101 research outputs found

    Comparison of Leishmania killicki (syn. L-tropica) and Leishmania tropica population structure in Maghreb by microsatellite typing

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    Leishmania (L.) killicki (syn. L. tropica), which causes cutaneous leishmaniasis in Maghreb, was recently described in this region and identified as a subpopulation of L. tropica. The present genetic analysis was conducted to explore the spatio-temporal distribution of L. killicki (syn. L. tropica) and its transmission dynamics. To better understand the evolution of this parasite, its population structure was then compared with that of L. tropica populations from Morocco. In total 198 samples including 85 L. killicki (syn. L. tropica) (from Tunisia, Algeria and Libya) and 113 L. tropica specimens (all from Morocco) were tested. Theses samples were composed of 168 Leishmania strains isolated from human skin lesions, 27 DNA samples from human skin lesion biopsies, two DNA samples from Ctenodactylus gundi bone marrow and one DNA sample from a Phlebotomus sergenti female. The sample was analyzed by using MultiLocus Enzyme Electrophoresis (MLEE) and MultiLocus Microsatellite Typing (MLMT) approaches. Analysis of the MLMT data support the hypothesis that L. killicki (syn. L. tropica) belongs to the L. tropica complex, despite its strong genetic differentiation, and that it emerged from this taxon by a founder effect. Moreover, it revealed a strong structuring in L. killicki (syn. L. tropica) between Tunisia and Algeria and within the different Tunisian regions, suggesting low dispersion of L. killicki (syn. L. tropica) in space and time. Comparison of the L. tropica (exclusively from Morocco) and L. killicki (syn. L. tropica) population structures revealed distinct genetic organizations, reflecting different epidemiological cycles

    Meeting sustainable development goals via robotics and autonomous systems

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    Robotics and autonomous systems are reshaping the world, changing healthcare, food production and biodiversity management. While they will play a fundamental role in delivering the UN Sustainable Development Goals, associated opportunities and threats are yet to be considered systematically. We report on a horizon scan evaluating robotics and autonomous systems impact on all Sustainable Development Goals, involving 102 experts from around the world. Robotics and autonomous systems are likely to transform how the Sustainable Development Goals are achieved, through replacing and supporting human activities, fostering innovation, enhancing remote access and improving monitoring. Emerging threats relate to reinforcing inequalities, exacerbating environmental change, diverting resources from tried-and-tested solutions and reducing freedom and privacy through inadequate governance. Although predicting future impacts of robotics and autonomous systems on the Sustainable Development Goals is difficult, thoroughly examining technological developments early is essential to prevent unintended detrimental consequences. Additionally, robotics and autonomous systems should be considered explicitly when developing future iterations of the Sustainable Development Goals to avoid reversing progress or exacerbating inequalities

    Investigation of bio-insecticidal activity of two aromatic essential oils against Tribolium castaneum (Herbst) (Coleoptera, Tenebrionidae)

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    Excessive application of synthetic insecticides damages not only the environment and agriculture, but also affects the human health. In this study we investigated greener methods to control an insect pest of stored products. We focalized our work on the characterization and study of the biological activity of Thymus algeriensis Boiss. and Reut (1852) and Thymus capitatus (L.) Hoffmanns. et Link (1809) essential oils against Tribolium castaneum Herbest (1797). The essential oils were obtained by hydrodistillation, analysed by GC/MS and screened for their insecticidal activity against T. castaneum using fumigation [1], topical application [2], repulsion [3], and feeding tests [4] at the doses of 1, 10 and 20%. The chemical analysis of the essential oils of these two species showed a qualitative and quantitative similarity. Indeed, they were both particularly rich in oxygenated monoterpenes (T. capitatus 85.1% and T. algeriensis 74.0%). The investigation of the bio-insecticidal activity of the essential oils by topical application showed that T. capitatus essential oil was more toxic against adults and nymphs (respectively 61% and 100% at the dose of 10%) than T. algeriensis. However, T. algeriensis was characterized by a higher repulsive activity (Class V at all the doses) and without any fumigant toxicity against T. castaneum adults. The study of the nutritional indices highlights a phagostimulant effect for T. capitatus and T. algeriensis oils. Even if quite similar, these different modes of action can be attributed to the different qualiquantitative composition of these two essential oils. More investigations, in particular about the mechanism of action, are needed in the aim of their possible future agronomic use in insect control to protect the environment and the living beings from insect pests

    Increase of canine leishmaniasis in a previously low-endemicity area in Tunisia

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    An epidemiological study of canine leishmaniasis (CanL) was carried out in nine districts of Sfax, in the southern central part of Tunisia. Sera from 250 dogs were tested by two serological methods: the indirect immunofluorescence antibody test and the counter-immunoelectrophoresis. Seven to eight months later, before the next season of transmission, seropositive dogs from the first test were re-examined and a second sampling was performed. Infection status was assessed by serology and by other methods. PCR, in vitro culture and direct examination were applied on blood and other samples (bone marrow, liver, lymph node, spleen and cutaneous biopsies). The seroprevalence of the infection in dogs was 6 %. Infection was then confirmed by at least one other method. The PCR is the method which agreed most with serology, all seropositive dogs were found PCR-positive. The sensitivity of the direct examination and the culture was only 33 % and 55 % respectively as compared with serology. A similar value of seroprevalence has been observed previously in Sousse, in the northern central part of Tunisia. The present report suggests a significant increase of CanL in the Sfax area and confirms that the disease is continuing to move southwards in Tunisia

    Increase of canine leishmaniasis in a previously low-endemicity area in Tunisia

    No full text
    An epidemiological study of canine leishmaniasis (CanL) was carried out in nine districts of Sfax, in the southern central part of Tunisia. Sera from 250 dogs were tested by two serological methods: the indirect immunofluorescence antibody test and the counter-immunoelectrophoresis. Seven to eight months later, before the next season of transmission, seropositive dogs from the first test were re-examined and a second sampling was performed. Infection status was assessed by serology and by other methods. PCR, in vitro culture and direct examination were applied on blood and other samples (bone marrow, liver, lymph node, spleen and cutaneous biopsies). The seroprevalence of the infection in dogs was 6 %. Infection was then confirmed by at least one other method. The PCR is the method which agreed most with serology, all seropositive dogs were found PCR-positive. The sensitivity of the direct examination and the culture was only 33 % and 55 % respectively as compared with serology. A similar value of seroprevalence has been observed previously in Sousse, in the northern central part of Tunisia. The present report suggests a significant increase of CanL in the Sfax area and confirms that the disease is continuing to move southwards in Tunisia

    Increase of canine leishmaniasis in a previously low-endemicity area in Tunisia

    No full text
    An epidemiological study of canine leishmaniasis (CanL) was carried out in nine districts of Sfax, in the southern central part of Tunisia. Sera from 250 dogs were tested by two serological methods: the indirect immunofluorescence antibody test and the counter-immunoelectrophoresis. Seven to eight months later, before the next season of transmission, seropositive dogs from the first test were re-examined and a second sampling was performed. Infection status was assessed by serology and by other methods. PCR, in vitro culture and direct examination were applied on blood and other samples (bone marrow, liver, lymph node, spleen and cutaneous biopsies). The seroprevalence of the infection in dogs was 6 %. Infection was then confirmed by at least one other method. The PCR is the method which agreed most with serology, all seropositive dogs were found PCR-positive. The sensitivity of the direct examination and the culture was only 33 % and 55 % respectively as compared with serology. A similar value of seroprevalence has been observed previously in Sousse, in the northern central part of Tunisia. The present report suggests a significant increase of CanL in the Sfax area and confirms that the disease is continuing to move southwards in Tunisia

    Chemical constituents and toxicity of essential oils from three Asteraceae plants against Tribolium confusum

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    Plants produce a high diversity of secondary metabolites with a prominent function in the protection against pests and pathogens. In this work, we studied the chemical composition and the effect of six essential oils extracted from three Asteraceae species (Heteromera fuscata, Coleostephus myconis and Mauranthemum paludosum) on nutritional indexes, adult emergence and larva and adult toxicity of Tribolium confusum. Flower and leaf essential oils were obtained by hydrodistillation. The study of their chemical composition was carried out by GC-MS. The results showed that they are rich on monoand sesquiterpens. The consumption of essential oils mixed with artificial diet of T. confusum larvae showed that H. fuscata leaf essential oil delayed the insect growth, reduced the food consumption and exhibited significant food deterrent index (0.02 ± 0.01 mg/mg/j, 0.05 ± 0.02 mg/mg/j, and 71.20 ± 19.22%, respectively) on treated larvae. Topical application of Asteraceae essential oils on pupae less than 24 h of age caused malformation on emerged adults. The highest level of malformation (18%) was induced by C. myconis leaf essential. Topical application of those essential oils on T. confusum adults (10 and 14 days-old) showed higher toxicity. The highest mortality of about 41% was recorded 7 days post-treatment on adults treated with essential oils from M. paludosum leaves. These preliminary results could represent the basis for further investigations on the susceptibility of the other developmental stages and elucidation of the mode of action of mono- and sesquiterpenoids against these insect pest

    Use of PCR, IFAT and

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    The aim of this study was to assess the use of parasitological, serological and molecular methods for the detection of Leishmania infection in blood of 67 dogs and to investigate the prevalence of canine leishmaniasis (CanL) in Kairouan (central Tunisia), an area known to be of reduced endemicity and has not been studied since 1973. Veterinarians clinically examined all dogs, and the titer of anti-Leishmania antibodies was determined by indirect immune-fluorescence antibody test. The presence of Leishmania was performed by PCR and in vitro culture. IFAT was positive in 12% of dogs and promastigote form of the parasite was isolated by in vitro culture from only 4.5% of them. However, DNA of Leishmania was detected by PCR in 20.9% of dogs. PCR was more sensitive than IFAT (p = 0.004) and in vitro culture (p < 10–5). A prevalence of 21% was found in Kairouan, which is significant high (p < 10–3) when compared to that of thirty years ago. This state is in correlation with the increase in other Mediterranean countries. Furthermore, 50% of positive dogs were asymptomatic. Preventive measures must be taken against these dogs as for symptomatic ones since their role in the transmission of the infection to vectors has been proven
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