Study on the role of the sylvatic cycle of African swine fever in Senegal

It is generally believed that African swine fever (ASF) virus in Sub-Saharan Africa is maintained in nature by warthogs (Phacochoerus africanus) and soft ticks from the genus Ornithodoros (Penrith et al., 2004). In Senegal, warthogs are present in some nature reserves and the presence of an argasid tick (O. sonrai) has been described (Vial et al., 2007). In order to verify the presence of such a sylvatic cycle in Senegal, 74 warthog sera from different locations were analysed for ASF antibodies by Blocking Elisa and Algenex anti rp-30 ELISA. Moreover, 48 warthog burrows were inspected in the Sine Saloum National Park. Equally, 132 sera from free-ranging pigs reared in central and South Senegal and 74 warthogs sera were analyzed for the presence of antibodies against Ornithodoros erraticus (Canals et al, 1990). All the warthog sera were negative against ASF antibodies and anti-tick antibodies. Equally, no presence of soft ticks were detected in the 48 warthog burrows inspected despite O. sonrai was found in neighbouring rodent burrows. Among the 132 pig sera tested against tick antibodies, 8.5% (n=12) showed positive titres. There was a strong correlation between the later sera and those sampled in the area of distribution of O. sonrai (OR=7.1; p="0.028)." In addition, among those sera, 36% (n=4) showed also positive titres to ASF virus. The absence of antibodies against ASF in warthog sera confirms the lack of circulation of ASFV among warthog populations in Senegal, even in areas where the tick is present. The absence of antibodies against soft ticks in warthogs from different regions confirms that contacts between warthogs and O. sonrai are inexistent. The detection of antibodies against O. sonrai in pig sera confirms that contacts between both species occur. Moreover, it seems to confirm that O. sonrai and O. erraticus are antigenically related and that this diagnostic method could be useful to determine the distribution of O. sonrai in Senegal and other countries. Finally, these results prove the absence of warthog involvement in the cycle of ASF virus and confirm a potential role of O. sonrai as a reservoir host for the virus in Senegal. (Texte intégral

Hard tick species of livestock and their bioecology in Golestan Province, North of Iran

Background: A survey on tick species composition was carried out in Golestan Province Iran during year 2010- 2011.The aim was to determine tick species parasitizing domestic ruminants and their seasonal population dynamics. Methods: A total of 124 sheep, 92 goats, 84 cattle, 74 camels and 12 horses in several villages were inspected for tick infestation. The collected ticks preserved in 70% alcohol and then were identified. Results: The overall 1059 ticks (453 female, 606 male) were collected. The ticks occur on sheep, goats, cattle, camels and horses as 72.1%, 77.3%, 75.8%, 69.3%, and 50% respectively. The frequency of ticks in spring was more than other seasons and the least was observed in winter. In the spring and summer, infestation rate in domestic ruminants were calculated as 100%. Six genus and fourteen hard and soft tick species were identified including Rhipicephalus sanguineus, R. bursa, Ixodes ricinus, Haemaphysalis punctata, H. sulcata, H. erinacei, H. inermis, Hyalomma marginatum, Hy. asiaticum, Hy. dromedarii, Hy. excavatum, Hy. anatolicum, Hy. detritum, Boophilus annulatus and Argas persicus. Rhipicephalus sanguineus was the most abundant species in the study area. The largest number of ticks was collected from animal ears and tails. Haemaphysalis, Hyalomma, Rhipicephalus and Boophilus occurred in mountainous, forest and plateau areas of Golestan Province but Ixodes occurred only in mountainous and forest areas, whereas Rhipicephalus and Hyalomma were present in coastal areas of Golestan Province. Conclusion: The result of this study is a survey on tick species from domestic animals in Iran and implication of possible prevention measures for diseases transmitted by ticks

Ornithodoros quilinensis sp. nov. (Acari, Argasidae), a new tick species from the Chacoan region in Argentina

Ornithodoros quilinensis sp. nov. (Acari: Argasidae) is described from larvae collected on the small rodents Graomys centralis (Cricetidae: Sigmodontinae) in Argentina. The diagnostic characters for this new species are a combination of small size (520-540 μm), a dorsal plate oval in shape with a length of approximately 200 μm, 14 pairs of dorsal setae, hypostome short and narrower at the base (length from Ph1 to apex 133 μm (120-141)) with dental formula 2/2 and apex blunt, and the capsule of the Haller's organ irregular in shape and without reticulations. The analysis of the 16S rDNA sequences available for the genus Ornithodoros indicate that, phylogenetically, O. quilinensis represents an independent lineage only related to a Bolivian tick species of the genus Ornithodoros yet not formally described.Fil: Venzal, José M.. Universidad de la Republica, Salto; UruguayFil: Nava, Santiago. Instituto Nacional de Tecnología Agropecuaria Eea, Rafaela; ArgentinaFil: Mangold, Atilio Jose. Instituto Nacional de Tecnología Agropecuaria Eea, Rafaela; ArgentinaFil: Mastropaolo, Mariano. Instituto Nacional de Tecnología Agropecuaria Eea, Rafaela; ArgentinaFil: Casás, Gustavo. UNIVERSIDAD DE LA REPUBLICA (UDELAR); . Universidad de la República; UruguayFil: Guglielmone, Alberto Alejandro. Instituto Nacional de Tecnología Agropecuaria Eea, Rafaela; Argentin

Can the Gram-negative bacterium Escherichia coli colonize the gut of Lone Star Tick (Amblyomma americanum)?

Ticks are obligate blood feeding ectoparasites and vectors of several mammalian pathogens (Williams-Newkirk et al, 2014). In addition to pathogens they also carry a bacterial community with commensal and symbiotic relationships (Bonnet et al, 2017). Using a culture-dependent approach we previously reported a high prevalence of Gram-positive bacteria in the gut of field collected lone star ticks (Amblyomma americanum). These results suggested that epithelial immunity functions to control Gram-negative bacteria in A. americanum. In this study, we used a culturing and non-culturing approach to measure the outcome of E.coli (Gram-negative) when fed to female adult lone star ticks (n=16). Results showed a significant reduction of E.coli at Days 1, 3 and 7 post bacterial feeding. qPCR of 16S rDNA confirmed reduction of bacterial rDNA when compared to water fed ticks (n=16). Our results suggest that there is a midgut epithelial immune response in place, which mainly targets Gram-negative bacteria

The Singing Insects of Michigan

Excerpt: The so-called singing insects are all those that make loud, rhythmical noises. They include members of three groups of Orthoptera (Gryllidae, Tettigoniidae, and Acridoidea) and one family of Homoptera (Cicadidae). There are about 300 noisy species in these four groups in eastern North America, perhaps a thousand in all of North America, and 25-30 thousand in the entire world. Only about 1000 of the world species have been studied in any detail, mostly in North America, Europe, Japan, and Australia

Model Exploration Using OpenMOLE - a workflow engine for large scale distributed design of experiments and parameter tuning

OpenMOLE is a scientific workflow engine with a strong emphasis on workload distribution. Workflows are designed using a high level Domain Specific Language (DSL) built on top of Scala. It exposes natural parallelism constructs to easily delegate the workload resulting from a workflow to a wide range of distributed computing environments. In this work, we briefly expose the strong assets of OpenMOLE and demonstrate its efficiency at exploring the parameter set of an agent simulation model. We perform a multi-objective optimisation on this model using computationally expensive Genetic Algorithms (GA). OpenMOLE hides the complexity of designing such an experiment thanks to its DSL, and transparently distributes the optimisation process. The example shows how an initialisation of the GA with a population of 200,000 individuals can be evaluated in one hour on the European Grid Infrastructure.Comment: IEEE High Performance Computing and Simulation conference 2015, Jun 2015, Amsterdam, Netherland