De novo assembly and functional annotations of the transcriptome of Metorchis orientalis (trematoda: Opisthorchiidae).

Metorchis orientalis is a neglected zoonotic parasite, living in the gallbladder and bile duct of poultry and some mammals as well as humans. In spite of its economic and medical importance, the information known about the transcriptome and genome of M. orientalis is limited. In this study, we performed de novo sequencing, transcriptome assembly and functional annotations of the adult M. orientalis, obtained about 77.4 million high-quality clean reads, among which the length of the transcript contigs ranged from 100 to 11,249 nt with mean length of 373 nt and N50 length of 919 nt. We then assembled 31,943 unigenes, of which 20,009 (62.6%) were annotated by BLASTn and BLASTx searches against the available database. Among these unigenes, 19,795 (62.0%), 3407 (10.7%), 10,620 (33.2%) of them had significant similarity in the NR, NT and Swiss-Prot databases, respectively; 5744 (18.0%) and 4678 (14.6%) unigenes were assigned to GO and COG, respectively; and 9099 (28.5%) unigenes were identified and mapped onto 256 pathways in the KEGG Pathway database. Furthermore, we found that 98 (1.08%) unigenes were related to bile secretion and 5 (0.05%) to primary bile acid biosynthesis pathways category. The characterization of these transcriptomic data has implications for the better understanding of the biology of M. orientalis, and will facilitate the development of intervention agents for this and other pathogenic flukes of human and animal health significance.

High prevalence of zoonotic trematodes in roach (Rutilus rutilus) in the Gulf of Finland.

The intention to increase roach (Rutilus rutilus) consumption is in focus for ecological and economic reasons in Finland. However, its safety as food has not been considered comprehensively. We collected and artificially digested 85 roach halves originating from the south-eastern coast of Finland, and found trematode metacercariae in 98.8% of the samples. Based on polymerase chain reaction (PCR) and sequencing of amplicons generated from the ITS2 gene region, zoonotic parasites of the family Opistorchiidae were identified as Pseudamphistomum truncatum and Metorchis bilis, and also non-zoonotic Holostephanus dubinini (family Cyathocotylidae) and Posthodiplostomum spp. (family Diplostomidae) were identified. The species identity of other trematodes found is currently being investigated. Mixed infections of several trematode species were common. The prevalence of morphologically identified zoonotic P. truncatum was 46%, and zoonotic M. bilis was found in one sequence sample. The high prevalence of zoonotic trematode metacercariae in roach from the Gulf of Finland is alarming. Only thoroughly cooked roach products can be recommended for human or animal consumption from the area.

Spermiogenesis and the spermatozoon ultrastructure of Robphildollfusium fractum (Digenea: Gyliauchenidae), an intestinal parasite of Sarpa salpa (Pisces: Teleostei).

Spermiogenesis in Robphildollfusium fractum begins with the formation of a differentiation zone containing: two centrioles, each bearing striated rootlets, nucleus, several mitochondria and an intercentriolar body constituted by seven electron-dense layers. The two centrioles originate two free flagella growing orthogonally to the median cytoplasmic process. Later, the free flagella rotate and undergo proximodistal fusion with the median cytoplasmic process. Nuclear and mitochondrial migrations occur before this proximodistal fusion. Finally, the young spermatozoon detaches from the residual cytoplasm after the constriction of the ring of arched membranes. The spermatozoon of R. fractum exhibits two axonemes of different length of the 9+'1' trepaxonematan pattern, nucleus, two mitochondria, two bundles of parallel cortical microtubules, external ornamentation of the plasma membrane, spine-like bodies and granules of glycogen. Additionally, a shorter axoneme, which does not reach the nuclear region, the presence of an electron-dense material in the anterior spermatozoon extremity and the morphologies of both spermatozoon extremities characterize the mature sperm of R. fractum.

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.

Assessment of stress-related bioindicators in winter flounder (Pleuronectes americanus) exposed to discharges from a pulp and paper mill in Newfoundland: a 5-year field study.

This study assessed the effects of discharges from a sulphite-bleaching paper mill on winter flounder (Pleuronectes americanus) sampled each spring over a 5-year period in St. George's Bay, Newfoundland, prior to foraging activity. The fish were captured by SCUBA divers near the mill and at a reference site 10 km up current. Several bioindicators were used to assess fish health. Larger and older flounder exhibiting gross and microscopic tissue lesions, lower condition factor, and elevated hepatosomatic index but lower gonadosomatic index that was associated with delayed development, were observed in samples caught near the mill compared to those at the reference site. Additionally, fish examined near the mill were infested with an ectoparasite, Cryptocotyle lingua, that causes black spot disease but harbored fewer numbers of a digene, Steringophorus furciger, in the digestive tract than samples taken at the reference site. These results suggest that abnormal size distribution, interruption of growth, high prevalence of lesions, lower condition factor, enlarged liver, delayed gonadal development, and differences in parasitic levels were indicative of stress in winter flounder caused by discharges from the mill compared to samples from a reference site. There was no evidence of a population decline in the inlet because of annual recruitment possibly from St. George's Bay into which it opens.

[Infection rates of mollusks and fishes with the larval stages of Trematoda of the family Opisthorchidae in the Yaroslavl Region].

The paper presents the results of a study of the infection rates of mollusks of the family Bythiniidae (Bithynia tentaculata, Opisthorchophorus troscheli) and fishes with the larval stages of Opisthorchidae in different districts of the Yaroslavl Region. A total of 3,708 mollusks from the water reservoirs of different types (small rivers, lakes, ponds, and canals) were examined in the Nekouzsky, Yaroslavsky, and Pereslavsky Districts of the Yaroslavl Region in 1989 to 1999. Opisthorchis cercarias were found in 7 of the 10 studied water reservoirs. The total rate of infection of mollusks with all types with Trematoda partenitas and cercarias in different water reservoirs averaged 18.5 +/- 3.5% for Bithynia tentaculata and 19.1 +/- 4.1% for Opisthorchophorus troscheli. Trematoda metacercarias of the family Opisthorchidae were revealed in roaches, ides, verkhovkas, silver breams, and chubs in four different water reservoirs (small rivers and a lake) of the region. Pseudamphistomum truncates, Opisthorchis felineus, and Metorchis xanthosomus were present among the metacercarias found. It is concluded that there may be sporadic cases of Opisthorchis infection in wild and domestic animals and humans in the Yaroslavl Region.

[Participation of Codiella troscheli (Mollusca: Prosobranchia) in the Metorchis albidus (Trematoda; Opisthorchidae) life cycle]. / Uchastie Codella troscheli (Mollusca: Prosobranchia) v zhiznennom tsikle Metorchis albidus (Trematoda: Opisthorchidae).

Investigating Mollusca prosobranchia of the Bithyniidae family in the water reservoirs of the Novosibirsk Region in 1994-1998 first revealed that Codiella troscheli had the trematode Metorchis albidus (Braun, 1893). The species affiliation of the trematode was experimentally verified. This paper presents the results of studies of the seasonal and daily emission of M. albidus cercariae and data on their longevity in the environment, on the ability of the cercariae to live in fish and that of metacercariae in the body of a definitive host. The studies have indicated that not only the trematode Opisthorchis felineus, but also C. troscheli may develop in the C. troscheli mollusks, which should be taken into account in both describing the natural foci of opisthorchiasis and diagnosing opisthorchiasis and metorchiasis.

[Growth and development of Metorchis orientalis in chicks and its adult morphology].

In order to observe the infectivity, growth and development and adult morphology of Metorchis orientalis, a total of 40 chicks were experimentally infected with 100 metacercariae respectively, collected from Pseudorasbora parva. The worms of various developmental stages were recovered from chicks at 1.5, 3, 5, 7, 9, 11, 14 and 21 days after infection, and they were prepared for morphological observations and measurements. All of the worms were found in the gallbladders of chicks, and their recovery rate was 32% in average. The growth of the body was rapid from 9 to 11 days after infection. The genital primordia appeared in 1.5 and 3-day old worms, and ovary and testes were first observed in 5-day old worms. Thereafter, genital organs gradually matured and completed up to 11 days after infection. The adult worm was leaf-like, and possessed a convoluted tubular seminal vesicle, an ovoid ovary, a sac-like seminal receptacle, 2 lobed-testes and follicular vitellaria. Eggs were 31.9 x 15.3 microns in average size, ellipsoid to elliptical in shape and possessed abopercular thickenings. From the above results, it is concluded that M. orientalis grows in sigmoid pattern in chicks, and their genital organs fully mature between days 9 and 11. It is also confirmed that a chick is a new definitive host of M. orientalis.

Occurrence of some medically important flukes (Trematoda: Opisthorchiidae and Heterophyidae) in Nam Ngum water reservoir, Laos.

Occurrence of some medically important flukes transmitted to man by eating of raw fish was observed at 18 localities of Nam Ngum water reservoir, an important source of fish for inhabitants of Vientiane Province, Laos. Cercariae of Opisthorchis viverrini were recorded in 0.9% of Bithynia siamensis goniomphalus examined but in the most populated sites, where the density of the snails was the highest up to 2.2% of the intermediate hosts were infected. Haplorchis cercariae were found in 2.0% of Tarebia granifera examined. O. viverrini metacercariae were found in flesh of four fish species (Hampala dispar. H. macrolepidota, Puntius gonionotus, Cyclocheilichthys repasson) from 9 localities with the highest prevalence (16%) in H. dispar. Metacercariae of Haplorchis pumilio and H. taichui were found in flesh of Hampala dispar, H. macrolepidota and Puntius gonionotus with the prevalence of infection 2-6%. Metacercarie of Stellantchasmus falcatus were localized in fins of Xenentodon canciloides. Domestic cats (Felis catus f. domestica) harbored the following trematode species: O. viverrini, H. pumilio, H. taichui, H. yokogawai, S. falcatus. Eggs of small flukes were found in stools of 44% of examined inhabitants of 3 villages and of the district center Thinkeo. The study revealed that the best predictor of the existence of small fluke foci and their species composition in the area studied was the second intermediate host-fish.

Kinase inhibition lengthens the period of the circadian pacemaker in the eye of Bulla gouldiana.

The inhibition of protein kinase activity by the isoquinoline sulfonamide, H-8, lengthens the period of the Bulla ocular circadian rhythm in a dose-dependent manner. In addition, the phosphorylation of 5 proteins is markedly affected by H-8. The observed correlation between H-8's period lengthening effects, and its effects on the phosphorylation of specific proteins, suggests that: (1) these proteins are candidate components regulating the period of the circadian rhythm; and (2) the daily changes in membrane potential underlying the circadian rhythm are mediated by similar mechanisms that serve to change neural function in other systems; modulation of protein kinases.