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The article dwells upon characteristics of the species richness of parasite communities in least cisco Coregonus sardinella Valenciennes in Polar water bodies: Kureyskoye Reservoir, Lake Kutaramakan, Khatanga River. The communities consist of parasite species common in coregonids. The main species in all the parasite communities in least cisco are Dibothriocephalus ditremus and D. dendriticus . Triaenophorus crassus plerocercoids dominate in the regulated water body (Kureyskoye Reservoir). To analyze the species richness of the component communities (s), coefficients of the power-law equation s  =  a  ×  n b were applied, where a is the expected species richness in the first host individual examined, and b is the rate of species accumulation in parasite component communities ( s ). The resulting curves of species accumulation give statistical rigor to the assessment of differences and similarities of the species richness of the component communities of parasites in least cisco of various ages and habitats. The species richness of infra- and component parasite communities in least cisco was found to be significantly lower in the lake and the storage reservoir than in riverine habitats (Khatanga River). At the same time, the species accumulation rate for parasite communities in least cisco from Lake Kutaramakan was higher than in the reservoir due to a higher diversity of parasite infracommunities.

Dibothriocephalus latus is the most frequent causative agent of fish-borne zoonosis (diphyllobothriosis) in Europe, where it is currently circulating mainly in the Alpine lakes region (ALR) and Russia. Three mitochondrial genes (cox1, cob and nad3) and 6 microsatellite loci were analysed to determine how is the recently detected triploidy/parthenogenesis in tapeworms from ALR displayed at the DNA level. A geographically distant population from the Krasnoyarsk Reservoir in Russia (RU-KR) was analysed as a comparative population. One or 2 alleles of each microsatellite locus was detected in plerocercoids from RU-KR, corresponding to the microsatellite pattern of a diploid organism. In contrast, 1–3 alleles were observed in tapeworms from ALR, in accordance with their triploidy. The high diversity of mitochondrial haplotypes in D. latus from RU-KR implied an original and relatively stable population, but the identical structure of mitochondrial genes of tapeworms from ALR was probably a consequence of a bottleneck typical of introduced populations. These results indicated that the diploid/sexually reproducing population from RU-KR was ancestral, located within the centre of the distribution of the species, and the triploid/parthenogenetically reproducing subalpine population was at the margin of the distribution. The current study revealed the allelic structure of the microsatellite loci in the triploid tapeworm for the first time.

The study investigates infection rates of perch by plerocercoids of the Dibothriocephalus latus (Linnaeus, 1758) Lühe, 1899 (syn. Diphyllobothrium latum) broad tapeworm in the creeks of the Krasnoyarsk Water Reservoir and in the Yenisei River (within the limits of the city of Krasnoyarsk). Plerocercoids were found in the perch in all study areas. The rates of invasion of the fish in the Yenisei River and in the creeks of the lower part of the Reservoir – Biryusa and Shumikha – were low (9.8, 6.9, and 13.5%, respectively); the infection of perch was higher in the middle part of the Reservoir, in the Sisim Creek (21.4%). The fish purchased at an unauthorized market was the most infected – 68.5%. The sample included large fish, weighing from 70 to 970 g. A positive correlation was noted between invasion rate and fish age (r=0.7). The plerocercoids found in the fish were viable. They were mainly localized in the fish muscle. Diphyllobothriosis is a commonly occurring helminthiasis in the riverine communities transformed because of the damming of rivers. In the Krasnoyarsk Water Reservoir, the broad tapeworms are usually transmitted along the plankton – perch – pike chain. The data obtained in this study show that small perch, consuming infected plankton, plays a leading role in maintaining the abundance of D. latus in the water reservoir. However, the main contribution to the epidemiological situation in the region is made by the large perch, which is heavily infected with broad tapeworm plerocercoids because of its cannibalistic feeding behavior. Both recreational fishermen and the people purchasing fish at unauthorized markets prefer large perch. Commercial and recreational fishing, settlements on the shores of the Reservoir, and the increasing number of tourists have contributed to the invasion of pathogenic organisms in the Reservoir. The perch caught in the Krasnoyarsk Water Reservoir or in the Yenisei River or purchased at unauthorized markets, which have not been inspected for disease, could be a source of diphyllobothriosis infection for people

Исследована зараженность окуня плероцеркоидами широкого лентеца Dibothriocephalus latus (Linnaeus, 1758) Lühe, 1899 (syn. Diphyllobothrium latum) в заливах Красноярского водохранилища и в р. Енисей (в черте г. Красноярска). Плероцеркоиды были обнаружены у окуня на всех исследованных участках. Низкий процент инвазии отмечен у рыб в р. Енисей - 9,8 % и в заливах нижней части водохранилища: Бирюса (6,9 %) и Шумиха (13,5 %), зараженность окуня выше в средней части: залив Сисим (21,4 %). Рыба, приобретенная на несанкционированном рынке г. Красноярска, оказалась наиболее зараженной - 68,5 % (в выборке присутствовали крупные особи, массой от 70 до 970 г). Отмечена положительная корреляция интенсивности инвазии c возрастом рыб. Обнаруженные плероцеркоиды были жизнеспособны. Основная локализация плероцеркоидов - мускулатура рыб. Дифиллоботриоз является распространенным гельминтозом в условиях трансформации речных сообществ при зарегулировании стока. В Красноярском водохранилище основной путь циркуляции широкого лентеца проходит в цепи: планктон - окунь - щука. Полученные данные показали, что мелкий окунь, потребляя зараженный планктон, играет ведущую роль в поддержании численности D. latus в водохранилище. Однако эпидемиологическая обстановка в регионе связана с крупным окунем, высокая зараженность которого плероцеркоидами широкого лентеца объясняется типом его питания (каннибализм). Крупный окунь - предпочитаемый пищевой продукт как для рыбаков-любителей, так и для населения, приобретающего рыбу на несанкционированных рынках. Промышленное и любительское рыболовство, населенные пункты на берегах водохранилища, а также увеличивающийся туристический поток способствуют поступлению в водоем инвазионного начала. Окунь, выловленный в Красноярском водохранилище или р. Енисей, а также приобретенный в местах несанкционированной торговли и не прошедший ветеринарно-санитарную экспертизу, может быть источником заражения человека дифиллоботриозом.

Herein we present the regio- and diastereoselective synthesis of novel pyrrolidine-fused spiro-dihydrophosphacoumarins via intermolecular [3 + 2] cycloaddition reaction. The presented approach is complementary to existing ones and provides an easy entry to the otherwise inaccessible derivatives. Additionally, the unprecedented pathway of the reaction of 4-hydroxycoumarin with azomethine ylides is described. The anti-cancer activity of the obtained compounds was tested in vitro, the most potent compound being 2.6-fold more active against the HuTu 80 cell line than the reference 5-fluorouracil, with a selectivity index > 32.