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The purpose of the research is to study the morphological changes in the capsules of Trichinella spiralis larvae and their distribution in muscles.Materials and methods. In the experiment, 12 white rats were used, divided into 3 groups of 4 animals each. Rats of the first group were infected with T. spiralis larvae at a dose of 5 larvae per 1 g of body weight, the second – at a dose of 40 larvae per 1 g, rats of the 3rd group served as control and were not infected. The selective dispersal of larvae was studied by determining the intensity of infection in post-mortem studies of the main muscle groups of the animal and measuring the capsules of larvae in different muscle groups.Results and discussion. In the entire muscle mass, 45±10 T. spiralis larvae/animal were found in the 1st group, in the 2nd group the number of larvae was 2250±180, in the control group no T. spiralis larvae were found. It has been established that the distribution of T. spiralis larvae in the muscles of infected animals depends on the dose of infection: at low doses, the largest number was found in the gastrocnemius muscles and diaphragm, at high doses, the number of larvae in the muscles of the head sharply increases.

The purpose of the research is to compare diagnostic and design characteristics of Gastros and AVT-L devices in order to determine the prospects for improving the veterinary and sanitary examination of carcasses with trichinellosis. Taking into account the requirements for ensuring the safety of food products, in particular meat and meat products, special requirements are imposed on the quality of trichinelloscopic control in the conditions of veterinary diagnostic laboratories of meat processing enterprises, markets and slaughterhouses. For this purpose, a fairly wide range of devices is used for both compressor trichinelloscopy and peptolysis of muscle tissue. Comparative tests were carried out for Gastros of Petrolaser LLC and AVT-L (VNIIP) type devices used for this purpose. In the process of work, we analyzed the features of the examination technology, the structural elements of the devices and the diagnostic efficiency. In general, the devices met the requirements of the veterinary and sanitary examination for trichinellosis in various production conditions, however, their design for manufacturability had significant differences. With equal diagnostic efficiency, the devices have significant design differences regarding the type of thermal stabilization, automation, control systems for the duration of the peptolysis and settling of the medium, and the dimensions of the devices. According to these parameters, Gastros is more promising at the present time. AVT-L requires some improvements.

The purpose of the research is study of morphological and functional characteristics of Trichinella sp. larvae in bears and badgers in the Kirov Region.Materials and methods. The compressor trichinelloscopy (CT) method was used to study 72 sections of muscle tissue samples (in accordance with the Guidelines "Prevention of helminthiasis transmitted through meat and meat products" dated September 23, 1996) from animals obtained during scientific culling. The sections were prepared from the diaphragmatic peduncle muscles and the diaphragm of bears and badgers along the muscle fibers, and placed in the compressorium. The sections were then transferred to glass slides, and provisional slides were prepared and examined using various magnifications (× 8, × 20, × 40). Morphometric measurements were performed using a microscope at × 40 magnification, then the capsule index was calculated. Digestion (peptolysis) in artificial gastric juice was performed according to the P. A. Vladimirova’s method modified by A. V. Uspensky and F. Skvortsova after the test samples were placed in various temperature conditions from 5 to -18 °C, and the parameters of both animal species were compared. The viability of Trichinella sp. larvae was evaluated in a Petri dish in saline at a room temperature. Morphological changes were recorded in the larvae structure (coiled larvae against the total number of isolated, coiled and stretched larvae) and their mobility.Results and discussion. We studied badgers and bears infected by Trichinella spiralis larvae in the Kirov Region. The Trichinella sp. larvae were found in all examined sections of the infected animals. The infection intensity was higher in the badger than the bear and amounted to 218±79.5 larvae per 1 g of muscle, while it was 115±28.5 in the bear. The stated above is explained by the fact that the badger eats carrion more often, and typically visits spontaneous dumps. For postmortem diagnosis of trichinellosis in the obtained bears and badgers, we can use trichinelloscopy and peptolysis methods which are aimed at detecting infection sources and preventing zoonosis in humans.

The experiment used white mice, which were divided into 4 groups. The first group of mice was injected with a saline solution with 0.04 mg of Trichinella antigen obtained by the Magat method subcutaneously, the second group of mice was injected with azoxymer bromide (polyoxidonium) at a dose of 0.004 mg/mouse, the third group was infected with Trichinella larvae without preliminary administration of drugs, group 4 served as a control. A week after the last injection of drugs, mice were infected with invasive Trichinella larvae at a dose of 40 larvae/animal. Evaluation of the protective properties of polyoxidonium in laboratory models was carried out by determining the intensity of invasion in studies of all muscle groups of the animal by the method of peptolysis and histological material to assess the cellular composition of the spleen. The protective effectiveness of polyoxidonium was 99.43%. The rearrangement of the structure of the spleen under the influence of an immunostimulant indicated a high degree of reactivity of the spleen of animals in response to the introduction of polyoxidonium (the ratio of red and white pulp and their cellular composition changes).

High Alaria alata infestation rates were found in the animals of the Kirov Region. The functioning of alariosis foci is maintained by a wide range of primary and intermediate hosts. The purpose of this article was to evaluate the activity of disinfectants against A. alata trematode eggs and their effects on soil microbiocenoses.