculatum and Strigea strigis, and the proportion of positive and dissected individual birds was 10:45 (22.2%). Both trematodes occurred in two or three owl species. In conclusion, apparent dissimilarity of trematode load of three unrelated lines of falcons, eagles, and owls was revealed. The present study extends our knowledge on the composition of the trematode fauna in Slovakia as all species except S. falconis and P. elegans that represent new host and species records in Slovakia.

Integrative taxonomy of European parasitic flatworms of the genus Metorchis Looss, 1899 (Trematoda: Opisthorchiidae)

Metorchis spp. are flukes (Platyhelminthes: Digenea) that infect vertebrates, including humans, dogs, cats, poultry and wild game, with cyprinid freshwater fish serving as typical second intermediate hosts. In their definitive hosts, the Metorchis spp. are difficult to identify to species. We provide and analyze sequences of two nuclear (18S rDNA and ITS2) and two mitochondrial (CO1 and ND1) DNA loci of four morphologically identified European species of the Metorchis, namely Metorchis albidus, Metorchis bilis, Metorchis crassiusculus and Metorchis xanthosomus, and of another opisthorchiid, Euamphimerus pancreaticus. DNA analysis suggests that the Metorchis specimens identified morphologically as M. albidus (from Lutra lutra), M. bilis (from Phalacrocorax carbo) and M. crassiusculus (from Aquila heliaca and Buteo rufinus) represent a single species. Thus, M. albidus (Braun, 1893) Loos, 1899 and M. crassiusculus (Rudolphi, 1809) Looss, 1899 are recognized as junior subjective synonyms of M. bilis (Braun, 1790) Odening, 1962. We also provide comparative measurements of the Central European Metorchis spp., and address their tissue specificity and prevalence based on the examination of extensive bird cohort from 1962 to 2015. M. bilis and M. xanthosomus can be morphologically diagnosed by measuring the extent of genitalia relative to body length and by the size ratio of their suckers. They also differ in their core definitive hosts, with ducks (Anas, Aythya) and coots (Fulica) hosting M. xanthosomus, and cormorants (Phalacrocorax), the birds of prey (Buteo, Aquila, etc.), piscivorous mammals (Lutra, Vulpes, Ursus, etc.) and humans hosting M. bilis. Previous reports on the Metorchis spp. contain numerous suspected misidentifications.

Distribution and molecular phylogeny of biliary trematodes (Opisthorchiidae) infecting native Lutra lutra and alien Neovison vison across Europe

The recent identification of Pseudamphistomum truncatum, (Rudolphi, 1819) (Trematoda: Opisthorchiidae) and Metorchis bilis (Braun, 1790) Odening, 1962 (synonymous with Metorchis albidus (Braun, 1893) Loos, 1899 and Metorchis crassiusculus (Rudolphi, 1809) Looss, 1899 (Trematoda: Opisthorchiidae)) in otters from Britain caused concern because of associated biliary damage, coupled with speculation over their alien status. Here, we investigate the presence, intensity and phylogeny of these trematodes in mustelids (principally otters) across Europe (Czech Republic, Denmark, France, Germany, Norway, Poland and Sweden and Britain). The trematodes were identified to species using the internal transcribed spacer II (ITS2) locus. Both parasites were found across Europe but at unequal frequency. In the German state of Saxony, eight out of eleven (73%) otters examined were infected with P. truncatum whilst this parasite was not found in either mink from Scotland (n=40) or otters from Norway (n=21). Differences in the phylogenies between the two species suggest divergent demographic histories possibly reflecting contrasting host diet or competitive exclusion, with M. bilis exhibiting greater mitochondrial diversity than P. truncatum. Shared haplotypes within the ranges of both parasite species probably reflect relatively unrestricted movements (both natural and anthropogenic) of intermediate and definitive hosts across Europe.

Opisthorchis felineus and Metorchis bilis are the main agents of liver fluke infection of humans in Russia

Liver fluke infections are gradually transforming from a local problem of individual geographic regions to a widespread problem. The observed expansion is likely to be connected with the ever-increasing intensity of traffic flow and migration of the infected carriers between cities, regions, and countries. Opisthorchis felineus, the trematode belonging to the family Opisthorchiidae, is a well known causative agent of the infection called opisthorchiasis. Metorchis bilis, also a member of the family Opisthorchiidae, causes metorchiasis, a disease very close to opisthorchiasis in symptomatology. Genetic markers can be used to develop methods for differential diagnostics of these diseases. However, the questions connected with epidemiology of these trematode infections, their clinical characteristics, prognosis and therapy remain open. This review briefs the general biological characteristics of O. felineus and M. bilis persisting in various countries of Eurasia, their geographical range, epidemiology and molecular diagnostics of these liver flukes.

Distribution of repetitive DNA sequences in chromosomes of five opisthorchid species (Trematoda, Opisthorchiidae)

Genomes of opisthorchid species are characterized by small size, suggesting a reduced amount of repetitive DNA in their genomes. Distribution of repetitive DNA sequences in the chromosomes of five species of the family Opisthorchiidae ( Opisthorchis felineus 2 n = 14 (Rivolta, 1884) , Opisthorchis viverrini 2 n = 12 (Poirier, 1886), Metorchis xanthosomus 2 n = 14 (Creplin, 1846), Metorchis bilis 2 n = 14 (Braun, 1890), Clonorchis sinensis 2 n = 14 (Cobbold, 1875)) was studied with C- and AgNOR-banding, generation of microdissected DNA probes from individual chromosomes and fluorescent in situ hybridization on mitotic and meiotic chromosomes. Small-sized C-bands were discovered in pericentric regions of chromosomes. Ag-NOR staining of opisthorchid chromosomes and FISH with ribosomal DNA probe showed that karyotypes of all studied species were characterized by the only nucleolus organizer region in one of small chromosomes. The generation of DNA probes from chromosomes 1 and 2 of O. felineus and M. xanthosomus was performed with chromosome microdissection followed by DOP-PCR. FISH of obtained microdissected DNA probes on chromosomes of these species revealed chromosome specific DNA repeats in pericentric C-bands. It was also shown that microdissected DNA probes generated from chromosomes could be used as the Whole Chromosome Painting Probes without suppression of repetitive DNA hybridization. Chromosome painting using microdissected chromosome specific DNA probes showed the overall repeat distribution in opisthorchid chromosomes.

Telomeric DNA in chromosomes of five opisthorchid species

The analysis of telomere repeat distribution in chromosomes of five opisthorchid species ( Opisthorchis felineus (Rivolta, 1884), Opisthorchis viverrini (Poirier, 1886), Metorchis xanthosomus (Creplin, 1846), Metorchis bilis (Braun, 1890), Clonorchis sinensis (Cobbold, 1875)) was performed with fluorescent in situ hybridization (FISH) of labeled (TTAGGG)n DNA-probe and PNA telomere probe on mitotic and meiotic chromosomes of these species. It was shown that chromosome telomeres of all studied species contain large clusters of (TTAGGG)n telomeric repeats. Interstitial clusters of the (TTAGGG)n repeats have not been revealed in the chromosomes of any studied species even when FISH of PNA telomere probe on pachytene chromosomes was performed. Furthermore interstitial clusters of the (TTAGGG)n repeats have not been detected in the chromosomes of O. viverrini, one of chromosomes of this species is the result of a fusion of two ancestral opisthorchid chromosomes.

Liver flukes in dogs and treatment with praziquantel

Opisthorchiid eggs were found in 6 out of 27 (22%) huskies while an ELISA detected antibodies against Opisthorchis felineus and Metorchis bilis in 24 (89%) and 25 (93%) sera taken from these dogs, respectively. All dogs showed an increased activity of glutamate dehydrogenase while aspartate aminotransferase was normal in all samples. Ten weeks after treatment with praziquantel no fluke eggs were found in the faeces from any animal and antibody titres dropped in all animals.

Assessment of the incidence of <i>Opisthorchis felineus</i> (Rivolta, 1884) and <i>Metorchis bilis</i> (Braun, 1890) infections in population of several regions of the West Siberia

The incidence of Opisthorchis felineu s (Rivolta, 1884) and Metorchis bilis (Braun, 1890) infections among people lived in several regions of the Ob-Irtysh River basin in the West Siberia has been assessed. Our results suggest that Metorchis bilis infection was common in many of the serologically tested people. Moreover, this helminth was obtained from the biliary ducts of humans in autopsy.

A sero-epidemiological survey on the occurrence of opisthorchiid liver flukes in red foxes ( Vulpes vulpes) in Berlin, Germany.

Serum samples collected from red foxes in the city of Berlin between 1996 and 1999 were analysed for the presence of antibodies against Opisthorchis felineus and Metorchis bilis using an indirect ELISA. Out of 1,000 specimens, 30.6% and 46.5% reacted positively with specific O. felineus and M. bilis antigens, respectively. Seroprevalence in adult foxes was always higher than in juveniles. While no significant differences were observed in adult foxes throughout the period, in juvenile specimens seroprevalence declined from 1996 to 1997, then stayed at a comparable level in 1998 and increased in 1999. A varying availability of fresh cyprinid fish in different years seems to be the reason for changes in seroprevalence. By grouping the samples from juvenile foxes by season, antibodies against both Metorchis and Opisthorchis antigens started to appear between April and June, increased between July and September()and reached a level comparable to adult foxes in the October to December quarter. The lowest seroprevalence was found in Pankow, which is the district with the lowest share of the surface water.

Liver enzyme activity and histological changes in the liver of silver foxes (Vulpes vulpes fulva) experimentally infected with opisthorchiid liver flukes. A contribution to the pathogenesis of opisthorchiidosis.

Blood samples from silver foxes experimentally infected with Opisthorchis felineus and Metorchis bilis, respectively, were examined for the activity of liver enzymes. The average activities of aspartate aminotransferase (AST), glutamate dehydrogenase (GLDH), alkaline phosphatase and alanine aminotransferase in uninfected control animals were 20, 1.8, 57 and 44 units/l, respectively. The liver enzymes in infected foxes reacted differently, depending on dose, species of flukes and individual peculiarities. The highest individual deviation of infected from control animals was registered in the case of GLDH, reaching increases of up to 200-fold. In contrast, AST showed the lowest deviation from control values (less than 10-fold). By the end of the study period, enzyme activities had declined. The prepatent periods for M. bilis and O. felineus in foxes were 2 weeks and 4 weeks, respectively. High egg per gram values were established at the beginning of the patent period. At necropsy, chronic inflammatory reactions were found in the bile ducts and in the wall of the gall bladder. The number of flukes at the end of the study was low.

Indirect ELISA for the detection of antibodies against Opisthorchis felineus (Rivolta, 1884) and Metorchis bilis (Braun, 1790) in foxes.

Serological investigations focused on the detection of specific opisthorchiid liver fluke antibodies in silver foxes (Vulpes vulpes fulva). Animals were experimentally infected with Opisthorchis felineus (nos. 1 and 2) and Metorchis bilis (nos. 3-8) by feeding fish with a counted number of metacercariae. Four foxes remained as non-infected negative controls (nos. 9-12). For the indirect ELISA, an excretory-secretory antigen was produced by in vitro cultivation of O. felineus and M. bilis adults isolated from livers of experimentally infected hamsters. Immunoglobulin G (IgG) seroconversion against homologous antigen took place between weeks 2 and 6 postinfection (p.i.) and foxes remained seropositive up to the end of the trial at week 41 p.i. In contrast, IgG titres against heterologous antigen remained significantly lower and stayed near the cut-off. All infected animals excreted opisthorchiid eggs, starting between weeks 2 and 4 p.i. The number of liver flukes found at necropsy was relatively low, except in one fox that was sacrificed at the week 11 p.i. These results suggest that the ELISA is a suitable tool for the detection of specific O. felineus and M. bilis antibodies in the fox.

Liver fluke (Opisthorchiidae) findings in red foxes (Vulpes vulpes) in the eastern part of the Federal State Brandenburg, Germany--a contribution to the epidemiology of opisthorchiidosis.

Parasitological examination of 677 livers from red foxes shot in connection with a rabies control programme were carried out in the eastern districts of the Federal State Brandenburg/Germany in 1996. Of the foxes, 32.5% were positive for opisthorchiid flukes. Metorchis bilis, the most frequently occurring fluke was found in 28.1% of foxes with numbers between 1 and 185. Opisthorchis felineus was found in 6.7% of fox livers. A maximum of 169 specimens was removed from one animal. Pseudamphistomum truncatum was present in only 2 foxes. The percentage of positive foxes in different districts varied between 15.8 and 43.3%. Significant differences in fluke prevalence were found between districts with a high share of surface water compared with a district with a low percentage of surface water. No sex-dependent differences in opisthorchiid prevalence were established.