[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.

[On the possibility of vertical transmission of Trichinella and the impact of its invasion].

Whether experimentally infected female rats can transmit Trichinella in utero and its invasion may affect the immunity of their offspring has been investigated. There is evidence that maternal antibodies have a significant impact on the humoral immunity of the offspring and as a result on the number of Trichinella larvae accustomed in the muscles. Immune interlayer formation in the populations of carnivorous mammals in the endemic areas occurs due to reinvasions and passive transmission of maternal antibodies to the offspring. High-tension immunity in the population and animals contributes to a reduction in the onset of invasion and to a predominance of the subclinical course of the disease and asymptomatic carriage in a specific focus. Passive immunity transmitted from the Trichinella-infected mother to its offspring is of importance in the development of epidemic and epizootic processes in the natural and synanthropic foci of trichinosis.

[Efficacy of a new fenbendazole formulation produced by nanotechnology-based drug delivery system against nematodosis].

The efficacy of a new fenbendazile formulation produced by nanotechnology-based drug delivery system was investigated in45 sheep naturally infected with gastrointestinal nematodes. The formulation showed 95.6% efficacy against Nematodes spp. at a dose of 1.0 mg/kg dw of its active ingredient and 100% efficacy against other species of gastrointestinal nematodes. Given at a dose of 10 mg/kg dw, the basic drug--fenbendazole (substance) displayed 96.39 and 100% efficacy, respectively.

[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.

[Significance of birds in the dissemination of Trichinella spp. larvae in coastal and aquatic biocenoses].

The real possibilities of mechanical transmission of trichinae through avian feces to terrestrial and aquatic mammals with the participation of a number of invertebrates (ostraceans, crustaceans, and dipteran larvae) and fishes were studied. Laboratory models have proven that the mammals can be biologically infected with trichinosis from the above species of vertebrates and invertebrates, the mechanical vectors of this infestation.

[Biological properties of the isolate of Trichinella spp. from a jackal in the North-Caucasian Region].

The biological properties of the isolate from Trichinella from ajackal in the North-Caucasian Region of the Russian Federation were studied. The jackal's muscle tissue showed two Trichinella species preserving their genetic isolation during 5 passages on mice. Oval capsules containing live larvae (on day 90 after infection) in the rat muscles corresponds to the conventional description of the species Trichinella spiralis in their morphometric and biological properties. The morphological data, biological properties, and poor adaptation of round capsule-enclosed parasites to rats indirectly show their affiliation to the other Trichinella species--T. native or T. britovi. There was a negative test for outbred albino rat muscle Trichinella resistance to freezing, which, might be associated with the poor adaptation of this Trichinella isolate to this species of rodents.

[Biological properties of Trichinella spp. isolated from the Central Region of the Russian Federation].

The biological properties of Trichinella isolated from the muscles of a common fox inhabiting in the Central Region of the Russian Federation have been studied. The paper presents the results of passaging this isolate of Trichinella on laboratory rats and mice, shows morphometric variability in relation to the change of Trichinella habitat. Evidence is provided that the shape and size of Trichinella capsules depend on the strain of the parasite and the species of an animal host the muscles of which contain these tissue helminths. The morphological data, biological properties, and high negative temperature resistance of the Trichinella that are present in the muscles of a fox shot in the Ryazan Region allow the above isolate to be classified as Trichinella nativa.

[Comparative immunochemical analysis of a complete somatic extract, somatic fractionated and excretory-secretory proteins and antigens of T. spiralis larvae].

The paper deals with the analysis of the protein composition of invasion Trichinella larvae, the immunochemical characteristics ofTrichinella antigens of varying molecular mass, the development of the optimum procedures for having the preparative quantities of immunogenic, the so-called major Trichinella antigens that are the major component for the production of diagnostic and prophylactic agents. Twenty nine protein bands were detected in the composite of a complete somatic Trichinella extract. It was ascertained that the most immunogenic peptides with molecular masses of 30, 43, 52-57, and 63-69 kDa were present in all Trichinella protein products while peptides with molecular masses of 43, 50-55 kDa are major antigens both in the fractionated somatic and excretory-secretory proteins in all incubation periods.

[Diagnostic efficiency of enzyme immunoassay system based on the recombinant antigen EgF in sheep larval hydatid disease (echinococcosis)].

The paper presents the results of designing a technology for the manufacture of enzyme immunoassay kits to detect class G antibodies to the Echinococcus granulosus antigen EgF with a molecular weight of 16.7 kDa in sheep. According to the results of field trials on flocks of sheep from various age groups, the diagnostic efficiency of the test system was 78.1% sensitivity and 73.9% specificity. The proposed test system may be used during mass sheep screenings for the epizootic monitoring of the prevalence ofechinococcosis in the Russian Federation, for the serological diagnosis of this disease in the female livestock at the level of a flock.

[Diagnostic efficiency of excretory-secretory Trichinella antigens in enzyme immunoassay].

The investigation deals with the enzyme immunodiagnosis of trichinosis in some mammalian species involved in the circulation of this widespread menacing anthropozoonosis in the natural synanthropic foci in the Russian Federation. The use of T. spiralis immunodominant antigens of a molecular mass of 63-29 kDa as enzyme immunoassay (EIA) diagnostic kits for the lifetime diagnosis may ensure a rather effective lifetime detected of the Trichinella-infested omnivores and carnivores (pigs and cats) participating in the circulation of the causative agent in the synanthropic foci. Also, these antigens are suitable for the study of the immunological aspects of tricinosis when T. spiralis invasion is simulated on laboratory animals (rodents). False-negative EIAs are associated with the specific features of immunological responsiveness of each organism, the degree of infectivity (immunological tolerance in intensive inoculation), the stage of invasion, the biological characteristics of a helminth (such as the immunosuppressive effect of the parasite on the host during larval migration), rather than with the quality of the used components of a response.

[Design of a recombinant antigen for the diagnosis and prevention of larval hydatidosis].

The paper deals with the design of recombinant vector make-ups, with the expression of Echinococcus hybrid proteins, and with the study of their immunogenic properties. Theoretical rationale is given for the choice of the parasitic gene superexpression system (E. coli cells of SG 13009 strain--recombinant plasmid pQE/EgF). The authors show that the use ofpolymerase chain reaction with oligonucleotide primers homologous to the structures of unique genes coding for Echinococcus antigen is promising for the run of the preparative quantities of fragments of these genes. They consider the basic stages of obtaining hybrid EgF antigen: the isolation of genomic DNA from Echinococcus protoscolexes; the run of preparative quantities of an EgF DNA fragment; the obtaining of vector pQE plasmid DNA; the design of a recombinant make-up; the screening of positive clones; the recombinant plasmid expression of hybrid protein and its purification. The commission tests of EgF antigen in enzyme immunoassay using 93 human serum samples revealed the following: the sensitivity and specificity were 83.8 and 77.4%, respectively. The recombinant protein of EgF was found to exert a significant protective action on the development of E. multilocularis larvocysts in non-inbred albino mice.

[Analyzing the time course of changes in the titers of specific antibodies while immunization of animals with the biological agent EgFB with different adjuvants].

The recombinant Echinococcus antigens EgF and EgB were prepared and purified by gel filtration and ion-exchange chromatography (800 and 780 mg, respectively being obtained). Four vaccinating complexes, the major component of which were the recombinant antigens EgF and EgB, were developed and tested in an experiment on rabbits. The time course of changes in antibody genesis was studied during a single immunization of the animals with the biological agent EgFB with different adjuvants for 120 days. The adjuvant substances ensuring as components of the biological agent EgFB a long circulation of specific antibodies to the Echinococcus antigens in the blood flow of the immunized animals (complete Freund's adjuvant, multicomponent oil emulsion) are presented.