Parazitologiia最新文献

The number of larvae in the Cosmocerca ornata (Dujardin, 1845) females from marshfrogs in vivo and period of larvae production of nematodes in vitro was studied. The numberof larvae in females of nematodes and quantity of born larvae depend on the size of parasites.The largest C. ornata females had the highest number of larvae and the longest periodof larvae production. The nematode sizes in its turn depends on density of infrapopulationof C. ornata and ambient temperature. The dependence of a number of the C. ornatalarvae on the host age and sex and on a season of the year was revealed. Different phenotypesof amphibians showed no influence on the number of larvae inside nematode females.In the experiment C. ornata females remained viable up to 8 days, producing larvae up to7 days. The optimum temperature for the larvae production constituted 24—28 °C. At atemperature of 12 °C and lower the nematode larvae output from females was stopped.

A case of tundra vole death as a result its hyperinvasion by ticks Ixodes angustus on the northern periphery of the Asiatic range of the parasite is given.

The Pacific saury Cololabis saira (Brevoort, 1856) is one of the important target species of commercial fisheries. Food manufacturers and consumers encounter problems due to the infection of the saury by acanthocephalans, which are quite difficult to clean out completely during on-board catch processing. Infection of C. saira was not studied on a regular basis, therefore, our knowledge about the parasites of saury is fragmentary. This paper contains infection indices (only acanthocephalans) of the Pacific saury caught in the Kuril Islands area (Russian Exclusive Economic Zone) in 2015.

The taiga tick (Icodes persulcatus, Schulze, 1930) is the main and most epidemiologically dangerous vector of tick-born encephalitis virus (TBEV) and Borrelia in most parts of Russia's territory (Alekseev et al., 2008). The purpose of this article is to describe the incidence rate of I. persulcatus males with exoskeleton anomalies in populations of the Asiatic part of Russia. A total of 2630 taiga tick males were morphologically analyzed. They were collected in Far Eastern, Siberian and Ural Federal Districts (respectively, FEFD, SFD, UFD) in 15 geographically remote locations. It is shown that in all populations there are adult ticks with impaired exoskeleton, among which two types dominate: twin dents at the back of conscutum (P11), and uneven surface of conscutum - a "shagreen skin" (P9). The frequency of abnormalities in males from the areas with temperate monsoon and temperate continental climate (FEFD) was definitely lower (6.5 ± 1.05 %), than in individuals from the territories of SFD (29.7 ± 1.03 %) and UFD (25.8 ± 3.93 %) with continental and sharply continental climate. FEFD territory is also characterized by a less number of males having two simultaneous exoskeleton anomalies. Similar district-preconditioned differences in the frequency of recorded body distortions are also typical of females, with a higher percentage of deviant individuals in comparison with males. Thus, the identified polymorphism of exoskeleton structure of the taiga tick may reflect the natural phenogeographical variability of this trait and might not be the result of human impact.

Phenotypic and genetic estimations of entomopathogenic ascomycete B.bassiana (strainSar-31) after 6-passaging through four hosts were shown. Increasing of virulence, changesin morpho-cultural characteristics and variations in Inter Simple Sequence Repeats(ISSR) assay between initial and reisolated cultures were registered.Six passages of entomopathogenic ascomycete Beauveria bassiana (strain Sar-31)through four hosts (Galleria mellonella, Tenebrio molitor, Leptinotarsa decemlineata, Locustamigratoria) and following estimation of phenotypic and genetic differences of theinitial strain and reisolated cultures were conducted. The passaging of strain through certainhost led to increasing of virulence for both this host and other test-insects. Unidirectionalchanges of morpho-cultural characteristics: colonies pigmentation and relief strengthening,increasing of conidia production and lipolytic activity were registered in all passagedcultures. Genetic analysis with 6 ISSR markers revealed variations between initial and reisolatedcultures in 3 markers. Taken together, the results of this study help us understandpotential ways of fungi strains changes during epizootic process and possibilities of ISSRassay applying for investigation of pathogen transmission.

Morphological features of R a u s c h i ta e n ia a n c o ra (Mamaev, 1959), a cestode with atypicalmode of attachment («anchoring» in the wall of the host intestine), are considered. AtI he center of the overgrown scolex there is a rostellum, size of which is close to that of thedeveloped metacestode. Large suckers are composed mainly of loose parenchyma and fineradial muscle fibers. Fragments of host tissue are noted in the suckers’ cavity. Surface ofI he scolex is covered with large microtriches, which are in contact with the host tissue havingsigns of degradation. Distal cytoplasm is filled with vesicles coming from tegumentalcytons. Rostellar glands that are common to cyclophyllids are not found. Excretory canalscontain fluid (closer to the surface) and numerous lipid droplets (deeper located canals).

The simplest modification of the dynamic extraction method using cottonwool filter based on the Baermann funnel principle, is described. This modification excludes the funnel because a great share of Sticky worms attach to sloping walls of a funnel and thus do not reach the collector Eppendorf tube. But the main principle of the Baermann funnel is used, I. e. sinking down of actively moving heavy narrow bodies via wide holes of filter and thus separating the active worms from passive non-Brownian moving substrate particles, which do not pass the filter and remain above it. This principle is illustrated because it has never been described before. In the proposed modification any sloping walls in the extraction paths are excluded and thus the probability to attach sticky nemotodes to walls is also excluded; only cylindrical equipment with abrupt vertical walls is used; procedures are extremely simplified to be user-friendly for beginners: only filter (cotton pads), Eppendorf tubes, plastic glasses and narrow PVC tubing are applied. The new simplified modification allows one to collect nematodes by non-professional workers, e. g. in Polar expeditions without microscopic study of results. As an addition, an efficient method to maintain extracted nematodes alive is proposed, using the "effect of water film" in foam rubber inside the Eppendorf tube. To maintain nematodes alive during several months it is recommended to suppress bacteria via addition of 0.2-0.4% formaldehyde solution and then keep the tube with nematodes in a refrigerator.

Flea fauna of Ciscaucasia is represented by 76 species, 13 of which are associated withbirds and all the other with mammals. Rodent parasites are most numerous; fleas associatedwith predators, bats and insectivora are less abundant. Fleas parasitize on different speciesof birds of the orders Passeriformes, Anseriformes, Falconiformes, and Strigiformes.Among 41 flea genera known from the Caucasus, species of the genera Amalaraeus, Araeopsylla,Atyphloceras, Caenopsylla, Callopsvlla, Doratopsvlla, Paraneopsvlla, Peromyscopsylla,Phaenopsylla, Tarsopsylla, and Wagnerina are absent in the Ciscaucasia. Onlytwo subendemic species were revealed in this area. Thirty three flea species are distributedover the entire territory; the distribution of other species is limited to landscapes of one ortwo natural areas.

The three phases system xenobiotic biotransformation in cells as prokaryotes as eukaryoteswas formed during the process of evolution. Clear and managed function of all threelinks of this system guarantee the survival of living organisms at alteration of chemicalcomponent of environment. Oxidation, reduction or hydrolysis of xenobiotics realize inphase I by insertion or opening reactive and hydrophilic groups in structure of drug molecule.In phase II xenobiotics or their metabolites from phase I conjugate with endogeniccompounds, main of there are glutathione, glucuronic acid, amino acids and sulphates.Active transport of substrata, metabolites and conjugates through cell lipid membranesspecial transport proteins carry out (phase III).The system of xenobiotics biotransformation of helminths has essential differencesfrom the same of vertebrate hosts. In particular, parasites do not reveal the activity of primeoxidases of phase I, such as CYP or FMO, in spite of the genes of these enzymes inDNA. As this phenomenon displays mainly in adult helminths, living in guts of vertebrates,then the hypothesis was formulated that this effect is related with adaptation to conditionsof strong deficiency of oxygen, arise in a process of evolution (Kotze et al., 2006).Literature data testify the existence in helminths of unique forms of enzymes of phaseII, the investigation of which present doubtless interest in relation with possible role inadaptation to parasitic mode of life. Notwithstanding that many of helminths GST in greateror lesser degree similar with enzymes of M, P, S and О classes of other organisms, neverthelessthey have essential structural differences as compared with enzymes of hoststhat makes perspective the search of specific anthelminthics vaccines.Transport of xenobiotics is now considered phase III of biotransformation. It wasshown that proteins of this phase (ATP binding cassette transporters (ABC ) of parasites)play a key role in efflux of lipophilic xenobiotics, hydrophilic metabolites and conjugatesand take part in forming of anthelminthics resistance. Some of these transporters, such asP-glycoprotein (Pgp), are important for drug resistance of helminths. In particular, a correlationbetween the level of expression of Pgp and resistance of S. mansoni and F. hepaticato widely used anthelminthics as praziquantel and triclabendazol exist.

The new data on the parasites fauna of the Lake Kronotskoe sympatric charr forms (genusSalvelinus (Nilsson) Richardson, 1836) is presented. Parasites fauna of Bigmouth andSmallmouth charr forms are described for the first time. The information about Longheadcharr, Nosed charr and White charr parasites is added. 29 species of parasites from 9 classeswere found: Oligohymenophorea, Myxosporea, Monogenea, Trematoda, Cestoda, Nematoda,Acantocephala, Crustacea and Hirudinea. Longhead charr was the most intensivelyinfected by Proteocephalus longicollis (Zeder, 1800) (abundance 306.0) and Neoechinorhynchussalmonis Ching, 1984 (abundance 230.0). White charr was mostly infected byCrepidostomum Braun, 1900 (abundance 242.2) and P. longicollis (abundance 183.4). Nosedcharr group that feed on gammarids was infected mostly by Crepidostomum spp.(abundance 3461.3), Cyathocephalus truncatus (Pallas, 1781) (abundance 179.9) and Cystidicolafarionis Fisher, 1798 (abundance 169.0); while Chironomidae consumers groupwas infected mostly by Diplostomum Nordmann, 1832 (abundance 62.3) and Phyllodistomumumblae (Fabricius, 1780) (abundance 27.3). Bigmouth charr was infected mostly byP. longicollis (abundance 17.0) and Eubolhrium salvelini Schrank, 1790 (abundance 11.0),Smallmouth charr form — by P. longicollis (abundance 67.0) and Diplostomum sp. (abundance64.2). Sympatric flock of charrs form the Lake Kronotskoe (Kamchatka) is the mostpolymorphic for the genus Salvelinus in Eurasia. According to the parasitological analysisthis flock consists six ecological forms.