321 research outputs found
Notes on African Haemaphysalis ticks : 11. H. (Rhipistoma) paraleachi (Ixodoidea : Ixodidae) distribution and hosts of adults
Notes on african Haemaphysalis ticks : 11. H. (Rhipistoma) punctaleachi sp. n., a parasite of West african forest carnivores (Ixodoidea : Ixodidae)
Notes on African Haemaphysalis ticks. XIII. Identity of H. (Rhipistoma) cooleyi, a parasite of the rock hyrax in South Africa (Acarina: Ixodidae)
The lectotype male, allotype female, and paratype nymph of Haemaphysalis (Rhipistoma) cooleyi Bedford, 1929, a parasite of the rock hyrax, Procavia capensis, in the Transvaal, are redescribed and illustrated to provide reliable criteria for differentiating between haemaphysaline parasites of hyraxes. Keys are included for identifying adults of these Haemaphysalis spp. (orientalis Nuttall & Warburton, 1915; bequaerti Hoogstraal, 1956; cooleyi Bedford, 1929; hyracophila Hoogstraal, Walker & Neitz, 1971).The articles have been scanned in colour with a HP Scanjet 5590; 600dpi.
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Notes on African Haemaphysalis ticks. XV. H. (Rhipistoma) norvali sp. n., a hedgehog parasite of the H. (R.) spinulosa group in Zimbabwe (Acarina: Ixodidae)
The male, female, nymph, and larva of Haemaphysalis (Rhipistoma) norvali sp. n., are described and compared with other members of the H. (R.) spinulosa group. Adult H. (R.) norvali parasitize the southern African hedgehog, Erinaceus frontalis Smith, in Matabeleland, Zimbabwe. Immatures were reared on a laboratory rabbit.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi.
Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format
Comments on the validity of Haemaphysalis cinnabarina Koch, 1844 (Acari: Ixodidae), a taxon known solely by the type specimens from Northern Brazil
Inespecificidade parasitária em Argas (Persicargas) miniatus Koch, 1844 (Acari: Argasidae)
The Rift Valley fever accessory proteins NSm and P78/NSm-GN are distinct determinants of virus propagation in vertebrate and invertebrate hosts.: Role of NSm-related proteins in RVFV infection
International audienceRift Valley fever virus (RVFV) is an enzootic virus circulating in Africa that is transmitted to its vertebrate host by a mosquito vector and causes severe clinical manifestations in humans and ruminants. RVFV has a tripartite genome of negative or ambisense polarity. The M segment contains five in-frame AUG codons that are alternatively used for the synthesis of two major structural glycoproteins, GN and GC, and at least two accessory proteins, NSm, a 14-kDa cytosolic protein, and P78/NSm-GN, a 78-kDa glycoprotein. To determine the relative contribution of P78 and NSm to RVFV infectivity, AUG codons were knocked out to generate mutant viruses expressing various sets of the M-encoded proteins. We found that, in the absence of the second AUG codon used to express NSm, a 13-kDa protein corresponding to an N-terminally truncated form of NSm, named NSm', was synthesized from AUG 3. None of the individual accessory proteins had any significant impact on RVFV virulence in mice. However, a mutant virus lacking both NSm and NSm' was strongly attenuated in mice and grew to reduced titers in murine macrophages, a major target cell type of RVFV. In contrast, P78 was not associated with reduced viral virulence in mice, yet it appeared as a major determinant of virus dissemination in mosquitoes. This study demonstrates how related accessory proteins differentially contribute to RVFV propagation in mammalian and arthropod hosts
Transport of Babesia venatorum-infected Ixodes ricinus to Norway by northward migrating passerine birds
<p>Abstract</p> <p>Background</p> <p>Bovine babesiosis is regarded as a limited health problem for Norwegian cows, and the incidence has decreased markedly since the 1930s. Rare cases of babesiosis in splenectomised humans from infection with <it>Babesia divergens </it>and <it>B.venatorum </it>have been described. The objective of this study was to determine whether birds can introduce <it>Babesia</it>-infected ticks. There are between 30 and 85 million passerine birds that migrate to Norway every spring.</p> <p>Methods</p> <p>Passerine birds were examined for ticks at four bird observatories along the southern Norwegian coast during the spring migrations of 2003, 2004 and 2005. The presence of <it>Babesia </it>was detected in the nymphs of <it>Ixodes ricinus </it>by real-time PCR. Positive samples were confirmed using PCR, cloning and phylogenetic analyses.</p> <p>Results</p> <p>Of 512 ticks examined, real-time PCR revealed five to be positive (1.0%). Of these, four generated products that indicated the presence of <it>Babesia </it>spp.; each of these were confirmed to be from <it>Babesia venatorum </it>(EU1). Two of the four <it>B. venatorum</it>-positive ticks were caught from birds having an eastern migratory route (<it>P</it>< 0.001).</p> <p>Conclusions</p> <p>Birds transport millions of ticks across the North Sea, the Skagerrak and the Kattegat every year. Thus, even with the low prevalence of <it>Babesia</it>-infected ticks, a substantial number of infected ticks will be transported into Norway each year. Therefore, there is a continuous risk for introduction of new <it>Babesia </it>spp. into areas where <it>I. ricinus </it>can survive.</p
Nuttalliella namaqua: A Living Fossil and Closest Relative to the Ancestral Tick Lineage: Implications for the Evolution of Blood-Feeding in Ticks
Ticks are monophyletic and composed of the hard (Ixodidae) and soft (Argasidae) tick families, as well as the Nuttalliellidae, a family with a single species, Nuttalliella namaqua. Significant biological differences in lifestyle strategies for hard and soft ticks suggest that various blood-feeding adaptations occurred after their divergence. The phylogenetic relationships between the tick families have not yet been resolved due to the lack of molecular data for N. namaqua. This tick possesses a pseudo-scutum and apical gnathostoma as observed for ixodids, has a leathery cuticle similar to argasids and has been considered the evolutionary missing link between the two families. Little knowledge exists with regard to its feeding biology or host preferences. Data on its biology and systematic relationship to the other tick families could therefore be crucial in understanding the evolution of blood-feeding behaviour in ticks. Live specimens were collected and blood meal analysis showed the presence of DNA for girdled lizards from the Cordylid family. Feeding of ticks on lizards showed that engorgement occurred rapidly, similar to argasids, but that blood meal concentration occurs via malpighian excretion of water. Phylogenetic analysis of the 18S nuclear and 16S mitochondrial genes indicate that N. namaqua grouped basal to the main tick families. The data supports the monophyly of all tick families and suggests the evolution of argasid-like blood-feeding behaviour in the ancestral tick lineage. Based on the data and considerations from literature we propose an origin for ticks in the Karoo basin of Gondwanaland during the late Permian. The nuttalliellid family almost became extinct during the End Permian event, leaving N. namaqua as the closest living relative to the ancestral tick lineage and the evolutionary missing link between the tick families
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