691 research outputs found

    A new filaria of a lizard transmitted by sandflies

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    A description is given of Madathamugadia wanjii n. sp., a Splendidofilariinae parasite of the gecko Ptyodactylus hasselquistii, on the west bank of the River Jordan and of its life cycle in Phlebotomus duboscqi. The new species is close to M. ivaschkini (Annaev, 1976) n. comb., of Turkmenistan, wich is also transmitted by sandflies (Reznik, 1982). The genus Madathamugadia is now comprised of four species, two from Madagascar and two from the Mediterranean sub-region; it differs from the genus Thamugadia by the presence of a double row of papillae anterior to the cloaca of the male. The larval characters of Splendidofilarinae of lizards confirm the affinity of these parasites to the Splendidofilarinae of birds (Chandlerella and Splendidofilaria); the first group could have arisen from the second by "captures" wich could have occurred in several places

    A possible role for Phlebotomus (Anaphlebotomus) rodhaini (Parrot, 1930) in transmission of Leishmania donovani

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    <p>Abstract</p> <p>Background</p> <p>Visceral leishmaniasis (VL, kala azar), caused by <it>Leishmania donovani </it>is a major health problem in Sudan and other East African countries. In this region the only proven vectors of <it>L. donovani </it>are <it>Phlebotomus orientalis </it>in eastern Sudan, Ethiopia and Upper Nile areas of Southern Sudan and <it>Phlebotomus martini </it>in Ethiopia, Kenya and Southern Sudan. In this report, we present the first evidence that <it>Phlebotomus rodhaini </it>may also play a role in maintaining transmission of <it>L. donovani </it>between animal reservoir hosts in eastern Sudan. The study was conducted in a zoonotic focus of visceral leishmaniasis in Dinder National Park, eastern Sudan, where previous work showed high infection rates of <it>L. donovani </it>in <it>P. orientalis</it>. Sand flies, captured by CDC traps were dissected and examined for infection with <it>Leishmania </it>parasites. Parasite isolates were subjected to <it>L. donovani </it>specific PCR. Field experiments were also carried out to compare efficiency of rodent baited and un-baited CDC traps in collection of <it>P. rodhaini </it>and determine its man-biting rate.</p> <p>Results</p> <p>Three female <it>P. rodhain</it>i were found infected with <it>Leishmania </it>parasites in an astonishingly small number of flies captured in three separate field trips. Two of these isolates were typed by molecular methods as <it>L. donovani</it>, while the third isolate was inoculated into a hamster that was subsequently lost. Although <it>P. rodhaini is </it>generally considered a rare species, results obtained in this study indicate that it can readily be captured by rodent-baited traps. Results of human landing collection showed that it rarely bites humans in the area.</p> <p>Conclusion</p> <p>It is concluded that <it>P. rodhaini </it>is a possible vector of <it>L. donovani </it>between animal reservoir hosts but is not responsible for infecting humans. It is suggested that the role of <it>P</it>. <it>rodhaini </it>in transmission of <it>L. donovani </it>in other zoonotic foci of visceral leishmaniasis in Africa should be re-examined.</p

    Fitness costs of disrupting circadian rhythms in malaria parasites

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    Circadian biology assumes that biological rhythms maximize fitness by enabling organisms to coordinate with their environment. Despite circadian clocks being such a widespread phenomenon, demonstrating the fitness benefits of temporal coordination is challenging and such studies are rare. Here, we tested the consequences—for parasites—of being temporally mismatched to host circadian rhythms using the rodent malaria parasite, Plasmodium chabaudi. The cyclical nature of malaria infections is well known, as the cell cycles across parasite species last a multiple of approximately 24 h, but the evolutionary explanations for periodicity are poorly understood. We demonstrate that perturbation of parasite rhythms results in a twofold cost to the production of replicating and transmission stages. Thus, synchronization with host rhythms influences in-host survival and between-host transmission potential, revealing a role for circadian rhythms in the evolution of host–parasite interactions. More generally, our results provide a demonstration of the adaptive value of circadian rhythms and the utility of using an evolutionary framework to understand parasite traits

    Species diversity and flagellate infections in the sand fly fauna near Porto Grande, State of Amapá, Brazil (Diptera: Psychodidae. Kinetoplastida: Trypanosomatidae)

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    Forty-six species of Lutzomyia and one species of Brumptomyia were identified among 20,008 sand flies collected in central Amapá. L. squamiventris maripaensis, L. infraspinosa, L. umbratilis and L. ubiquitalis accounted for 66% of the specimens caught in light traps, and L. umbratilis was the commonest of the 16 species found on tree bases. Seven species of Lutzomyia including L. umbratilis were collected in a plantation of Caribbean pine. Sixty out of 511 female sand flies dissected were positive for flagellates. Among the sand flies from which Leishmania was isolated, promastigotes were observed in the salivary glands and foregut of 13 out of 21 females scored as having very heavy infections in the remainder of the gut, reinforcing the idea that salivary gland invasion may be part of the normal life cycle of Leishmania in nature. Salivary gland infections were detected in specimens of L. umbratilis, L. whitmani and L. spathotrichia. Parasites isolated from L. umbratilis, L. whitmani and also from one specimen of L. dendrophyla containing the remains of a bloodmeal, were compatible with Le. guyanensis by morphology and behaviour in hamsters
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