Search results for " parasite"
showing 10 items of 133 documents
Differences in Attachment and Phagocytosis of Salmonella minnesota Strains (S Form, Re Mutant) by Mouse Peritoneal Macrophages: Participation of Endo…
1985
The virulence of bacteria in many phagocytic systems has been studied for several years and it is known that macrophages play an important role in host defence against invading microorganisms and in cooperation with cellular and humoral immune mechanisms. Pathogenic bacteria can be divided into two groups with regard to their fate within phagocytes: (a) extracellular bacteria which are promptly killed after phagocytosis and (b) facultative intracellular bacteria which are resistant to intracellular killing unless macrophages are activated. Humoral immune mechanisms (antibody, complement) deal mainly with extracellular bacteria, while cellular immune mechanisms (T cells, macrophages) deal wi…
Are the helminth communities from unisexual and bisexual lizards different? Evidences from gastrointestinal parasites of Darevskia spp. in Turkey
2015
1Departament de Zoologia, Facultat de Ciencies Biologiques, Universitat de Valencia Dr. Moliner, 50, 46100 Burjassot, Spain; E-mail: vicente.roca@uv.es 2CIBIO Research Centre in Biodiversity and Genetic Resources, InBIO Universidade do Porto, Campus Agrario de Vairao, Rua Padre Armando Quintas, 7. 4485–661 Vairao, Vila do Conde, Portugal; E-mail: carretero@cibio.up.pt 3Departamento de Biologia, Faculdade de Ciencias da Universidade do Porto R. Campo Alegre, s/n, 4169–007 Porto, Portugal; E-mail: fatima.esperanca@cibio.up.pt 4Department of Biology, Faculty of Science, Dokuz Eylul University, Buca, Izmir, Turkey E-mails: cetin.ilgaz@deu.edu.tr, yusuf.kumlutas@deu.edu.tr 5Department of Biology…
GTPases of the Rho Subfamily Are Required for Brucella abortus Internalization in Nonprofessional Phagocytes
2001
Members of the genus Brucella are intracellular -Proteobacteria responsible for brucellosis, a chronic disease of humans and animals. Little is known about Brucella virulence mechanisms, but the abilities of these bacteria to invade and to survive within cells are decisive factors for causing disease. Transmission electron and fluorescence microscopy of infected nonprofessional phagocytic HeLa cells revealed minor membrane changes accompanied by discrete recruitment of F-actin at the site of Brucella abortus entry. Cell uptake of B. abortus was negatively affected to various degrees by actin, actin-myosin, and microtubule chemical inhibitors. Modulators of MAPKs and protein-tyrosine kinases…
New distributional data on Haemogregarina stepanowi (Apicomplexa) and Placobdella costata (Hirudinea) parasitising the Sicilian pond turtle Emys trin…
2022
The host-parasite system "Emys trinacris - Placobdella costata - Haemogregarina stepanowi"is known for Sicily, but scarce information is available to date about the distribution of the two parasites P. costata and H. stepanowi on the island. Therefore, an extensive sampling effort through visual census and collection and analysis of blood smears of the endemic Sicilian pond turtle E. trinacris was carried out in 46 water bodies scattered throughout mainland Sicily. Our findings revealed that the distribution of both parasites is limited to the Nebrodi area, where the infection of H. stepanowi has shown a high incidence on the local turtle populations. Our data suggest no correlation between…
Continental-scale patterns of pathogen prevalence: a case study on the corncrake
2014
Pathogen infections can represent a substantial threat to wild populations, especially those already limited in size. To determine how much variation in the pathogens observed among fragmented populations is caused by ecological factors, one needs to examine systems where host genetic diversity is consistent among the populations, thus controlling for any potentially confounding genetic effects. Here, we report geographic variation in haemosporidian infection among European populations of corncrake. This species now occurs in fragmented populations, but there is little genetic structure and equally high levels of genetic diversity among these populations. We observed a longitudinal gradient…
Influence of Environmental Pollution and Living Conditions on Parasite Transmission among Indigenous Ecuadorians
2022
The purpose of this study was to evaluate the influence of environmental pollution and the living conditions of indigenous Ecuadorians on the transmission of enteroparasites in an Andean agricultural area located at high altitude. Environmental pollution was recorded after observation in each community. The parasites were identified by microscopic sediment analysis using physiological saline solution from macerated arthropods, washed vegetables, and human stools, utilizing four coproparasitological techniques (direct examination, Kato–Katz, ether concentration, and Ziehl–Neelsen). The results show that the inadequate disposal of human and animal excreta that contaminate soil and…
A contribution to the inventory of parasitic microfungi on land plants in Champsaur region (French Alps, “Parc National des Ecrins”).
2023
A preliminary investigation of the flora of parasitic microfungi on land plants is reported, focused upon the mountain and the base of the subalpine ranges, in Champsaur region, (south-western French Alps, mainly within the “Parc National des Ecrins”). Sheltered by 128 host-plant species, 182 species of microfungi have been identified. Their respective distributions, among 24 investigated localities (including four located within the Central Zone of the “Parc National des Ecrins”), are specified. Moreover, seven of these 182 microfungi do not match satisfactorily any of the consulted diagnosis in the specialized literature. Accordingly, a detailed description of the main distinctive traits …
Experimental approaches to study the transmission and infection of Cardiocephaloides longicollis (Rudolphi, 1819) Dubois, 1982 (Trematoda, Strigeidae…
2023
Los trematodos (Platyhelminthes, Trematoda) son componentes ubicuos de los ecosistemas y, en las últimas décadas, los investigadores han mostrado un interés creciente en ellos, especialmente en sus estrategias y mecanismos de transmisión e infección. Los digeneos forman un grupo grande y generalmente tienen un ciclo de vida complejo con tres huéspedes. El primer huésped intermedio suele ser un molusco, el segundo huésped intermedio puede ser un huésped invertebrado o vertebrado, y el huésped definitivo suele ser un vertebrado. En el huésped definitivo, el parásito se convierte en adulto y se reproduce sexualmente. Luego, los huevos del parásito se liberan en el medio ambiente donde el mirac…
Recurrent domestication by Lepidoptera of genes from their parasites mediated by Bracoviruses
2015
Bracoviruses are symbiotic viruses associated with tens of thousands of species of parasitic wasps that develop within the body of lepidopteran hosts and that collectively parasitize caterpillars of virtually every lepidopteran species. Viral particles are produced in the wasp ovaries and injected into host larvae with the wasp eggs. Once in the host body, the viral DNA circles enclosed in the particles integrate into lepidopteran host cell DNA. Here we show that bracovirus DNA sequences have been inserted repeatedly into lepidopteran genomes, indicating this viral DNA can also enter germline cells. The original mode of Horizontal Gene Transfer (HGT) unveiled here is based on the integrativ…
Glochidia Infection of Endemic Fishes from Lake Prespa, N. Macedonia
2022
Large freshwater mussels (Unionida) are long-lived, have large bodies, and produce thousands to millions of larvae (glochidia) that usually must attach to host fish tissue to complete their life cycle. This is an obligate parasitic stage of mussel larvae. However, less than one in onemillion find a suitable host and survive. The degree of host specificity varies among unionid species, from specialists that can successfully parasitize only one or a few closely related fish species to generalists that can complete development on a taxonomically broad range of fish species. In addition, freshwater mussels are among the most threatened groups of animals. This is due to habitat destruction, the …