A survey of helminths of polar bears in the Russian Arctic

The polar bear Ursus maritimus is a circumpolar species classified as vulnerable and included in the IUCN Red List. It is considered to be practically free of helminth parasites with the only species reported being Trichinella spiralis s. l. Samples of feces were collected on Chukotka coast, Wrangel Island and on ice floes in the Kara, Laptev and Chukchi seas in 2013-2015 in different seasons of the year. Coprological diagnostics was carried out using the standard flotation and sedimentation methods. In the samples collected in the snow-free period, a single sample (3.7%) was found to contain eggs of the nematode Toxascaris sp. In three out of 9 samples collected in the winter, eggs of a cestode Diphyllobothrium sp., of unidentified trematodes (presumably Heterophyidae) and of the strongylid nematode Uncinaria stenocephala were found as well as the first stage nematode larvae tentatively identified as Crenosoma sp. Viable Trichinella nativa larvae were recovered from the muscles of a female animal from north of Yakutia

Dimethyl 11,13-dimethyl-16-[1,2-bis­(methoxy­carbon­yl)ethen­yl]-12-oxo-16,17-dioxa-18-aza­hexa­cyclo­[7.5.1.11,4.16,9.110,14.05,15]octa­deca-2,7-diene-2,3-dicarboxyl­ate

The title compound, C27H29NO11, is a product of the tandem ‘domino’ Diels–Alder reaction. The mol­ecule comprises a fused hexa­cyclic system containing four five-membered rings (two dihydro­furan and two tetra­hydro­furan) in the usual envelope conformations and two six-membered rings (tetra­hydro­pyridinone and piperidine) adopting slightly flattened boat and chair conformations, respectively. The dispositions of the carboxyl­ate substituents relative to each other are determined by both steric reasons and inter­molecular C—H⋯O hydrogen bonding and attractive anti­parallel C=O⋯C=O inter­actions [C⋯O = 2.995 (2) Å]

2,25-Dioxo-27,28-diphenyl-30-oxa-29-thia-3,10,17,24-tetra­aza­penta­cyclo­[24.2.1.112,15.04,9.018,23]triaconta-5,7,9(4),10,12,14,16,18,20,22,26,28-dodeca­ene chloro­form disolvate

The macrocycle of the title compound, C36H24N4O3S·2CHCl3, contains a rigid framework with the nitro­gen and oxygen heteroatoms pointing in towards the center of the macrocyclic cavity. The macrocycle is essentially planar (r.m.s. deviation = 0.027 Å) except for the thio­phene ring. The dihedral angle between the thio­phene ring plane and the mean plane of the central macrocyclic core including all atoms except sulfur is 21.6 (1)°. Four intra­molecular hydrogen bonds occur: two are between the amide hydrogen atoms and the Schiff base nitro­gen atoms, while the others are between the amide hydrogen atoms and the sulfur atom of the thio­phene. The two solvate chloro­form mol­ecules are bound to the carbonyl oxygen atoms of the ligand by weak C—H⋯O hydrogen bonding. In addition, the structure reveals inter­molecular Cl⋯Cl close contacts [3.308 (2), 3.404 (2) and 3.280 (2) Å] between the chloro­form solvate mol­ecules. In the crystal, the macrocycles form layers parallel to (101), with an inter­layer distance of 3.362 (3) Å. This short distance is determined by the stacking inter­actions between the amide carbonyl and imine fragments of neighboring ligands

Review of pulmonary nematodoses of domestic cats with description of the first case of aelurostrongylosis in a cat in Russia

The purpose of the research is to outline the current state of the problem of pulmonary nematodoses of domestic cats, to draw the attention of veterinarians to it, to raise their awareness of the peculiarities of methods for diagnosing these helminthoses.Materials and methods. The literature data on the distribution, species composition, differential morphology, biology, pathogenic influence, methods of diagnostics of the causative agents of pulmonary nematodes in cats are analyzed. When describing a case of aelurostrongylosis in a kitten, its clinical state was observed, general clinical and biochemical blood tests, diagnostics of viral infections, and ultrasound examination of the abdominal cavity were carried out. Parasitological examination of feces was carried out by the flotation method and by the method of Berman.Results and discussion. The review of the world literature on pulmonary nematodes of domestic cats is carried out. Most pathogens are represented by species of several families of metastrongyloids, the most common and clinically significant representatives are: Aelurostrongylus abstrusus (family Angiostrongylidae), Troglostrongylus brevior (Crenosomatidae), Oslerus rostratus (Filaroididae). Also in the respiratory system of cats can be parasitized Eucoleus aerophilus (Trichurida: Capillariidae) and Metathelazia massinoi (Spirurida: Pneumospiruridae). The first Russian case of aelurostrongylosis in a domestic cat is described. The larvae of the first stage of pulmonary nematodes of the species Aelurostrongylus abstrusus were found in the study of feces according to the Berman method in a homeless 3-month-old kitten from the Moscow region. The number of larvae was 104 per gram of feces. The size of the larvae was 360–380 µm in length, the tail end had a characteristic structure – a double bend in the shape of the letter “S”, a dorsal spine-like outgrowth and a ventral notch. For veterinary practice, it is recommended that, in the presence of clinical signs of respiratory system damage in cats at risk (free-walking animals, kittens, street cats), pulmonary nematodes should be included in the differential diagnosis using appropriate diagnostic tests

The problem of anthelminthic resistance in horse breeding

The purpose of the research is to outline the growing problem of anthelmintic resistance of horse nematodes in the world, to describe the methods currently used to detect it, and the proposed ways to overcome it.Materials and methods. A review of the world literature on the resistance of horse nematodes to anthelmintic drugs is carried out.Results and discussion. Currently, veterinary parasitology is faced with the growing problem of the emergence of resistant races of helminths, against which previously tested anthelmintic drugs in recommended doses are ineffective. This phenomenon has been noted in many animal species and manifests itself in relation to many drugs of the main groups of anthelmintics. This is evidenced by numerous reports. In horse breeding, benzimidazoles have been used for over 40 years, leading to widespread resistance to them in intestinal nematodes. There is a loss or weakening of the effectiveness of treatment of nematodes of horses with anthelmintic drugs: thiabendazole, pyrantel pamoat, drugs from the benzimidazole groups and macrocyclic lactones. There is no doubt that a similar situation of the spread of resistant races of helminths is also typical for Russia, since here the same anthelmintic drugs are used for treatment as abroad. However, this problem in our country remains practically unexplored. In this situation, the uncontrolled use of anthelmintics, which does not take into account the possibility of resistance to them, inevitably leads (and possibly in some cases has already led) to the emergence and spread of resistant populations of helminths, against which existing drugs will be ineffective

N,N′-Bis(2-amino­phen­yl)-3,4-diphenyl­thio­phene-2,5-dicarboxamide acetonitrile solvate

In the title solvate, C30H24N4O2S·CH3CN, the substituted thiophene possesses approximate Cs(m) intrinsic symmetry, with the mirror plane passing through the S atom and the mid-point of the (Ph)C—C(Ph) bond. Despite the main backbone of the mol­ecule being a long chain of conjugated bonds, it adopts a non-planar conformation due to the presence of various intra- and inter­molecular hydrogen bonds. The hydrogen bonds result in twist configurations for both the amido and amino­phenyl fragments relative to the central thio­phene ring. There are two intra­molecular Namine—H⋯O hydrogen bonds within the thio­phene-2,5-dicarboxamide mol­ecule that form seven-membered rings. In the crystal, the thio­phene-2,5-dicarboxamide mol­ecules form inversion dimers by four amide–amine N—H⋯N hydrogen bonds. The dimers are further linked into layers propagating in (100) both directly (via Namine—H⋯O hydrogen bonds) and through the acetonitrile solvate mol­ecules (via amine–cyano N—H⋯N and CMe—H⋯O inter­actions)