Molecular Characterization of Echinococcus canadensis (Cestoda, Taeniidae) in Wolf from the Kirov Region.

This work presents the results of studying the molecular characteristics of parasitic tapeworms Echinococcus canadensis. The helminths were discovered during the autopsy of a wolf (Canis lupus Linnaeus, 1758) killed by hunters in the Kirov oblast in 2021. A molecular phylogenetic study was performed by analyzing the sequence of a fragment of the first subunit of the mitochondrial cytochrome oxidase gene (CoxI). It was found that the detected echinococci belong to the G10 genotype of E. canadensis, which is common in wolves in the northern territories of the Holarctic. We discovered four positions at which the substitutions characteristic only of this genotype are revealed. A substitution at one of the positions that is characteristic exclusively for the representatives of the G10 genotype found in Russia and Finland was also discovered.

The epidemiology of trichinellosis in the Arctic territories of a Far Eastern District of the Russian Federation.

Trichinellosis, a zoonotic disease caused by nematodes of the genus Trichinella, is still a public health concern in the Arctic. The aims of this study were to investigate the seroprevalence of anti-Trichinella IgG in aboriginal peoples of two settlements in the Chukotka Autonomous Okrug (Russian Federation) on the Arctic coast of the Bering Sea, and to evaluate the survival of Trichinella nativa larvae in local fermented and frozen meat products. A seroprevalence of 24.3% was detected in 259 people tested by an enzyme-linked immunosorbent assay (ELISA). The highest prevalence was detected among people who consumed traditional local foods made from the meat of marine mammals. Trichinella nativa larvae were found to survive for up to 24 months in a fermented and frozen marine mammal meat product called kopalkhen. Since the T. nativa life cycle can be completed in the absence of humans, it can be expected to persist in the environment and therefore remain a cause of morbidity in the human populations living in Arctic regions.

[Possible sources of Trichinella infection in the indigenous population of Chukotka].

Statistical methods confirmed that the dietary intake of traditionally made meat from marine mammals and polar bear could cause Trichinella infection in the residents of the communities of the Chukotka Peninsula.

[Gastropods and their role in the transmission of Trichinella invasion].

Gastropods were established to be able to absorb decapsulated and encapsulated Trichinella larvae located in muscle tissue. Trichinella larvae remain viable and infectious for 24 to 48 hours after passing through the gastrointenstinal tract of gastropods.

[Molecular taxonomic identification of Trichinella spp. from the Arctic coasts of the Russian Federation].

Epizootological surveys on the Arctic coasts of the Russian Federation revealed 8 terrestrial andmarine mammal species that were Trichinella carriers. The infection rate varied with the animal species from 1.6 to 92.8%. Analysis of the taxonomic affiliation of Trichinella isolated from the muscles of the terrestrial and marine mammals indicated that the Trichinella species T. nativa was widespread in the arctic areas of the Russian Federation. Analysis of sequences in the Cob gene of mtDNA revealed nucleotide differences between several isolates of this species.

[The intensity of immune response to T. native antigen in the residents of coastal settlements in the Chukotka district, Chukotka Autonomous Okrug].

Sixty-three (24.3%) out of 259 residents of coastal settlements were found to have a positive immune response to Trichinella antigen. All the seropositive cases were represented by people belonging to three ethnic groups: Chukchi (97.8%), Eskimos (1.2%), and Yakuts (1.0%). The antibody titers varied from 1:100 (32.8%) to 1:1600 (8.7%). The highest titer reactivity was observed in marine mammal hunters, retired persons, and non-manual employees. There was a direct relationship between the antibody titer values and the dietary habits of the respondents preferring traditional foods prepared from marine mammal meat.

[Analysis of the diagnostic efficiency of excretory-secretory antigens of Trichinella spiralis and Trichinella nativa with sera from rats experimentally infected with arctic Trichinella, by using ELISA].

The diagnostic efficiency of excretory-secretory antigens of Trichinella spiralis and Trichinella nativa with sera from Wistar rats experimentally infected with arctic Trichinella was comparatively tested. Trichinella derived from the muscles of wild carnivorous mammals inhabiting the biocenoses of Chukotka were used to infest animals and to obtain the antigen. There was a considerable excess of the effectiveness of enzyme immunoassay when the antigen derived from T. native larvae was used to analyze the titers of sera from the rats experimentally infected with arctic Trichinella.

[Seroepidemiological study of native inhabitants of the Chukotka Autonomous District for trichinosis].

The 2010 seroepidemiological study of sera from 259 inhabitants of two settlements located on the shore of the Chukchi Sea revealed 63 (24.32%) seropositive respondents, which suggests the intensity of an epidemic process in these populated areas. The detection of specific antibodies in the population to the pathogen of trichinosis is of great importance for the objective assessment of the epidemic situation in the foci of invasion and the prediction of sporadically occurring epidemics of this anthropozoonosis.

[The status of the immunity system in diphtheria]. / Sostoianie sistemy immuniteta pri difterii.

The complex study of cell-mediated and humoral immunity characteristics, as well as nonspecific protective factors, in 30 diphtheria patients, 9 clinically healthy carriers and 54 healthy subjects was carried out. In healthy immunized subjects normal characteristics of all elements of immunity were observed in combination with high titers of antitoxins and sensitization of lymphocytes to diphtheria toxoid. In healthy carriers the presence of cell-mediated and humoral immunity to diphtheria was associated with disturbances of the metabolic activity of phagocytes and a decrease in the proliferation of lymphocytes in response to the mitogen. Diphtheria patients were found to have changes in all elements of immunity, especially pronounced in severe forms of the disease.