The purpose of the research is to determine whether definitive hosts – mammals and birds – and intermediate hosts – mollusks and fish – were infected by trematodes of the order Echinostomatida and to identify potential zoonosis in them.Materials and methods. The study was conducted in the Laboratory of Parasitology, the Department of Infectious Diseases, the Faculty of Veterinary Medicine and Animal Technology of the Perm State Agro-Technological University. The research was performed in 2024–2025. The material included 340 freshwater mollusks, 592 fish from reservoirs in the Perm Territory, and 16 carcasses of wild waterfowl and 7 mustelids. Further a study was conducted on 1,121 fecal samples collected from domestic cats and dogs from private veterinary clinics in Perm. The mollusks were examined by the compression method; the fish were dissected using the common method of I. E. Bykhovskaya-Pavlovskaya; and the bird and mammal carcasses were undergone partial helminthological dissection according to K. I. Skryabin. Faeces were collected three times to containers with the Turdyev preservative and analyzed by the sedimentation method.Results and discussion. The study of potential intermediate hosts of echinostomatids in the Perm Territory revealed infections of freshwater mollusks L. fragilis with Echinoparyphium sp. (7.69%) and L. stagnalis with H. conoideum (8.33%). No infections were detected in the fish. The waterfowl were infected with E. revolutum, E. coaxatus, and Echinochasmus sp., and Acanthoparyphium sp. was also detected in a transient species, the long-tailed duck (Clangula hyemalis) in one case. A single case of Isthmiophora melis was found in an American mink. These helminths are widespread in various Russian regions and are specific to their hosts; some have zoonotic potential. The identified cases indicate persistent echinostomatid infection in the Krasnokamsk District and, potentially, the Perm and Chusovsky Districts where special attention should be paid to preventing infections among the population and domestic animals.
The purpose of the research is to study a structural organization of lymphoid tissue in white laboratory rats with trichinellosis.Materials and methods. White rats were used as a study subject. The animals (n = 30) were divided into 4 groups: Group 1, 7 animals infected with Trichinella larvae at a dose of 2000±50 and examined on day 28 post-infection; Group 2, 7 animals (infected at the same dose) examined on day 50; Group 3, 7 animals examined on day 90. In the control group (9 clinically healthy animals), intestinal samples from 3 rats were examined on days 28, 50, and 90 post-infection. The study used dissection, immunomorphological Hellmann method, and light microscopy.Results and discussion. The infected male rats were found to have the total number of intestinal nodules increased; all visible lymphoid nodules found in the small intestine were round and slightly oval in shape, excluding a patch at the duodenum and jejunum border.Conclusion. In studying the immune response in trichinellosis, it is necessary to consider changes in lymphoid tissue and, in addition to immunostimulants used, explore methods for stimulating M cells, which can initiate an immune response and induce anthelmintic protection.
The purpose of the research is to compare two methods for assessing natural foci of prosthogonimosis based on definitive and/or first intermediate hosts infected with trematodes of the family Prosthоgonimidae (Lühe, 1909).Materials and methods. Birds for the study were obtained by hunters in the basin of Lake Chany (Novosibirsk Region), the largest lake in Western Siberia. Bursa fabricii was examined in 336 young birds of 25 species from 6 orders. Quantitative assessments and collections of bithyniid snails were conducted in river and lake biotopes of the Lake Chany basin in summer time of 2014–2025. A total of 3,103 bithyniids were examined by the compression method. The species of the trematode parthenites was determined based on mature cercariae obtained during their emission.Results and discussion. Natural foci of prosthogonimosis were studied based on the trematode infection rate in first intermediate and definitive hosts in the ecosystems of the Lake Chany basin. The maritae of trematodes of the family Prosthоgonimidae were found in 14 bird species (102 specimens) from four orders. The average infection intensity was 9 maritae, with an abundance index of 2.93 specimens. The infection of the first intermediate hosts with parthenites of trematodes of the family Prosthogonimidae was determined in both river (0.5–1.4%) and lake (4.7–7.3%) biotopes. The detected maritae and cercariae of the trematodes belong to three species: Schistogonimus rarus (Braun, 1901), Prosthogonimus ovatus (Rud., 1803), and P. cuneatus (Rud., 1809). The assessment of natural foci of avian prosthogonimosis based on first intermediate hosts infected with trematodes of the family Prosthоgonimidae is discussed.
The purpose of the research is to study the functioning parameters of the Irkutsk focus of opisthorchosis in the Taishetsky District of the Irkutsk Region.Materials and methods. The study was conducted from 2019 to 2024. A total of 810 mollusks, 941 cyprinids, and 47 muskrats were collected. We found Bithynia in two of the 45 water bodies studied: Baikal bayou lake (connected to the Biryusa River only in flood periods) and a backwater on the Kontorka River (a permanent tributary of the Biryusa). The mollusks were collected manually using a metal sieve. Bithynia were collected from plant stems and leaves, the underwater parts of hummocks, and by sifting coastal sediment. A microaquarium method was used to determine the Opisthorchis parthenita infection in mollusks. Cercariae was found in the water using a magnifying glass during daily inspection. Molecular genetic testing of the Bithynia was conducted using a universal primer for CO1 fragment of mitochondrial genome that encodes cytochrome c oxidase subunit I. DNA was extracted from a fragment of the mollusk's muscle tissue by a modified Doyle and Dixon method. Gill nets with 18–22 mm mesh were used to catch cyprinids. The fish were dissected and examined according to guidelines for studying Opisthorchidae, and infection rates were calculated by common methods. Muskrats were caught with traps and a metal mesh trap. Twelve muskrats were captured in Lake Rzhavoe and the Kontorka River in 2022, and 35 muskrats were captured in the same area in 2023. The animals were dissected using standard methods.Results and discussion. No Opisthorchis parthenites were found in a study of 810 Bithynia specimens. The CO1 sequences obtained in this study cluster on the phylogenetic tree with 100% support along with other Bithynia troschelii CO1 sequences from GenBank. This allows us to conclude that the studied samples belong to Bithynia troschelii (Paasch, 1842). The Bithynia distribution in the water bodies of the Taishetsky District is significantly limited by water chemical composition. The O. felineus parasitic system in the Irkutsk focus is characterized by a relatively poor composition of second intermediate hosts. In the study period, the population sizes of the roach and dace and their infection with Opisthorchis changed significantly. Currently, the roach is the most common fish species and the one most infected with the trematode O. felineus in the Taishetsky District waters. The muskrat plays the most significant role in the parasite's life cycle among all definitive hosts of Opisthorchis. Infection rates in muskrats were 16.7% in 2022, with the abundance index of 0.42 specimens, and 2.9% in 2023, with the AI of 0.03 specimens.
The purpose of the research is to test the EmDEA device for detecting B. xylophilus nematodes using various sampling methods.Materials and methods. The portable EmDEA device is designed to detect organisms outside the laboratory and works on the basis of enzyme-mediated duplex exponential amplification, which allows B. xylophilus nematodes to be detected in a wood sample within 20 to 30 minutes. The first test included variants where 3, 5, 10, and 20 nematodes were placed in test tubes in different variants together with clean wood sawdust. The second test used pine logs (Pinus sylvestris) infected with B. xylophilus. In the second test, we used B. xylophilus-infected pine logs (Pinus sylvestris).Results and discussion. National plant protection organizations (NPPO) conduct continuous monitoring of forests and imported timber shipments for infestation with the dangerous quarantine species B. xylophilus, therefore the use of a rapid and reliable method for detecting this organism in wood is a pressing issue. The authors of the article tested the EmDEA device, which allows B. xylophilus to be detected outside laboratories. The detection rate of nematodes in test I in variants with 3, 5, 10 and 20 nematodes per tube was 29%, 79, 64 and 71%, respectively. The detection rate of nematodes in test II was 29–79% for 1–3 nematodes in a wood sample and 100 % for 4 nematodes. It was concluded that the EmDEA portable device showed high sensitivity in the detection and diagnosis of B. xylophilus nematodes and can be used in forest surveys and quarantine control in international trade.
