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Trypanosoma dionisii, for which only bat bugs (Cimicidae) had previously been demonstrated as vectors, was, for the first time, detected in the gamasine mite Steatonyssus periblepharus in Russia. The molecular phylogenetic analysis indicated that trypanosomes found in these mites belong to the "clade A" of T. dionisii, which, based on genetic distances, can be considered as a species separate from the sister clade B, and according to available data also has a distinct geographic distribution. The presence of developmental forms of T. dionisii resembling those previously described during the development of this trypanosome in cimicids suggests that S. periblepharus is a novel vector of the studied trypanosome. [ABSTRACT FROM AUTHOR]

Tatra chamois (Rupicapra rupicapra tatrica (Blahout 1972)) and Tatra marmot (Marmota marmota latirostris (Kratochvíl 1961)) are significant endemic subspecies of the subalpine and alpine ranges of the Tatra Mountains in Central Europe. In four studied localities in the range of their typical biotopes in Slovakia and Poland, we investigated intestinal parasites of Tatra chamois and Tatra marmots, with an emphasis on anoplocephalid tapeworms. We also studied the occurrence, species diversity, and abundance of oribatid mites as intermediate hosts thereof, and the prevalence of cysticercoid larval stages of anoplocephalid tapeworms in collected oribatids using morphological and molecular methods. Coprological analyses revealed the average positivity of Moniezia spp. in chamois faeces at 23.5% and Ctenotaenia marmotae in marmot samples at 71.1%, with significant differences between the localities under study. Morphological analyses determined the presence of cysticercoids in five oribatid species: Ceratozetes gracilis, Edwardzetes edwardsi, Scheloribates laevigatus, Trichoribates novus, and Tectocepheus velatus sarekensis. This is the first record of T. v. sarekensis as an intermediate host of anoplocephalid tapeworms, as well as the first report of Andrya cuniculi occurrence in the territory of the Tatra Mountains, confirmed also by molecular methods. [ABSTRACT FROM AUTHOR]

Most trypanosomatid flagellates do not have catalase. In the evolution of this group, the gene encoding catalase has been independently acquired at least three times from three different bacterial groups. Here, we demonstrate that the catalase of Vickermania was obtained by horizontal gene transfer from Gammaproteobacteria, extending the list of known bacterial sources of this gene. Comparative biochemical analyses revealed that the enzymes of V. ingenoplastis, Leptomonas pyrrhocoris, and Blastocrithidia sp., representing the three independent catalase-bearing trypanosomatid lineages, have similar properties, except for the unique cyanide resistance in the catalase of the latter species. [ABSTRACT FROM AUTHOR]

Protein phosphorylation/dephosphorylation is an important regulatory mechanism that controls many key physiological processes. Numerous pathogens successfully use kinases and phosphatases to internalize, replicate, and survive, modifying the host′s phosphorylation profile or signal transduction pathways. Multiple phosphatases and kinases from diverse bacterial pathogens have been implicated in human infections before. In this work, we have identified and characterized the dual specificity protein/lipid phosphatase LmDUSP1 as a novel virulence factor governing Leishmania mexicana infection. The LmDUSP1-encoding gene (LmxM.22.0250 in L. mexicana) has been acquired from bacteria via horizontal gene transfer. Importantly, its orthologues have been associated with virulence in several bacterial species, such as Mycobacterium tuberculosis and Listeria monocytogenes. Leishmania mexicana with ablated LmxM.22.0250 demonstrated severely attenuated virulence in the experimental infection of primary mouse macrophages, suggesting that this gene facilitates Leishmania pathogenicity in vertebrates. Despite significant upregulation of LmxM.22.0250 expression in metacyclic promastigotes, its ablation did not affect the ability of mutant cells to differentiate into virulent stages in insects. It remains to be further investigated which specific biochemical pathways involve LmDUSP1 and how this facilitates the parasite′s survival in the host. One of the interesting possibilities is that LmDUSP1 may target host′s substrate(s), thereby affecting its signal transduction pathways. [ABSTRACT FROM AUTHOR]