Movsesyan’s research while affiliated with National Academy of Sciences of Armenia and other places

We studied blood samples from 48 rabbits aged 3 months. The hematological studies were performed in the Alphalab Veterinary Diagnostic Laboratory (blood samples were taken from the jugular vein of the rabbits) and the Laboratory of General Helminthology and Parasitology of the Institute of Zoology of the Scientific Center of Zoology and Hydroecology of the Armenian NAS (blood samples were taken from the peripheral ear vein of the rabbits). We studied healthy (control) and artificially infected (with coccidia) giant and Californian rabbits. A comparative analysis of blood cells was also performed for the rabbits infected with Eimeria. The experiment results showed that all morphological blood parameters of the giant and Californian rabbits with intense infection by coccidiosis pathogens changed significantly (p<0.05–0.001). A comparative analysis of quantitative indicators of blood cells in the infected rabbits showed that the most heavily infected animals had significantly reduced erythrocytes (RBC), hemoglobin (Hb), leukocytes (WBC), lymphocytes (LYMPH) and monocytes (MONO), while segmented neutrophils (NEUT), eosinophils (EO) and the erythrocyte sedimentation rate (ESR) increased significantly. The blood parameters of the healthy rabbits were within normal limits.

The article analyzes own and published data concerning muscle elements present in various parts of the trematode reproductive system. The data on the presence of serotonergic and peptidergic (FMRFamidergic) nerve elements evidence the innervation of the trematode reproductive system departments by these neurotransmitters. The available literature information was supplemented by results of the study carried out on Prodistomum alaskense, a representative of the family Lepocreadiidae, an intestinal parasite of deep-sea fish (Zaprora silenus and Aptocyclus ventricosus). The localization of serotonergic and FMRFamidergic nerve structures was determined by immunocytochemistry. The musculature was stained using TRITC (tetramethylrhodamine-isothiocyanate) conjugated phalloidin. The slides were examined using a fluorescent microscope and a confocal laser scanning microscope. An analysis of the data and information in the literature suggest that the muscular system of the reproductive system is well developed in trematodes of various taxonomic groups and represented by circular, longitudinal, and, in some cases, by diagonal muscle fibers. The musculature of the trematode reproductive system is innervated by serotonergic and peptidergic (FMRFamidergic) neurons and their fibers which may be involved in regulating the contractile activity in various parts of the trematode reproductive system.

Monitoring studies were performed on biological diversity of parasite fauna in domesticated animals at the territory of the Joint Russian-Armenian Scientific Experimental Centre, within the piedmont zone of Armenia with moderate continental climate at 900-1200 m above the sea level. The study species were large and small ruminants, rabbits and hens. All the animals except sheep were kept indoors (stalls). We found 3 trematode species, 4 cestode species and 5 nematode species based on seasonal coproovoscopic and larvoscopic examinations, as well as an incomplete helminthological dissections of 5 sheep. The infection of sheep and cattle with hematophagous parasites was also detected and the infection of hens and rabbits with helminths and protozoa was found. Oribatid mites Scheloribates sp. were isolated from the studied soil samples. We also found and studied land and freshwater molluscs, intermediate hosts of a number of important parasite species for the infection. The land molluscs were found to have naturally-acquired invasions with larval forms of Protostrongylidae and Dicrocoeliidae. In total, we found 20 helminth species, 5 ixodid ticks, 1 oribatid mite and 7 protozoa, and vectors: 2 species of freshwater molluscs and 1 species of land molluscs.

In two landscape zones of the Republic of Armenia, the regularities of the course of one of the most common haemosporidiosis in cattle, piroplasmosis, were studied. Based on our research, a difference was established in the timing of the onset of the disease, the number of outbreaks, and the severity of clinical signs in animals of the lowland and foothill zones. We have proved that 4 outbreaks of the disease took place in the farms of the lowland zone: the first at the end of April after the attack of ticks on the animal. At the same time, the first symptoms of the disease were noted. The second outbreak of the disease and a high degree of ticks were recorded in the second half of July. The third outbreak was in early August and the fourth in autumn starting from the 10th of October. In contrast to the lowland, there were 3 outbreaks of piroplasmosis in the farms of the foothill zone, and they were not very pronounced. This phenomenon can be explained by the difference in the temperature regime of the natural habitat. In the lowland zone, 4 species of ticks were recorded with the dominant species being Boophilus annulatus rarely found in the foothill zone. In the foothill zone, the same species of ticks as in the lowland were identified, along with the species Dermacentor marginatus.

Our studies were aimed at analyzing biodiversity of ecto- and endoparasites of sheep, cattle, rabbits, domestic birds and dogs in the lowland zone of the Republic, with semidesert climate and height of 850 m above the sea level. This is one of the warm regions of the Republic. The studies performed have established moderate and high degree of animal infection with parasites. We identified 33 parasite species, mostly helminths (15 species), including 10 species of nematodes (Trichocephalus ovis, Nematodirus spathiger, Haemonchus contortus, Chabertia ovina, Dictyocaulus filaria, Muellerius capillaris, Protostrongylus spp., Passalurus ambiqus, Ascaridia galli, Heterakis gallinarum), 4 species of trematodes (Fasciola hepatica, F. gigantica, Dicrocoelium dendriticum, Paramphistomum cervi), 1 species of cestodes (Moniezia expansa), 9 protozoan species (Piroplasma bigeminum, Babesia ovis, Eimeria perforans, E. magna, E. irresidua, E. tenella, E. acervulina), 7 species of ticks, 1 species of insects, and 1 species of leishmaniasis vector, the mosquitos from the genus Phlebotomus. We registered 5 species of freshwater molluscs (Lymnaea auricularia, L. stagnalis, L. ovata, L. truncatula, Planorbis planorbis), and 2 species of terrestrial molluscs (Helicella derbentina, Napaeopsis hohenackeri).

Original long-term studies of the authors on the sheep infestation by D. filaria in conditions of pronounced vertical zonal character of climate and landscape belts (300–2000 m above sea level) have shown a presence of wide infestation among all age groups of the animals: in lambs up to 60%, in young sheep up to 57% and in adult sheep up to 45%. Dictyocaulus is also present in moufflons and bezoar goats in Armenia. The main reasons for such a wide infection are the following: • a monoxenous character of D. filaria life cycle, i.e. the parasite being a geohelminth; • its survivability in wide range of biotic conditions; • an insufficient volume of planned prophylaxis measures against dictyocaulosis. A study of seasonal and age dynamics on author's own and literature data was also performed. Dynamics of infestation of lambs with Dictyocaulus is in both lowlands and mountain zones characterized with 2 peaks: summer and autumn ones (prevalence reaching 29.0% for lowlands, 42.0% for highlands in contrast to 5.7% and 2.8% respectively in the spring) with no invasion at start of the year. For young and adult sheep, dynamics of invasion with Dictyocaulus is characterized with high prevalence in spring and autumn periods (start of the year prevalence up to 45.0%, decrease to 15–25.0% in summer, rising to 40.0% and higher in October-December).

In this paper we analyzed the results of our own and published data concerning the presence of muscle elements in various parts of the digestive system in adult and larval forms of trematodes. The data on the localization of the circular and longitudinal muscle fibers in the pharynx, esophagus, and intestine of various representatives of trematodes are presented. The results of immunocytochemical studies indicate the presence the serotonergic and peptidergic (FMRFamidergic) nerve elements in the parts of the digestive system of trematodes. The available literature date is supplemented by the studies conducted on Prodistomum alaskense, a representative of the family Lepocreadiidae, an intestinal parasite of deep-sea fish (Zaprora silenus and Aptocyclus ventricosus). The localization of the serotoninergic and FMRFamidergic nervous structures was identified using immunocytochemical methods and the confocal scanning laser microscopy. For musculature staining the TRITC (tetramethylrhodamine isothiocyanate) – conjugated phalloidin was used. The preparations were examined using a fluorescence microscope and a confocal scanning laser microscope. The analysis of the data obtained and the information available in the literature suggests that the muscular system of the digestive tract is well developed in trematodes of various taxonomic groups. The musculature of the digestive system of trematodes is innervated by serotonergic and peptidergic (FMRFamidergic) nerve elements, which are involved in the regulation of the contractile activity of various parts of the digestive system of trematodes.

Trematodes of the Bucephalidae family differ from all other trematodes by the number of morphological characteristics including the structure of their attachment organ as well as the digestive and reproductive systems. In this study, the muscular system and nerve components containing serotonin and neuropeptide FMRFamid were investigated in Rhipidocotyle campanula (Bucephalidae family) from the intestine of the pike. Using immunocytochemical methods and confocal scanning laser microscopy (CSLM), data on the presence and distribution of neurotransmitters serotonin as well as the neuropeptide FMRFamide in the central and peripheral nervous system of Rh. campanula were obtained. When studying the relationship of nerve structures containing the studied neurotransmitters, muscle fibers of the muscle elements of the parasite were stained using the phalloidin associated with the fluorophore. Information on the organization of the muscular system, attachment organ, digestive and reproductive systems is given. The data obtained suggest that serotonergic and FMRF-amidergic nerve structures are involved in the regulation of the function of the attachment organ, as well as the digestive and terminal departments of the eproductive system of Rh. campanula. A comparative analysis of the obtained results and related data available in the literature for other trematodes was carried out.

A haemoparasitic disease, babesiasis was studied in dogs, brought to the Laura Dog Club, located in Yerevan city. Work in this direction was conducted from midApril till the end of November 2019. 25 working and hunting dogs, and 5 stray dogs were examined. Peripheral blood smears were prepared from animals with severe clinical symptoms of haemoparasitic disease to differentiate babesiasis. After fixing and staining, smear microscopy was performed under an immersion microscope system. Studies of blood smears showed that Babesia canis was found in red blood cells of examined dogs. The carriers of Babesia canis are Ixodid tics of the species Rhipicephalus sanguineus, Rh. bursa, Dermacentor marginatus, the latter species was found in a dog brought from the territory of the forest-mountain zone of Armenia. The species of Ixodid ticks, and the degree of tick infestation, were determined. It turned out that the dogs were mainly infected by the species Rh. sanguineus. It was found that the intensity of infection by Ixodid ticks in dogs in summer was 100%, and the intensity of infection was 10–20 ticks in each animal. Almost the same picture of ticking was observed in autumn.

A compilation of data on life cycles of cestodes structured into 6 suborders basing on our own data and literature analysis is given for the first time. It is established that world fauna of Cyclophyllidea currently consists of 1381 species life cycles of many of which are studied but poorly. Data from literature and our own studies shows that life cycles of Cyclophyllidea include two or sometimes three hosts: a definitive one, an intermediate one and sometimes additional (or second intermediate) one. As a result, characteristics of the life cycles and role of the specific definitive and intermediate hosts have been established for each Cyclophyllidea suborder. E.g., the suborder Acoleata's definitive hosts are birds connected to water environment, the intermediate ones are dragonfly larvae, for suborder Anoplocephalata definitive hosts are mammals, reptiles, rarely birds, intermediate ones are Oribatidae ticks, Psocoptera, for suborder Davaineata definitive ones are birds (mainly land ones), mammals (rodents, rarely humans), intermediate ones are worms, mollusks, arthropods, for Hymenolepidata definitive hosts are birds (mainly aquatic ones), mammals, intermediate ones are water invertebrates: crustaceans, rarely oligochaetes, mollusks and land mammals, for Mesocestoidata definitive hosts are carnivorous mammals and birds, intermediate ones are amphibia, reptiles, birds, mammals, for Taeniata definitive hosts are carnivorous mammals, birds, humans, intermediate ones are various vertebrates. Taking into account their great number of species, character and broad area of distribution, it is certain that this group of parasites is at the state of biological progress.