FORMATION OF BIODIVERSITY OF THE FAUNA OF ECTO- AND ENDOPARASITES ON THE ARARAT PLAIN OF ARMENIA

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).

Prevalence of trematodes and host risk factors associated with dairy cattle in Colombia

El estudio se llevó a cabo para establecer la prevalencia e identificar los factores de riesgo asociados con las infecciones por trematodes en ganado lechero de las tierras altas de Boyacá, Colombia. Las muestras fecales recogidas de 300 bovinos seleccionados al azar se examinaron utilizando una técnica de sedimentación simple para el recuento diferencial de huevos de trematodes. En el ganado estudiado fueron encontrados huevos de tres grupos de trematodes, a saber: Fasciola hepatica, Paramphistomum cervi y Cotylophoron cotylophorum. La prevalencia específica para estas tres especies fueron de 11,6%, 9,3% y 3,7% respectivamente. Se observó una superposición importante entre F. hepatica y P. cervi. La prevalencia de los tres trematodes identificados en este estudio se asoció significativamente (p<0,05) con la condición corporal y la raza, mientras que la prevalencia de Fasciola sp y Paramphistomum sp fue asociada con la edad. La prevalencia de los tres principales trematodes de importancia para la salud animal y la alta tasa de infección mixta, junto al deterioro de la condición corporal, determinan una pérdida económica sustancial debida a la reducción de la productividad del ganado en el área estudiada.

Molecular Characterization of Paramphistomum cervi in Buffaloes

Background: Paramphistomiasis (Rumen fluke disease) in ruminants is a major health problem, while documented reports on Paramphistomum species are limited in Asian countries. The present study aimed to identify paramphistomoid flukes that infects buffaloes with the goal of characterization of prevalence in Pakistan and its comparison with neighbor countries.Materials, Methods & Results: In 2018, a total of 178 slaughtered buffaloes aged four to six years were examined and flukes were collected from their infected rumen and reticulum using sterilized forceps. After amplification and sequencing of 18S rRNA partial fragment, the generated sequences were edited (810bp) and aligned with the other sequences of Paramphistomum species retrieved from NCBI. A phylogenetic tree was constructed using maximum likelihood method in MEGA X. The 18S rRNA sequence was found 100% similar with Paramphistomum cervi of China and 98% with Paramphistomum epiclitum and other Paramphistomum species of India. The parasitic Pharamphistomum species was identified molecularly as P. cervi.Discussion: Molecular studies provide insight into the biology and phylogenetic relationship among various parasites. These studies are reliable in the genetic-based identification and description of several disease causing agents. The 18S rRNA sequence of P. cervi generated in this study was found closely identical to the P. cervi of the neighbor countries (China and India) which may be due to the similar geographical, environmental conditions and transboundary movement of infected hosts. This is the first nature of study which provides the molecular-based evidence of P. cervi existence in Pakistan and revealed the 18S rRNA as novel molecular marker for the identification and further characterization of Paramphistomum species across Pakistan. The submitted sequence of this study will provide a baseline for further molecular characterization and to compare with other Paramphistoma species from different regions of Pakistan.

FEATURES OF TREMATODE INFECTION IN PASTURE OF DIFFERENT TYPES OF LOWLAND DAGESTAN

In the lowland of Dagestan, sheep are infected with 5 species of trematodes – Fasciola hepatica (L., 1758), Fasciola gigantica (Cobbold, 1856), Dicrocoelium lanceatum (Stiles et Hassal, 1896), Paramphistomum cervi (Zeder, 1990), Calicophoron calicophorum (Fischoeder, 1901). The total infection of sheep with trematodas varies the extensity of invasion (EI) 56.0–76.0%, with the intensity of invasion (II) 2–2360 species. The sheep are intensely infected with fascioles on low-lying wetlands, with paramphistomatids on pastures of the lower reaches of the Sulak, Terek, Talovka, lakes Temirgoe, Achikol, and with Dicrocoelium in areas where flat steppes. Sheep are limited to trematodes invaded by salt marshes and desert lands, EI 1.6–6.6%, II 2–28 species. Sheep are intensively infected with these pathogens in the spring-summer-autumn time, when intermediate, additional hosts and the formation of parthenogenetic stages in them to adoleskarii, metacercarii are active in the biotopes between the rivers Sulak and Terek. Infection with Adolescaria fascial and Paramphistomum occurs in winter when they are snowless. Adolescaria are formed on water plants, on water surface, near sources of water. The lush greenery around the watering holes always attracts animals. In these areas, there is always a high risk of infection of sheep with fascioles, paramphistomatids.

Evaluation of anthelmintic drugs against egg development of rumen flukes recovered from cattle raised in the humid tropics of Mexico

Paramphistomosis is a parasitic disease endemic in ruminants nearly worldwide. In the present study, an in vitro screening of the main anthelmintics used in Mexico was carried out to determine the mean lethal dose for rumen fluke eggs from cattle in a humid, warm region. Rumen flukes were obtained from cattle slaughtered in the states of Tabasco and Chiapas in Mexico. Eggs were collected using a 37-μm sieve and quantified. Then, an in vitro incubation study was performed: 100 eggs were placed into the wells of polystyrene microtiter plates. Anthelmintic products were tested on the eggs at concentrations ranging from 0.0015 to 3.0 mg/ml for rafoxanide, 0.0025 to 10.20 mg/ml for nitroxinil and 0.0015 to 3 mg/ml for closantel to determine the median lethal dose (LD50) and maximum lethal dose (LD99). A control group (water) was included in each plate. Three different species of rumen flukes (Calicophoron brothriophoron, Calicophoron clavula and Paramphistomum cervi) belonging to five isolates were identified. Nitroxinil had the highest efficacy against rumen fluke eggs, with an LD50 of 0.11 to 65 μg/ml, whereas rafoxanide showed the lowest efficacy with an LD50 ranging from 500 to 1713 μg/ml. Closantel showed high variability in the LD50 among the different analysed isolates (17 to 122 μg/ml). The evaluated flukicidal drugs presented differential efficacy against the development of rumen fluke eggs. The efficacy of the drugs will vary depending on the geographical area of origin of the animals.

Prevalence of Paramphistomosis in Domestic Ruminants in Chittoor District of Andhra Pradesh, India

A total of 1169 dung samples from domestic ruminants were examined to record the prevalence of paramphistomosis infection. In cattle, the prevalence of infection by direct smear (DS) and sedimentation method (SD) was 17.43% and 31.19%, respectively. In sheep, the prevalence rates were recorded higher than cattle (26.09% and 33.18%). In goats, the prevalence of paramphistomosis was 20.66% and 30.52%. Out of 109 cattle carcasses, 47 were found with flukes in rumen, reticulum and bile duct during slaughterhouse examination (SH). In sheep and goat, the prevalence rates were 42.15% and 40.85%, respectively by SH. Age-wise the highest prevalence was recorded in cattle of 2-4 years (50.0%) by SH. In goats, the prevalence of infection was lower in the age group oflessthan1 year, when compared to their counterparts in sheep. In contrast, the higher prevalence was noticed in >1-2 years old goats (63.27%) than sheep of the same age group (36.85%). Sex-wise, statistically no significant difference was observed between male and female animals. Morphologically identified, Cotylophoron cotylophorum, Paramphistomum cervi, Gastrothylax crumenifer, Fischoederius elongatus and Gigantocotyle spp. In conclusion, an overall prevalence of 24.29%, 32.51% and 42.0% of paramphistomosis infection was recorded in cattle, sheep and goats by DS, SD and SH examinations, respectively.