Parasitic organisms inhabiting the alimentary canal should permanently resist the destructive action of host digestive enzymes. The intestinal parasites were shown to produce specific protease inhibitors protecting them from proteolysis. However, little is known about this adaptive mechanism in cestodes so far, especially for the tapeworms dwelling inside the fish intestines. Here, we explored the ability to inactivate proteolytic enzymes in the fish tapeworm Eubothrium rugosum (Batsch, 1786) (Bothriocephalidea) parasitising the intestine of wild burbot, Lota lota (Linnaeus). The assays were conducted with different concentrations of commercial trypsin and homogenate of intestinal mucosa both being the sources of proteinases. The incubation of live E. rugosum in trypsin solutions of two different concentrations caused a significant decrease in the enzyme activity. The extent of activity reduction was dependent on trypsin concentration. At the same time, the inhibitory effect of the worm incubation medium turned out to be statistically insignificant. These findings suggest partial adsorption of the enzyme to the tegument surface, with its further inactivation. In contrast to the incubation medium, the worm extract suppressed over 80% of trypsin activity and nearly half of the proteolytic activity in the mucosa homogenate. Notably, the inhibitory activity of the tapeworms hardly depended on their size characteristics. Finally, the research has demonstrated secretion of proteinase inhibitor in E. rugosum, which appears to be essential for its survival in enzymatically hostile environment., Galina I. Izvekova, Tatyana V. Frolova, Evgeny I. Izvekov., and Obsahuje bibliografii
The biology of sialic acids has been an object of interest in many models of acquired and inherited skeletal muscle pathology. The present study focuses on the sialylation changes in mouse skeletal muscle after invasion by the parasitic nematode Trichinella spiralis (Owen, 1835). Asynchronous infection with T. spiralis was induced in mice that were sacrificed at different time points of the muscle phase of the disease. The amounts of free sialic acid, sialylated glycoproteins and total sialyltransferase activity were quantified. Histochemistry with lectins specific for sialic acid was performed in order to localise distribution of sialylated glycoconjugates and to clarify the type of linkage of the sialic acid residues on the carbohydrate chains. Elevated intracellular accumulation of α-2,3- and α-2,6-sialylated glycoconjugates was found only within the affected sarcoplasm of muscle fibres invaded by the parasite. The levels of free and protein-bound sialic acid were increased and the total sialyltransferase activity was also elevated in the skeletal muscle tissue of animals with trichinellosis. We suggest that the biological significance of this phenomenon might be associated with securing integrity of the newly formed nurse cell within the surrounding healthy skeletal muscle tissue. The increased sialylation might inhibit the affected muscle cell contractility through decreased membrane ion gating, helping the parasite accommodation process., Rositsa Milcheva, Dimitar Ivanov, Ivan Iliev, Russy Russev, Svetlozara Petkova, Pavel Babál., and Obsahuje bibliografii
Two new species of Polydictya Guérin-Méneville, 1844 from Vietnam, P. grootaerti sp. n. from Central Vietnam and P. drumonti sp. n. from North Vietnam, are described and compared with the closest species, P. chantrainei Nagai & Porion, 2004 and P. kuntzi Nagai & Porion, 2004. The male genitalia are described and illustrated for the two new species as well as for P. vietnamica Constant & Pham, 2008 for the first time. Habitus details and photographs, a distribution map and photographs of specimens in nature when available, are provided. The occurrence of P. vietnamica from Thailand and Northeast India, noted here for the first time based on photographs taken in nature, requires confirmation based on the examination of specimens. An identification key to the species of Polydictya from the Indochinese region is provided., Jérôme Constant, Hong-Thai Pham., and Obsahuje bibliografii
Chyliza vittata is known to utilize leaves, stems and underground parts of several leafy and leafless orchids. Compared to the well-recorded feeding habits of C. vittata in Europe, its feeding habits in Japan are poorly studied. Thus, further records of its host plants and the habits of its larvae in Japan are likely to reveal the similarities and differences in its feeding habits in Europe and Japan. The current study reports C. vittata feeding on the stems of the mycoheterotrophic orchid Yoania japonica in central Japan. This study also showed that in spite of the small size of Yoania its reproductive success is not severely reduced when infested with C. vittata, whereas the robust stems of Gastrodia elata, which is its main host plant in Japan, are thought to be a defence against infestation by C. vittata., Kenji SUETSUGU., and Obsahuje bibliografii
We have studied the influence of both levamisole (AL) and Freund's adjuvant (AF) on the immunisation of mice with the secretory antigens of adults of the liver fluke Fasciola hepatica Linnaeus, 1758. Total IgG antibodies were detected in all groups where the F. hepatica antigen was administered, been levels of IgG1 increased respect to IgG2a antibodies. During immunisation, IL-4 and IFN-γ were only detected in AL and AF groups, but after infection, IL-4 boosted in all groups. IFN-γ increased two fold in AF and AL groups compared to the saline solution (AS) group. Worm recovering was of 32-35% in groups administered without antigen whereas in AS, AL and AF groups recovering was of 25%, 12% and 8%, respectively. Macroscopical lesions in the liver were scarce in AL and AF groups. Our data suggest that immunisation of mice with antigens of F. hepatica enhances the immune response avoiding both liver damage and worm establishment after challenge infection. The murine model of fasciolosis has appeared to be useful to elucidate the mechanism by which the parasite modulates immune responses toward a Th2 type but also the development of Th1 type-inducing vaccines., María de los Ángeles Gutiérrez-Sánchez, Julieta Luna-Herrera, Lauro Trejo-Castro, Natividad Montenegro-Cristino, Alfredo Almanza-González, Alejandro Escobar-Gutiérrez, Jorge Luis de la Rosa-Arana., and Obsahuje bibliografii
Parasite life history traits influence the rate of gene flow between populations and the effective population size, both of which determine the levels of genetic variability and the geographic distribution of such variability. In this short review targeted to parasitologists, we summarise how life history traits influence the population genetic structure of parasitic helminths. These organisms are characterised by a wide variety of life cycles and are ecologically different from microparasites, which have been studied in more detail. In order to provide the reader a concise review that illustrates key aspects of the subject matter, we have limited ourselves to studying examples selected for their clarity and relevance., Severo Vázquez-Prieto, Román Vilas, Esperanza Paniagua, Florencio M. Ubeira., and Obsahuje bibliografii
Spalangia cameroni Perkins (Hymenoptera: Pteromalidae) is sold commercially as a biocontrol agent of filth flies, including the house fly, Musca domestica L. (Diptera: Muscidae). For this reason, S. cameroni is mass-reared for inundative releases to control harmful flies. However, the mass-rearing protocols include very little information on the influence of natal host on subsequent host selection by parasitoids with more than one potential host as in the genus Spalangia. Here, we report on the use of S. cameroni against M. domestica. The S. cameroni were reared using Ceratitis capitata Wiedemann (Diptera: Tephritidae) (natal host) pupae for several generations. Freeze-killed fly pupae were used in assays to determine the fecundity, number of adult progeny and sex-ratio of this parasitoid. Realized fecundity and number of adult progeny were greater when provided with house fly pupae than Mediterranean fruit fly pupae. Thus S. cameroni parasitized more house fly pupae than C. capitata pupae, even though the parasitoid was reared on Mediterranean fruit fly for many generations. These results indicate that S. cameroni reared on C. capitata can be successfully used in inundative releases against both fruit flies (agriculture) and house flies (livestock farming)., Francisco Beitia, Erik Valencia, Bernat Peris, Luis De Pedro, Josep D. Asís, José Tormos., and Obsahuje bibliografii
In Lepidoptera, larval dietary experience of volatile cues can induce adult preference for these cues. However, such induction may require several generations, depending in part on the degree of specialization of the insects. In a previous study, using species of noctuid stem borers with different diet breadths, namely the polyphagous Sesamia nonagrioides, the oligophagous Busseola fusca and monophagous Busseola nairobica, it was shown that in S. nonagrioides, one generation was enough to induce a preference for vanillin in the resulting gravid females, whereas even two generations failed to induce a response in adults of Busseola spp. In this study, we checked whether a higher number of generations of exposure to a vanillin-enriched medium could induce a significant olfactory preference for this medium in the species B. fusca and B. nairobica, which have narrower host-plant utilization ranges than S. nonagrioides. Larvae were reared to the adult stage on an artificial diet enriched with vanillin for periods of from 2 to 7 or 8 generations, followed by two-choice tests on gravid females using a Y-tube olfactometer. The results showed different responses according to the species: for the oligophagous B. fusca, there was no significant effect of the conditioning, while a significant preference for the odours emitted by this new vanillin-enriched diet was recorded for the polyphagous S. nonagrioides and monophagous B. nairobica, but after different numbers of generations. In conclusion, different diet breadths seem to be associated with different levels of plasticity in the odour preference of adults. The implication of this result for insects' adaptability in a changing landscape is discussed., Christophe Petit, Peter Ahuya, Bruno Le Ru, Laure Kaiser-Arnauld, Myriam Harry, Paul-André Calatayud., and Obsahuje bibliografii
Urban gardens can harbour a high diversity of insects, which are critically important components of urban ecosystems. In this work, we investigate the richness and diversity of a major taxon of economic and ecological importance, the aphids (Hemiptera: Aphididae), and their main insect predators, the hoverflies (Diptera: Syrphidae) and ladybirds (Coleoptera: Coccinellidae), in urban gardens. We examined how variation in environmental factors associated with urbanisation (garden host plant abundance, garden plant richness, garden size, proportion of impervious surfaces in the surrounding area) directly and indirectly (via prey and predator abundance) influence the local diversity and abundance of aphids, ladybirds, and hoverflies. Sixty-seven domestic gardens located in southern England were surveyed during the peak period of aphid abundance, and the numbers and identity of aphids and their predators were recorded. We observed 45 aphid species (179917 individuals in total), 15 hoverfly species (494 individuals) and 8 ladybird species (173 individuals). We found that aphid species richness and abundance were positively associated with utilised host plant abundance and garden plant species richness. Hoverfly abundance was positively correlated with garden plant richness. The abundance of ladybirds was positively correlated with aphid abundance and garden plant species richness, and negatively associated to the proportion of impervious surfaces in the surrounding environment. The difference in responses between the two major taxa of aphid predators may reflect differences in their behaviour and natural history. Our results indicate that overall increases in urban land cover are not favourable for ladybirds as a group, and that fine scale habitat variables that are determined by garden owners have the potential to greatly affect the diversity of aphids and their primary predators., Elise A. Rocha, Estevão N.F. Souza, Lewis A.D. Bleakley, Christopher Burley, Jade L. Mott, Gloria Rue-Glutting, Mark D.E. Fellowes., and Obsahuje bibliografii
Betasyringophiloidus Skoracki, 2011 is a genus of quill mites (Prostigmata: Syringophilidae) that is believed to contain mono-, steno- and polyxenous parasites associated with a wide range of passerine birds (Passeriformes) across the world. In this work we applied the DNA-barcode marker (mitochondrial cytochrome c oxidase subunit I gene fragment, COI) to verify whether Betasyringophiloidus schoeniclus (Skoracki, 2002) and Betasyringophiloidus seiuri (Clark, 1964) are actual steno- and polyxenous species associated with the currently recognised host ranges, or their populations are highly host-specific, cryptic species. Our results revealed that a population living on the Tristram's bunting Emberiza tristrami Swinhoe (Emberizidae) in Russia, so far classified as B. schoeniclus, is a new cryptic species Betasyringophiloidus emberizae sp. nov. Both topologies of the neighbor-joining and maximum likelihood phylogenetic trees as well as genetic distance (11.9% Kimura 2-parameter distance) (K2P) support species status of the mite population from E. tristrami. The same data support previously established conspecific status of B. seiuri found on the ovenbird Seiurus aurocapilla (Linnaeus) (Parulidae) (type host) and the northern waterthrush Parkesia noveboracensis (Gmelin) (Parulidae) and expand its range with a population found on a new host species Icterus pustulatus (Wagler) (Icteridae) with intraspecific K2P distance up to 1.9% and interpopulation distances ranging from 1.3 to 3.1%., Eliza Glowska, Lukasz Broda, Miroslawa Dabert., and Obsahuje bibliografii