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Sample records for tsetse flies trypanosomes

  1. A systematic review and meta-analysis of trypanosome prevalence in tsetse flies

    Science.gov (United States)

    Background: The optimisation of trypanosomosis control programs warrants a good knowledge of the main vector of animal and human trypanosomes in sub-Saharan Africa, the tsetse fly. An important aspect of the tsetse fly population is its trypanosome infection prevalence, as it determines the intensit...

  2. Seasonal variation of tsetse fly species abundance and prevalence of trypanosomes in the Maasai Steppe, Tanzania.

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    Nnko, Happiness J; Ngonyoka, Anibariki; Salekwa, Linda; Estes, Anna B; Hudson, Peter J; Gwakisa, Paul S; Cattadori, Isabella M

    2017-06-01

    Tsetse flies, the vectors of trypanosomiasis, represent a threat to public health and economy in sub-Saharan Africa. Despite these concerns, information on temporal and spatial dynamics of tsetse and trypanosomes remain limited and may be a reason that control strategies are less effective. The current study assessed the temporal variation of the relative abundance of tsetse fly species and trypanosome prevalence in relation to climate in the Maasai Steppe of Tanzania in 2014-2015. Tsetse flies were captured using odor-baited Epsilon traps deployed in ten sites selected through random subsampling of the major vegetation types in the area. Fly species were identified morphologically and trypanosome species classified using PCR. The climate dataset was acquired from the African Flood and Drought Monitor repository. Three species of tsetse flies were identified: G. swynnertoni (70.8%), G. m. morsitans (23.4%), and G.pallidipes (5.8%). All species showed monthly changes in abundance with most of the flies collected in July. The relative abundance of G. m. morsitans and G. swynnertoni was negatively correlated with maximum and minimum temperature, respectively. Three trypanosome species were recorded: T. vivax (82.1%), T. brucei (8.93%), and T. congolense (3.57%). The peak of trypanosome infections in the flies was found in October and was three months after the tsetse abundance peak; prevalence was negatively correlated with tsetse abundance. A strong positive relationship was found between trypanosome prevalence and temperature. In conclusion, we find that trypanosome prevalence is dependent on fly availability, and temperature drives both tsetse fly relative abundance and trypanosome prevalence. © 2017 The Society for Vector Ecology.

  3. A systematic review and meta-analysis of trypanosome prevalence in tsetse flies.

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    Abdi, Reta D; Agga, Getahun E; Aregawi, Weldegebrial G; Bekana, Merga; Van Leeuwen, Thomas; Delespaux, Vincent; Duchateau, Luc

    2017-04-13

    The optimisation of trypanosomosis control programs warrants a good knowledge of the main vector of animal and human trypanosomes in sub-Saharan Africa, the tsetse fly. An important aspect of the tsetse fly population is its trypanosome infection prevalence, as it determines the intensity of the transmission of the parasite by the vector. We therefore conducted a systematic review of published studies documenting trypanosome infection prevalence from field surveys or from laboratory experiments under controlled conditions. Publications were screened in the Web of Science, PubMed and Google Scholar databases. Using the four-stage (identification, screening, eligibility and inclusion) process in the PRISMA statement the initial screened total of 605 studies were reduced to 72 studies. The microscopic examination of dissected flies (dissection method) remains the most used method to detect trypanosomes and thus constituted the main focus of this analysis. Meta-regression was performed to identify factors responsible for high trypanosome prevalence in the vectors and a random effects meta-analysis was used to report the sensitivity of molecular and serological tests using the dissection method as gold standard. The overall pooled prevalence was 10.3% (95% confidence interval [CI] = 8.1%, 12.4%) and 31.0% (95% CI = 20.0%, 42.0%) for the field survey and laboratory experiment data respectively. The country and the year of publication were found to be significantly factors associated with the prevalence of trypanosome infection in tsetse flies. The alternative diagnostic tools applied to dissection positive samples were characterised by low sensitivity, and no information on the specificity was available at all. Both temporal and spatial variation in trypanosome infection prevalence of field collected tsetse flies exists, but further investigation on real risk factors is needed how this variation can be explained. Improving the sensitivity and determining the

  4. Trypanosome infection establishment in the tsetse fly gut is influenced by microbiome-regulated host immune barriers.

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    Brian L Weiss

    Full Text Available Tsetse flies (Glossina spp. vector pathogenic African trypanosomes, which cause sleeping sickness in humans and nagana in domesticated animals. Additionally, tsetse harbors 3 maternally transmitted endosymbiotic bacteria that modulate their host's physiology. Tsetse is highly resistant to infection with trypanosomes, and this phenotype depends on multiple physiological factors at the time of challenge. These factors include host age, density of maternally-derived trypanolytic effector molecules present in the gut, and symbiont status during development. In this study, we investigated the molecular mechanisms that result in tsetse's resistance to trypanosomes. We found that following parasite challenge, young susceptible tsetse present a highly attenuated immune response. In contrast, mature refractory flies express higher levels of genes associated with humoral (attacin and pgrp-lb and epithelial (inducible nitric oxide synthase and dual oxidase immunity. Additionally, we discovered that tsetse must harbor its endogenous microbiome during intrauterine larval development in order to present a parasite refractory phenotype during adulthood. Interestingly, mature aposymbiotic flies (Gmm(Apo present a strong immune response earlier in the infection process than do WT flies that harbor symbiotic bacteria throughout their entire lifecycle. However, this early response fails to confer significant resistance to trypanosomes. Gmm(Apo adults present a structurally compromised peritrophic matrix (PM, which lines the fly midgut and serves as a physical barrier that separates luminal contents from immune responsive epithelial cells. We propose that the early immune response we observe in Gmm(Apo flies following parasite challenge results from the premature exposure of gut epithelia to parasite-derived immunogens in the absence of a robust PM. Thus, tsetse's PM appears to regulate the timing of host immune induction following parasite challenge. Our results

  5. Delivery of a functional anti-trypanosome Nanobody in different tsetse fly tissues via a bacterial symbiont, Sodalis glossinidius.

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    De Vooght, Linda; Caljon, Guy; De Ridder, Karin; Van Den Abbeele, Jan

    2014-11-07

    Sodalis glossinidius, a vertically transmitted microbial symbiont of the tsetse fly, is currently considered as a potential delivery system for anti-trypanosomal components that reduce or eliminate the capability of the tsetse fly host to transmit parasitic trypanosomes, an approach also known as paratransgenesis. An essential step in developing paratransgenic tsetse is the stable colonization of adult flies and their progeny with recombinant Sodalis bacteria, expressing trypanocidal effector molecules in tissues where the parasite resides. In this study, Sodalis was tested for its ability to deliver functional anti-trypanosome nanobodies (Nbs) in Glossina morsitans morsitans. We characterized the in vitro and in vivo stability of recombinant Sodalis (recSodalis) expressing a potent trypanolytic nanobody, i.e. Nb_An46. We show that recSodalis is competitive with WT Sodalis in in vivo conditions and that tsetse flies transiently cleared of their endogenous WT Sodalis population can be successfully repopulated with recSodalis at high densities. In addition, vertical transmission to the offspring was observed. Finally, we demonstrated that recSodalis expressed significant levels (ng range) of functional Nb_An46 in different tsetse fly tissues, including the midgut where an important developmental stage of the trypanosome parasite occurs. We demonstrated the proof-of-concept that the Sodalis symbiont can be genetically engineered to express and release significant amounts of functional anti-trypanosome Nbs in different tissues of the tsetse fly. The application of this innovative concept of using pathogen-targeting nanobodies delivered by insect symbiotic bacteria could be extended to other vector-pathogen systems.

  6. Spatial distribution and trypanosome infection of tsetse flies in the sleeping sickness focus of Zimbabwe in Hurungwe District

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    William Shereni

    2016-11-01

    Full Text Available Abstract Background In Zimbabwe, cases of human African trypanosomiasis (HAT are caused by the unicellular protozoan Trypanosoma brucei, sub-species T. b. rhodesiense. They are reported from the tsetse-infested area in the northern part of the country, broadly corresponding to the valley of the Zambezi River. Tsetse-transmitted trypanosomes, in particular T. congolense and T. vivax, also cause morbidity and mortality in livestock, thus generating poverty and food insecurity. Two species of tsetse fly, Glossina morsistans morsitans and G. pallidipes, are known to be present in the Zambezi Valley, although their distributional patterns and densities have not been investigated in detail. The present study tries to address this gap by providing some insight into the dynamics of trypanosomiasis in humans and livestock. Methods Tsetse distribution and trypanosome infections were studied using traps and fixed fly rounds located at 10 km intervals along a 110 km long transect straddling the southern escarpment of the Zambezi Valley. Three km long fly rounds were conducted on 12 sites, and were repeated 11 times over a 7-month period. Additional traps were deployed and monitored in selected sites. Microscopic examination of 2092 flies for trypanosome infections was conducted. Results Surveys confirmed the presence of G. morsitans morsitans and G. pallidipes in the Zambezi Valley floor. Moving south, the apparent density of tsetse flies appears to peak in the vicinity of the escarpment, then drops on the highlands. Only one fly was caught south of the old game fence separating protected and settled areas. A trypanosome infection rate of 6.31% was recorded in tsetse flies dissected. Only one infection of the T. brucei-type was detected. Conclusions Tsetse fly distribution in the study area appears to be driven by ecological factors such as variation in land use and altitude-mediated climatic patterns. Although targeted control of tsetse flies have played

  7. A tsetse and tabanid fly survey of African great apes habitats reveals the presence of a novel trypanosome lineage but the absence of Trypanosoma brucei.

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    Votýpka, Jan; Rádrová, Jana; Skalický, Tomáš; Jirků, Milan; Jirsová, Dagmar; Mihalca, Andrei D; D'Amico, Gianluca; Petrželková, Klára J; Modrý, David; Lukeš, Julius

    2015-10-01

    Tsetse and tabanid flies transmit several Trypanosoma species, some of which are human and livestock pathogens of major medical and socioeconomic impact in Africa. Recent advances in molecular techniques and phylogenetic analyses have revealed a growing diversity of previously unidentified tsetse-transmitted trypanosomes potentially pathogenic to livestock and/or other domestic animals as well as wildlife, including African great apes. To map the distribution, prevalence and co-occurrence of known and novel trypanosome species, we analyzed tsetse and tabanid flies collected in the primary forested part of the Dzanga-Sangha Protected Areas, Central African Republic, which hosts a broad spectrum of wildlife including primates and is virtually devoid of domestic animals. Altogether, 564 tsetse flies and 81 tabanid flies were individually screened for the presence of trypanosomes using 18S rRNA-specific nested PCR. Herein, we demonstrate that wildlife animals are parasitized by a surprisingly wide range of trypanosome species that in some cases may circulate via these insect vectors. While one-third of the examined tsetse flies harbored trypanosomes either from the Trypanosoma theileri, Trypanosoma congolense or Trypanosoma simiae complex, or one of the three new members of the genus Trypanosoma (strains 'Bai', 'Ngbanda' and 'Didon'), more than half of the tabanid flies exclusively carried T. theileri. To establish the putative vertebrate hosts of the novel trypanosome species, we further analyzed the provenance of blood meals of tsetse flies. DNA individually isolated from 1033 specimens of Glossina spp. and subjected to high-throughput library-based screening proved that most of the examined tsetse flies engorged on wild ruminants (buffalo, sitatunga, bongo), humans and suids. Moreover, they also fed (albeit more rarely) on other vertebrates, thus providing indirect but convincing evidence that trypanosomes can be transmitted via these vectors among a wide range of

  8. Surveillance of tsetse fly and cattle populations for trypanosomes in the BICOT area during the sterile insect technique control programme

    International Nuclear Information System (INIS)

    Ekejindu, G.O.C.

    1990-01-01

    Between March 1984 and March 1988 animal surveys for bovine trypanosomiasis were conducted periodically on resident herds in the Biological Control of Tsetse (BICOT) Project area in Lafia, Plateau State, Nigeria, using standard detection methods. Over a specified period sentinel herds were also examined in selected locations within the project area. Fly trapping and dissection were similarly used for trypanosome screening of wild and released flies. In both resident and sentinel herds, infections were detected consistently, showing the persistence of the disease throughout the period of survey. Fly trapping and dissection revealed that the target species, Glossina palpalis palpalis, was effectively eliminated from the control zone, or may be persisting only at an undetectable level. However, G. tachinoides was present in most of these areas and may therefore have been responsible for the persistence of infection. Infection among resident herds could have also been due to their migratory activities, taking them to areas outside the control project. (author). 10 refs, 9 tabs

  9. Insights into the trypanosome-host interactions revealed through transcriptomic analysis of parasitized tsetse fly salivary glands.

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    Erich Loza Telleria

    2014-04-01

    Full Text Available The agents of sleeping sickness disease, Trypanosoma brucei complex parasites, are transmitted to mammalian hosts through the bite of an infected tsetse. Information on tsetse-trypanosome interactions in the salivary gland (SG tissue, and on mammalian infective metacyclic (MC parasites present in the SG, is sparse. We performed RNA-seq analyses from uninfected and T. b. brucei infected SGs of Glossina morsitans morsitans. Comparison of the SG transcriptomes to a whole body fly transcriptome revealed that only 2.7% of the contigs are differentially expressed during SG infection, and that only 263 contigs (0.6% are preferentially expressed in the SGs (SG-enriched. The expression of only 37 contigs (0.08% and 27 SG-enriched contigs (10% were suppressed in infected SG. These suppressed contigs accounted for over 55% of the SG transcriptome, and included the most abundant putative secreted proteins with anti-hemostatic functions present in saliva. In contrast, expression of putative host proteins associated with immunity, stress, cell division and tissue remodeling were enriched in infected SG suggesting that parasite infections induce host immune and stress response(s that likely results in tissue renewal. We also performed RNA-seq analysis from mouse blood infected with the same parasite strain, and compared the transcriptome of bloodstream form (BSF cells with that of parasites obtained from the infected SG. Over 30% of parasite transcripts are differentially regulated between the two stages, and reflect parasite adaptations to varying host nutritional and immune ecology. These differences are associated with the switch from an amino acid based metabolism in the SG to one based on glucose utilization in the blood, and with surface coat modifications that enable parasite survival in the different hosts. This study provides a foundation on the molecular aspects of the trypanosome dialogue with its tsetse and mammalian hosts, necessary for future

  10. Identification of different trypanosome species in the mid-guts of tsetse flies of the Malanga (Kimpese sleeping sickness focus of the Democratic Republic of Congo

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    Simo Gustave

    2012-09-01

    Full Text Available Abstract Background The Malanga sleeping sickness focus of the Democratic Republic of Congo has shown an epidemic evolution of disease during the last century. However, following case detection and treatment, the prevalence of the disease decreased considerably. No active survey has been undertaken in this focus for a couple of years. To understand the current epidemiological status of sleeping sickness as well as the animal African trypanosomiasis in the Malanga focus, we undertook the identification of tsetse blood meals as well as different trypanosome species in flies trapped in this focus. Methods Pyramidal traps were use to trap tsetse flies. All flies caught were identified and live flies were dissected and their mid-guts collected. Fly mid-gut was used for the molecular identification of the blood meal source, as well as for the presence of different trypanosome species. Results About 949 Glossina palpalis palpalis were trapped; 296 (31.2% of which were dissected, 60 (20.3% blood meals collected and 57 (19.3% trypanosome infections identified. The infection rates were 13.4%, 5.1%, 3.5% and 0.4% for Trypanosoma congolense savannah type, Trypanosoma brucei s.l., Trypanosoma congolense forest type and Trypanosoma vivax, respectively. Three mixed infections including Trypanosoma brucei s.l. and Trypanosoma congolense savannah type, and one mixed infection of Trypanosoma vivax and Trypanosoma congolense savannah type were identified. Eleven Trypanosoma brucei gambiense infections were identified; indicating an active circulation of this trypanosome subspecies. Of all the identified blood meals, about 58.3% were identified as being taken on pigs, while 33.3% and 8.3% were from man and other mammals, respectively. Conclusion The presence of Trypanosoma brucei in tsetse mid-guts associated with human blood meals is indicative of an active transmission of this parasite between tsetse and man. The considerable number of pig blood meals combined

  11. Identification of different trypanosome species in the mid-guts of tsetse flies of the Malanga (Kimpese) sleeping sickness focus of the Democratic Republic of Congo.

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    Simo, Gustave; Silatsa, Barberine; Flobert, Njiokou; Lutumba, Pascal; Mansinsa, Philemon; Madinga, Joule; Manzambi, Emile; De Deken, Reginald; Asonganyi, Tazoacha

    2012-09-19

    The Malanga sleeping sickness focus of the Democratic Republic of Congo has shown an epidemic evolution of disease during the last century. However, following case detection and treatment, the prevalence of the disease decreased considerably. No active survey has been undertaken in this focus for a couple of years. To understand the current epidemiological status of sleeping sickness as well as the animal African trypanosomiasis in the Malanga focus, we undertook the identification of tsetse blood meals as well as different trypanosome species in flies trapped in this focus. Pyramidal traps were use to trap tsetse flies. All flies caught were identified and live flies were dissected and their mid-guts collected. Fly mid-gut was used for the molecular identification of the blood meal source, as well as for the presence of different trypanosome species. About 949 Glossina palpalis palpalis were trapped; 296 (31.2%) of which were dissected, 60 (20.3%) blood meals collected and 57 (19.3%) trypanosome infections identified. The infection rates were 13.4%, 5.1%, 3.5% and 0.4% for Trypanosoma congolense savannah type, Trypanosoma brucei s.l., Trypanosoma congolense forest type and Trypanosoma vivax, respectively. Three mixed infections including Trypanosoma brucei s.l. and Trypanosoma congolense savannah type, and one mixed infection of Trypanosoma vivax and Trypanosoma congolense savannah type were identified. Eleven Trypanosoma brucei gambiense infections were identified; indicating an active circulation of this trypanosome subspecies. Of all the identified blood meals, about 58.3% were identified as being taken on pigs, while 33.3% and 8.3% were from man and other mammals, respectively. The presence of Trypanosoma brucei in tsetse mid-guts associated with human blood meals is indicative of an active transmission of this parasite between tsetse and man. The considerable number of pig blood meals combined with the circulation of Trypanosoma brucei gambiense in this focus

  12. Expression and extracellular release of a functional anti-trypanosome Nanobody® in Sodalis glossinidius, a bacterial symbiont of the tsetse fly

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    De Vooght Linda

    2012-02-01

    Full Text Available Abstract Background Sodalis glossinidius, a gram-negative bacterial endosymbiont of the tsetse fly, has been proposed as a potential in vivo drug delivery vehicle to control trypanosome parasite development in the fly, an approach known as paratransgenesis. Despite this interest of S. glossinidius as a paratransgenic platform organism in tsetse flies, few potential effector molecules have been identified so far and to date none of these molecules have been successfully expressed in this bacterium. Results In this study, S. glossinidius was transformed to express a single domain antibody, (Nanobody® Nb_An33, that efficiently targets conserved cryptic epitopes of the variant surface glycoprotein (VSG of the parasite Trypanosoma brucei. Next, we analyzed the capability of two predicted secretion signals to direct the extracellular delivery of significant levels of active Nb_An33. We show that the pelB leader peptide was successful in directing the export of fully functional Nb_An33 to the periplasm of S. glossinidius resulting in significant levels of extracellular release. Finally, S. glossinidius expressing pelBNb_An33 exhibited no significant reduction in terms of fitness, determined by in vitro growth kinetics, compared to the wild-type strain. Conclusions These data are the first demonstration of the expression and extracellular release of functional trypanosome-interfering Nanobodies® in S. glossinidius. Furthermore, Sodalis strains that efficiently released the effector protein were not affected in their growth, suggesting that they may be competitive with endogenous microbiota in the midgut environment of the tsetse fly. Collectively, these data reinforce the notion for the potential of S. glossinidius to be developed into a paratransgenic platform organism.

  13. Study of trypanosome and anaemia indicators during the eradication of tsetse flies from Unguja island, United Republic of Tanzania

    International Nuclear Information System (INIS)

    Dwinger, R.H.; Holland, W.G.; Ndegwa, T.K.; Wint, W.; Kassim, S.S.; Hongjie, P.; Slingenbergh, J.H.W.

    2000-01-01

    A large number of cattle has been monitored regularly during a ten-year period on Unguja island, United Republic of Tanzania, as part of a number of consecutive programmes to initially control and eventually eradicate tsetse and trypanosomosis. Haematological and parasitological results were used among others to monitor and adjust the control and eradication programmes from 1988 to 1997. A Geographic Information System (GIS) was applied to the data set to assess changes of animal health parameters in time and space. Analysis of the data showed significant changes over the years in infection status and degree of anaemia. Moreover, differences in health status of cattle populations between adjacent geographic areas were detected. Regular monitoring using standardized protocols by a multidisciplinary team resulted eventually in the eradication of tsetse flies from the island. (author)

  14. Interactions between mutualist Wigglesworthia and tsetse peptidoglycan recognition protein (PGRP-LB) influence trypanosome transmission.

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    Wang, Jingwen; Wu, Yineng; Yang, Guangxiao; Aksoy, Serap

    2009-07-21

    Tsetse flies, the sole vectors of African trypanosomes, have coevolved with mutualistic endosymbiont Wigglesworthia glossinidiae. Elimination of Wigglesworthia renders tsetse sterile and increases their trypanosome infection susceptibility. We show that a tsetse peptidoglycan recognition protein (PGRP-LB) is crucial for symbiotic tolerance and trypanosome infection processes. Tsetse pgrp-lb is expressed in the Wigglesworthia-harboring organ (bacteriome) in the midgut, and its level of expression correlates with symbiont numbers. Adult tsetse cured of Wigglesworthia infections have significantly lower pgrp-lb levels than corresponding normal adults. RNA interference (RNAi)-mediated depletion of pgrp-lb results in the activation of the immune deficiency (IMD) signaling pathway and leads to the synthesis of antimicrobial peptides (AMPs), which decrease Wigglesworthia density. Depletion of pgrp-lb also increases the host's susceptibility to trypanosome infections. Finally, parasitized adults have significantly lower pgrp-lb levels than flies, which have successfully eliminated trypanosome infections. When both PGRP-LB and IMD immunity pathway functions are blocked, flies become unusually susceptible to parasitism. Based on the presence of conserved amidase domains, tsetse PGRP-LB may scavenge the peptidoglycan (PGN) released by Wigglesworthia and prevent the activation of symbiont-damaging host immune responses. In addition, tsetse PGRP-LB may have an anti-protozoal activity that confers parasite resistance. The symbiotic adaptations and the limited exposure of tsetse to foreign microbes may have led to the considerable differences in pgrp-lb expression and regulation noted in tsetse from that of closely related Drosophila. A dynamic interplay between Wigglesworthia and host immunity apparently is influential in tsetse's ability to transmit trypanosomes.

  15. Tsetse fly microbiota: form and function

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    Jingwen eWang

    2013-10-01

    Full Text Available Tsetse flies are the primary vectors of African trypanosomes, which cause Human and Animal African trypanosomiasis in 36 countries in sub-Saharan Africa. These flies have also established symbiotic associations with bacterial and viral microorganisms. Laboratory-reared tsetse flies harbor up to four vertically transmitted organisms - obligate Wigglesworthia, commensal Sodalis, parasitic Wolbachia and Salivary Gland Hypertrophy Virus (SGHV. Field-captured tsetse can harbor these symbionts as well as environmentally acquired commensal bacteria. This microbial community influences several aspects of tsetse’s physiology, including nutrition, fecundity and vector competence. This review provides a detailed description of tsetse’s microbiome, and describes the physiology underlying host-microbe, and microbe-microbe, interactions that occur in this fly.

  16. Tsetse GmmSRPN10 has anti-complement activity and is important for successful establishment of trypanosome infections in the fly midgut.

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    Cher-Pheng Ooi

    2015-01-01

    Full Text Available The complement cascade in mammalian blood can damage the alimentary tract of haematophagous arthropods. As such, these animals have evolved their own repertoire of complement-inactivating factors, which are inadvertently exploited by blood-borne pathogens to escape complement lysis. Unlike the bloodstream stages, the procyclic (insect stage of Trypanosoma brucei is highly susceptible to complement killing, which is puzzling considering that a tsetse takes a bloodmeal every 2-4 days. In this study, we identified four tsetse (Glossina morsitans morsitans serine protease inhibitors (serpins from a midgut expressed sequence tag (EST library (GmmSRPN3, GmmSRPN5, GmmSRPN9 and GmmSRPN10 and investigated their role in modulating the establishment of a T. brucei infection in the midgut. Although not having evolved in a common blood-feeding ancestor, all four serpins have an active site sharing remarkable homology with the human complement C1-inhibitor serpin, SerpinG1. RNAi knockdown of individual GmmSRPN9 and GmmSRPN10 genes resulted in a significant decreased rate of infection by procyclic form T. brucei. Furthermore, recombinant GmmSRPN10 was both able to inhibit the activity of human complement-cascade serine proteases, C1s and Factor D, and to protect the in vitro killing of procyclic trypanosomes when incubated with complement-activated human serum. Thus, the secretion of serpins, which may be part of a bloodmeal complement inactivation system in tsetse, is used by procyclic trypanosomes to evade an influx of fresh trypanolytic complement with each bloodmeal. This highlights another facet of the complicated relationship between T. brucei and its tsetse vector, where the parasite takes advantage of tsetse physiology to further its chances of propagation and transmission.

  17. Tsetse GmmSRPN10 has anti-complement activity and is important for successful establishment of trypanosome infections in the fly midgut.

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    Ooi, Cher-Pheng; Haines, Lee R; Southern, Daniel M; Lehane, Michael J; Acosta-Serrano, Alvaro

    2015-01-01

    The complement cascade in mammalian blood can damage the alimentary tract of haematophagous arthropods. As such, these animals have evolved their own repertoire of complement-inactivating factors, which are inadvertently exploited by blood-borne pathogens to escape complement lysis. Unlike the bloodstream stages, the procyclic (insect) stage of Trypanosoma brucei is highly susceptible to complement killing, which is puzzling considering that a tsetse takes a bloodmeal every 2-4 days. In this study, we identified four tsetse (Glossina morsitans morsitans) serine protease inhibitors (serpins) from a midgut expressed sequence tag (EST) library (GmmSRPN3, GmmSRPN5, GmmSRPN9 and GmmSRPN10) and investigated their role in modulating the establishment of a T. brucei infection in the midgut. Although not having evolved in a common blood-feeding ancestor, all four serpins have an active site sharing remarkable homology with the human complement C1-inhibitor serpin, SerpinG1. RNAi knockdown of individual GmmSRPN9 and GmmSRPN10 genes resulted in a significant decreased rate of infection by procyclic form T. brucei. Furthermore, recombinant GmmSRPN10 was both able to inhibit the activity of human complement-cascade serine proteases, C1s and Factor D, and to protect the in vitro killing of procyclic trypanosomes when incubated with complement-activated human serum. Thus, the secretion of serpins, which may be part of a bloodmeal complement inactivation system in tsetse, is used by procyclic trypanosomes to evade an influx of fresh trypanolytic complement with each bloodmeal. This highlights another facet of the complicated relationship between T. brucei and its tsetse vector, where the parasite takes advantage of tsetse physiology to further its chances of propagation and transmission.

  18. Africa and the tsetse fly

    International Nuclear Information System (INIS)

    1985-01-01

    Trypanosomiasis, an infection transmitted by the tsetse fly and causing sleeping sickness in man and Nagana disease in animals, is widespread in Africa. It affects 37 countries (an area as large as the United States) and leads to great losses in the national economy. It can be fought effectively by programmes to eradicate the tsetse fly with the sterile insect technique. The film shows the tsetse habitats and biology and demonstrates how its reproduction circle can be interrupted by sterilization of male flies with gamma rays. This method has proven an effective alternative to the use of pesticides because its efficiency increases with each generation and it causes no environmental pollution problems

  19. Spatial distribution of tsetse flies in some areas within western ...

    African Journals Online (AJOL)

    Accurate identification of tsetse fly endemic-foci using spatially explicit maps could be important in the strategic control of tsetse flies. This survey presents spatially explicit maps of tsetse flies in some tsetse fly-endemic areas in the Western, Eastern and Northern Regions of Ghana. Field samplings for tsetse flies using ...

  20. Japanese, UN support for Ethiopian tsetse fly removal

    International Nuclear Information System (INIS)

    2006-01-01

    Full text: The Japanese Government and the United Nations have committed 1,760,000 dollars to a joint IAEA FAO project to remove the tsetse fly and the diseases it transmits from the Southern Rift Valley in Ethiopia. The money is being made available through the UN Trust Fund for Human Security, which has distributed 256 million dollars since it was established in the UN Secretariat at the initiative of the Japanese Government in 1999. Ridding the Southern Rift Valley of the tsetse fly will reduce pressure on overcrowded hillsides to which farmers have retreated to escape the spread of the tsetse fly leaving fertile river valleys unused. The tsetse fly transmits the trypanosome parasite. In Ethiopia trypanosomosis causes a devastating disease among domestic livestock. Elsewhere in some of the 37 sub-Sahara Africa countries infested by the tsetse fly trypanosomosis also causes sleeping sickness in humans. Welcoming the Japanese commitment IAEA and FAO officials said that the assistance marks the conclusion of years of consensus building on the right approach to follow in fighting the tsetse and trypanosomosis problem. It also follows a major effort by the Ethiopian Government to invite international agencies to agree on a national approach to be pursued in the tsetse infested Southern Rift Valley. The programme in Ethiopia will integrate the Sterile Insect Technique (SIT), which involves the release of colony bred sterilised flies with other control methods to suppress the wild population coupled with the development of a programme for sustainable use of newly available land. (FAO/IAEA)

  1. Patterns of tsetse abundance and trypanosome infection rates among habitats of surveyed villages in Maasai steppe of northern Tanzania.

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    Ngonyoka, Anibariki; Gwakisa, Paul S; Estes, Anna B; Salekwa, Linda P; Nnko, Happiness J; Hudson, Peter J; Cattadori, Isabella M

    2017-09-04

    Changes of land cover modify the characteristics of habitat, host-vector interaction and consequently infection rates of disease causing agents. In this paper, we report variations in tsetse distribution patterns, abundance and infection rates in relation to habitat types and age in the Maasai Steppe of northern Tanzania. In Africa, Tsetse-transmitted trypanosomiasis negatively impacted human life where about 40 million people are at risk of contracting the disease with dramatic socio-economical consequences, for instance, loss of livestock, animal productivity, and manpower. We trapped tsetse flies in dry and wet seasons between October 2014 and May 2015 in selected habitats across four villages: Emboreet, Loiborsireet, Kimotorok and Oltukai adjacent to protected areas. Data collected include number and species of tsetse flies caught in baited traps, PCR identification of trypanosome species and extraction of monitored Normalized Difference Vegetation Index (NDVI) data from Moderate Resolution Imaging Spectrometer (MODIS). Our findings demonstrate the variation of tsetse fly species abundance and infection rates among habitats in surveyed villages in relation to NDVI and host abundance. Results have shown higher tsetse fly abundance in Acacia-swampy ecotone and riverine habitats for Emboreet and other villages, respectively. Tsetse abundance was inconsistent among habitats in different villages. Emboreet was highly infested with Glossina swynnertoni (68%) in ecotone and swampy habitats followed by G. morsitans (28%) and G. pallidipes (4%) in riverine habitat. In the remaining villages, the dominant tsetse fly species by 95% was G. pallidipes in all habitats. Trypanosoma vivax was the most prevalent species in all infected flies (95%) with few observations of co-infections (with T. congolense or T. brucei). The findings of this study provide a framework to mapping hotspots of tsetse infestation and trypanosomiasis infection and enhance the communities to plan for

  2. The tsetse fly and African trypanosomosis: Towards a lasting solution

    International Nuclear Information System (INIS)

    Kabayo, John P.; Agubuzu, Lawrence

    2001-01-01

    Tsetse flies carry and transmit infective microscopic parasitic microorganisms, called trypanosomes, which cause sleeping sickness in man and a similar devastating disease in domestic animals, known as nagana. Over the past couple of centuries, periodic epidemic outbreaks of sleeping sickness wiped out entire communities in villages and settlements in various parts of Africa and caused massive depopulation of many areas. Many communities lost their domestic animals to trypanosomosis and gave up livestock production altogether; they concentrated on crop production, preferring to settle in elevated areas where they were comparatively safe from the diseases commonly found in low-lying areas. Other communities persisted with livestock production and settled in areas, e.g. savanna plains, where the limited vegetation cover was relatively tsetse-free. Over the years, this pattern of settlement, and the attendant separation of crop production from livestock production, has changed. Tsetse eradication was declared in Zanzibar in September 1997, after a 3-year campaign that involved a combination of suppression of the tsetse population with conventional insecticide-based methods and the Sterile Insect Technique. Since then, reports of an economic turnaround for the island have attracted attention and confirmed the view that tsetse eradication has indeed been the missing key in Africa's rural development schemes. In the absence of tsetse flies on Zanzibar, farmers have introduced exotic breeds of livestock and have reported increases in milk production. This success has inspired countries in the rest of Africa to initiate programmes aimed at eradicating tsetse flies and eliminating the associated constraints to land use and agricultural productivity

  3. Tsetse fly saliva: Could it be useful in fly infection when feeding in chronically aparasitemic mammalian hosts

    Directory of Open Access Journals (Sweden)

    E.O. Awuoche

    2012-09-01

    Full Text Available Sleeping sickness and nagana are two important diseases cuased by African trypanosomes in humans and animals respectively, in tropical african countries. A number of trypanosome species are implicated in these diseases, but it is the Trypanosoma brucei group that is responsible for the chronic form of sleeping sickness. During the course of this chronic infection the parasite shows a clear tropism for organs and tissues and only sporadically appears in the blood stream. Notwithstanding this feature, tsetse flies normally get infected from chronically infected apparasitemic hosts. For some pathogens like the microfilaria, it has already shown that the saliva of the vector, black fly saliva contribute to orient the pathogen to the site of the vector bite. Chemotaxis of tsetse saliva may perhaps stimulate movement of Trypanosoma brucei parasites from tissues to the bloodstream and via the vascular to the tsetse feeding site, and could explain the relatively high infection rate of tsetse flies feeding on chronically infected animals. This review paper looks into the possible role of trypanosome-vector saliva in ensuring parasite acquisition and its application in the tsetsetrypanosome interaction at the host skin interphase.

  4. Improved attractants for enhancing tsetse fly suppression

    International Nuclear Information System (INIS)

    2003-09-01

    At the initiation of this co-ordinated research project (CRP), the available visually attractant devices and odours for entomological monitoring and for suppression of tsetse fly populations were not equally effective against all economically important tsetse fly species. For species like G. austeni, G. brevipalpis, G. swynnertoni and some species of the PALPALIS-group of tsetse flies no sufficiently effective combinations of visual or odour attractants were available for efficient suppression and standardized monitoring as part of an operational integrated intervention campaign against the tsetse and trypanosomosis (T and T) problem. The Co-ordinated Research Project on Improved Attractants for Enhancing the Efficiency of Tsetse Fly Suppression Operations and Barrier Systems used in Tsetse Control/Eradication Campaigns involved (a) the identification, synthesis and provision of candidate kairomones, their analogues and of dispensers; (b) laboratory screening of synthesised candidate kairomones through electrophysiological studies and wind tunnel experiments; (c) field tests of candidate kairomones alone or as part of odour blends, in combination with available and or new trap designs; and (d) analysis of hydrocarbons that influence tsetse sexual behaviour. The CRP accomplished several main objectives, namely: - The screening of new structurally related compounds, including specific stereoisomers, of known tsetse attractants resulted in the identification of several new candidate odour attractants with promising potential. - An efficient two-step synthetic method was developed for the pilot plant scale production of 3-n-propyphenol, synergistic tsetse kairomone component. - Electrophysiological experiments complemented with wind tunnel studies provided an efficient basis for the laboratory screening of candidate attractants prior to the initiation of laborious field tests. - New traps were identified and modifications of existing traps were tested for some species

  5. A tsetse and tabanid fly survey of African great apes habitats reveals the presence of a novel trypanosome lineage but the absence of Trypanosoma brucei

    Czech Academy of Sciences Publication Activity Database

    Votýpka, J.; Rádrová, J.; Skalický, T.; Jirků, M.; Jirsová, D.; Mihalca, A. D.; D'Amico, G.; Petrželková, Klára Judita; Modrý, D.; Lukeš, J.

    2015-01-01

    Roč. 45, č. 12 (2015), s. 741-748 ISSN 0020-7519 Institutional support: RVO:68081766 Keywords : Trypanosoma * Tsetse * Tabanids * African great apes * Gorillas * Transmission * Bloodmeal * Feeding preference Subject RIV: FN - Epidemiology, Contagious Diseases ; Clinical Immunology Impact factor: 4.242, year: 2015

  6. Suppressing Tsetse Flies to Improve Lives

    International Nuclear Information System (INIS)

    Potterton, Louise; Pavlicek, Petr; Parker, Andrew

    2013-01-01

    In 2009, the government-run Southern Tsetse Eradication Project (STEP) in Ethiopia, with the support of the IAEA, started to carry out intensive activities to suppress the fly population using insecticides. The fly population is now down by 90%. The benefits of tsetse suppression can be seen all over the region. Diary produce is now widely available at markets and healthy animals can be seen everywhere in farming and transport

  7. A tsetse and tabanid fly survey of African great apes habitats reveals the presence of a novel trypanosome lineage but the absence of Trypanosoma brucei

    Czech Academy of Sciences Publication Activity Database

    Votýpka, Jan; Rádrová, Jana; Skalický, Tomáš; Jirků, Milan; Jirsová, D.; Mihalca, A. D.; D'Amico, G.; Petrželková, Klára Judita; Modrý, David; Lukeš, Julius

    2015-01-01

    Roč. 45, OCT 2015 (2015), s. 741-748 ISSN 0020-7519 R&D Projects: GA MŠk(CZ) EE2.3.30.0032 EU Projects: European Commission(XE) 316304 Grant - others:GA MŠk(CZ) EE2.3.20.0300 Institutional support: RVO:60077344 Keywords : Trypanosoma * Tsetse * Tabanids * African great apes * Gorillas * Transmission * Bloodmeal * Feeding preference Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 4.242, year: 2015

  8. Eradicating tsetse flies: Senegal nears first victory

    International Nuclear Information System (INIS)

    Dixit, Aabha

    2015-01-01

    After a four-year eradication programme including nuclear techniques, the Niayes region of Senegal is now almost free of the tsetse fly, which used to decimate livestock. “I have not seen a single tsetse fly for a year now,” said cattle farmer Oumar Sow. “This is in contrast to earlier, when they increased in numbers, especially during the cold season. The flies were really a nuisance to our animals and we had to carefully select the time for milking. Now, there is no problem with that.” The tsetse fly is a bloodsucking insect that kills more than three million livestock in sub-Saharan Africa every year, costing the agriculture industry more than US $4 billion annually. The tsetse fly transmits parasites that cause a wasting disease called nagana in cattle. In some parts of Africa the fly also causes over 75 000 cases of human ‘sleeping sickness’, which affects the central nervous system, and causes disorientation, personality changes, slurred speech, seizures, difficulty walking and talking, and ultimately death.

  9. Campaign launched to eliminate tsetse fly, which has turned much of Africa into a green desert

    International Nuclear Information System (INIS)

    2002-01-01

    A new campaign to control the deadly tsetse fly in Africa, parasitic carrier of sleeping sickness, has been launched by the Organization of African Unity (OAU). African sleeping sickness affects as many as 500,000 people, 80 percent of whom eventually die, and the bite of the fly causes more than $4 billion in economic losses annually. The tsetse fly has turned much of the fertile African landscape into an uninhabited 'green desert', spreading sleeping sickness -- and killing 3 million livestock animals every year. The fly is the carrier of the single cell parasite, trypanosome, which attacks the blood and nervous system of its victims, causing sleeping sickness in humans and nagana in livestock. The biting tsetse fly transmits it when its seeks a blood meal. Despite various drastic efforts over the past 100 years to eradicate the tsetse fly, most of the time it has recovered. The tsetse, about the size of a house fly, infests 37 sub-Saharan African countries - 32 of them among the 42 most Heavily Indebted Poor Countries (HIPCs) in the world. Much of Africa's best land - particularly in river valleys and moist areas, where the potential for mixed farming is good - lies uncultivated, while tsetse free areas face collapse from overuse by humans. The range of the fly is expanding and in some parts of Africa renewed outbreaks of sleeping sickness are killing more people than any other disease. In 1997 the Tanzanian island of Zanzibar was declared free of the tsetse after conventional methods reduced its numbers and the release of hundreds of thousands of infertile male flies into the wild - sterilized using a nuclear technology - clinched its success. In Burkina Faso in 2001, the Organization of African Unity, inaugurated the Pan African Tsetse and Trypanosomosis Eradication Campaign (PATTEC), based on the successful Zanzibar program

  10. Tsetse Fly Genome Breakthrough: The FAO and IAEA Crack the Code

    International Nuclear Information System (INIS)

    Dixit, Aabha

    2014-01-01

    With the breakthrough in sequencing the genome of the tsetse fly species Glossina morsitans in April 2014, another milestone has been achieved in helping to solve a problem that has had horrendous ramifications for Africa. Finding a solution to the havoc created by tsetse flies to livestock has been a major challenge for the combined scientific efforts of the IAEA and the Food and Agriculture Organization of the United Nations (FAO), as well as for the World Health Organization (WHO), which has focused on combating human sleeping sickness. Joint research over the past decades to block the spread of severe infection from tsetse flies resulted in the introduction by the FAO and IAEA of the environmentally friendly sterile insect technique (SIT), a biologically-based method for the management of key insect pests of agricultural, medical and veterinary importance. A form of insect birth control, the SIT involves releasing mass-bred male flies that have been sterilized by low doses of radiation into infested areas, where they mate with wild females. These do not produce offspring and, as a result, the technique can suppress and, if applied systematically on an area-wide basis, eventually eradicate populations of wild flies. The newly acquired knowledge of the tsetse fly genome provides a wealth of information for the improvement of the entire SIT package and can help unravel interactions between tsetse flies, symbionts and trypanosomes. The decoding of the genome was detailed in a press release issued by the IAEA on 24 April 2014 entitled Tsetse Fly Genome Breakthrough Brings Hope for African Farmers. Tsetse flies were successfully eradicated in 1997 from the Tanzanian island of Zanzibar using the SIT. Ethiopia and Senegal are making significant progress in infested areas with the same method. The FAO and IAEA are helping 14 countries control tsetse populations through applying area-wide integrated pest management approaches

  11. Infections with immunogenic trypanosomes reduce tsetse reproductive fitness: potential impact of different parasite strains on vector population structure.

    Directory of Open Access Journals (Sweden)

    Changyun Hu

    2008-03-01

    Full Text Available The parasite Trypanosoma brucei rhodesiense and its insect vector Glossina morsitans morsitans were used to evaluate the effect of parasite clearance (resistance as well as the cost of midgut infections on tsetse host fitness. Tsetse flies are viviparous and have a low reproductive capacity, giving birth to only 6-8 progeny during their lifetime. Thus, small perturbations to their reproductive fitness can have a major impact on population densities. We measured the fecundity (number of larval progeny deposited and mortality in parasite-resistant tsetse females and untreated controls and found no differences. There was, however, a typanosome-specific impact on midgut infections. Infections with an immunogenic parasite line that resulted in prolonged activation of the tsetse immune system delayed intrauterine larval development resulting in the production of fewer progeny over the fly's lifetime. In contrast, parasitism with a second line that failed to activate the immune system did not impose a fecundity cost. Coinfections favored the establishment of the immunogenic parasites in the midgut. We show that a decrease in the synthesis of Glossina Milk gland protein (GmmMgp, a major female accessory gland protein associated with larvagenesis, likely contributed to the reproductive lag observed in infected flies. Mathematical analysis of our empirical results indicated that infection with the immunogenic trypanosomes reduced tsetse fecundity by 30% relative to infections with the non-immunogenic strain. We estimate that a moderate infection prevalence of about 26% with immunogenic parasites has the potential to reduce tsetse populations. Potential repercussions for vector population growth, parasite-host coevolution, and disease prevalence are discussed.

  12. Effectiveness of monoscreen traps for tsetse fly control

    African Journals Online (AJOL)

    Mo

    occurred in tsetse catches between monoscreen traps made out of medium blue, light blue and standard (control) materials. However, for the male flies, the standard blue material (control) proved superior in tsetse catch than the other shades of blue materials. Key words: Glossina fuscipes, tsetse fly catches. Introduction.

  13. Feeding and rearing behaviour in tsetse flies

    International Nuclear Information System (INIS)

    Otieno, L.H.; Youdeowei, Y.

    1980-01-01

    Batwing membrane was used to study salivation and feeding behaviour of tsetse flies. Probing and salivation were observed to be stimulated by tarsal contact with the membrane. Salivation and feeding responses varied from day to day with characteristic alternating high and low responses. The feeding process was invariably accompanied by a resting period. Attempts to rear G. morsitans artificially through the use of batwing membrane showed that the flies needed an initial adjustment period to in vitro maintenance. (author)

  14. Description of a nanobody-based competitive immunoassay to detect tsetse fly exposure.

    Directory of Open Access Journals (Sweden)

    Guy Caljon

    2015-02-01

    Full Text Available Tsetse flies are the main vectors of human and animal African trypanosomes. The Tsal proteins in tsetse fly saliva were previously identified as suitable biomarkers of bite exposure. A new competitive assay was conceived based on nanobody (Nb technology to ameliorate the detection of anti-Tsal antibodies in mammalian hosts.A camelid-derived Nb library was generated against the Glossina morsitans morsitans sialome and exploited to select Tsal specific Nbs. One of the three identified Nb families (family III, TsalNb-05 and TsalNb-11 was found suitable for anti-Tsal antibody detection in a competitive ELISA format. The competitive ELISA was able to detect exposure to a broad range of tsetse species (G. morsitans morsitans, G. pallidipes, G. palpalis gambiensis and G. fuscipes and did not cross-react with the other hematophagous insects (Stomoxys calcitrans and Tabanus yao. Using a collection of plasmas from tsetse-exposed pigs, the new test characteristics were compared with those of the previously described G. m. moristans and rTsal1 indirect ELISAs, revealing equally good specificities (> 95% and positive predictive values (> 98% but higher negative predictive values and hence increased sensitivity (> 95% and accuracy (> 95%.We have developed a highly accurate Nb-based competitive immunoassay to detect specific anti-Tsal antibodies induced by various tsetse fly species in a range of hosts. We propose that this competitive assay provides a simple serological indicator of tsetse fly presence without the requirement of test adaptation to the vertebrate host species. In addition, the use of monoclonal Nbs for antibody detection is innovative and could be applied to other tsetse fly salivary biomarkers in order to achieve a multi-target immunoprofiling of hosts. In addition, this approach could be broadened to other pathogenic organisms for which accurate serological diagnosis remains a bottleneck.

  15. Evaluation of the antigen ELISA as a tool for assessing the impact of tsetse control programmes on the incidence of trypanosome infections in livestock

    International Nuclear Information System (INIS)

    Diall, O.; Diarra, B.; Sanogo, Y.

    1997-01-01

    The objective of the present study was to determine the suitability of the antigen ELISA as a method for assessing the efficacy of a tsetse control programme, based on the use of traps and screens impregnated with Deltamethrine. The efficacy of a tsetse control programme can be measured by monitoring the tsetse density on the one hand and by monitoring the infection rate and packed red cell volume (PCV) level of cattle on the other hand. We have used both monitoring methods as reference points to evaluate the Ag-ELISA, by determining how results of the Ag-ELISA correlated with those of the two reference methods. The monitoring was carried out in 8 localities: 4 situated in the tsetse control area and 4 located in a region without tsetse control (untreated area). The results were collected over a 12-month-study period. In the Deltamethrine treated area the tsetse density was reduced by nearly 95% after one month of control and virtually no tsetse fly could be caught after 12 months of tsetse control. A similar tendency was observed for the trypanosome infection rate in cattle, which decreased from 6% to 2% in the treated area, but increased from 3% to 10% in the untreated area. At the beginning of the experiment, the average PCV values (29.4%) were identical for animals in the treated and the untreated areas. Following 12 months of tsetse control, the average PCV value of animals in the treated area was 4.7 percentage units higher than of animals in the untreated area. The study of antigenaemia covered the first three months of the experiment. The rate of antigen positivity did not seem to correlate with trypanosome infection rates in cattle, nor with tsetse fly densities. This may be attributed to the low sensitivity of the test, while the specificity as studied on sera from tsetse free areas was high (98%). The monitoring period using the Ag-ELISA should be extended to cover the entire 12-month-study period to verify the preliminary conclusion. In addition

  16. Optimal strategies for controlling riverine tsetse flies using targets: a modelling study.

    Directory of Open Access Journals (Sweden)

    Glyn A Vale

    2015-03-01

    Full Text Available Tsetse flies occur in much of sub-Saharan Africa where they transmit the trypanosomes that cause the diseases of sleeping sickness in humans and nagana in livestock. One of the most economical and effective methods of tsetse control is the use of insecticide-treated screens, called targets, that simulate hosts. Targets have been ~1 m2, but recently it was shown that those tsetse that occupy riverine situations, and which are the main vectors of sleeping sickness, respond well to targets only ~0.06 m2. The cheapness of these tiny targets suggests the need to reconsider what intensity and duration of target deployments comprise the most cost-effective strategy in various riverine habitats.A deterministic model, written in Excel spreadsheets and managed by Visual Basic for Applications, simulated the births, deaths and movement of tsetse confined to a strip of riverine vegetation composed of segments of habitat in which the tsetse population was either self-sustaining, or not sustainable unless supplemented by immigrants. Results suggested that in many situations the use of tiny targets at high density for just a few months per year would be the most cost-effective strategy for rapidly reducing tsetse densities by the ~90% expected to have a great impact on the incidence of sleeping sickness. Local elimination of tsetse becomes feasible when targets are deployed in isolated situations, or where the only invasion occurs from populations that are not self-sustaining.Seasonal use of tiny targets deserves field trials. The ability to recognise habitat that contains tsetse populations which are not self-sustaining could improve the planning of all methods of tsetse control, against any species, in riverine, savannah or forest situations. Criteria to assist such recognition are suggested.

  17. Transcriptome analysis of reproductive tissue and intrauterine developmental stages of the tsetse fly (Glossina morsitans morsitans

    Directory of Open Access Journals (Sweden)

    Wu Yineng

    2010-03-01

    Full Text Available Abstract Background Tsetse flies, vectors of African trypanosomes, undergo viviparous reproduction (the deposition of live offspring. This reproductive strategy results in a large maternal investment and the deposition of a small number of progeny during a female's lifespan. The reproductive biology of tsetse has been studied on a physiological level; however the molecular analysis of tsetse reproduction requires deeper investigation. To build a foundation from which to base molecular studies of tsetse reproduction, a cDNA library was generated from female tsetse (Glossina morsitans morsitans reproductive tissues and the intrauterine developmental stages. 3438 expressed sequence tags were sequenced and analyzed. Results Analysis of a nonredundant catalogue of 1391 contigs resulted in 520 predicted proteins. 475 of these proteins were full length. We predict that 412 of these represent cytoplasmic proteins while 57 are secreted. Comparison of these proteins with other tissue specific tsetse cDNA libraries (salivary gland, fat body/milk gland, and midgut identified 51 that are unique to the reproductive/immature cDNA library. 11 unique proteins were homologus to uncharacterized putative proteins within the NR database suggesting the identification of novel genes associated with reproductive functions in other insects (hypothetical conserved. The analysis also yielded seven putative proteins without significant homology to sequences present in the public database (unknown genes. These proteins may represent unique functions associated with tsetse's viviparous reproductive cycle. RT-PCR analysis of hypothetical conserved and unknown contigs was performed to determine basic tissue and stage specificity of the expression of these genes. Conclusion This paper identifies 51 putative proteins specific to a tsetse reproductive/immature EST library. 11 of these proteins correspond to hypothetical conserved genes and 7 proteins are tsetse specific.

  18. An update of the tsetse fly (Diptera: Glossinidae distribution and African animal trypanosomosis prevalence in north-eastern KwaZulu-Natal, South Africa

    Directory of Open Access Journals (Sweden)

    Chantel J. de Beer

    2016-06-01

    Full Text Available An unpredicted outbreak of African animal trypanosomosis or nagana in 1990 in north-eastern KwaZulu-Natal necessitated an emergency control programme, utilising the extensive cattledipping system in the area, as well as a reassessment of the tsetse and trypanosomosis problem in the province. Since 1990, sporadic blood sampling of cattle at the dip tanks in the naganainfested areas were undertaken to identify trypanosome species involved and to determine the infection prevalence in cattle. The distribution and species composition of the tsetse populations in the area were also investigated. From November 2005 to November 2007 selected dip tanks were surveyed for trypanosome infection prevalence. During April 2005 to August 2009 the distribution and abundance of tsetse populations were assessed with odour-baited H traps. The tsetse and trypanosome distribution maps were updated and potential correlations between tsetse apparent densities (ADs and the prevalence of trypanosomosis were assessed. Glossina brevipalpis Newstead and Glossina austeni Newstead were recorded in locations where they have not previously been collected. No significant correlation between tsetse relative abundance and nagana prevalence was found, which indicated complex interactions between tsetse fly presence and disease prevalence. This was epitomised by data that indicated that despite large differences in the ADs of G. austeni and G. brevipalpis, trypanosome infection prevalence was similar in all three districts in the area. This study clearly indicated that both tsetse species play significant roles in trypanosome transmission and that it will be essential that any control strategy, which aims at sustainable management of the disease, should target both species. Keywords: Tsetse distribution; Glossina brevipalpis; Glossina austeni; trypanosome infection prevalence

  19. Host-seeking efficiency can explain population dynamics of the tsetse fly Glossina morsitans morsitans in response to host density decline.

    Science.gov (United States)

    Lord, Jennifer S; Mthombothi, Zinhle; Lagat, Vitalis K; Atuhaire, Fatumah; Hargrove, John W

    2017-07-01

    Females of all blood-feeding arthropod vectors must find and feed on a host in order to produce offspring. For tsetse-vectors of the trypanosomes that cause human and animal African trypanosomiasis-the problem is more extreme, since both sexes feed solely on blood. Host location is thus essential both for survival and reproduction. Host population density should therefore be an important driver of population dynamics for haematophagous insects, and particularly for tsetse, but the role of host density is poorly understood. We investigate the issue using data on changes in numbers of tsetse (Glossina morsitans morsitans Westwood) caught during a host elimination experiment in Zimbabwe in the 1960s. During the experiment, numbers of flies caught declined by 95%. We aimed to assess whether models including starvation-dependent mortality could explain observed changes in tsetse numbers as host density declined. An ordinary differential equation model, including starvation-dependent mortality, captured the initial dynamics of the observed tsetse population. However, whereas small numbers of tsetse were caught throughout the host elimination exercise, the modelled population went extinct. Results of a spatially explicit agent-based model suggest that this discrepancy could be explained by immigration of tsetse into the experimental plot. Variation in host density, as a result of natural and anthropogenic factors, may influence tsetse population dynamics in space and time. This has implications for Trypanosoma brucei rhodesiense transmission. Increased tsetse mortality as a consequence of low host density may decrease trypanosome transmission, but hungrier flies may be more inclined to bite humans, thereby increasing the risk of transmission to humans. Our model provides a way of exploring the role of host density on tsetse population dynamics and could be incorporated into models of trypanosome transmission dynamics to better understand how spatio-temporal variation in

  20. Host-seeking efficiency can explain population dynamics of the tsetse fly Glossina morsitans morsitans in response to host density decline.

    Directory of Open Access Journals (Sweden)

    Jennifer S Lord

    2017-07-01

    Full Text Available Females of all blood-feeding arthropod vectors must find and feed on a host in order to produce offspring. For tsetse-vectors of the trypanosomes that cause human and animal African trypanosomiasis-the problem is more extreme, since both sexes feed solely on blood. Host location is thus essential both for survival and reproduction. Host population density should therefore be an important driver of population dynamics for haematophagous insects, and particularly for tsetse, but the role of host density is poorly understood. We investigate the issue using data on changes in numbers of tsetse (Glossina morsitans morsitans Westwood caught during a host elimination experiment in Zimbabwe in the 1960s. During the experiment, numbers of flies caught declined by 95%. We aimed to assess whether models including starvation-dependent mortality could explain observed changes in tsetse numbers as host density declined. An ordinary differential equation model, including starvation-dependent mortality, captured the initial dynamics of the observed tsetse population. However, whereas small numbers of tsetse were caught throughout the host elimination exercise, the modelled population went extinct. Results of a spatially explicit agent-based model suggest that this discrepancy could be explained by immigration of tsetse into the experimental plot. Variation in host density, as a result of natural and anthropogenic factors, may influence tsetse population dynamics in space and time. This has implications for Trypanosoma brucei rhodesiense transmission. Increased tsetse mortality as a consequence of low host density may decrease trypanosome transmission, but hungrier flies may be more inclined to bite humans, thereby increasing the risk of transmission to humans. Our model provides a way of exploring the role of host density on tsetse population dynamics and could be incorporated into models of trypanosome transmission dynamics to better understand how spatio

  1. Shifting from wild to domestic hosts: the effect on the transmission of Trypanosoma congolense to tsetse flies.

    Science.gov (United States)

    Chitanga, Simbarashe; Namangala, Boniface; De Deken, Reginald; Marcotty, Tanguy

    2013-01-01

    The epidemiology and impact of animal African trypanosomosis are influenced by the transmissibility and the pathogenicity of the circulating trypanosome strains in a particular biotope. The transmissibility of 22 Trypanosoma congolense strains isolated from domestic and wild animals was evaluated in a total of 1213 flies. Multivariate mixed models were used to compare infection and maturation rates in function of trypanosome origin (domestic or sylvatic) and pathogenicity. Both trypanosome pathogenicity and origin significantly affected the ability to establish a midgut infection in tsetse flies but not the maturation rates. The interaction between pathogenicity and origin was not significant. Since being pathogenic and having a domestic origin both increased transmissibility, dominant lowly pathogenic trypanosomes from domestic environments and highly pathogenic trypanosomes from sylvatic environments presented similar levels of transmissibility: 12% and 15%, respectively. Blood meals with parasite concentration ranging from 0.05 to 50trypanosomes/μl blood for 3 strains of T. congolense were provided to different batches of tsetse flies to evaluate the relationship between the parasite load in blood meals and the likelihood for a fly to become infected. A linear relationship between parasite load and transmissibility was observed at low parasitaemia and a plateau was observed for meals containing more than 5trypanosomes/μl. Maximum transmission was reached with 12.5trypanosomes/μl blood. About 50% of the flies were refractory to T. congolense, whatever their concentration in the blood meal. The results suggest that the dose-transmissibility relationship presents a similar profile for different T. congolense isolates. Copyright © 2012 Elsevier B.V. All rights reserved.

  2. The cyclical development of Trypanosoma vivax in the tsetse fly involves an asymmetric division

    Directory of Open Access Journals (Sweden)

    Cher Pheng Ooi

    2016-09-01

    Full Text Available Trypanosoma vivax is the most prevalent trypanosome species in African cattle. It is thought to be transmitted by tsetse flies after cyclical development restricted to the vector mouthparts. Here, we investigated the kinetics of T. vivax development in Glossina morsitans morsitans by serial dissections over one week to reveal differentiation and proliferation stages. After 3 days, stable numbers of attached epimastigotes were seen proliferating by symmetric division in the cibarium and proboscis, consistent with colonisation and maintenance of a parasite population for the remaining lifespan of the tsetse fly. Strikingly, some asymmetrically dividing cells were also observed in proportions compatible with a continuous production of pre- metacyclic trypomastigotes. The involvement of this asymmetric division in T. vivax metacyclogenesis is discussed and compared to other trypanosomatids.

  3. The Cyclical Development of Trypanosoma vivax in the Tsetse Fly Involves an Asymmetric Division.

    Science.gov (United States)

    Ooi, Cher-Pheng; Schuster, Sarah; Cren-Travaillé, Christelle; Bertiaux, Eloise; Cosson, Alain; Goyard, Sophie; Perrot, Sylvie; Rotureau, Brice

    2016-01-01

    Trypanosoma vivax is the most prevalent trypanosome species in African cattle. It is thought to be transmitted by tsetse flies after cyclical development restricted to the vector mouthparts. Here, we investigated the kinetics of T. vivax development in Glossina morsitans morsitans by serial dissections over 1 week to reveal differentiation and proliferation stages. After 3 days, stable numbers of attached epimastigotes were seen proliferating by symmetric division in the cibarium and proboscis, consistent with colonization and maintenance of a parasite population for the remaining lifespan of the tsetse fly. Strikingly, some asymmetrically dividing cells were also observed in proportions compatible with a continuous production of pre- metacyclic trypomastigotes. The involvement of this asymmetric division in T. vivax metacyclogenesis is discussed and compared to other trypanosomatids.

  4. Effect of rearing diet on the infection rate in flies released for the control of tsetse populations by sterile males

    International Nuclear Information System (INIS)

    Maudlin, I.

    1990-01-01

    In areas where sleeping sickness is endemic, it is the practice of sterile insect technique (SIT) programmes to give sterilized males a bloodmeal before release into the wild in order to reduce the risk of these released flies acting as disease vectors. This strategy has been adopted because of experimental evidence which showed that it was essential to infect flies at their first feed to establish a Tripanosoma brucei gambiense or T. b rhodesiense infection in tsetse flies. The aim of the work was to test artificial tsetse diets produced in the IAEA Laboratory at Seibersdorf in order to determine whether they were as effective as whole blood in inhibiting T. brucei sensu lato (sl) infections in flies. Seven artificial diets were tested with T.b. rhodesiense; Glossina morsitans morsitans males were fed one meal of the diet and then starved for 3 days before the infective feed. None of these diets significantly altered the infection rate of the treated flies and the seven groups produced statistically homogeneous results, with a mean midgut rate of 16% (control flies fed pig blood: 17%). Flies infected as tenerals with the same trypanosome stock produced midgut rates of 61%. Three of the diets were also tested with a T. congolense stock. There were no significant differences between flies fed artificial (mean midgut infection rate: 15%) and whole blood diets (19%). G. m. morsitans infected as tenerals with this trypanosome stock produced midgut rates of 66%. As with T. brucei sl infections, teneral flies were far more likely to develop a T. congolense infection than fed flies; this result suggests that all the tsetse flies used in SIT programmes should be fed before release in order to reduce the risk both to man and his livestock. Artificial diets are as effective as whole blood in inhibiting trypanosome infections. The effect of bloodmeal on the fly infection rates is discussed in relation to lectin production in fed flies. (author). 13 refs, 2 tabs

  5. Properties Of A Midgut Trypanolysin From The Tsetse Fly Glossina Morsitans Morsitans

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    Mahamat H.Abakar

    2015-08-01

    Full Text Available The properties of a bloodmeal-induced trypanolysin from the midgut of the tsetse G. m. morsitans was studied in vitro. The semi-purified trypanolysin from twice-fed tsetse had the highest trypanolysin activity against bloodstream trypanosomes followed by those once-fed and the unfed flies. Serum found to display trypanolysin activity. The trypanolysin had no trypsin activity nor even affected by the enzyme. In addition trypanolysin was not affected by protease inhibitors such as soy bean trypsin inhibitor STI N-a-p-Tosyl-L-lysine chromethyl ketone TLCK phenylmethyl sulphonyl fluoride PMSF diisopropyl fluoro-phosphate DFP and tosylamide-2-phenylethyl chloromethyl ketone TPCK. However the activity was completely inhibited by diethyl pyrocarbonate DEPC and partially by aprotinin. The induction of trypanolysin activity by bloodmeal increased gradually reaching a peak at 72-120 h after the bloodmeal and then decreased rapidly with only 25 of the peak activity remaining after 192 h. The trypanolysin was inactivated during storage at 27amp8451 and 4amp8451 after 15 and 32 days respectively. Similarly heating the midguts trypanolysin to 60 - 80amp8451 led to loss of activity. On the other hand 50amp8451 was found to be the optimum temperature for trypanolysin activity. The activity was also unstable by freeze-thaw at 80amp8451 -70amp8451 -20amp8451 and 0amp8451 after 33 41 55 and 63 days respectively. Trypanolysin caused lyses of bloodstream-form T. b. brucei while the procyclic trypanosomes were unaffected. The highest trypanolysin activity in different tsetse species was found with Glossina longipennis followed by Glossina pallidipes Glossina morsitans centralis Glossina fuscipes fuscipes and G. m. morsitans. When the midgut homogenate was separated by anion-exchange chromatography the trypanolysin activity was recovered in the bound fraction. These results suggest that the midgut trypanolysin plays an important role in the establishment of

  6. Serological Responses and Biomarker Evaluation in Mice and Pigs Exposed to Tsetse Fly Bites

    Science.gov (United States)

    De Deken, Reginald; Schauvliege, Stijn; Gasthuys, Frank; Duchateau, Luc; Van Den Abbeele, Jan

    2014-01-01

    Background Tsetse flies are obligate blood-feeding insects that transmit African trypanosomes responsible for human sleeping sickness and nagana in livestock. The tsetse salivary proteome contains a highly immunogenic family of the endonuclease-like Tsal proteins. In this study, a recombinant version of Tsal1 (rTsal1) was evaluated in an indirect ELISA to quantify the contact with total Glossina morsitans morsitans saliva, and thus the tsetse fly bite exposure. Methodology/Principal Findings Mice and pigs were experimentally exposed to different G. m. morsitans exposure regimens, followed by a long-term follow-up of the specific antibody responses against total tsetse fly saliva and rTsal1. In mice, a single tsetse fly bite was sufficient to induce detectable IgG antibody responses with an estimated half-life of 36–40 days. Specific antibody responses could be detected for more than a year after initial exposure, and a single bite was sufficient to boost anti-saliva immunity. Also, plasmas collected from tsetse-exposed pigs displayed increased anti-rTsal1 and anti-saliva IgG levels that correlated with the exposure intensity. A strong correlation between the detection of anti-rTsal1 and anti-saliva responses was recorded. The ELISA test performance and intra-laboratory repeatability was adequate in the two tested animal models. Cross-reactivity of the mouse IgGs induced by exposure to different Glossina species (G. m. morsitans, G. pallidipes, G. palpalis gambiensis and G. fuscipes) and other hematophagous insects (Stomoxys calcitrans and Tabanus yao) was evaluated. Conclusion This study illustrates the potential use of rTsal1 from G. m. morsitans as a sensitive biomarker of exposure to a broad range of Glossina species. We propose that the detection of anti-rTsal1 IgGs could be a promising serological indicator of tsetse fly presence that will be a valuable tool to monitor the impact of tsetse control efforts on the African continent. PMID:24853371

  7. Serological responses and biomarker evaluation in mice and pigs exposed to tsetse fly bites.

    Directory of Open Access Journals (Sweden)

    Guy Caljon

    2014-05-01

    Full Text Available BACKGROUND: Tsetse flies are obligate blood-feeding insects that transmit African trypanosomes responsible for human sleeping sickness and nagana in livestock. The tsetse salivary proteome contains a highly immunogenic family of the endonuclease-like Tsal proteins. In this study, a recombinant version of Tsal1 (rTsal1 was evaluated in an indirect ELISA to quantify the contact with total Glossina morsitans morsitans saliva, and thus the tsetse fly bite exposure. METHODOLOGY/PRINCIPAL FINDINGS: Mice and pigs were experimentally exposed to different G. m. morsitans exposure regimens, followed by a long-term follow-up of the specific antibody responses against total tsetse fly saliva and rTsal1. In mice, a single tsetse fly bite was sufficient to induce detectable IgG antibody responses with an estimated half-life of 36-40 days. Specific antibody responses could be detected for more than a year after initial exposure, and a single bite was sufficient to boost anti-saliva immunity. Also, plasmas collected from tsetse-exposed pigs displayed increased anti-rTsal1 and anti-saliva IgG levels that correlated with the exposure intensity. A strong correlation between the detection of anti-rTsal1 and anti-saliva responses was recorded. The ELISA test performance and intra-laboratory repeatability was adequate in the two tested animal models. Cross-reactivity of the mouse IgGs induced by exposure to different Glossina species (G. m. morsitans, G. pallidipes, G. palpalis gambiensis and G. fuscipes and other hematophagous insects (Stomoxys calcitrans and Tabanus yao was evaluated. CONCLUSION: This study illustrates the potential use of rTsal1 from G. m. morsitans as a sensitive biomarker of exposure to a broad range of Glossina species. We propose that the detection of anti-rTsal1 IgGs could be a promising serological indicator of tsetse fly presence that will be a valuable tool to monitor the impact of tsetse control efforts on the African continent.

  8. Analysis of multiple tsetse fly populations in Uganda reveals limited diversity and species-specific gut microbiota.

    Science.gov (United States)

    Aksoy, Emre; Telleria, Erich L; Echodu, Richard; Wu, Yineng; Okedi, Loyce M; Weiss, Brian L; Aksoy, Serap; Caccone, Adalgisa

    2014-07-01

    The invertebrate microbiome contributes to multiple aspects of host physiology, including nutrient supplementation and immune maturation processes. We identified and compared gut microbial abundance and diversity in natural tsetse flies from Uganda using five genetically distinct populations of Glossina fuscipes fuscipes and multiple tsetse species (Glossina morsitans morsitans, G. f. fuscipes, and Glossina pallidipes) that occur in sympatry in one location. We used multiple approaches, including deep sequencing of the V4 hypervariable region of the 16S rRNA gene, 16S rRNA gene clone libraries, and bacterium-specific quantitative PCR (qPCR), to investigate the levels and patterns of gut microbial diversity from a total of 151 individuals. Our results show extremely limited diversity in field flies of different tsetse species. The obligate endosymbiont Wigglesworthia dominated all samples (>99%), but we also observed wide prevalence of low-density Sodalis (tsetse's commensal endosymbiont) infections (microbiota composition among the genetically distinct G. f. fuscipes flies and between different sympatric species. Interestingly, Wigglesworthia density varied in different species (10(4) to 10(6) normalized genomes), with G. f. fuscipes having the highest levels. We describe the factors that may be responsible for the reduced diversity of tsetse's gut microbiota compared to those of other insects. Additionally, we discuss the implications of Wigglesworthia and Sodalis density variations as they relate to trypanosome transmission dynamics and vector competence variations associated with different tsetse species. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  9. Environmental insecticide residues from tsetse fly control measures in Uganda

    International Nuclear Information System (INIS)

    Sserunjoji-Sebalija, J.

    1976-01-01

    Up to June 1974 areas in Uganda totalling 8600km 2 have been successfully reclaimed from tsetse fly infestation by ground spray of 3% dieldrin water emulsions. A search for equally effective but less persistent and toxic compounds against tsetse flies has been unsuccessful. Fourteen insecticide formulations have been tested for their persistence on tree bark surfaces and, therefore, their availability and toxicity to the target tsetse flies. Only those compounds with a high immediate insecticidal activity (some higher than dieldrin) like endosulfan, Chlorfenvinphos and propoxur could merit further consideration in tsetse control. While some were toxic to tsetse as fresh deposits, they lacked sufficient persistence. A study of the environmental implication from the continued use of the highly persistent and toxic dieldrin has provided useful data on residues likely to be found both in terrestrial and aquatic fauna and flora. These are generally low. Moreover, there is evidence of degradation in some fish species (Protopterus aethiopicus and Clarias). Also, dilution factors and adsorption involving the muddy nature of water run-off, etc., and controlled burning of grasses after tsetse eradication would tend to inactivate the residual insecticide and protect aquatic systems. The general findings have indicated less risk than anticipated of the environmental contamination from tsetse control by application of persistent and toxic insecticides. (author)

  10. Differential virulence and tsetse fly transmissibility of Trypanosoma congolense and Trypanosoma brucei strains

    Directory of Open Access Journals (Sweden)

    Purity K. Gitonga

    2017-01-01

    Full Text Available African animal trypanosomiasis causes significant economic losses in sub-Saharan African countries because of livestock mortalities and reduced productivity. Trypanosomes, the causative agents, are transmitted by tsetse flies (Glossina spp.. In the current study, we compared and contrasted the virulence characteristics of five Trypanosoma congolense and Trypanosoma brucei isolates using groups of Swiss white mice (n = 6. We further determined the vectorial capacity of Glossina pallidipes, for each of the trypanosome isolates. Results showed that the overall pre-patent (PP periods were 8.4 ± 0.9 (range, 4–11 and 4.5 ± 0.2 (range, 4–6 for T. congolense and T. brucei isolates, respectively (p < 0.01. Despite the longer mean PP, T. congolense–infected mice exhibited a significantly (p < 0.05 shorter survival time than T. brucei–infected mice, indicating greater virulence. Differences were also noted among the individual isolates with T. congolense KETRI 2909 causing the most acute infection of the entire group with a mean ± standard error survival time of 9 ± 2.1 days. Survival time of infected tsetse flies and the proportion with mature infections at 30 days post-exposure to the infective blood meals varied among isolates, with subacute infection–causing T. congolense EATRO 1829 and chronic infection–causing T. brucei EATRO 2267 isolates showing the highest mature infection rates of 38.5% and 23.1%, respectively. Therefore, our study provides further evidence of occurrence of differences in virulence and transmissibility of eastern African trypanosome strains and has identified two, T. congolense EATRO 1829 and T. brucei EATRO 2267, as suitable for tsetse infectivity and transmissibility experiments.

  11. Differential virulence and tsetse fly transmissibility of Trypanosoma congolense and Trypanosoma brucei strains

    Directory of Open Access Journals (Sweden)

    Purity K. Gitonga

    2017-06-01

    Full Text Available African animal trypanosomiasis causes significant economic losses in sub-Saharan African countries because of livestock mortalities and reduced productivity. Trypanosomes, the causative agents, are transmitted by tsetse flies (Glossina spp.. In the current study, we compared and contrasted the virulence characteristics of five Trypanosoma congolense and Trypanosoma brucei isolates using groups of Swiss white mice (n = 6. We further determined the vectorial capacity of Glossina pallidipes, for each of the trypanosome isolates. Results showed that the overall pre-patent (PP periods were 8.4 ± 0.9 (range, 4–11 and 4.5 ± 0.2 (range, 4–6 for T. congolense and T. brucei isolates, respectively (p < 0.01. Despite the longer mean PP, T. congolense–infected mice exhibited a significantly (p < 0.05 shorter survival time than T. brucei–infected mice, indicating greater virulence. Differences were also noted among the individual isolates with T. congolense KETRI 2909 causing the most acute infection of the entire group with a mean ± standard error survival time of 9 ± 2.1 days. Survival time of infected tsetse flies and the proportion with mature infections at 30 days post-exposure to the infective blood meals varied among isolates, with subacute infection–causing T. congolense EATRO 1829 and chronic infection–causing T. brucei EATRO 2267 isolates showing the highest mature infection rates of 38.5% and 23.1%, respectively. Therefore, our study provides further evidence of occurrence of differences in virulence and transmissibility of eastern African trypanosome strains and has identified two, T. congolense EATRO 1829 and T. brucei EATRO 2267, as suitable for tsetse infectivity and transmissibility experiments.

  12. Differential virulence and tsetse fly transmissibility of Trypanosoma congolense and Trypanosoma brucei strains.

    Science.gov (United States)

    Gitonga, Purity K; Ndung'u, Kariuki; Murilla, Grace A; Thande, Paul C; Wamwiri, Florence N; Auma, Joanna E; Ngae, Geoffrey N; Kibugu, James K; Kurgat, Richard; Thuita, John K

    2017-06-27

    African animal trypanosomiasis causes significant economic losses in sub-Saharan African countries because of livestock mortalities and reduced productivity. Trypanosomes, the causative agents, are transmitted by tsetse flies (Glossina spp.). In the current study, we compared and contrasted the virulence characteristics of five Trypanosoma congolense and Trypanosoma brucei isolates using groups of Swiss white mice (n = 6). We further determined the vectorial capacity of Glossina pallidipes, for each of the trypanosome isolates. Results showed that the overall pre-patent (PP) periods were 8.4 ± 0.9 (range, 4-11) and 4.5 ± 0.2 (range, 4-6) for T. congolense and T. brucei isolates, respectively (p < 0.01). Despite the longer mean PP, T. congolense-infected mice exhibited a significantly (p < 0.05) shorter survival time than T. brucei-infected mice, indicating greater virulence. Differences were also noted among the individual isolates with T. congolense KETRI 2909 causing the most acute infection of the entire group with a mean ± standard error survival time of 9 ± 2.1 days. Survival time of infected tsetse flies and the proportion with mature infections at 30 days post-exposure to the infective blood meals varied among isolates, with subacute infection-causing T. congolense EATRO 1829 and chronic infection-causing T. brucei EATRO 2267 isolates showing the highest mature infection rates of 38.5% and 23.1%, respectively. Therefore, our study provides further evidence of occurrence of differences in virulence and transmissibility of eastern African trypanosome strains and has identified two, T. congolense EATRO 1829 and T. brucei EATRO 2267, as suitable for tsetse infectivity and transmissibility experiments.

  13. Genome-Wide Comparative Analysis of Chemosensory Gene Families in Five Tsetse Fly Species.

    Directory of Open Access Journals (Sweden)

    Rosaline Macharia

    2016-02-01

    Full Text Available For decades, odour-baited traps have been used for control of tsetse flies (Diptera; Glossinidae, vectors of African trypanosomes. However, differential responses to known attractants have been reported in different Glossina species, hindering establishment of a universal vector control tool. Availability of full genome sequences of five Glossina species offers an opportunity to compare their chemosensory repertoire and enhance our understanding of their biology in relation to chemosensation. Here, we identified and annotated the major chemosensory gene families in Glossina. We identified a total of 118, 115, 124, and 123 chemosensory genes in Glossina austeni, G. brevipalpis, G. f. fuscipes, G. pallidipes, respectively, relative to 127 reported in G. m. morsitans. Our results show that tsetse fly genomes have fewer chemosensory genes when compared to other dipterans such as Musca domestica (n>393, Drosophila melanogaster (n = 246 and Anopheles gambiae (n>247. We also found that Glossina chemosensory genes are dispersed across distantly located scaffolds in their respective genomes, in contrast to other insects like D. melanogaster whose genes occur in clusters. Further, Glossina appears to be devoid of sugar receptors and to have expanded CO2 associated receptors, potentially reflecting Glossina's obligate hematophagy and the need to detect hosts that may be out of sight. We also identified, in all species, homologs of Ir84a; a Drosophila-specific ionotropic receptor that promotes male courtship suggesting that this is a conserved trait in tsetse flies. Notably, our selection analysis revealed that a total of four gene loci (Gr21a, GluRIIA, Gr28b, and Obp83a were under positive selection, which confers fitness advantage to species. These findings provide a platform for studies to further define the language of communication of tsetse with their environment, and influence development of novel approaches for control.

  14. Eradicating the tsetse fly on Zanzibar Island: A model project

    International Nuclear Information System (INIS)

    2003-01-01

    Tsetse flies infest vast areas of Africa and transmit a parasitic disease which devastates livestock herds and spreads debilitating 'sleeping sickness' amongst people. Past efforts to control the disease - Trypanosomosis - and the carrier insects have met with only limited success. But now an environmentally friendly technology called the Sterile Insect Technique (SIT) may provide a lasting solution to this scourge. Working with the Tanzanian Government and Zanzibar authorities, the Department of Technical Co-operation has sponsored a 'Model Project', with technical support from the Joint FAO/IAEA Division, to eradicate the tsetse fly completely from Zanzibar Island by applying SIT. (IAEA)

  15. Tsetse Fly Genome Breakthrough Brings Hope for African Farmers

    International Nuclear Information System (INIS)

    2014-01-01

    Scientists have cracked the genetic code of the bloodsucking tsetse fly, prompting hope that the breakthrough will help future efforts to control one of the most devastating livestock diseases in sub-Saharan Africa spread by the insect. The tsetse genome was sequenced and annotated during a 10-year international collaborative effort that involved the Insect Pest Control Laboratory run jointly by the United Nations Food and Agriculture Organization (FAO) and the International Atomic Energy Agency (IAEA) in Vienna. The achievement allows scientists to better study the fly's genes and their functions, knowledge that should open the door for researching ways to control the insect

  16. Dual control of ticks and tsetse flies using deltamethrin through ...

    African Journals Online (AJOL)

    Dual control of ticks and tsetse flies using deltamethrin through community participatory methods. M Ocaido, C P Otim, N M Okuna, C Ssekitto, D Kakaire, J Erume, R Z O Wafula, J Walubengo, G Musisi, Okello Bwangamoi, S Okure, W Ebiaru, G Monrad ...

  17. Molecular identification of tsetse fly (Diptera: Glossinidae) species ...

    African Journals Online (AJOL)

    Christopher

    2015-05-13

    May 13, 2015 ... species group, palpalis or morsitans demonstrated a common ancestry and closer relatedness by .... Molecular methods. DNA extraction and PCR was done at the Molecular Biology. Laboratory of the National Veterinary Research Institute (NVRI), ..... Training Manual for Tsetse fly Control Personnel Vol.

  18. THE MODULATED SOUNDS MADE BY THE TSETSE FLY ...

    African Journals Online (AJOL)

    Tsetse flies produce modulated sounds, variously described as singing, buzzing, squeaking or pinging. The calls are closely related to the vital functions of the community namely hunting, feeding, mating and larviposition. The ecological significance of this faculty, therefore, needs further investigation. The flight sounds ...

  19. Population vulnerability and disability in Kenya's tsetse fly habitats.

    Directory of Open Access Journals (Sweden)

    Sue C Grady

    2011-02-01

    Full Text Available Human African Trypanosomiasis (HAT, also referred to as sleeping sickness, and African Animal Trypanosomaisis (AAT, known as nagana, are highly prevalent parasitic vector-borne diseases in sub-Saharan Africa. Humans acquire trypanosomiasis following the bite of a tsetse fly infected with the protozoa Trypanosoma brucei (T.b. spp. -i.e., T.b. gambiense in West and Central Africa and T.b. rhodesiense in East and Southern Africa. Over the last decade HAT diagnostic capacity to estimate HAT prevalence has improved in active case-finding areas but enhanced passive surveillance programs are still lacking in much of rural sub-Saharan Africa.This retrospective-cross-sectional study examined the use of national census data (1999 to estimate population vulnerability and disability in Kenya's 7 tsetse belts to assess the potential of HAT-acquired infection in those areas. A multilevel study design estimated the likelihood of disability in individuals, nested within households, nested within tsetse fly habitats of varying levels of poverty. Residents and recent migrants of working age were studied. Tsetse fly's impact on disability was conceptualised via two exposure pathways: directly from the bite of a pathogenic tsetse fly resulting in HAT infection or indirectly, as the potential for AAT takes land out of agricultural production and diseased livestock leads to livestock morbidity and mortality, contributing to nutritional deficiencies and poverty. Tsetse belts that were significantly associated with increased disability prevalence were identified and the direct and indirect exposure pathways were evaluated.Incorporating reports on disability from the national census is a promising surveillance tool that may enhance future HAT surveillance programs in sub-Saharan Africa. The combined burdens of HAT and AAT and the opportunity costs of agricultural production in AAT areas are likely contributors to disability within tsetse-infested areas. Future research

  20. Wolbachia symbiont infections induce strong cytoplasmic incompatibility in the tsetse fly Glossina morsitans.

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    Uzma Alam

    2011-12-01

    Full Text Available Tsetse flies are vectors of the protozoan parasite African trypanosomes, which cause sleeping sickness disease in humans and nagana in livestock. Although there are no effective vaccines and efficacious drugs against this parasite, vector reduction methods have been successful in curbing the disease, especially for nagana. Potential vector control methods that do not involve use of chemicals is a genetic modification approach where flies engineered to be parasite resistant are allowed to replace their susceptible natural counterparts, and Sterile Insect technique (SIT where males sterilized by chemical means are released to suppress female fecundity. The success of genetic modification approaches requires identification of strong drive systems to spread the desirable traits and the efficacy of SIT can be enhanced by identification of natural mating incompatibility. One such drive mechanism results from the cytoplasmic incompatibility (CI phenomenon induced by the symbiont Wolbachia. CI can also be used to induce natural mating incompatibility between release males and natural populations. Although Wolbachia infections have been reported in tsetse, it has been a challenge to understand their functional biology as attempts to cure tsetse of Wolbachia infections by antibiotic treatment damages the obligate mutualistic symbiont (Wigglesworthia, without which the flies are sterile. Here, we developed aposymbiotic (symbiont-free and fertile tsetse lines by dietary provisioning of tetracycline supplemented blood meals with yeast extract, which rescues Wigglesworthia-induced sterility. Our results reveal that Wolbachia infections confer strong CI during embryogenesis in Wolbachia-free (Gmm(Apo females when mated with Wolbachia-infected (Gmm(Wt males. These results are the first demonstration of the biological significance of Wolbachia infections in tsetse. Furthermore, when incorporated into a mathematical model, our results confirm that Wolbachia can

  1. Know your foe: lessons from the analysis of tsetse fly behaviour.

    Science.gov (United States)

    Torr, S J; Vale, G A

    2015-03-01

    The emergence of new vector-borne diseases requires new methods of vector control. These diseases are often zoonoses associated with wilderness areas, and established methods of vector control used in domestic settings (e.g., indoor-residual spraying, insecticide-treated bednets) are therefore inappropriate. Similar difficulties are also emerging with the control of 'old' vector-borne diseases such as malaria. Understanding the host-finding behaviour of vectors assists the development and application of control methods and aids the understanding of epidemiology. Some general lessons are illustrated by reference to a century of research on the host-finding behaviour of tsetse flies which transmit trypanosomes causing human and animal trypanosomiases, including Rhodesian sleeping sickness, a zoonosis associated with wilderness areas of sub-Saharan Africa. Copyright © 2015. Published by Elsevier Ltd.

  2. Genetic structure of Trypanosoma congolense "forest type" circulating in domestic animals and tsetse flies in the South-West region of Cameroon.

    Science.gov (United States)

    Fogue, Pythagore Soubgwi; Njiokou, Flobert; Simo, Gustave

    2017-01-01

    Despite the economic impact of trypanosome infections, few investigations have been undertaken on the population genetics and transmission dynamics of animal trypanosomes. In this study, microsatellite markers were used to investigate the population genetics of Trypanosoma congolense "forest type", with the ultimate goal of understanding its transmission dynamics between tsetse flies and domestic animals. Blood samples were collected from pigs, sheep, goats and dogs in five villages in Fontem, South-West region of Cameroon. In these villages, tsetse were captured, dissected and their mid-guts collected. DNA was extracted from blood and tsetse mid-guts and specific primers were used to identify T. congolense "forest type". All positive samples were genetically characterized with seven microsatellite markers. Genetic analyses were performed on samples showing single infections of T. congolense "forest type". Of the 299 blood samples, 137 (46%) were infected by T. congolense "forest type". About 3% (54/1596) of tsetse fly mid-guts were infected by T. congolense "forest type". Of 182 samples with T. congolense "forest type", 52 were excluded from the genetic analysis. The genetic analysis on the 130 remaining samples revealed polymorphism within and between subpopulations of the target trypanosome. The dendrogram of genetic similarities was subdivided into two clusters and three sub-clusters, indicating one major and several minor genotypes of T. congolense "forest type" in tsetse and domestic animals. The low F ST values suggest low genetic differentiation and no sub-structuration within subpopulations. The same T. congolense genotypes appear to circulate in tsetse and domestic animals. © P.S. Fogue et al., published by EDP Sciences, 2017.

  3. Genetic structure of Trypanosoma congolense “forest type” circulating in domestic animals and tsetse flies in the South-West region of Cameroon

    Directory of Open Access Journals (Sweden)

    Fogue Pythagore Soubgwi

    2017-01-01

    Full Text Available Despite the economic impact of trypanosome infections, few investigations have been undertaken on the population genetics and transmission dynamics of animal trypanosomes. In this study, microsatellite markers were used to investigate the population genetics of Trypanosoma congolense “forest type”, with the ultimate goal of understanding its transmission dynamics between tsetse flies and domestic animals. Blood samples were collected from pigs, sheep, goats and dogs in five villages in Fontem, South-West region of Cameroon. In these villages, tsetse were captured, dissected and their mid-guts collected. DNA was extracted from blood and tsetse mid-guts and specific primers were used to identify T. congolense “forest type”. All positive samples were genetically characterized with seven microsatellite markers. Genetic analyses were performed on samples showing single infections of T. congolense “forest type”. Of the 299 blood samples, 137 (46% were infected by T. congolense “forest type”. About 3% (54/1596 of tsetse fly mid-guts were infected by T. congolense “forest type”. Of 182 samples with T. congolense “forest type”, 52 were excluded from the genetic analysis. The genetic analysis on the 130 remaining samples revealed polymorphism within and between subpopulations of the target trypanosome. The dendrogram of genetic similarities was subdivided into two clusters and three sub-clusters, indicating one major and several minor genotypes of T. congolense “forest type” in tsetse and domestic animals. The low FSTvalues suggest low genetic differentiation and no sub-structuration within subpopulations. The same T. congolense genotypes appear to circulate in tsetse and domestic animals.

  4. Genetic structure of Trypanosoma congolense “forest type” circulating in domestic animals and tsetse flies in the South-West region of Cameroon

    Science.gov (United States)

    Fogue, Pythagore Soubgwi; Njiokou, Flobert; Simo, Gustave

    2017-01-01

    Despite the economic impact of trypanosome infections, few investigations have been undertaken on the population genetics and transmission dynamics of animal trypanosomes. In this study, microsatellite markers were used to investigate the population genetics of Trypanosoma congolense “forest type”, with the ultimate goal of understanding its transmission dynamics between tsetse flies and domestic animals. Blood samples were collected from pigs, sheep, goats and dogs in five villages in Fontem, South-West region of Cameroon. In these villages, tsetse were captured, dissected and their mid-guts collected. DNA was extracted from blood and tsetse mid-guts and specific primers were used to identify T. congolense “forest type”. All positive samples were genetically characterized with seven microsatellite markers. Genetic analyses were performed on samples showing single infections of T. congolense “forest type”. Of the 299 blood samples, 137 (46%) were infected by T. congolense “forest type”. About 3% (54/1596) of tsetse fly mid-guts were infected by T. congolense “forest type”. Of 182 samples with T. congolense “forest type”, 52 were excluded from the genetic analysis. The genetic analysis on the 130 remaining samples revealed polymorphism within and between subpopulations of the target trypanosome. The dendrogram of genetic similarities was subdivided into two clusters and three sub-clusters, indicating one major and several minor genotypes of T. congolense “forest type” in tsetse and domestic animals. The low FSTvalues suggest low genetic differentiation and no sub-structuration within subpopulations. The same T. congolense genotypes appear to circulate in tsetse and domestic animals. PMID:29261481

  5. Genetics of tsetse fly. Part of a coordinated programme on sterile insect techniques for tsetse fly control or eradication

    International Nuclear Information System (INIS)

    Helle, W.

    1977-08-01

    Genetic variation in the tsetse fly, Glossina m. morsitans was studied using isoenzyme patterns. As the investigators intended to show that the method could be used for field collected material, several factors which may affect isoenzyme analysis such as fly age, reproductive status, nutrition, storage at low temperatures etc. were studied. Fifteen enzyme systems were included. Seven of these showed genetic polymorphism and some differences were related to geographic distribution. Because of interference from various factors, it is recommended that pupae be collected and that flies be analyzed at least 24 hours after the last blood meal. Methods of holding material for analysis are suggested

  6. More than one rabbit out of the hat: Radiation, transgenic and symbiont-based approaches for sustainable management of mosquito and tsetse fly populations

    International Nuclear Information System (INIS)

    Bourtzis, K.; Lees, R.S.; Hendrichs, J.; Vreysen, M.J.B.

    2016-01-01

    Mosquitoes (Diptera: Culicidae) and tsetse flies (Diptera: Glossinidae) are bloodsucking vectors of human and animal pathogens. Mosquito-borne diseases (malaria, filariasis, dengue, chikungunya and Zika) cause severe mortality and morbidity annually, and tsetse fly-borne diseases (African trypanosomes causing sleeping sickness in humans and nagana in livestock) cost Sub-Saharan Africa an estimated US$ 4750 million annually. Current reliance on insecticides for vector control is unsustainable: due to increasing insecticide resistance and growing concerns about health and environmental impacts of chemical control there is a growing need for novel, effective and safe biologically- based methods that are more sustainable. The integration of the sterile insect technique has proven successful to manage crop pests and disease vectors, particularly tsetse flies, and is likely to prove effective against mosquito vectors, particularly once sexseparation methods are improved. Transgenic and symbiont-based approaches are in development, and more advanced in (particularly Aedes) mosquitoes than in tsetse flies; however, issues around stability, sustainability and biosecurity have to be addressed, especially when considering population replacement approaches. Regulatory issues and those relating to intellectual property and economic cost of application must also be overcome. Standardised methods to assess insect quality are required to compare and predict efficacy of the different approaches. Different combinations of these three approaches could be integrated to maximise their benefits, and all have the potential to be used in tsetse and mosquito area-wide integrated pest management programmes. (author)

  7. Radiation induced sterility to control tsetse flies : the effect of ionising radiation and hybridisation on tsetse biology and the use of the sterile insect technique in integrated tsetse control

    NARCIS (Netherlands)

    Vreysen, M.J.B.

    1995-01-01

    The induction of dominant lethal mutations by exposing tsetse flies as pupae or adult insects to ionising radiation and the use of hybrid sterility resulting from crosses of closely related tsetse species or subspecies, are potential methods of genetic control of tsetse flies. In this

  8. Trypanosoma brucei rhodesiense transmitted by a single tsetse fly bite in vervet monkeys as a model of human African trypanosomiasis.

    Directory of Open Access Journals (Sweden)

    John K Thuita

    Full Text Available We have investigated the pathogenicity of tsetse (Glossina pallidipes-transmitted cloned strains of Trypanosoma brucei rhodesiense in vervet monkeys. Tsetse flies were confirmed to have mature trypanosome infections by xenodiagnosis, after which nine monkeys were infected via the bite of a single infected fly. Chancres developed in five of the nine (55.6% monkeys within 4 to 8 days post infection (dpi. All nine individuals were successfully infected, with a median pre-patent period of 4 (range = 4-10 days, indicating that trypanosomes migrated from the site of fly bite to the systemic circulation rapidly and independently of the development of the chancre. The time lag to detection of parasites in cerebrospinal fluid (CSF was a median 16 (range = 8-40 days, marking the onset of central nervous system (CNS, late stage disease. Subsequently, CSF white cell numbers increased above the pre-infection median count of 2 (range = 0-9 cells/microl, with a positive linear association between their numbers and that of CSF trypanosomes. Haematological changes showed that the monkeys experienced an early microcytic-hypochromic anaemia and severe progressive thrombocytopaenia. Despite a 3-fold increase in granulocyte numbers by 4 dpi, leucopaenia occurred early (8 dpi in the monkey infection, determined mainly by reductions in lymphocyte numbers. Terminally, leucocytosis was observed in three of nine (33% individuals. The duration of infection was a median of 68 (range = 22-120 days. Strain and individual differences were observed in the severity of the clinical and clinical pathology findings, with two strains (KETRI 3741 and 3801 producing a more acute disease than the other two (KETRI 3804 and 3928. The study shows that the fly-transmitted model accurately mimics the human disease and is therefore a suitable gateway to understanding human African trypanosomiasis (HAT; sleeping sickness.

  9. Trypanosoma brucei rhodesiense Transmitted by a Single Tsetse Fly Bite in Vervet Monkeys as a Model of Human African Trypanosomiasis

    Science.gov (United States)

    Thuita, John K.; Kagira, John M.; Mwangangi, David; Matovu, Enock; Turner, C. M. R.; Masiga, Daniel

    2008-01-01

    We have investigated the pathogenicity of tsetse (Glossina pallidipes)-transmitted cloned strains of Trypanosoma brucei rhodesiense in vervet monkeys. Tsetse flies were confirmed to have mature trypanosome infections by xenodiagnosis, after which nine monkeys were infected via the bite of a single infected fly. Chancres developed in five of the nine (55.6%) monkeys within 4 to 8 days post infection (dpi). All nine individuals were successfully infected, with a median pre-patent period of 4 (range = 4–10) days, indicating that trypanosomes migrated from the site of fly bite to the systemic circulation rapidly and independently of the development of the chancre. The time lag to detection of parasites in cerebrospinal fluid (CSF) was a median 16 (range = 8–40) days, marking the onset of central nervous system (CNS, late) stage disease. Subsequently, CSF white cell numbers increased above the pre-infection median count of 2 (range = 0–9) cells/µl, with a positive linear association between their numbers and that of CSF trypanosomes. Haematological changes showed that the monkeys experienced an early microcytic-hypochromic anaemia and severe progressive thrombocytopaenia. Despite a 3-fold increase in granulocyte numbers by 4 dpi, leucopaenia occurred early (8 dpi) in the monkey infection, determined mainly by reductions in lymphocyte numbers. Terminally, leucocytosis was observed in three of nine (33%) individuals. The duration of infection was a median of 68 (range = 22–120) days. Strain and individual differences were observed in the severity of the clinical and clinical pathology findings, with two strains (KETRI 3741 and 3801) producing a more acute disease than the other two (KETRI 3804 and 3928). The study shows that the fly-transmitted model accurately mimics the human disease and is therefore a suitable gateway to understanding human African trypanosomiasis (HAT; sleeping sickness). PMID:18846231

  10. Tsetse fly saliva: Could it be useful in fly infection when feeding in ...

    African Journals Online (AJOL)

    During the course of this chronic infection the parasite shows a clear tropism for organs and tissues and only sporadically appears in the blood stream. Notwithstanding this feature, tsetse flies normally get infected from chronically infected apparasitemic hosts. For some pathogens like the microfilaria, it has already shown ...

  11. Vector susceptibility to African trypanosomes.

    Science.gov (United States)

    Le Ray, D

    1989-01-01

    Susceptibility of tsetse fly to trypanosome depends on two distinct barriers controlling respectively colonization of midgut and, migration to salivary glands. Those barriers are modulated by barely known factors, pertaining to the physiological status of the fly as well as to cytoplasmic and nuclear inheritance. Quantification of colonization (p) and migration (m) rates provides a way to calculate intrinsic vectorial capacity (IVC) as a product IVC = p x m, and to undergo comparative analysis of underlying factors.

  12. Standard Operating Procedures for Preparing and Handling Sterile Male Tsetse flies for Release

    International Nuclear Information System (INIS)

    Argiles-Herrero, Rafa; Leak, Stephen G.A.

    2016-01-01

    The purpose of this SOP is to describe the procedures involved in preparing tsetse flies reared in a breeding facility for release in the field for the sterile insect technique (SIT) as a component of Area-Wide Insect pest Management (AW-IPM). Following the procedures which are outlined will help to ensure that the released sterile male tsetse flies are of optimal quality.

  13. More than one rabbit out of the hat: Radiation, transgenic and symbiont-based approaches for sustainable management of mosquito and tsetse fly populations.

    Science.gov (United States)

    Bourtzis, Kostas; Lees, Rosemary Susan; Hendrichs, Jorge; Vreysen, Marc J B

    2016-05-01

    Mosquitoes (Diptera: Culicidae) and tsetse flies (Diptera: Glossinidae) are bloodsucking vectors of human and animal pathogens. Mosquito-borne diseases (malaria, filariasis, dengue, zika, and chikungunya) cause severe mortality and morbidity annually, and tsetse fly-borne diseases (African trypanosomes causing sleeping sickness in humans and nagana in livestock) cost Sub-Saharan Africa an estimated US$ 4750 million annually. Current reliance on insecticides for vector control is unsustainable: due to increasing insecticide resistance and growing concerns about health and environmental impacts of chemical control there is a growing need for novel, effective and safe biologically-based methods that are more sustainable. The integration of the sterile insect technique has proven successful to manage crop pests and disease vectors, particularly tsetse flies, and is likely to prove effective against mosquito vectors, particularly once sex-separation methods are improved. Transgenic and symbiont-based approaches are in development, and more advanced in (particularly Aedes) mosquitoes than in tsetse flies; however, issues around stability, sustainability and biosecurity have to be addressed, especially when considering population replacement approaches. Regulatory issues and those relating to intellectual property and economic cost of application must also be overcome. Standardised methods to assess insect quality are required to compare and predict efficacy of the different approaches. Different combinations of these three approaches could be integrated to maximise their benefits, and all have the potential to be used in tsetse and mosquito area-wide integrated pest management programmes. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  14. Detection of Trypanozoon trypanosomes infections on Glossina ...

    African Journals Online (AJOL)

    TOSHIBA

    Accepted 16 November, 2012. Tsetse flies transmit many species of trypanosomes in Africa, some of which are human and livestock pathogens of ... important (Leak and Rowlands, 1997). Although seven species of Glossina ... 1.4 M NaCl) (Navajas et al.,. 1998). Lastly, the DNA was re- suspended in 200 µl of PCR water.

  15. Potential for area-wide control or eradication of tsetse flies in Africa

    International Nuclear Information System (INIS)

    Kabayo, J.P.; Feldmann, U.

    2000-01-01

    Tsetse flies (Glossina) are found in Africa over an area, estimated by various authors, of 7-11 million sq. km. The northern limit of this area corresponds closely to the southern edges of the Sahara and Somali Deserts, running along 14 deg. N and extending across the continent from Senegal in the west to Somalia in the east. The southern limit of tsetse distribution corresponds closely to the northern edges of the Kalahari and Namibian Deserts in the west and runs generally at 20-30 deg. S to the east of the continent (Ford and Katondo 1977). This tsetse fly belt covers the following 38 countries (listed below) in which the tsetse flies spread African trypanosomosis, a severe disease that affects man and his domestic livestock, and is among the factors responsible for limiting the pace and extent of development in those countries. The disease is of a major economic importance. Throughout the affected countries within the fly belt, areas that are heavily infested by the tsetse fly are virtually devoid of cattle and other species of domestic livestock. Distribution of livestock in all countries on the African continent where densely infested foci exist is almost exactly the reverse of the distribution of the fly (Finelle 1974, Brunhes et al. 1994). Attempts to control African trypanosomosis date back to the beginning of this century. Several different methods of control, some aimed at the disease-causing organism and other aimed at the vector, were employed (Nagel 1995, Jordan 1986). Until after the Second World War, when insecticides became available for use in tsetse control campaigns, the most widely used control measure against tsetse flies was habitat destruction (involving felling trees and bush-clearing), the elimination of host animals (involving killing of wild game) and, to a certain extent, the use of various trapping devices to catch the flies. The tsetse control campaigns mounted in the 40s, 50s and 60s were invariably extensive 'roll up the country

  16. The Status of the Tsetse Fly as the Vector of Human ...

    African Journals Online (AJOL)

    cause has recently been re-examined as part of an on-going Programme. The Regional Tsetse and Trypanosomiasis Con- ... ment Fund to investigate the feasibility, possible costs, likely benefits and possible negative conse- quences of eradicating the flies in the "common fly-beltn. • The RTTCP was therefore established ...

  17. Proteomic analysis of Glossina pallidipes salivary gland hypertrophy virus virions for immune intervention in tsetse fly colonies

    NARCIS (Netherlands)

    Kariithi, H.M.; Ince, I.A.; Boeren, S.; Vervoort, J.J.M.; Bergoin, M.; Oers, van M.M.; Abd-Alla, A.M.M.; Vlak, J.M.

    2010-01-01

    Many species of tsetse flies (Diptera: Glossinidae) can be infected by a virus that causes salivary gland hypertrophy (SGH). The viruses isolated from Glossina pallidipes (GpSGHV) and Musca somestica (MdSGHV) have recently been sequenced. Tsetse flies with SGH have a reduced fecundity and fertility

  18. Detection and characterization of Wolbachia infections in laboratory and natural populations of different species of tsetse flies (genus Glossina

    Directory of Open Access Journals (Sweden)

    Doudoumis Vangelis

    2012-01-01

    Full Text Available Abstract Background Wolbachia is a genus of endosymbiotic α-Proteobacteria infecting a wide range of arthropods and filarial nematodes. Wolbachia is able to induce reproductive abnormalities such as cytoplasmic incompatibility (CI, thelytokous parthenogenesis, feminization and male killing, thus affecting biology, ecology and evolution of its hosts. The bacterial group has prompted research regarding its potential for the control of agricultural and medical disease vectors, including Glossina spp., which transmits African trypanosomes, the causative agents of sleeping sickness in humans and nagana in animals. Results In the present study, we employed a Wolbachia specific 16S rRNA PCR assay to investigate the presence of Wolbachia in six different laboratory stocks as well as in natural populations of nine different Glossina species originating from 10 African countries. Wolbachia was prevalent in Glossina morsitans morsitans, G. morsitans centralis and G. austeni populations. It was also detected in G. brevipalpis, and, for the first time, in G. pallidipes and G. palpalis gambiensis. On the other hand, Wolbachia was not found in G. p. palpalis, G. fuscipes fuscipes and G. tachinoides. Wolbachia infections of different laboratory and natural populations of Glossina species were characterized using 16S rRNA, the wsp (Wolbachia Surface Protein gene and MLST (Multi Locus Sequence Typing gene markers. This analysis led to the detection of horizontal gene transfer events, in which Wobachia genes were inserted into the tsetse flies fly nuclear genome. Conclusions Wolbachia infections were detected in both laboratory and natural populations of several different Glossina species. The characterization of these Wolbachia strains promises to lead to a deeper insight in tsetse flies-Wolbachia interactions, which is essential for the development and use of Wolbachia-based biological control methods.

  19. A desk evaluation review of project URT/5/007 tsetse fly eradication. Project desk evaluation

    International Nuclear Information System (INIS)

    1993-01-01

    Project URT/5/007 was initiated in 1984 to assist the Government of the United Republic of Tanzania in developing membrane feeding technology for the mass breeding of tsetse flies, which is required for the application of the sterile insect technique to eradicate the tsetse fly from the island of Zanzibar. As the project progressed the objectives focused on the development of inter-related management practices with SIT to control and eventually eradicate the tsetse species infesting Zanzibar. As depicted by the project title, tsetse fly eradication on Zanzibar is the ultimate goal of on-going work of project URT/5/007; however, tsetse fly eradication is not the immediate objective of this project. The total budget of the project for the years 1984 through 1994 includes 53 man-months of expert services, $402,755 for equipment, and $1,959 for fellowship training. Additional funds for 57 man-months of fellowship training were provided from sources outside of the project. Resources provided by the United Republic of Tanzania for the project included staff, local facilities, and local running costs. A Desk Evaluation Review (DER) of Project URT/5/007 was requested by the Africa Section to provide an assessment of project achievements and to determine to what end the project may lead in the near future. Also the review could help determine how experiences gained during the developments of this project might be utilized in the management and implementation of similar projects in Tanzania or the region

  20. Genome sequence of the tsetse fly (Glossina morsitans ): Vector of African trypanosomiasis

    KAUST Repository

    Watanabe, Junichi

    2014-04-24

    Tsetse flies are the sole vectors of human African trypanosomiasis throughout sub-Saharan Africa. Both sexes of adult tsetse feed exclusively on blood and contribute to disease transmission. Notable differences between tsetse and other disease vectors include obligate microbial symbioses, viviparous reproduction, and lactation. Here, we describe the sequence and annotation of the 366-megabase Glossina morsitans morsitans genome. Analysis of the genome and the 12,308 predicted protein-encoding genes led to multiple discoveries, including chromosomal integrations of bacterial (Wolbachia) genome sequences, a family of lactation-specific proteins, reduced complement of host pathogen recognition proteins, and reduced olfaction/chemosensory associated genes. These genome data provide a foundation for research into trypanosomiasis prevention and yield important insights with broad implications for multiple aspects of tsetse biology.

  1. Trypanosomes - versatile microswimmers

    Science.gov (United States)

    Krüger, Timothy; Engstler, Markus

    2016-11-01

    Evolution has generated a plethora of flagellate microswimmers. They populate all natural waters, from the deep sea to the ponds in our neighbourhood. But flagellates also thrive in the bodies of higher organisms, where they mostly remain undetected, but can also become pathogenic. Trypanosomes comprise a large group of mostly parasitic flagellates that cause many diseases, such as human sleeping sickness or the cattle plague nagana. We consider African trypanosomes as extremely versatile microswimmers, as they have to adapt to very diverse microenvironments. They swim efficiently in the blood of their mammalian hosts, but also in various tissue spaces and even in the human brain. Furthermore, in the transmitting tsetse fly, trypanosomes undergo characteristic morphological changes that are accompanied by amazing transitions between solitary and collective types of motion. In this review, we provide a basic introduction to trypanosome biology and then focus on the complex type of rotational movement that trypanosomes display. We relate their swimming performance to morphological parameters and the respective microenvironment, developing a contemporary view on the physics of trypanosome motility. The genetically programmed successions of life style-dependent motion patterns provide challenges and opportunities for interdisciplinary studies of microswimmers.

  2. Protecting cows in small holder farms in East Africa from tsetse flies by mimicking the odor profile of a non-host bovid

    Science.gov (United States)

    Orindi, Benedict O.; Mbahin, Norber; Muasa, Peter N.; Mbuvi, David M.; Muya, Caroline M.; Pickett, John A.; Borgemeister, Christian W.

    2017-01-01

    Background For the first time, differential attraction of pathogen vectors to vertebrate animals is investigated for novel repellents which when applied to preferred host animals turn them into non-hosts thereby providing a new paradigm for innovative vector control. For effectively controlling tsetse flies (Glossina spp.), vectors of African trypanosomosis, causing nagana, repellents more powerful than plant derived, from a non-host animal the waterbuck, Kobus ellipsiprymnus defassa, have recently been identified. Here we investigate these repellents in the field to protect cattle from nagana by making cattle as unattractive as the buck. Methodology/Principal findings To dispense the waterbuck repellents comprising guaiacol, geranylacetone, pentanoic acid and δ-octalactone, (patent application) we developed an innovative collar-mounted release system for individual cattle. We tested protecting cattle, under natural tsetse challenge, from tsetse transmitted nagana in a large field trial comprising 1,100 cattle with repellent collars in Kenya for 24 months. The collars provided substantial protection to livestock from trypanosome infection by reducing disease levels >80%. Protected cattle were healthier, showed significantly reduced disease levels, higher packed cell volume and significantly increased weight. Collars >60% reduced trypanocide use, 72.7% increase in ownership of oxen per household and enhanced traction power (protected animals ploughed 66% more land than unprotected). Land under cultivation increased by 73.4%. Increase in traction power of protected animals reduced by 69.1% acres tilled by hand per household per ploughing season. Improved food security and household income from very high acceptance of collars (99%) motivated the farmers to form a registered community based organization promoting collars for integrated tsetse control and their commercialization. Conclusion/Significance Clear demonstration that repellents from un-preferred hosts

  3. The use of entomopathogenic fungi in the control of tsetse flies.

    Science.gov (United States)

    Maniania, Nguya K; Ekesi, Sunday

    2013-03-01

    Tsetse flies harbor a number of pathogens in nature; but their potential as biological control agents has not been fully exploited, especially due to the difficulty of their application in the field. Since entomopathogenic fungi infect their target organisms through the cuticle, it has been possible to develop a device that deliver and autodisseminate inoculum among tsetse in the field, resulting in population reduction, comparable to mass-trapping technology. However, the success of this technology depends on the effective horizontal transmission of the inoculum between insects. We present an overview of the prospects of entomopathogenic fungi for the control of tsetse flies and highlight the challenges. Copyright © 2013 International Atomic Energy Agency. Published by Elsevier Inc. All rights reserved.

  4. Neural coding in antennal olfactory cells of tsetse flies (Glossina spp.)

    NARCIS (Netherlands)

    Voskamp, K.E; Noorman, N; Mastebroek, H.A K; van Schoot, N.E.G.; den Otter, C.J

    1998-01-01

    Spike trains from individual antennal olfactory cells of tsetse flies (Glossina spp.) obtained during steady-state conditions (spontaneous as well as during stimulation with 1-octen-3-ol) and dynamic stimulation with repetitive pulses of 1-octen-3-ol were investigated by studying the spike frequency

  5. High trypanosome infections in Glossina palpalis palpalis Robineau ...

    African Journals Online (AJOL)

    A survey was undertaken to determine the prevalence of trypanosome infection in Glossina species in Kaura Local Government Area (LGA) of Kaduna State, Southern Guinea Savanna, Nigeria, aimed at identifying areas to be prioritized for area-wide tsetse eradication. The flies were trapped from a relic forest and also from ...

  6. Preliminary survey on tsetse flies and trypanosomosis at grazing ...

    African Journals Online (AJOL)

    Impact of Trypanosomosis on African Agriculture. PAAT Technical and Scientific Series 2. FAO, Rome, Italy. Vreysen,M.J.B. 2000. Southern Rift Valley tsetse eradication programme.Analysis of the entomological baseline data collected between October 1998 and September. 1999.Report to the IAEA, IAEA, Vienna, Austria.

  7. Dual control of ticks and tsetse flies using deltamethrin through ...

    African Journals Online (AJOL)

    Mo

    The baseline survey was carried out in three parishes to establish the initial tsetse density, tick burdens, level of tick control and prevalence of trypanosomosis and TBDs in cattle. Initially, samples were taken from 200 head of cattle and were ear tagged for future monitoring. Stained blood smears were examined for TBDs.

  8. Ecology of Glossina species inhabiting peridomestic agroecosystems in relation to options for tsetse fly control

    International Nuclear Information System (INIS)

    Madubunyi, L.C.

    1990-01-01

    Unbaited blue biconical traps were used to sample populations of Glossina once a week from April 1984 to March 1988 in three peridomestic agroecosystems of the Nsukka area, Nigeria. Serological analysis of 1764 fly midgut contents revealed that G. tachinoides had fed on reptiles, birds and mammals, with the domestic pig accounting for 88.08% of the 730 identifiable bloodmeals. The frequency distribution of flies in various stages of the trophic cycle showed that males and females feed at 2.88 ± 0.42 and 2.43 ± 0.44 day intervals, respectively. Flies were caught in greater numbers in biotopes containing domestic pigs, while the presence of man depressed trap catches. The larger the pig population in an agroecosystem, the larger the G. tachinoides population. However, reduction in the pig population to below five triggered the collapse of one of the G. tachinoides populations, which disappeared following the removal of all the pigs. The fly populations exhibited marked seasonal fluctuations in apparent density, largely caused by routine agronomic practices. These density fluctuations undermine recruitment of new adults into the population, especially during the wet season. It is suggested that tsetse populations in this area, already being kept at low density by routine agricultural procedures, could be further reduced by combining insecticides impregnated traps or targets with insect proofing of the piggeries. Methods aimed at undermining the recruitment of young adults into tsetse populations, capitalizing on naturally occurring sex ratio distortion as well as on maintaining populations of preferred hosts of the tsetse fly at low levels, should form part of integrated tsetse control packages. Selection of sterile male release sites and the number of sterile males to be released in them during sterile insect technique campaigns should take into account the sex ratio dynamics of target tsetse populations. 28 ref, 9 figs, 8 tabs

  9. Impact of habitat fragmentation on tsetse populations and trypanosomosis risk in Eastern Zambia.

    Science.gov (United States)

    Mweempwa, Cornelius; Marcotty, Tanguy; De Pus, Claudia; Penzhorn, Barend Louis; Dicko, Ahmadou Hamady; Bouyer, Jérémy; De Deken, Reginald

    2015-08-04

    Fragmentation of tsetse habitat in eastern Zambia is largely due to encroachments by subsistence farmers into new areas in search of new agricultural land. The impact of habitat fragmentation on tsetse populations is not clearly understood. This study was aimed at establishing the impact of habitat fragmentation on physiological and demographic parameters of tsetse flies in order to enhance the understanding of the relationship between fragmentation and African animal trypanosomosis (AAT) risk. A longitudinal study was conducted to establish the age structure, abundance, proportion of females and trypanosome infection rate of Glossina morsitans morsitans Westwood (Diptera: Glossinidae) in areas of varying degrees of habitat fragmentation in Eastern Zambia. Black screen fly rounds were used to sample tsetse populations monthly for 1 year. Logistic regression was used to analyse age, proportion of females and infection rate data. Flies got significantly older as fragmentation increased (p fragmented site (Lusandwa) to 74.2% (CI 56.8-86.3) at the highly fragmented site (Chisulo). In the most fragmented area (Kasamanda), tsetse flies had almost disappeared. In the highly fragmented area a significantly higher trypanosome infection rate in tsetse (P fragmentation was observed. Consequently a comparatively high trypanosomosis incidence rate in livestock was observed there despite lower tsetse density (p fragmentation reduced. The proportion increased from 0.135 (CI 0.10-0.18) to 0.285 (CI 0.26-0.31) at the highly and least fragmented sites, respectively. Habitat fragmentation creates conditions to which tsetse populations respond physiologically and demographically thereby affecting tsetse-trypanosome interactions and hence influencing trypanosomosis risk. Temperature rise due to fragmentation coupled with dominance of old flies in populations increases infection rate in tsetse and hence creates high risk of trypanosomosis in fragmented areas. Possibilities of how

  10. Identification of a Tsal152-75 salivary synthetic peptide to monitor cattle exposure to tsetse flies.

    Science.gov (United States)

    Somda, Martin Bienvenu; Cornelie, Sylvie; Bengaly, Zakaria; Mathieu-Daudé, Françoise; Poinsignon, Anne; Dama, Emilie; Bouyer, Jeremy; Sidibé, Issa; Demettre, Edith; Seveno, Martial; Remoué, Franck; Sanon, Antoine; Bucheton, Bruno

    2016-03-15

    The saliva of tsetse flies contains a cocktail of bioactive molecules inducing specific antibody responses in hosts exposed to bites. We have previously shown that an indirect-ELISA test using whole salivary extracts from Glossina morsitans submorsitans was able to discriminate between (i) cattle from tsetse infested and tsetse free areas and (ii) animals experimentally exposed to low or high numbers of tsetse flies. In the present study, our aim was to identify specific salivary synthetic peptides that could be used to develop simple immunoassays to measure cattle exposure to tsetse flies. In a first step, 2D-electrophoresis immunoblotting, using sera from animals exposed to a variety of bloodsucking arthropods, was performed to identify specific salivary proteins recognised in cattle exposed to tsetse bites. Linear epitope prediction software and Blast analysis were then used to design synthetic peptides within the identified salivary proteins. Finally, candidate peptides were tested by indirect-ELISA on serum samples from tsetse infested and tsetse free areas, and from exposure experiments. The combined immunoblotting and bioinformatics analyses led to the identification of five peptides carrying putative linear epitopes within two salivary proteins: the tsetse salivary gland protein 1 (Tsal1) and the Salivary Secreted Adenosine (SSA). Of these, two were synthesised and tested further based on the absence of sequence homology with other arthropods or pathogen species. IgG responses to the Tsal152-75 synthetic peptide were shown to be specific of tsetse exposure in both naturally and experimentally exposed hosts. Nevertheless, anti-Tsal152-75 IgG responses were absent in animals exposed to high tsetse biting rates. These results suggest that Tsal152-75 specific antibodies represent a biomarker of low cattle exposure to tsetse fly. These results are discussed in the light of the other available tsetse saliva based-immunoassays and in the perspective of developing

  11. Hearing in tsetse flies? Morphology and mechanics of a putative auditory organ.

    Science.gov (United States)

    Tuck, E J; Windmill, J F C; Robert, D

    2009-04-01

    Tympanal hearing organs are widely used by insects to detect sound pressure. Such ears are relatively uncommon in the order Diptera, having only been reported in two families thus far. This study describes the general anatomical organization and experimentally examines the mechanical resonant properties of an unusual membranous structure situated on the ventral prothorax of the tsetse fly, Glossina morsitans (Diptera: Glossinidae). Anatomically, the prosternal membrane is backed by an air filled chamber and attaches to a pair of sensory chordotonal organs. Mechanically, the membrane shows a broad resonance around 5.3-7.2 kHz. Unlike previously reported dipteran tympana, a directional response to sound was not found in G. morsitans. Collectively, the morphology, the resonant properties and acoustic sensitivity of the tsetse prothorax are consistent with those of the tympanal hearing organs in Ormia sp. and Emblemasoma sp. (Tachinidae and Sarcophagidae). The production of sound by several species of tsetse flies has been repeatedly documented. Yet, clear behavioural evidence for acoustic behaviour is sparse and inconclusive. Together with sound production, the presence of an ear-like structure raises the enticing possibility of auditory communication in tsetse flies and renews interest in the sensory biology of these medically important insects.

  12. Midgut absorption of proteins by tsetse flies, Glossina morsitans morsitans Westwood (Diptera: Glossinidae)

    International Nuclear Information System (INIS)

    Nogge, G.; Giannetti, M.

    1980-01-01

    Experiments have been conducted to determine how far tsetse flies are able to absorb undigested proteins from the midgut and to transport into the haemolymph. Comparison of the protein pattern of blood serum and haemolymph as revealed by electrophoresis shows no congruency except for the albumin fraction, which is about 10% of the total protein contents. The peritrophic membrane of tsetse flies allows the passage of FITC-conjugated dextrans up to but not greater than a molecular weight of approximately 45,000. It can be concluded therefore that complete serum globulins cannot pass through the peritrophic membrane, but fragments of globulins and albumin might do so. The presence of serum proteins in the haemolymph of tsetse flies after oral administration was investigated by immunological techniques. With the help of immunoelectrophoresis as well as Ouchter-Lony tests, albumin, Fab-, and Fc-fragments were found to be present in the haemolymph. Tsetse flies usually fed on bovine blood replace bovine albumin present in their haemolymph by human albumin when fed on human blood. Quantitative determinations with the aid of rocket immunoelectrophoresis after Laurell revealed the occurrence of human albumin in relation to the size and number of blood meals. When fed continuously on human blood, the amount of human albumin rises following eight to ten blood meals after which the achieved level is maintained. Human albumin disappears from the haemolymph and is replaced by bovine albumin when the flies are fed again with bovine blood. On the basis of these results the amount of albumin absorbed from a single blood meal lies in the range of 0.01 to 0.035% of its albumin contents. (author)

  13. Molecular characterization of trypanosomes isolated from naturally ...

    African Journals Online (AJOL)

    SARAH

    2014-11-30

    Nov 30, 2014 ... trypanocide drug coverage. Nevertheless the wide spread use and the misuse of drug has contributed .... containing 10 mM of Tris-HCL pH 8.3, 50 mM of KCl, 3. mM of MgCl23, 200 ml of each deoxynucleotide ..... LH, Maloo S, 1994. Detection of trypanosome infections in the saliva of tsetse flies and buffy-.

  14. Acoustic Method for Testing the Quality of Sterilized Male Tsetse Flies Glossina Pallidipes

    International Nuclear Information System (INIS)

    Kratochvil, H.; Noll, A.; Bolldorf, J.; Parker, A.G.

    2012-01-01

    Tsetse flies are able to emit different acoustic signals. An acoustic method to test the quality of sterilized male tsetse flies was developed. Differences in the sound characteristics between males and females, between sterilized and unsterilized males, and between males sterilized in air and nitrogen, were determined. Also, the acoustic parameters (frequency, time, sound pressure level) of the sounds that are useful as criteria for quality control were determined. It was demonstrated that only the so-called 'feeding sounds' can be used as a quality criterion. Both sexes emitted feeding sounds while feeding on a host. These sounds were also used to find sexual partners, and had an effect on male copulation success. An acoustic sound analysis programme was developed; it automatically measured sound activity (only feeding sounds) under standard conditions (random sample, relative humidity, temperature, light intensity). (author)

  15. Mass rearing and radiation sterilization of tsetse flies. Part of a coordinated programme on control and eradication of tsetse flies by the sterile insect technique

    International Nuclear Information System (INIS)

    Offori, E.

    1980-12-01

    Studies were conducted with the tsetse flies Glossina palpalis palpalis, G.p. gambiensis and G. tachinoides to evaluate the practicality in Ghana of various laboratory and field procedures used to conduct a sterile insect release programme. Investigations revealed that in colony rearing rabbits, guinea pigs and goats could be used as host animals and that alternation of hosts had little effect on colony performance. Over 90% sterility in 10-day-old males irradiated at 12 kR was obtained with little or no effect on survival. At 15 kR, 98% sterility was obtained but with some loss in viability observed. In mating experiments, G. p. palpalis and G. p. gambiensis mated readily with each other and indicated that sterile males of one sub-species could be released with advantage into an area predominantly occupied by the other sub-species. In field tests, the moving vehicle traps proved most efficient of the various sampling techniques evaluated. It was noted that in spite of the rapid expansion of the city of Accra, tsetse flies were still present within a distance of 4 km of the city

  16. New systems for the large-scale production of male tsetse flies (Diptera: Glossinidae)

    International Nuclear Information System (INIS)

    Opiyo, E.; Luger, D.; Robinson, A.S.

    2000-01-01

    Tsetse flies, vectors of trypanosomiasis, infest 36 African countries and their distribution covers approximately 10 million km 2 . Trypanosomiasis is a debilitating and often fatal disease of domestic livestock and humans and is considered the most important limiting factor for the development of the livestock sector in Africa. Approximately 50 million cattle and scores of millions of small ruminants are at risk of contracting trypanosomiasis. Direct losses in meat production, milk yield and traction power and the cost of control programmes are estimated to amount to more than US$500 million each year (FAO 1994). In addition, 100 million people are at risk of contracting the disease. According to the World Health Organization, about 300,000 new cases of human trypanosomiasis occur annually (WHO 1997). If the lost potential in livestock production is combined with that of crop production through loss of traction power, trypanosomiasis is estimated to cost Africa US$4 billion or more each year (FAO 1994). The available and environmentally accepted intervention methods for the management of tsetse and trypanosomiasis include parasite control using drugs, the promotion of trypanotolerant livestock and vector control. Parasite control is plagued by the development of resistance to the available drugs and programmes for the development of new drugs are limited. Vector control and eradication involve application of insecticide treated attractive devices on animals including cattle, and the sterile insect technique (SIT). In spite of the efforts spent on the control of the disease and the vector, tsetse flies remain a threat to agricultural development of the region. Experience indicates that only a combination of several of these intervention methods can effectively support sustainable agricultural systems. The feasibility of rearing tsetse flies in Africa for use in SIT was first demonstrated in Tanzania (Williamson et al. 1983) where a colony of 60,000 Glossina

  17. Tsetse Flies (Glossina as Vectors of Human African Trypanosomiasis: A Review

    Directory of Open Access Journals (Sweden)

    Florence Njeri Wamwiri

    2016-01-01

    Full Text Available Human African Trypanosomiasis (HAT transmitted by the tsetse fly continues to be a public health issue, despite more than a century of research. There are two types of the disease, the chronic gambiense and the acute rhodesiense-HAT. Fly abundance and distribution have been affected by changes in land-use patterns and climate. However, disease transmission still continues. Here, we review some aspects of HAT ecoepidemiology in the context of altered infestation patterns and maintenance of the transmission cycle as well as emerging options in disease and vector control.

  18. Tsetse Flies (Glossina) as Vectors of Human African Trypanosomiasis: A Review.

    Science.gov (United States)

    Wamwiri, Florence Njeri; Changasi, Robert Emojong

    2016-01-01

    Human African Trypanosomiasis (HAT) transmitted by the tsetse fly continues to be a public health issue, despite more than a century of research. There are two types of the disease, the chronic gambiense and the acute rhodesiense-HAT. Fly abundance and distribution have been affected by changes in land-use patterns and climate. However, disease transmission still continues. Here, we review some aspects of HAT ecoepidemiology in the context of altered infestation patterns and maintenance of the transmission cycle as well as emerging options in disease and vector control.

  19. Sterile insect technique for tsetse control and eradication

    International Nuclear Information System (INIS)

    1990-01-01

    The current publication contains the contributions made by scientists who participated in the fourth Co-ordinated Research Programme. A range of topics, covering both field and laboratory activities, was addressed: Eradication of Glossina palpalis palpalis (Robineau-Desvoidy) (Diptera: Glossinidae) from agropastoral land in Central Nigeria by means of the sterile insect technique; Research and development in the IAEA Laboratory at Seibersdorf in support of BICOT for the eradication of Glossina palpalis palpalis; Tsetse fly eradication in Burkina Faso and evaluation of traps and targets; Ecology of Glossina species inhabiting peridomestic agroecosystems in relation to options for tsetse fly control; Population dynamics of Glossina fuscipes fuscipes on Buvuma Island, Lake Victoria, Uganda; Population estimation from mark-recapture data: Equations for a pooled mark system and for pooled data, with applications to a study on island populations of tsetse flies in Zimbabwe; Surveillance of tsetse fly and cattle populations for trypanosomes in the BICOT area during the sterile insect technique control programme; Freeze dried blood and development of an artificial diet for blood feeding anthropods; Effects of the nutritional quality of locally obtained blood diets on the performance of Glossina palpalis palpalis fed in vitro; Mycetomes and symbionts of tsetse flies maintained on a membrane feeding system and the agents interfering with natural reproduction; Virus particles infection in laboratory reared Glossina pallidipes Austen (Diptera: Glossinidae); Influence of different nutritional sources on haemolymph composition and vitellogenesis in haematophagous arthropods; Effect of rearing diet on the injection rate in flies released for the control of tsetse populations by sterile males; Use of juvenile hormone mimics in the sterilization of tsetse flies; Studies of Glossina pallidipes and G. morsitans subspecies related to the genetic control of tsetse flies

  20. Community-based tsetse fly control minimizes the effect of trypanosomosis on livestock in Metekel zone, Ethiopia.

    Science.gov (United States)

    Girmay, Gebrerufael; Arega, Bezna; Berkvens, Dirk; Altaye, Solomon Z; Muleta, Gadisa

    2018-03-01

    Tsetse-related trypanosomosis threatens integrated crop-livestock production system in Ethiopia. Metekel zone is among the tsetse-infested areas in Ethiopia. Community-based tsetse fly and trypanosomosis control using targets was conducted from June 2011 to May 2012 in the zone. In coordination with the control project, a questionnaire survey was administered to assess the economic importance of the tsetse fly and trypanosomosis control conducted in the Zone. On average, there were 3 livestock deaths/household before control and this was decreased to 0.07 after control. This death was contributed from all possible livestock diseases. A household loss 4380 (95% CI = 4223.98-4541.79) EB (1 US$ = 17.9 EB) only due to the deaths of his/her livestock was reduced to 90.78 (95% CI = 89.15-92.42) EB after control. Morbidity of oxen in the study areas was significantly decreased by 70.7%. As a result, the monetary loss to rent for healthy draught oxen was decreased by 96.4%. When a household with one cattle harvest 10.9 quintals (1090 kg), his neighbor's household with ten cattle maximize his/her yield to about 50.5 quintals (5050 kg) of crops indicating that trypanosomosis has great economic impact in crop-livestock production system. As the community-based tsetse fly control approach is simple, cost effective, and appropriate for riverine tsetse species, we conclude that farmers can minimize the negative impact of tsetse flies and trypanosomosis in the tsetse-infested areas of African countries.

  1. 2013 Annual Report: Project to combat the Tsetse Fly and Trypanosomiasis in the Niayes Area

    International Nuclear Information System (INIS)

    2014-05-01

    The period 2009-2010 was a transition phase, used to analyze the basic data collected, in particular those relating to entomology and parasitology, in order to define a control strategy. An entomological and parasitological follow-up aimed at understanding the spatio-temporal dynamics of the system before the struggle has thus been put in place. Similarly, socio-economic studies have continued with the finalization of the survey and test reports produced by certain breeders. On the basis of the results of the feasibility study which confirmed the presence of Glossina palpalis gambiensis on the Dakar-Thies-Kayar triangle and the disease it transmits (trypanosomiasis) and Isolated from the area in relation to other tsetse infested areas, the fighting phase started in 2010 in block I (Kayar) and then in 2012 in block II (Sebikotane, Diacsaw Peulh, Pout) with the deployment of impregnated traps Deltamethrin and livestock ''on'' treatment. Entomological controls (monthly measurements of apparent densities) showed a significant decrease in tsetse populations in the target areas.The phase of elimination of tsetse flies began in 2011 in the Kayar area with weekly releases of sterile males to the soil. Operational air releases began in 2013 with cardboard boxes. They will continue in 2014 with an automatic machine specially designed by a Mexican company specializing in the release of fruit flies.On the parasitological level, sick animals are detected and treated, in order to reduce the prevalence of the disease. (Author)

  2. Explaining the host-finding behavior of blood-sucking insects : computerized simulation of the effects of habitat geometry on tsetse fly movement

    OpenAIRE

    Vale, G. A.; Hargrove, J. W.; Solano, Philippe; Courtin, Fabrice; Rayaisse, J. B.; Lehane, M. J.; Esterhuizen, J.; Tirados, I.; Torr, S. J.

    2014-01-01

    Background\\ud \\ud Male and female tsetse flies feed exclusively on vertebrate blood. While doing so they can transmit the\\ud diseases of sleeping sickness in humans and nagana in domestic stock. Knowledge of the host-orientated behavior of tsetse is important in designing bait methods of sampling and controlling the flies, and in understanding the epidemiology of the diseases. For this we must explain several puzzling distinctions in the behavior of the different sexes and species of tsetse. ...

  3. Tsetse fly eradication in Burkina Faso and evaluation of traps and targets

    International Nuclear Information System (INIS)

    Clair, M.; Cuisance, D.; Politzar, H.; Merot, P.; Bauer, B.

    1990-01-01

    Control operations against tsetse flies with the sterile insect technique (SIT) were conducted by the Centre de recherches sur les trypanosomoses animales (CRTA) (Institut d'elevage et de medecine veterinaire des pays tropicaux/Gesellschaft fuer Technische Zusammenarbeit (IEMVT/GTZ) Project), Bobo-Dioulasso (Burkina Faso). The project ended in 1984 with the eradication in the Sideradougou pastoral zone of the three tsetse species present there (Glossina palpalis gambiensis, G. tachinoides and G. morsitans submorsitans). Since 1985, besides monitoring of this area, the CRTA oriented its activities towards improving trapping by carrying out research on the form and colour of targets as well as the use of olfactory attractants. (author). 34 refs, 5 figs

  4. The interaction of taste and heat on the biting response of the tsetse fly Glossina fuscipes fuscipes

    NARCIS (Netherlands)

    van der Goes van Naters, W.M; den Otter, C.J; Cuisance, D.

    Tsetse flies probe more on a heated surface with a trace of uric acid than on one without. Uric acid is one of the components of human sweat and it elicits spike responses from taste hairs on the flies' legs. In this paper it is examined how heat from the surface and taste interact to affect the

  5. Tsetse flies, biodiversity and the control of sleeping sickness. Structure of a Glossina guild in southwest Côte d'Ivoire

    Science.gov (United States)

    Gouteux, Jean-Paul; Jarry, Marc

    1998-10-01

    reason for such a process is quite obvious, how it occurs still remains to be explained. Other observations may provide a clue. For example, the sex ratios of both the main species fluctuate in opposite phases during the annual cycle. This strongly suggests that interspecific interactions occur through sexual mediation. Finally, the authors discuss the consequences of dynamic cohabitation on disease systems (trypanosomes, tsetse flies, hosts) and on control possibilities.

  6. Variation of tsetse fly abundance in relation to habitat and host presence in the Maasai Steppe, Tanzania.

    Science.gov (United States)

    Ngonyoka, Anibariki; Gwakisa, Paul S; Estes, Anna B; Nnko, Happiness J; Hudson, Peter J; Cattadori, Isabella M

    2017-06-01

    Human activities modify ecosystem structure and function and can also alter the vital rates of vectors and thus the risk of infection with vector-borne diseases. In the Maasai Steppe ecosystem of northern Tanzania, local communities depend on livestock and suitable pasture that is shared with wildlife, which can increase tsetse abundance and the risk of trypanosomiasis. We monitored the monthly tsetse fly abundance adjacent to Tarangire National Park in 2014-2015 using geo-referenced, baited epsilon traps. We examined the effect of habitat types and vegetation greenness (NDVI) on the relative abundance of tsetse fly species. Host availability (livestock and wildlife) was also recorded within 100×100 m of each trap site. The highest tsetse abundance was found in the ecotone between Acacia-Commiphora woodland and grassland, and the lowest in riverine woodland. Glossina swynnertoni was the most abundant species (68%) trapped throughout the entire study, while G. pallidipes was the least common (4%). Relative species abundance was negatively associated with NDVI, with greatest abundance observed in the dry season. The relationship with the abundance of wildlife and livestock was more complex, as we found positive and negative associations depending on the host and fly species. While habitat is important for tsetse distribution, hosts also play a critical role in affecting fly abundance and, potentially, trypanosomiasis risk. © 2017 The Society for Vector Ecology.

  7. A phylogenetic lineage of closely related trypanosomes (Trypanosomatidae, Kinetoplastida) of anurans and sand flies (Psychodidae, Diptera) sharing the same ecotopes in brazilian amazonia.

    Science.gov (United States)

    Ferreira, Robson C; De Souza, Adelson A; Freitas, Rui A; Campaner, Marta; Takata, Carmem S A; Barrett, Toby V; Shaw, Jeffrey J; Teixeira, Marta M G

    2008-01-01

    Analysis of the phylogenetic relationships among trypanosomes from vertebrates and invertebrates disclosed a new lineage of trypanosomes circulating among anurans and sand flies that share the same ecotopes in Brazilian Amazonia. This assemblage of closely related trypanosomes was determined by comparing whole SSU rDNA sequences of anuran trypanosomes from the Brazilian biomes of Amazonia, the Pantanal, and the Atlantic Forest and from Europe, North America, and Africa, and from trypanosomes of sand flies from Amazonia. Phylogenetic trees based on maximum likelihood and parsimony corroborated the positioning of all new anuran trypanosomes in the aquatic clade but did not support the monophyly of anuran trypanosomes. However, all analyses always supported four major clades (An01-04) of anuran trypanosomes. Clade An04 is composed of trypanosomes from exotic anurans. Isolates in clades An01 and An02 were from Brazilian frogs and toads captured in the three biomes studied, Amazonia, the Pantanal and the Atlantic Forest. Clade An01 contains mostly isolates from Hylidae whereas clade An02 comprises mostly isolates from Bufonidae; and clade An03 contains trypanosomes from sand flies and anurans of Bufonidae, Leptodactylidae, and Leiuperidae exclusively from Amazonia. To our knowledge, this is the first study describing morphological and growth features, and molecular phylogenetic affiliation of trypanosomes from anurans and phlebotomines, incriminating these flies as invertebrate hosts and probably also as important vectors of Amazonian terrestrial anuran trypanosomes.

  8. Candidatus Sodalis melophagi sp. nov.: phylogenetically independent comparative model to the tsetse fly symbiont Sodalis glossinidius.

    Directory of Open Access Journals (Sweden)

    Tomáš Chrudimský

    Full Text Available Bacteria of the genus Sodalis live in symbiosis with various groups of insects. The best known member of this group, a secondary symbiont of tsetse flies Sodalis glossinidius, has become one of the most important models in investigating establishment and evolution of insect-bacteria symbiosis. It represents a bacterium in the early/intermediate state of the transition towards symbiosis, which allows for exploring such interesting topics as: usage of secretory systems for entering the host cell, tempo of the genome modification, and metabolic interaction with a coexisting primary symbiont. In this study, we describe a new Sodalis species which could provide a useful comparative model to the tsetse symbiont. It lives in association with Melophagus ovinus, an insect related to tsetse flies, and resembles S. glossinidius in several important traits. Similar to S. glossinidius, it cohabits the host with another symbiotic bacterium, the bacteriome-harbored primary symbiont of the genus Arsenophonus. As a typical secondary symbiont, Candidatus Sodalis melophagi infects various host tissues, including bacteriome. We provide basic morphological and molecular characteristics of the symbiont and show that these traits also correspond to the early/intermediate state of the evolution towards symbiosis. Particularly, we demonstrate the ability of the bacterium to live in insect cell culture as well as in cell-free medium. We also provide basic characteristics of type three secretion system and using three reference sequences (16 S rDNA, groEL and spaPQR region we show that the bacterium branched within the genus Sodalis, but originated independently of the two previously described symbionts of hippoboscoids. We propose the name Candidatus Sodalis melophagi for this new bacterium.

  9. Candidatus Sodalis melophagi sp. nov.: phylogenetically independent comparative model to the tsetse fly symbiont Sodalis glossinidius.

    Science.gov (United States)

    Chrudimský, Tomáš; Husník, Filip; Nováková, Eva; Hypša, Václav

    2012-01-01

    Bacteria of the genus Sodalis live in symbiosis with various groups of insects. The best known member of this group, a secondary symbiont of tsetse flies Sodalis glossinidius, has become one of the most important models in investigating establishment and evolution of insect-bacteria symbiosis. It represents a bacterium in the early/intermediate state of the transition towards symbiosis, which allows for exploring such interesting topics as: usage of secretory systems for entering the host cell, tempo of the genome modification, and metabolic interaction with a coexisting primary symbiont. In this study, we describe a new Sodalis species which could provide a useful comparative model to the tsetse symbiont. It lives in association with Melophagus ovinus, an insect related to tsetse flies, and resembles S. glossinidius in several important traits. Similar to S. glossinidius, it cohabits the host with another symbiotic bacterium, the bacteriome-harbored primary symbiont of the genus Arsenophonus. As a typical secondary symbiont, Candidatus Sodalis melophagi infects various host tissues, including bacteriome. We provide basic morphological and molecular characteristics of the symbiont and show that these traits also correspond to the early/intermediate state of the evolution towards symbiosis. Particularly, we demonstrate the ability of the bacterium to live in insect cell culture as well as in cell-free medium. We also provide basic characteristics of type three secretion system and using three reference sequences (16 S rDNA, groEL and spaPQR region) we show that the bacterium branched within the genus Sodalis, but originated independently of the two previously described symbionts of hippoboscoids. We propose the name Candidatus Sodalis melophagi for this new bacterium.

  10. The homeodomain protein ladybird late regulates synthesis of milk proteins during pregnancy in the tsetse fly (Glossina morsitans.

    Directory of Open Access Journals (Sweden)

    Geoffrey M Attardo

    2014-04-01

    Full Text Available Regulation of tissue and development specific gene expression patterns underlies the functional specialization of organs in multi-cellular organisms. In the viviparous tsetse fly (Glossina, the female accessory gland is specialized to generate nutrients in the form of a milk-like secretion to support growth of intrauterine larva. Multiple milk protein genes are expressed specifically in the female accessory gland and are tightly linked with larval development. Disruption of milk protein synthesis deprives developing larvae of nutrients and results in extended larval development and/or in abortion. The ability to cause such a disruption could be utilized as a tsetse control strategy. Here we identify and delineate the regulatory sequence of a major milk protein gene (milk gland protein 1:mgp1 by utilizing a combination of molecular techniques in tsetse, Drosophila transgenics, transcriptomics and in silico sequence analyses. The function of this promoter is conserved between tsetse and Drosophila. In transgenic Drosophila the mgp1 promoter directs reporter gene expression in a tissue and stage specific manner orthologous to that of Glossina. Analysis of the minimal required regulatory region of mgp1, and the regulatory regions of other Glossina milk proteins identified putative homeodomain protein binding sites as the sole common feature. Annotation and expression analysis of Glossina homeodomain proteins identified ladybird late (lbl as being accessory gland/fat body specific and differentially expressed between lactating/non-lactating flies. Knockdown of lbl in tsetse resulted in a significant reduction in transcript abundance of multiple milk protein genes and in a significant loss of fecundity. The role of Lbl in adult reproductive physiology is previously unknown. These results suggest that Lbl is part of a conserved reproductive regulatory system that could have implications beyond tsetse to other vector insects such as mosquitoes. This

  11. Electroantennogram responses of tsetse flies (Glossina pallidipes) to host odours in an open field and riverine woodland

    NARCIS (Netherlands)

    Voskamp, K.E; den Otter, C.J; Noorman, N

    The present study was initiated to gain insight into the way in which tsetse flies (Glossina spp.) sense odours at different locations in odour plumes in both an open field and a wooded area. We recorded the antennal responses (EAGs) from stationary living female G. pallidipes 15 m upwind and at

  12. Studies on the role of serum proteins in the ovarian function of the tsetse fly, Glossina palpalis palpalis

    NARCIS (Netherlands)

    Takken, W.

    1980-01-01

    Nutritional factors in the diet of the obligatory haematophagous tsetse fly Glossina p. palpalis have been investigated, as an initial step towards the development of an artificial diet for this insect. Emphasis was laid on the role of serum proteins in the reproductive

  13. Adaptations in the glucose metabolism of procyclic Trypanosoma brucei isolates from Tsetse flies and during differentiation of bloodstream forms.

    NARCIS (Netherlands)

    van Grinsven, K.W.A.; van den Abbeele, J.; van den Bossche, P.; van Hellemond, J.J.; Tielens, A.G.M.

    2009-01-01

    Procyclic forms of Trypanosoma brucei isolated from the midguts of infected tsetse flies, or freshly transformed from a strain that is close to field isolates, do not use a complete Krebs cycle. Furthermore, short stumpy bloodstream forms produce acetate and are apparently metabolically preadapted

  14. Generic Design, Technical Guidelines and Optimal Location of Tsetse Fly Mass-Rearing Facilities. Working Material

    International Nuclear Information System (INIS)

    2004-01-01

    Tsetse and trypanosomosis (T and T) severely affect human health - sleeping sickness - and there is evidence for a causal relationship of T and T with food insecurity, rural poverty and overall development constraints for people living in 36 countries of sub-Saharan Africa. Direct annual losses in livestock production and the cost of continuous control measures have been estimated to range between US$ 600 million and $1.2 billion, and the lost potential in agriculture and livestock productivity may be as high as $ 4.75 billion per year. T and T must be considered and treated as one of the most serious pest problems and development constraints in the world today. Several developments in recent years contributed to an increased feasibility and sustainability of efforts against the T and T problem: 1. Following a decision of the African Heads of State and Government at their Lome summit in 2000, to eventually eradicate tsetse flies from Africa, there is an increased commitment among the national and international authorities and other stakeholders to solve the T and T problem in a sustainable manner through the creation and subsequent expansion of T and T free zones. 2. The concept of areawide integrated pest management (AW-IPM), including a sterile insect technique (SIT) component, where feasible and justifiable, was adopted for intervention against the T and T problem in the context of overall efforts towards sustainable agriculture and rural development (SARD). 3. The AU-Pan-African Tsetse and Trypanosomosis Eradication Campaign (PATTEC) and the Programme Against African Trypanosomiases (PAAT; a forum used by AU, FAO, IAEA and WHO to harmonize their efforts against T and T) jointly developed criteria and guidelines for identifying priority areas for T and T intervention, where there is high potential for agriculture and livestock development and where intervention measures would likely result in early and sustainable success. SIT will likely play a role in several

  15. 2010 Annual Report: Project to combat the Tsetse Fly and Trypanosomiasis in the Niayes

    International Nuclear Information System (INIS)

    2011-03-01

    Several control campaigns were carried out in the 70-80 years in the Niayes area to rid it of the only tsetse species that lives there, Glossina palpalis gambiensis.The tsetse or tsetse fly is responsible for trypanosomiasis in animals and sleeping sickness in humans. Untreated, disease leads to death. After a 15 - year respite following the aforementioned control campaigns, the presence of the vector and the disease it transmits has again been detected in the area thanks to studies carried out in 1999 with FAO support.To solve the problem in a sustainable way, the Ministry of Livestock set up a new program in 2006, with the support of the International Atomic Energy Agency (IAEA), based on the use of the Sterile Insect.This program is coordinated by the Department of Veterinary Services (DSV) in partnership with the Senegalese Institute of Agricultural Research (ISRA) for the research component and the Ecological Monitoring Center (CSE) for the Geographic Information System (GIS). The Center for International Cooperation in Agronomic Research for Development (CIRAD) provides scientific support to the project. The environmental study started in 2010 with the implementation of the protocol on the environmental impact assessment and the preparation of the dossier of the Strategic Environmental Assessment (SEA). During the phase of control preparation, currently underway, a suppression device was tested on a small area in Kayar, and experimental releases of sterile males were set up at two sites to assess their survival and competitiveness, after having set up a transport system running the irradiated pupae of the CIRDES insectarium (Bobo Dioulasso, Burkina Faso) to that of Senegalese Institute for Agricultural Research (ISRA). (Author)

  16. Post eclosion age predicts the prevalence of midgut trypanosome infections in Glossina.

    Directory of Open Access Journals (Sweden)

    Deirdre P Walshe

    Full Text Available The teneral phenomenon, as observed in Glossina sp., refers to the increased susceptibility of the fly to trypanosome infection when the first bloodmeal taken is trypanosome-infected. In recent years, the term teneral has gradually become synonymous with unfed, and thus fails to consider the age of the newly emerged fly at the time the first bloodmeal is taken. Furthermore, conflicting evidence exists of the effect of the age of the teneral fly post eclosion when it is given the infected first bloodmeal in determining the infection prevalence. This study demonstrates that it is not the feeding history of the fly but rather the age (hours after eclosion of the fly from the puparium of the fly when it takes the first (infective bloodmeal that determines the level of fly susceptibility to trypanosome infection. We examine this phenomenon in male and female flies from two distinct tsetse clades (Glossina morsitans morsitans and Glossina palpalis palpalis infected with two salivarian trypanosome species, Trypanosoma (Trypanozoon brucei brucei and Trypanosoma (Nannomonas congolense using Fisher's exact test to examine differences in infection rates. Teneral tsetse aged less than 24 hours post-eclosion (h.p.e. are twice as susceptible to trypanosome infection as flies aged 48 h.p.e. This trend is conserved across sex, vector clade and parasite species. The life cycle stage of the parasite fed to the fly (mammalian versus insect form trypanosomes does not alter this age-related bias in infection. Reducing the numbers of parasites fed to 48 h.p.e., but not to 24 h.p.e. flies, increases teneral refractoriness. The importance of this phenomenon in disease biology in the field as well as the necessity of employing flies of consistent age in laboratory-based infection studies is discussed.

  17. Macrogeographic population structure of the tsetse fly, Glossina pallidipes (Diptera: Glossinidae)

    International Nuclear Information System (INIS)

    Ouma, J.O.; Marquez, J.G.; Krafsur, E.S

    2005-01-01

    Tsetse flies are confined to sub-Saharan Africa where they occupy discontinuous habitats. In anticipation of area-wide control programmes, estimates of gene flow among tsetse populations are necessary. Genetic diversities were partitioned at eight microsatellite loci and five mitochondrial loci in 21 Glossina pallidipes Austin populations. At microsatellite loci, Nei's unbiased gene diversity averaged over loci was 0.659 and the total number of alleles was 214, only four of which were shared among all populations. The mean number of alleles per locus was 26.8. Random mating was observed within but not among populations (fixation index FST=0.18) and 81% of the genetic variance was within populations. Thirty-nine mitochondrial variants were detected. Mitochondrial diversities in populations varied from 0 to 0.85 and averaged 0.42, and FST=0.51. High levels of genetic differentiation were characteristic, extending even to subpopulations separated by tens and hundreds of kilometres, and indicating low rates of gene flow. (author)

  18. Mapping Landscape Friction to Locate Isolated Tsetse Populations that are Candidates for Elimination

    International Nuclear Information System (INIS)

    Bouyer, Jérémy; Dicko, Ahmadou H.; Cecchi, Giuliano; Ravel, Sophie; Solano, Philippe; Guerrini, Laure; Vreysen, Marc J. B.; De Meeûs, Thierry; Lancelot, Renaud

    2016-01-01

    Tsetse flies are the cyclical vectors of deadly human and animal trypanosomes in sub-Saharan Africa. Tsetse control is a key component for the integrated management of both plagues, but local eradication successes have been limited to less than 2% of the infested area. This is attributed to either resurgence of residual populations that were omitted from the eradication campaign or reinvasion from neighboring infested areas. Here we focused on Glossina palpalis gambiensis, a riverine tsetse species representing the main vector of trypanosomoses in West Africa. We mapped landscape resistance to tsetse genetic flow, hereafter referred to as friction, to identify natural barriers that isolate tsetse populations. For this purpose, we fitted a statistical model of the genetic distance between 37 tsetse populations sampled in the region, using a set of remotely sensed environmental data as predictors. The least-cost path between these populations was then estimated using the predicted friction map. The method enabled us to avoid the subjectivity inherent in the expert-based weighting of environmental parameters. Finally, we identified potentially isolated clusters of G. p. gambiensis habitat based on a species distribution model and ranked them according to their predicted genetic distance to the main tsetse population. The methodology presented here will inform the choice on the most appropriate intervention strategies to be implemented against tsetse flies in different parts of Africa. It can also be used to control other pests and to support conservation of endangered species. (author)

  19. Towards an early warning system for Rhodesian sleeping sickness in savannah areas: man-like traps for tsetse flies.

    Directory of Open Access Journals (Sweden)

    Glyn A Vale

    Full Text Available BACKGROUND: In the savannahs of East and Southern Africa, tsetse flies (Glossina spp. transmit Trypanosoma brucei rhodesiense which causes Rhodesian sleeping sickness, the zoonotic form of human African trypanosomiasis. The flies feed mainly on wild and domestic animals and are usually repelled by humans. However, this innate aversion to humans can be undermined by environmental stresses on tsetse populations, so increasing disease risk. To monitor changes in risk, we need traps designed specifically to quantify the responsiveness of savannah tsetse to humans, but the traps currently available are designed to simulate other hosts. METHODOLOGY/PRINCIPAL FINDINGS: In Zimbabwe, two approaches were made towards developing a man-like trap for savannah tsetse: either modifying an ox-like trap or creating new designs. Tsetse catches from a standard ox-like trap used with and without artificial ox odor were reduced by two men standing nearby, by an average of 34% for Glossina morsitans morsitans and 56% for G. pallidipes, thus giving catches more like those made by hand-nets from men. Sampling by electrocuting devices suggested that the men stopped flies arriving near the trap and discouraged trap-entering responses. Most of human repellence was olfactory, as evidenced by the reduction in catches when the trap was used with the odor of hidden men. Geranyl acetone, known to occur in human odor, and dispensed at 0.2 mg/h, was about as repellent as human odor but not as powerfully repellent as wood smoke. New traps looking and smelling like men gave catches like those from men. CONCLUSION/SIGNIFICANCE: Catches from the completely new man-like traps seem too small to give reliable indices of human repellence. Better indications would be provided by comparing the catches of an ox-like trap either with or without artificial human odor. The chemistry and practical applications of the repellence of human odor and smoke deserve further study.

  20. Identification of Tsetse (Glossina spp. using matrix-assisted laser desorption/ionisation time of flight mass spectrometry.

    Directory of Open Access Journals (Sweden)

    Antje Hoppenheit

    Full Text Available Glossina (G. spp. (Diptera: Glossinidae, known as tsetse flies, are vectors of African trypanosomes that cause sleeping sickness in humans and nagana in domestic livestock. Knowledge on tsetse distribution and accurate species identification help identify potential vector intervention sites. Morphological species identification of tsetse is challenging and sometimes not accurate. The matrix-assisted laser desorption/ionisation time of flight mass spectrometry (MALDI TOF MS technique, already standardised for microbial identification, could become a standard method for tsetse fly diagnostics. Therefore, a unique spectra reference database was created for five lab-reared species of riverine-, savannah- and forest- type tsetse flies and incorporated with the commercial Biotyper 3.0 database. The standard formic acid/acetonitrile extraction of male and female whole insects and their body parts (head, thorax, abdomen, wings and legs was used to obtain the flies' proteins. The computed composite correlation index and cluster analysis revealed the suitability of any tsetse body part for a rapid taxonomical identification. Phyloproteomic analysis revealed that the peak patterns of G. brevipalpis differed greatly from the other tsetse. This outcome was comparable to previous theories that they might be considered as a sister group to other tsetse spp. Freshly extracted samples were found to be matched at the species level. However, sex differentiation proved to be less reliable. Similarly processed samples of the common house fly Musca domestica (Diptera: Muscidae; strain: Lei did not yield any match with the tsetse reference database. The inclusion of additional strains of morphologically defined wild caught flies of known origin and the availability of large-scale mass spectrometry data could facilitate rapid tsetse species identification in the future.

  1. Influence of Pastoralists' Sociocultural Activities on Tsetse-Trypanosome-Cattle Reservoir Interface: The Risk of Human African Trypanosomiasis in North-Central Nigeria.

    Science.gov (United States)

    Alhaji, N B; Kabir, J

    2016-06-01

    The study investigated socio-cultural characteristics of pastoralists that influenced on the tsetse-trypanosome-cattle reservoir interface thereby predisposing them to HAT in Niger State, North-central Nigeria. It was a cross-sectional survey of adult pastoral herders, aged 30 years and above, and conducted between October 2012 and February 2013. A face-to-face structured questionnaire was administered on the pastoralists nested in 96 cattle herds with questions focused on pastoralists' socio-cultural activities and behavioral practices related to HAT risk. Descriptive and analytic statistics were used to describe the obtained data. A total of 384 pastoralists participated, with mean age of 49.6  ± 10.76 SD years. Male respondents constituted 86.7% of gender, while pastoralists of age group 40-49 years constituted 35.4% of respondents. About 59.4% of the pastoralists had knowledge about HAT and its symptoms and only 33.9% of them believed that cattle served as reservoir of HAT trypanosome. Knowledge/belief levels of the pastoralists about African trypanosomiasis occurrence in humans and animals were statistically significant. Males were four times more likely to be exposed to HAT (OR = 3.67; 95% CI: 1.42, 9.52); age group 60-69 was also four times more likely to be exposed (OR = 3.59; 95% CI: 1.56, 8.28); and nomadic pastoralists were two times more likely to be exposed to HAT (OR = 2.07; 95% CI: 1.37, 3.14). All cultural practices significantly influenced exposure to HAT with extensive husbandry system three times more likely to predisposed pastoralists to HAT (OR = 3.21; 95% CI: 1.65, 6.24). Socio-cultural characteristics of pastoralists influenced exposure to HAT risk and, therefore, there is a need to sensitize them to bring changes to their socio-cultural practices and perceptions to achieve effective and long term sustainable HAT control. Elimination strategies of parasites in animals and vectors should be considered to avoid reintroduction

  2. FAO/IAEA Consultants Group Meeting on The Potential for Tsetse Flies to Develop Resistance to Insecticides

    International Nuclear Information System (INIS)

    1993-01-01

    Chemical insecticides are playing an increasingly important role in control of tsetse flies (Glossina spp), vectors of human and animal trypanosomiasis in large regions of Africa. Although insecticide resistance has not yet been reported in tsetse, there is no cause for complacency regarding its occurrence in the future. As new reports of insecticide resistance in other disease vectors and agronomic pests continue to accumulate at a rapid rate, it is increasingly clear that no comprehensive approach to tsetse control can afford to ignore the potential resistance problem, as the loss of insecticides from the limited set of options for control would be disastrous. it is likely that one or more of the pyrethroid resistance mechanisms already known from several other species of Diptera will manifest itself in tsetse, in response to the increased selection engendered by the wider adoption of deltamethrin-treated targets in tsetse control at the local level and in eradication efforts. Also, selection for behavioural avoidance of traps and targets could result in decreased control efficiency, although the mechanisms that might cause such behavioural resistance are poorly understood at present. There is thus an increasingly urgent need for information on the potential for resistance development in tsetse, on accurate and feasible methods for detection, monitoring, and characterization of resistance, on properties of resistant strains, and on appropriate tactics for resistance prevention and management. Because of the extraordinary difficulties in rearing posed by tsetse life history, it is essential that these research efforts get underway immediately. The Consultants Group on the Possibility of Development of Insecticide Resistance in Tsetse has accordingly prepared this report with a consideration of the present state of knowledge, a discussion of the essential elements of a resistance research program, and specific recommendations. A summary of the recommendations in

  3. Potential impact of tsetse fly control involving the sterile insect technique

    International Nuclear Information System (INIS)

    Feldmann, U.; Dyck, V.A.; Mattioli, R.C.; Jannin, J.

    2005-01-01

    Hunger and poverty persist in rural sub-Saharan Africa. Many affected communities could produce enough food for themselves, and even for sale, if they had the basics - livestock and crops. In most of these communities, the presence of tsetse flies and the disease they vector, trypanosomosis, prevents optimal productive livestock-keeping and mixed farming, resulting in inadequate local food production. Since a vast majority of the rural communities depends on agriculture, the removal of a key development problem like tsetse and trypanosomosis (T and T) will permit increased local agricultural production, socio-economic and market development, and alleviate hunger and poverty. A sustained alleviation, if possible a complete, lasting removal of the T and T problem, is therefore considered a prerequisite to rural self-sufficient agriculture, in which productive livestock can provide milk, meat, draught power to cultivate the land, and eventually generate higher income and market opportunities. Hence the removal of such a key problem would catalyse overall development in rural areas. However, the poverty and food security status of communities in Africa is rather heterogeneous, and reflects the impact of various constraining factors, including T and T on the current agricultural production process and human well-being, as well as on the overall development potential. Correspondingly, the benefits to sustainable agriculture and rural development (SARD), resulting from an elimination of the T and T problem, will also vary from area to area. In view of the substantial finding required over the next decades to address this key problem, and the need for early 'success stories' that show tangible benefits, it is important that the initial T and T control areas are carefully selected according to technical feasibility, and to the predicted potential in the context of SARD. Trypanosomosis is a major, but technically solvable, development problem, and the effectiveness of the

  4. Patterns of Genome-Wide Variation in Glossina fuscipes fuscipes Tsetse Flies from Uganda

    Directory of Open Access Journals (Sweden)

    Andrea Gloria-Soria

    2016-06-01

    Full Text Available The tsetse fly Glossina fuscipes fuscipes (Gff is the insect vector of the two forms of Human African Trypanosomiasis (HAT that exist in Uganda. Understanding Gff population dynamics, and the underlying genetics of epidemiologically relevant phenotypes is key to reducing disease transmission. Using ddRAD sequence technology, complemented with whole-genome sequencing, we developed a panel of ∼73,000 single-nucleotide polymorphisms (SNPs distributed across the Gff genome that can be used for population genomics and to perform genome-wide-association studies. We used these markers to estimate genomic patterns of linkage disequilibrium (LD in Gff, and used the information, in combination with outlier-locus detection tests, to identify candidate regions of the genome under selection. LD in individual populations decays to half of its maximum value (r2max/2 between 1359 and 2429 bp. The overall LD estimated for the species reaches r2max/2 at 708 bp, an order of magnitude slower than in Drosophila. Using 53 infected (Trypanosoma spp. and uninfected flies from four genetically distinct Ugandan populations adapted to different environmental conditions, we were able to identify SNPs associated with the infection status of the fly and local environmental adaptation. The extent of LD in Gff likely facilitated the detection of loci under selection, despite the small sample size. Furthermore, it is probable that LD in the regions identified is much higher than the average genomic LD due to strong selection. Our results show that even modest sample sizes can reveal significant genetic associations in this species, which has implications for future studies given the difficulties of collecting field specimens with contrasting phenotypes for association analysis.

  5. Migration of African trypanosomes across the blood-brain barrier.

    Science.gov (United States)

    Masocha, Willias; Rottenberg, Martin E; Kristensson, Krister

    2007-09-10

    Subspecies of the extracellular parasite, Trypanosoma brucei, which are spread by the tsetse fly in sub-Saharan Africa, cause in humans Sleeping Sickness. In experimental rodent models the parasite can at a certain stage of disease pass through the blood-brain barrier across or between the endothelial cells and the vessel basement membranes. The laminin composition of the basement membranes determines whether they are permissive to parasite penetration. One cytokine, interferon-gamma, plays an important role in regulating the trypanosome trafficking into the brain. Treatment strategies aim at developing drugs that can impede penetration of trypanosomes into the brain and/or that can eliminate trypanosomes once they are inside the brain parenchyma, but have lower toxicity than the ones presently in use.

  6. Tsetse eradication: Zanzibar

    International Nuclear Information System (INIS)

    2003-01-01

    Tsetse flies (Glossina sp.) continue to make livestock production difficult or impossible throughout a very large part of Africa. One of the most promising techniques for eradicating tsetse from certain locations is the environmentally safe Sterile Insect Technique (SIT). In collaboration with the Tanzanian authorities, the Department of Technical Co-operation is sponsoring a programme, with technical support from the Joint FAO/IAEA Division, to eradicate tsetse from Zanzibar using the SIT. (IAEA)

  7. Prevalence of mixed Trypanosoma congolense infections in livestock and tsetse in KwaZulu-Natal, South Africa

    Directory of Open Access Journals (Sweden)

    K. Gillingwater

    2010-05-01

    Full Text Available Trypanosoma congolense causes the most economically important animal trypanosomosis in Africa. In South Africa, a rinderpest pandemic of the 1890s removed many host animals, resulting in the near-eradication of most tsetse species. Further suppression was achieved through spraying with dichlorodiphenyltrichloroethane (DDT; however, residual populations of Glossina austeni and G. brevipalpis remained in isolated pockets. A total of 506 of these tsetse flies were captured in the Hluhluwe-iMfolozi Park, the St Lucia Wetland Park and Boomerang commercial farm. The polymerase chain reaction (PCR was used to determine the infection rate and frequency of mixed infections of these flies. Additionally, 473 blood samples were collected from cattle at communal diptanks and a commercial farm in the area and each one examined by the haematocrit centrifugation technique (HCT. Furthermore, buffy coats from these blood samples were spotted onto FTA Elute cards and the DNA extracted from each one tested using 3 separate PCRs. The HCT revealed the presence of trypanosomes in only 6.6 % of the blood samples; by contrast, species-specific PCR detected trypanosome DNA in 50 % of the samples. The species-specific PCR detected trypanosome DNA in 17 % of the tsetse flies, compared with the nested PCR targeting rDNA which detected trypanosome DNA in only 14 % of the samples. Over time, the transmission of Savannah-type T. congolense and Kilifi-type T. congolense as mixed infections could have an impact on disease manifestation in different hosts in the area.

  8. African trypanosomes: celebrating diversity

    NARCIS (Netherlands)

    Adams, Emily R.; Hamilton, Patrick B.; Gibson, Wendy C.

    2010-01-01

    Recent advances in molecular identification techniques and phylogenetic analysis have revealed the presence of previously unidentified tsetse-transmitted trypanosomes in Africa. This is surprising in a comparatively well-known group of pathogens that includes the causative agents of human and animal

  9. Explaining the host-finding behavior of blood-sucking insects: computerized simulation of the effects of habitat geometry on tsetse fly movement.

    Directory of Open Access Journals (Sweden)

    Glyn A Vale

    2014-06-01

    Full Text Available BACKGROUND: Male and female tsetse flies feed exclusively on vertebrate blood. While doing so they can transmit the diseases of sleeping sickness in humans and nagana in domestic stock. Knowledge of the host-orientated behavior of tsetse is important in designing bait methods of sampling and controlling the flies, and in understanding the epidemiology of the diseases. For this we must explain several puzzling distinctions in the behavior of the different sexes and species of tsetse. For example, why is it that the species occupying savannahs, unlike those of riverine habitats, appear strongly responsive to odor, rely mainly on large hosts, are repelled by humans, and are often shy of alighting on baits? METHODOLOGY/PRINCIPAL FINDINGS: A deterministic model that simulated fly mobility and host-finding success suggested that the behavioral distinctions between riverine, savannah and forest tsetse are due largely to habitat size and shape, and the extent to which dense bushes limit occupiable space within the habitats. These factors seemed effective primarily because they affect the daily displacement of tsetse, reducing it by up to ∼70%. Sex differences in behavior are explicable by females being larger and more mobile than males. CONCLUSION/SIGNIFICANCE: Habitat geometry and fly size provide a framework that can unify much of the behavior of all sexes and species of tsetse everywhere. The general expectation is that relatively immobile insects in restricted habitats tend to be less responsive to host odors and more catholic in their diet. This has profound implications for the optimization of bait technology for tsetse, mosquitoes, black flies and tabanids, and for the epidemiology of the diseases they transmit.

  10. Explaining the host-finding behavior of blood-sucking insects: computerized simulation of the effects of habitat geometry on tsetse fly movement.

    Science.gov (United States)

    Vale, Glyn A; Hargrove, John W; Solano, Philippe; Courtin, Fabrice; Rayaisse, Jean-Baptiste; Lehane, Michael J; Esterhuizen, Johan; Tirados, Inaki; Torr, Stephen J

    2014-06-01

    Male and female tsetse flies feed exclusively on vertebrate blood. While doing so they can transmit the diseases of sleeping sickness in humans and nagana in domestic stock. Knowledge of the host-orientated behavior of tsetse is important in designing bait methods of sampling and controlling the flies, and in understanding the epidemiology of the diseases. For this we must explain several puzzling distinctions in the behavior of the different sexes and species of tsetse. For example, why is it that the species occupying savannahs, unlike those of riverine habitats, appear strongly responsive to odor, rely mainly on large hosts, are repelled by humans, and are often shy of alighting on baits? A deterministic model that simulated fly mobility and host-finding success suggested that the behavioral distinctions between riverine, savannah and forest tsetse are due largely to habitat size and shape, and the extent to which dense bushes limit occupiable space within the habitats. These factors seemed effective primarily because they affect the daily displacement of tsetse, reducing it by up to ∼70%. Sex differences in behavior are explicable by females being larger and more mobile than males. Habitat geometry and fly size provide a framework that can unify much of the behavior of all sexes and species of tsetse everywhere. The general expectation is that relatively immobile insects in restricted habitats tend to be less responsive to host odors and more catholic in their diet. This has profound implications for the optimization of bait technology for tsetse, mosquitoes, black flies and tabanids, and for the epidemiology of the diseases they transmit.

  11. Application of the Sterility Principle for Tsetse Fly Eradication or Control. Revision.

    Science.gov (United States)

    1981-08-14

    lea trypanosomes animales . Bobo Dioulasso, Haute Volta. Rapport d’Activite - 1978. Anon. 1974. Control programs for trypanosomiases and their vectors...Gruvel. 1978. Elimination des glossines et trypanosomes animale : RUsultats de quelques sondages dans Ia rigion du Lac Tchad. Rev. Elev. Mid. vdt. Pays

  12. Peptidomics of Neuropeptidergic Tissues of the Tsetse Fly Glossina morsitans morsitans

    Science.gov (United States)

    Caers, Jelle; Boonen, Kurt; Van Den Abbeele, Jan; Van Rompay, Liesbeth; Schoofs, Liliane; Van Hiel, Matthias B.

    2015-12-01

    Neuropeptides and peptide hormones are essential signaling molecules that regulate nearly all physiological processes. The recent release of the tsetse fly genome allowed the construction of a detailed in silico neuropeptide database (International Glossina Genome Consortium, Science 344, 380-386 (2014)), as well as an in-depth mass spectrometric analysis of the most important neuropeptidergic tissues of this medically and economically important insect species. Mass spectrometric confirmation of predicted peptides is a vital step in the functional characterization of neuropeptides, as in vivo peptides can be modified, cleaved, or even mispredicted. Using a nanoscale reversed phase liquid chromatography coupled to a Q Exactive Orbitrap mass spectrometer, we detected 51 putative bioactive neuropeptides encoded by 19 precursors: adipokinetic hormone (AKH) I and II, allatostatin A and B, capability/pyrokinin (capa/PK), corazonin, calcitonin-like diuretic hormone (CT/DH), FMRFamide, hugin, leucokinin, myosuppressin, natalisin, neuropeptide-like precursor (NPLP) 1, orcokinin, pigment dispersing factor (PDF), RYamide, SIFamide, short neuropeptide F (sNPF) and tachykinin. In addition, propeptides, truncated and spacer peptides derived from seven additional precursors were found, and include the precursors of allatostatin C, crustacean cardioactive peptide, corticotropin releasing factor-like diuretic hormone (CRF/DH), ecdysis triggering hormone (ETH), ion transport peptide (ITP), neuropeptide F, and proctolin, respectively. The majority of the identified neuropeptides are present in the central nervous system, with only a limited number of peptides in the corpora cardiaca-corpora allata and midgut. Owing to the large number of identified peptides, this study can be used as a reference for comparative studies in other insects.

  13. Laboratory colonisation and genetic bottlenecks in the tsetse fly Glossina pallidipes.

    Directory of Open Access Journals (Sweden)

    Marc Ciosi

    2014-02-01

    Full Text Available The IAEA colony is the only one available for mass rearing of Glossina pallidipes, a vector of human and animal African trypanosomiasis in eastern Africa. This colony is the source for Sterile Insect Technique (SIT programs in East Africa. The source population of this colony is unclear and its genetic diversity has not previously been evaluated and compared to field populations.We examined the genetic variation within and between the IAEA colony and its potential source populations in north Zimbabwe and the Kenya/Uganda border at 9 microsatellites loci to retrace the demographic history of the IAEA colony. We performed classical population genetics analyses and also combined historical and genetic data in a quantitative analysis using Approximate Bayesian Computation (ABC. There is no evidence of introgression from the north Zimbabwean population into the IAEA colony. Moreover, the ABC analyses revealed that the foundation and establishment of the colony was associated with a genetic bottleneck that has resulted in a loss of 35.7% of alleles and 54% of expected heterozygosity compared to its source population. Also, we show that tsetse control carried out in the 1990's is likely reduced the effective population size of the Kenya/Uganda border population.All the analyses indicate that the area of origin of the IAEA colony is the Kenya/Uganda border and that a genetic bottleneck was associated with the foundation and establishment of the colony. Genetic diversity associated with traits that are important for SIT may potentially have been lost during this genetic bottleneck which could lead to a suboptimal competitiveness of the colony males in the field. The genetic diversity of the colony is lower than that of field populations and so, studies using colony flies should be interpreted with caution when drawing general conclusions about G. pallidipes biology.

  14. Achievements 2006-Activities 2007: Feasibility study on the application of the sterile insect technique for the establishment of a zone free of tsetse flies

    International Nuclear Information System (INIS)

    Sall, Baba

    2007-01-01

    The Project ''Feasibility study on the application of the sterile insect technique for the creation of a zone free of tsetse flies'' aims to eradicate the tsetse fly and the trypanosomiasis it transmits from the Niayes area and part of the small coast. These areas were re-infested after several decades of lull following the eradication campaigns of the 1970s and 1980s. The project began in 2006 for a period of 4 years.This document presents the achievements of 2006 and the activities planned in 2007 within the framework of the project.

  15. Tsetse research developments

    International Nuclear Information System (INIS)

    1969-01-01

    Progress has been made in the difficult task of controlling the harmful effects of the tsetse fly on human beings and cattle. One of the methods towards which research is being devoted in a number of countries is aimed at eventual use of the sterile male technique. At the Agency's laboratory near Vienna an advance has been made which may make it possible to rear the tsetse fly in captivity as a step to further experiments. (author)

  16. Partnerships for fighting rural poverty. Africa steps up campaign against the tsetse fly

    International Nuclear Information System (INIS)

    Kabayo, J.P.; Boussaha, A.

    2002-01-01

    A Plan of Action to guide the process of implementing the decision by the African Heads of State on tsetse eradication was designed by an OAU's Task Force of 22 experts drawn from different African countries. The Plan proposes the initiation and co-ordination of a Pan African Tsetse and Trypanosomosis Eradication Campaign (PATTEC) and describes the key activities along with recommendations regarding the effective methods of work in the execution of the campaign. It recognizes the trans-boundary nature of the tsetse and trypanosomosis problem and advocates an area-wide approach, involving the identification and targeting of individual zones of tsetse infestations and the application of cost-effective tsetse suppression methods integrated with the Sterile Insect Technique. While the African tsetse belt covers an area of about 10 million km 2 , stretching from Senegal in the north to South Africa in the south, tsetse infestation is not continuous and uniform over the entire expanse of the tsetse belt. The tsetse belt is in the form of pockets, 'islands' or discrete zones of infestation under the influence of ecological, geographical, physical or biological factors. The application of the area-wide principle to systematically eliminate tsetse infestations in each individual area at a time will create an ever-expanding tsetse-free zone, with minimal risks of re-invasion from neighbouring areas or re-infestation from relic populations in the treated areas. This systematic elimination of tsetse populations from these areas, one at a time, will ultimately cover Africa's entire tsetse belt. The tsetse eradication activities in each identified area will be managed as an independent project, with emphasis on setting clear targets, involving clear goals and deadlines, designed to ensure short-term success while maintaining focus on the long-term objective. The Plan of Action recognizes the need for one coordinated campaign whose operational unit will be at the level of project

  17. The Dynamics of TseTse Fly in and Around Intensive Suppression ...

    African Journals Online (AJOL)

    Agency (IAEA) - initiated a project in the Southern Rift Valley called the Southern. Tsetse Eradication Project (STEP) with its ... in and around intensive suppression area of the Southern Rift Valley of Ethiopia, located between 4045` and 7015` northern ..... tsé-tsé. Logiciel d'identification. In Glossine Expert. Manuel illustré ...

  18. In Silico Identification of a Candidate Synthetic Peptide (Tsgf118–43) to Monitor Human Exposure to Tsetse Flies in West Africa

    Science.gov (United States)

    Dama, Emilie; Cornelie, Sylvie; Camara, Mamadou; Somda, Martin Bienvenu; Poinsignon, Anne; Ilboudo, Hamidou; Elanga Ndille, Emmanuel; Jamonneau, Vincent; Solano, Philippe; Remoue, Franck; Bengaly, Zakaria; Belem, Adrien Marie Gaston; Bucheton, Bruno

    2013-01-01

    Background The analysis of humoral responses directed against the saliva of blood-sucking arthropods was shown to provide epidemiological biomarkers of human exposure to vector-borne diseases. However, the use of whole saliva as antigen presents several limitations such as problems of mass production, reproducibility and specificity. The aim of this study was to design a specific biomarker of exposure to tsetse flies based on the in silico analysis of three Glossina salivary proteins (Ada, Ag5 and Tsgf1) previously shown to be specifically recognized by plasma from exposed individuals. Methodology/Principal Findings Synthetic peptides were designed by combining several linear epitope prediction methods and Blast analysis. The most specific peptides were then tested by indirect ELISA on a bank of 160 plasma samples from tsetse infested areas and tsetse free areas. Anti-Tsgf118–43 specific IgG levels were low in all three control populations (from rural Africa, urban Africa and Europe) and were significantly higher (p<0.0001) in the two populations exposed to tsetse flies (Guinean HAT foci, and South West Burkina Faso). A positive correlation was also found between Anti-Tsgf118–43 IgG levels and the risk of being infected by Trypanosoma brucei gambiense in the sleeping sickness foci of Guinea. Conclusion/Significance The Tsgf118–43 peptide is a suitable and promising candidate to develop a standardize immunoassay allowing large scale monitoring of human exposure to tsetse flies in West Africa. This could provide a new surveillance indicator for tsetse control interventions by HAT control programs. PMID:24086785

  19. Wolbachia, Sodalis and trypanosome co-infections in natural populations of Glossina austeni and Glossina pallidipes

    Science.gov (United States)

    2013-01-01

    Background Tsetse flies harbor at least three bacterial symbionts: Wigglesworthia glossinidia, Wolbachia pipientis and Sodalis glossinidius. Wigglesworthia and Sodalis reside in the gut in close association with trypanosomes and may influence establishment and development of midgut parasite infections. Wolbachia has been shown to induce reproductive effects in infected tsetse. This study was conducted to determine the prevalence of these endosymbionts in natural populations of G. austeni and G. pallidipes and to assess the degree of concurrent infections with trypanosomes. Methods Fly samples analyzed originated from Kenyan coastal forests (trapped in 2009–2011) and South African G. austeni collected in 2008. The age structure was estimated by standard methods. G. austeni (n=298) and G. pallidipes (n= 302) were analyzed for infection with Wolbachia and Sodalis using PCR. Trypanosome infection was determined either by microscopic examination of dissected organs or by PCR amplification. Results Overall we observed that G. pallidipes females had a longer lifespan (70 d) than G. austeni (54 d) in natural populations. Wolbachia infections were present in all G. austeni flies analysed, while in contrast, this symbiont was absent from G. pallidipes. The density of Wolbachia infections in the Kenyan G. austeni population was higher than that observed in South African flies. The infection prevalence of Sodalis ranged from 3.7% in G. austeni to about 16% in G. pallidipes. Microscopic examination of midguts revealed an overall trypanosome infection prevalence of 6% (n = 235) and 5% (n = 552), while evaluation with ITS1 primers indicated a prevalence of about 13% (n = 296) and 10% (n = 302) in G. austeni and G. pallidipes, respectively. The majority of infections (46%) were with T. congolense. Co-infection with all three organisms was observed at 1% and 3.3% in G. austeni and G. pallidipes, respectively. Eleven out of the thirteen (85%) co-infected flies

  20. Phenotypic characteristics and trypanosome prevalence of Mursi cattle breed in the Bodi and Mursi districts of South Omo Zone, southwest Ethiopia.

    Science.gov (United States)

    Terefe, Endashaw; Haile, Aynalem; Mulatu, Wudyalew; Dessie, Tadelle; Mwai, Okeyo

    2015-03-01

    The study was conducted to characterize the morphological features of Mursi cattle breed and to identify the species of trypanosome infecting the cattle and its prevalence in these traditionally managed cattle in the Bodi and Mursi pastoral communities. Cattle body description and measurements were made on 201 matured animals. Blood samples were collected from 409 animals into heparin-treated capillary tubes and were centrifuged to 12,000 rpm for 5 min to identify trypanosome species from the wet smeared buffy coat and to estimate the degree of anemia (PCV). Tsetse flies were collected using phenol-treated biconical trap and the caught flies identified to species level. The breed possesses variable coat color pattern, coat color type, and have small to medium hump size on the thoracic vertebrae. Body measurement of Mursi cattle in the two locations did not show significant differences except chest girth, rump width, and horn length. Trypanosome prevalence in the Mursi cattle breed was 6.1%. The highest trypanosome infection was caused by Trypanosoma congolense (56%) followed by Trypanosoma vivax (40%) and Trypanosoma brucei (4%). Trypanosome prevalence significantly varies between dry (2.0%) and late rainy (10.1%) seasons (P fly species identified in the study area were Glossina pallidipes, Glossina morsitans submorsitans, and Glossina fuscipes. The number of flies captured in late rainy season was higher than in dry season (P fly infestation in the areas, large proportion of the Mursi cattle shows medium BCS, low trypanosome prevalence, and higher PCV value.

  1. New insights from Gorongosa National Park and Niassa National Reserve of Mozambique increasing the genetic diversity of Trypanosoma vivax and Trypanosoma vivax-like in tsetse flies, wild ungulates and livestock from East Africa.

    Science.gov (United States)

    Rodrigues, Carla Mf; Garcia, Herakles A; Rodrigues, Adriana C; Costa-Martins, André G; Pereira, Carlos L; Pereira, Dagmar L; Bengaly, Zakaria; Neves, Luis; Camargo, Erney P; Hamilton, Patrick B; Teixeira, Marta Mg

    2017-07-17

    Trypanosoma (Duttonella) vivax is a major pathogen of livestock in Africa and South America (SA), and genetic studies limited to small sampling suggest greater diversity in East Africa (EA) compared to both West Africa (WA) and SA. Multidimensional scaling and phylogenetic analyses of 112 sequences of the glycosomal glyceraldehyde phosphate dehydrogenase (gGAPDH) gene and 263 sequences of the internal transcribed spacer of rDNA (ITS rDNA) were performed to compare trypanosomes from tsetse flies from Gorongosa National Park and Niassa National Reserve of Mozambique (MZ), wild ungulates and livestock from EA, and livestock isolates from WA and SA. Multidimensional scaling (MDS) supported Tvv (T. vivax) and TvL (T. vivax-like) evolutionary lineages: 1) Tvv comprises two main groups, TvvA/B (all SA and WA isolates plus some isolates from EA) and TvvC/D (exclusively from EA). The network revealed five ITS-genotypes within Tvv: Tvv1 (WA/EA isolates), Tvv2 (SA) and Tvv3-5 (EA). EA genotypes of Tvv ranged from highly related to largely different from WA/SA genotypes. 2) TvL comprises two gGAPDH-groups formed exclusively by EA sequences, TvLA (Tanzania/Kenya) and TvLB-D (MZ). This lineage contains more than 11 ITS-genotypes, seven forming the lineage TvL-Gorongosa that diverged from T. vivax Y486 enough to be identified as another species of the subgenus Duttonella. While gGAPDH sequences were fundamental for classification at the subgenus, major evolutionary lineages and species levels, ITS rDNA sequences permitted identification of known and novel genotypes. Our results corroborate a remarkable diversity of Duttonella trypanosomes in EA, especially in wildlife conservation areas, compared to the moderate diversity in WA. Surveys in wilderness areas in WA may reveal greater diversity. Biogeographical and phylogenetic data point to EA as the place of origin, diversification and spread of Duttonella trypanosomes across Africa, providing relevant insights towards the

  2. Escape mechanisms of African trypanosomes: why trypanosomosis is keeping us awake.

    Science.gov (United States)

    Cnops, Jennifer; Magez, Stefan; De Trez, Carl

    2015-03-01

    African trypanosomes have been around for more than 100 million years, and have adapted to survival in a very wide host range. While various indigenous African mammalian host species display a tolerant phenotype towards this parasitic infection, and hence serve as perpetual reservoirs, many commercially important livestock species are highly disease susceptible. When considering humans, they too display a highly sensitive disease progression phenotype for infections with Trypanosoma brucei rhodesiense or Trypanosoma brucei gambiense, while being intrinsically resistant to infections with other trypanosome species. As extracellular trypanosomes proliferate and live freely in the bloodstream and lymphatics, they are constantly exposed to the immune system. Due to co-evolution, this environment however no longer poses a hostile threat, but has become the niche environment where trypanosomes thrive and obligatory await transmission through the bites of tsetse flies or other haematophagic vectors, ideally without causing severe side infection-associated pathology to their host. Hence, African trypanosomes have acquired various mechanisms to manipulate and control the host immune response, evading effective elimination. Despite the extensive research into trypanosomosis over the past 40 years, many aspects of the anti-parasite immune response remain to be solved and no vaccine is currently available. Here we review the recent work on the different escape mechanisms employed by African Trypanosomes to ensure infection chronicity and transmission potential.

  3. Dynamics of tsetse natural infection rates in the Mouhoun river, Burkina Faso, in relation with environmental factors

    Directory of Open Access Journals (Sweden)

    Jérémy eBouyer

    2013-08-01

    Full Text Available In Burkina Faso, the cyclical vectors of African animal trypanosomoses (AAT are riverine tsetse species, namely Glossina palpalis gambiensis Vanderplank (G.p.g. and Glossina tachinoides Westwood (G. t. (Diptera: Glossinidae. Experimental work demonstrated that environmental stress can increase the sensitivity of tsetse to trypanosome infection.Seasonal variations of the tsetse infection rates were monitored monthly over 17 months (May 2006-Sept 2007 in two sites (Douroula and Kadomba. In total, 1,423 flies were dissected and the infection of the proboscis, middle intestine and salivary glands was noted. All the positive organs were analyzed using monospecific polymerase chain reaction (PCR primers. To investigate the role of different environmental factors, fly infection rates were analyzed using generalized linear mixed binomial models using the species, sex, and monthly averages of the maximal, minimal and mean daily temperatures, rainfalls, Land Surface Temperature day (LSTd and night (LSTn as fixed effects and the trap position as a random effect.The overall infection rate was 10% from which the predominant species was T. congolense (7.6% of the flies, followed by T. vivax (2.2% of the flies. The best model (lowest AICc for the global infection rates was the one with the maximal daily temperature only as fixed effect (p<0.001. For T. congolense, the best model was the one with the tsetse species, sex, maximal daily temperature and rainfalls as fixed effect, where the maximal daily temperature was the main effect (p<0.001. The number of T. vivax infections was too low to allow the models to converge. The maturation rate of T. congolense was very high (94%, and G. t. harbored a higher maturation rate (p=0.03.The results are discussed in view of former laboratory studies showing that temperature stress can increase the susceptibility of tsetse to trypanosomes, as well as the possibility to improve AAT risk mapping using satellite images.

  4. Farmers' perception of impacts of bovine trypanosomosis and tsetse fly in selected districts in Baro-Akobo and Gojeb river basins, Southwestern Ethiopia.

    Science.gov (United States)

    Seyoum, Zewdu; Terefe, Getachew; Ashenafi, Hagos

    2013-10-20

    Trypanosomosis, via causing anaemia, emaciation, production loss and death, is arguably the most important constraint to livestock development in Sub-Saharan countries, including Ethiopia and its impact in Baro-Akobo and Gojeb river basins (endemic areas for tsetse flies) is unknown. This study was carried out from November 2011 to April 2012 to assess farmers' perception on the presence, impact, management and the need of intervention programs of bovine trypanosomosis and tsetse fly in selected districts located in Baro-Akobo and Gojeb river basins, Southwestern Ethiopia. A standardized questionnaire survey was employed to collect the relevant information from the farmers. The result of this study showed that 94.1% of the respondents considered bovine trypanosomosis as an economically important cattle disease which accounted for 64.6% of the total annual deaths in the year 2011/2012. Estimated mean annual financial loss via mortality due to trypanosomosis was reported to be 3501 Ethiopian Birr (US$200)/household. The reported trypanosomosis suggestive signs were consistent with published reports and farmers strongly associated the occurrence of the disease with biting flies (particularly, tsetse fly). Respondents also explained that the seasonality of the disease and its vectors, i.e. May and June are peak risk months of the year. Chemotherapy was reported the major method to combating the problem, mean frequency of treatment being 5.7 times per animal per year. Because of the economic burden of the disease, farmers expressed their strong interest and support for the establishment of intervention program in their area. The study revealed that livestock keepers are familiar with bovine trypanosomosis and its vectors as well as its impacts. Thus, trypanosomosis and tsetse control strategies should be integrated with the local communities' participation to minimize the impacts of the disease and its vectors in the area.

  5. The dynamics of TseTse Fly in and around intensive suppression ...

    African Journals Online (AJOL)

    Total catch of flies were 95 and zero with averages of apparent densities of 1.6 and zero flies per trap per day during dry and wet seasons, respectively in ISA and a total catch of 8417 and 2028 with averages of apparent densities of 280.6 and 67.6 flies per trap per day in dry and wet seasons, respectively in Nech Sar ...

  6. Screening of Trypanosoma brucei gambiense in Domestic Livestock and Tsetse Flies from an Insular Endemic Focus (Luba, Equatorial Guinea)

    Science.gov (United States)

    Cordon-Obras, Carlos; García-Estébanez, Carmen; Ndong-Mabale, Nicolás; Abaga, Simón; Ndongo-Asumu, Pedro; Benito, Agustín; Cano, Jorge

    2010-01-01

    Background Sleeping sickness is spread over 36 Sub-Saharan African countries. In West and Central Africa, the disease is caused by Trypanosoma brucei gambiense, which produces a chronic clinical manifestation. The Luba focus (Bioko Island, Equatorial Guinea) has not reported autochthonous sleeping sickness cases since 1995, but given the complexity of the epidemiological cycle, the elimination of the parasite in the environment is difficult to categorically ensure. Methodology/Principal Findings The aim of this work is to assess, by a molecular approach (Polymerase Chain Reaction, PCR), the possible permanence of T. b. gambiense in the vector (Glossina spp.) and domestic fauna in order to improve our understanding of the epidemiological situation of the disease in an isolated focus considered to be under control. The results obtained show the absence of the parasite in peridomestic livestock but its presence, although at very low rate, in the vector. On the other hand, interesting entomological data highlight that an elevated concentration of tsetse flies was observed in two out of the ten villages considered to be in the focus. Conclusions These findings demonstrate that even in conditions of apparent control, a complete parasite clearance is difficult to achieve. Further investigations must be focused on animal reservoirs which could allow the parasites to persist without leading to human cases. In Luba, where domestic livestock are scarcer than other foci in mainland Equatorial Guinea, the epidemiological significance of wild fauna should be assessed to establish their role in the maintenance of the infection. PMID:20544031

  7. Improving the cost-effectiveness of visual devices for the control of riverine tsetse flies, the major vectors of human African trypanosomiasis.

    Directory of Open Access Journals (Sweden)

    Johan Esterhuizen

    2011-08-01

    Full Text Available Control of the Riverine (Palpalis group of tsetse flies is normally achieved with stationary artificial devices such as traps or insecticide-treated targets. The efficiency of biconical traps (the standard control device, 1×1 m black targets and small 25×25 cm targets with flanking nets was compared using electrocuting sampling methods. The work was done on Glossina tachinoides and G. palpalis gambiensis (Burkina Faso, G. fuscipes quanzensis (Democratic Republic of Congo, G. f. martinii (Tanzania and G. f. fuscipes (Kenya. The killing effectiveness (measured as the catch per m(2 of cloth for small targets plus flanking nets is 5.5-15X greater than for 1 m(2 targets and 8.6-37.5X greater than for biconical traps. This has important implications for the costs of control of the Riverine group of tsetse vectors of sleeping sickness.

  8. Intestinal Bacterial Communities of Trypanosome-Infected and Uninfected Glossina palpalis palpalis from Three Human African Trypanomiasis Foci in Cameroon

    Directory of Open Access Journals (Sweden)

    Franck Jacob

    2017-08-01

    Full Text Available Glossina sp. the tsetse fly that transmits trypanosomes causing the Human or the Animal African Trypanosomiasis (HAT or AAT can harbor symbiotic bacteria that are known to play a crucial role in the fly's vector competence. We hypothesized that other bacteria could be present, and that some of them could also influence the fly's vector competence. In this context the objectives of our work were: (a to characterize the bacteria that compose the G. palpalis palpalis midgut bacteriome, (b to evidence possible bacterial community differences between trypanosome-infected and non-infected fly individuals from a given AAT and HAT focus or from different foci using barcoded Illumina sequencing of the hypervariable V3-V4 region of the 16S rRNA gene. Forty G. p. palpalis flies, either infected by Trypanosoma congolense or uninfected were sampled from three trypanosomiasis foci in Cameroon. A total of 143 OTUs were detected in the midgut samples. Most taxa were identified at the genus level, nearly 50% at the species level; they belonged to 83 genera principally within the phyla Actinobacteria, Bacteroidetes, Firmicutes, and Proteobacteria. Prominent representatives included Wigglesworthia (the fly's obligate symbiont, Serratia, and Enterobacter hormaechei. Wolbachia was identified for the first time in G. p. palpalis. The average number of bacterial species per tsetse sample was not significantly different regarding the fly infection status, and the hierarchical analysis based on the differences in bacterial community structure did not provide a clear clustering between infected and non-infected flies. Finally, the most important result was the evidence of the overall very large diversity of intestinal bacteria which, except for Wigglesworthia, were unevenly distributed over the sampled flies regardless of their geographic origin and their trypanosome infection status.

  9. Dynamics of tsetse natural infection rates in the Mouhoun river, Burkina Faso, in relation with environmental factors.

    Science.gov (United States)

    Bouyer, Jérémy; Koné, Naférima; Bengaly, Zakaria

    2013-01-01

    In Burkina Faso, the cyclical vectors of African animal trypanosomoses (AAT) are riverine tsetse species, namely Glossina palpalis gambiensis Vanderplank (G.p.g.) and Glossina tachinoides Westwood (G.t.) (Diptera: Glossinidae). Experimental work demonstrated that environmental stress can increase the sensitivity of tsetse to trypanosome infection. Seasonal variations of the tsetse infection rates were monitored monthly over 17 months (May 2006-September 2007) in two sites (Douroula and Kadomba). In total, 1423 flies were dissected and the infection of the proboscis, middle intestine and salivary glands was noted. All the positive organs were analyzed using monospecific polymerase chain reaction (PCR) primers. To investigate the role of different environmental factors, fly infection rates were analyzed using generalized linear mixed binomial models using the species, sex, and monthly averages of the maximum, minimum and mean daily temperatures, rainfalls, Land Surface Temperature day (LSTd) and night (LSTn) as fixed effects and the trap position as a random effect. The overall infection rate was 10% from which the predominant species was T. congolense (7.6% of the flies), followed by T. vivax (2.2% of the flies). The best model (lowest AICc) for the global infection rates was the one with the maximum daily temperature only as fixed effect (p temperature and rainfalls as fixed effect, where the maximum daily temperature was the main effect (p rate of T. congolense was very high (94%), and G. t. harbored a higher maturation rate (p = 0.03). The results are discussed in view of former laboratory studies showing that temperature stress can increase the susceptibility of tsetse to trypanosomes, as well as the possibility to improve AAT risk mapping using satellite images.

  10. A Molecular Method to Discriminate between Mass-Reared Sterile and Wild Tsetse Flies during Eradication Programmes That Have a Sterile Insect Technique Component.

    Directory of Open Access Journals (Sweden)

    Soumaïla Pagabeleguem

    2016-02-01

    Full Text Available The Government of Senegal has embarked several years ago on a project that aims to eradicate Glossina palpalis gambiensis from the Niayes area. The removal of the animal trypanosomosis would allow the development more efficient livestock production systems. The project was implemented using an area-wide integrated pest management strategy including a sterile insect technique (SIT component. The released sterile male flies originated from a colony from Burkina Faso.Monitoring the efficacy of the sterile male releases requires the discrimination between wild and sterile male G. p. gambiensis that are sampled in monitoring traps. Before being released, sterile male flies were marked with a fluorescent dye powder. The marking was however not infallible with some sterile flies only slightly marked or some wild flies contaminated with a few dye particles in the monitoring traps. Trapped flies can also be damaged due to predation by ants, making it difficult to discriminate between wild and sterile males using a fluorescence camera and / or a fluorescence microscope. We developed a molecular technique based on the determination of cytochrome oxidase haplotypes of G. p. gambiensis to discriminate between wild and sterile males. DNA was isolated from the head of flies and a portion of the 5' end of the mitochondrial gene cytochrome oxidase I was amplified to be finally sequenced. Our results indicated that all the sterile males from the Burkina Faso colony displayed the same haplotype and systematically differed from wild male flies trapped in Senegal and Burkina Faso. This allowed 100% discrimination between sterile and wild male G. p. gambiensis.This tool might be useful for other tsetse control campaigns with a SIT component in the framework of the Pan-African Tsetse and Trypanosomosis Eradication Campaign (PATTEC and, more generally, for other vector or insect pest control programs.

  11. Monitoring of a tsetse and trypanosomosis control programme in plateau and Bauchi State, Nigeria, using antigen ELISA and parasitological techniques

    International Nuclear Information System (INIS)

    Ajayi, S.A.; Ogedengbe, J.D.; Dogo, G.I.; Frame, I.A.

    1997-01-01

    Between July 1994 and January 1995 a total of 1153 samples were collected from cattle in Plateau and Bauchi State, Nigeria, and analyzed for the presence of trypanosome infections using parasitological (Buffy Coat Technique [BCT] and blood film smears) and serological techniques (Ag-ELISA). A simple random sampling technique was employed. Tsetse flies and other insects were trapped during the same period using NITSE and biconical traps. Twenty two tsetse flies (6 Glossina p. palpalis, 3 G. longipalpis and 13 G. tachinoides) were caught, identified and dissected to check for trypanosomal infections. The results obtained using parasitological techniques showed an average prevalence rate in the two states surveyed of 3.4%. The antigen-capture ELISA technique (Ag-ELISA) was used to analyze 280 serum samples which were negative for trypanosomes when checked by BCT. Of these samples none were positive for T. congolense and 4 (1.4%) were detected positive for T. brucei. A subset of 120 samples was analyzed for the presence of T. vivax and 3 (2.5%) were found to be positive. The relative specificity of the Ag-ELISA for T. brucei, T. congolense and T. vivax was 98.5% 100% and 97.5%, respectively. (author). 8 refs, 1 fig., 3 tabs

  12. Arsenophonus and Sodalis Symbionts in Louse Flies: an Analogy to the Wigglesworthia and Sodalis System in Tsetse Flies

    Czech Academy of Sciences Publication Activity Database

    Nováková, Eva; Husník, Filip; Sochová, E.; Hypša, Václav

    2015-01-01

    Roč. 81, č. 18 (2015), s. 6189-6199 ISSN 0099-2240 Grant - others:GA ČR(CZ) GA13-01878S Institutional support: RVO:60077344 Keywords : bat flies * phylogenetic analysis * Glossina morsitans Subject RIV: EH - Ecology, Behaviour Impact factor: 3.823, year: 2015

  13. Candidatus Sodalis melophagi sp. nov.: Phylogenetically Independent Comparative Model to the Tsetse Fly Symbiont Sodalis glossinidius

    Czech Academy of Sciences Publication Activity Database

    Chrudimský, T.; Husník, Filip; Nováková, Eva; Hypša, Václav

    2012-01-01

    Roč. 7, č. 7 (2012), e40354 E-ISSN 1932-6203 R&D Projects: GA MŠk LC06073 Grant - others:GA MŠk(CZ) LM2010005; GA ČR(CZ) GAP505/10/1401 Program:GA Institutional support: RVO:60077344 Keywords : III SECRETION SYSTEMS * SECONDARY ENDOSYMBIONT * INSECT ENDOSYMBIONT * WIGGLESWORTHIA-GLOSSINIDIA * MAXIMUM-LIKELIHOOD * MULTIPLE TIMES * FLIES * EVOLUTION * HOST * BACTERIA Subject RIV: EE - Microbiology, Virology Impact factor: 3.730, year: 2012 http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0040354

  14. Standardizing visual control devices for tsetse flies: East African species Glossina swynnertoni.

    Directory of Open Access Journals (Sweden)

    Furaha Mramba

    Full Text Available BACKGROUND: Here we set out to standardize long-lasting, visually-attractive devices for Glossina swynnertoni, a vector of both human and animal trypanosomiasis in open savannah in Tanzania and Kenya, and in neighbouring conservation areas used by pastoralists. The goal was to determine the most practical device/material that would induce the strongest landing response in G. swynnertoni for use in area-wide population suppression of this fly with insecticide-impregnated devices. METHODS AND FINDINGS: Trials were conducted in wet and dry seasons in the Serengeti and Maasai Mara to measure the performance of traps and targets of different sizes and colours, with and without chemical baits, at different population densities and under different environmental conditions. Adhesive film was used as a simple enumerator at these remote locations to compare trapping efficiencies of devices. Independent of season or presence of chemical baits, targets in phthalogen blue or turquoise blue cloth with adhesive film were the best devices for capturing G. swynnertoni in all situations, catching up to 19 times more flies than pyramidal traps. Baiting with chemicals did not affect the relative performance of devices. Fly landings were two times higher on 1 m(2 blue-black targets as on pyramidal traps when equivalent areas of both were covered with adhesive film. Landings on 1 m(2 blue-black targets were compared to those on smaller phthalogen blue 0.5 m(2 all-blue or blue-black-blue cloth targets, and to landings on all-blue plastic 0.32-0.47 m(2 leg panels painted in phthalogen blue. These smaller targets and leg panels captured equivalent numbers of G. swynnertoni per unit area as bigger targets. CONCLUSIONS: Leg panels and 0.5 m(2 cloth targets show promise as cost effective devices for management of G. swynnertoni as they can be used for both control (insecticide-impregnated cloth and for sampling (rigid plastic with insect glue or adhesive film of

  15. Achievable breakthrough: Viewpoint on the challenge of creating tsetse-free zones in Sub-Saharan Africa

    International Nuclear Information System (INIS)

    Qian Jihui; Tisue, T.

    2000-01-01

    The tsetse fly transmits trypanosomes that sicken and kill both animals and man. It is one of the major roots of poverty in countries south of the Sahara, an ecological factor that exists nowhere else in the world. The SIT is the most environment friendly pest control method. It involves mass production and systematic aerial releases of radiation-sterilized but behaviourally competent male insects, who seek out females in the wild for mating. These unproductive matings interfere with reproduction of the target population, which declines to the point where it is no longer self-sustaining, leading to eradication

  16. A dynamic model for estimating adult female mortality from ovarian dissection data for the tsetse fly Glossina pallidipes Austen sampled in Zimbabwe.

    Directory of Open Access Journals (Sweden)

    Sarah F Ackley

    2017-08-01

    Full Text Available Human and animal trypanosomiasis, spread by tsetse flies (Glossina spp, is a major public health concern in much of sub-Saharan Africa. The basic reproduction number of vector-borne diseases, such as trypanosomiasis, is a function of vector mortality rate. Robust methods for estimating tsetse mortality are thus of interest for understanding population and disease dynamics and for optimal control. Existing methods for estimating mortality in adult tsetse, from ovarian dissection data, often use invalid assumptions of the existence of a stable age distribution, and age-invariant mortality and capture probability. We develop a dynamic model to estimate tsetse mortality from ovarian dissection data in populations where the age distribution is not necessarily stable. The models correspond to several hypotheses about how temperature affects mortality: no temperature dependence (model 1, identical temperature dependence for mature adults and immature stages, i.e., pupae and newly emerged adults (model 2, and differential temperature dependence for mature adults and immature stages (model 3. We fit our models to ovarian dissection data for G. pallidipes collected at Rekomitjie Research Station in the Zambezi Valley in Zimbabwe. We compare model fits to determine the most probable model, given the data, by calculating the Akaike Information Criterion (AIC for each model. The model that allows for a differential dependence of temperature on mortality for immature stages and mature adults (model 3 performs significantly better than models 1 and 2. All models produce mortality estimates, for mature adults, of approximately 3% per day for mean daily temperatures below 25°C, consistent with those of mark-recapture studies performed in other settings. For temperatures greater than 25°C, mortality among immature classes of tsetse increases substantially, whereas mortality remains roughly constant for mature adults. As a sensitivity analysis, model 3 was

  17. Standardising visual control devices for tsetse flies: Central and West African species Glossina palpalis palpalis.

    Directory of Open Access Journals (Sweden)

    Dramane Kaba

    Full Text Available BACKGROUND: Glossina palpalis palpalis (G. p. palpalis is one of the principal vectors of sleeping sickness and nagana in Africa with a geographical range stretching from Liberia in West Africa to Angola in Central Africa. It inhabits tropical rain forest but has also adapted to urban settlements. We set out to standardize a long-lasting, practical and cost-effective visually attractive device that would induce the strongest landing response by G. p. palpalis for future use as an insecticide-impregnated tool in area-wide population suppression of this fly across its range. METHODOLOGY/PRINCIPAL FINDINGS: Trials were conducted in wet and dry seasons in the Ivory Coast, Cameroon, the Democratic Republic of Congo and Angola to measure the performance of traps (biconical, monoconical and pyramidal and targets of different sizes and colours, with and without chemical baits, at different population densities and under different environmental conditions. Adhesive film was used as a practical enumerator at these remote locations to compare landing efficiencies of devices. Independent of season and country, both phthalogen blue-black and blue-black-blue 1 m(2 targets covered with adhesive film proved to be as good as traps in phthalogen blue or turquoise blue for capturing G. p. palpalis. Trap efficiency varied (8-51%. There was no difference between the performance of blue-black and blue-black-blue 1 m(2 targets. Baiting with chemicals augmented the overall performance of targets relative to traps. Landings on smaller phthalogen blue-black 0.25 m(2 square targets were not significantly different from either 1 m(2 blue-black-blue or blue-black square targets. Three times more flies were captured per unit area on the smaller device. CONCLUSIONS/SIGNIFICANCE: Blue-black 0.25 m(2 cloth targets show promise as simple cost effective devices for management of G. p. palpalis as they can be used for both control when impregnated with insecticide and for

  18. Consultants Group Meeting on Development of Cost-Effective Diets for Use in Mass Production of Tsetse Flies. Working Material

    International Nuclear Information System (INIS)

    2000-10-01

    The increasing demand for employing tsetse SIT for area-wide tsetse and trypanosomosis management programmes on mainland Africa has compelled the IAEA to concentrate on the development of semi-automated processes for standardising laborious and quality sensitive components of the sterile male mass production. The size of facilities required to produce the sterile males will continue to increase with time and demand. The current diet for tsetse is decontaminated vertebrate blood and it will need to be supplied to centres without access to a suitable local blood source. In view of the increasing demand for sterile male tsetse and uncertainty of obtaining high quality decontaminated blood locally, ways need to be explored to ensure availability of inexpensive, standard quality diets. Towards this goal a consultants group meeting on the development of cost-effective diets for tsetse was held at the IAEA headquarters in Vienna, Austria from 17 to 21 July 2000. The major objective of the consultants group meeting was to identify research that is needed to ensure the availability of large quantities of high quality diet for tsetse mass production. Seven papers were presented and discussed. A visit was made to the Entomology Unit, at the FAO/IAEA Agriculture and Biotechnology Laboratories, Seibersdorf to see the present tsetse rearing facility and the various steps of blood processing and quality assurance used in the evaluation of blood quality before use for colony feeding. The meeting noted that commercially available products are used to prepare standard diets for screwworm mass production. These products have not yet been adequately evaluated for tsetse. However, it is necessary to improve the current procedure applied to the use fresh blood. Possibilities of utilising commercially available dietary ingredients should also be explored. A three-step approach was proposed: Improvement and optimisation of the current blood collection, processing etc.; Use of additives

  19. The Fantastic Voyage of the Trypanosome: A Protean Micromachine Perfected during 500 Million Years of Engineering

    Directory of Open Access Journals (Sweden)

    Timothy Krüger

    2018-02-01

    Full Text Available The human body is constantly attacked by pathogens. Various lines of defence have evolved, among which the immune system is principal. In contrast to most pathogens, the African trypanosomes thrive freely in the blood circulation, where they escape immune destruction by antigenic variation and incessant motility. These unicellular parasites are flagellate microswimmers that also withstand the harsh mechanical forces prevailing in the bloodstream. They undergo complex developmental cycles in the bloodstream and organs of the mammalian host, as well as the disease-transmitting tsetse fly. Each life cycle stage has been shaped by evolution for manoeuvring in distinct microenvironments. Here, we introduce trypanosomes as blueprints for nature-inspired design of trypanobots, micromachines that, in the future, could explore the human body without affecting its physiology. We review cell biological and biophysical aspects of trypanosome motion. While this could provide a basis for the engineering of microbots, their actuation and control still appear more like fiction than science. Here, we discuss potentials and challenges of trypanosome-inspired microswimmer robots.

  20. Monitoring of tsetse and trypanosomosis control programmes in south easter Uganda

    International Nuclear Information System (INIS)

    Okuna, N.M.; Magona, J.

    1997-01-01

    A total of 3035 cattle, 2733 from a tsetse infested area and 302 from a tsetse free area, were screened for trypanosomosis by the buffy coat technique (BCT). In addition, sample from the tsetse free area were analysed for the presence of trypasonome antigens by antigen ELISA (Ag-ELISA). Using the BCT, trypanosome were detected in 64 cattle from the tsetse infested are and none were detected in the animals from the tsetse free area. However, using the Ag-ELISA, 17(5.6%) of the cattle from the tsetse free area were found positive for T. brucei, one (0.3%) for T. vivax and none for T. congolense. The results indicate that the tsetse and animal trypanosomosis situation has improved markedly since the control programme started in 1990. However both tsetse and animal trypanosomosis still occur particularly in the souther zones of the control area. (author). 5 refs, 1 fig., 4 tabs

  1. The phylogeography of trypanosomes from South American alligatorids and African crocodilids is consistent with the geological history of South American river basins and the transoceanic dispersal of Crocodylus at the Miocene.

    Science.gov (United States)

    Fermino, Bruno R; Viola, Laerte B; Paiva, Fernando; Garcia, Herakles A; de Paula, Catia D; Botero-Arias, Robinson; Takata, Carmen S A; Campaner, Marta; Hamilton, Patrick B; Camargo, Erney P; Teixeira, Marta M G

    2013-10-29

    Little is known about the diversity, phylogenetic relationships, and biogeography of trypanosomes infecting non-mammalian hosts. In this study, we investigated the influence of host species and biogeography on shaping the genetic diversity, phylogenetic relationship, and distribution of trypanosomes from South American alligatorids and African crocodilids. Small Subunit rRNA (SSU rRNA) and glycosomal Glyceraldehyde Phosphate Dehydrogenase (gGAPDH) genes were employed for phylogenetic inferences. Trypanosomes from crocodilians were obtained by haemoculturing. Growth behaviour, morphology, and ultrastructural features complement the molecular description of two new species strongly supported by phylogenetic analyses. The inferred phylogenies disclosed a strongly supported crocodilian-restricted clade comprising three subclades. The subclade T. grayi comprised the African Trypanosoma grayi from Crocodylus niloticus and tsetse flies. The subclade T. ralphi comprised alligatorid trypanosomes represented by Trypanosoma ralphi n. sp. from Melanosuchus niger, Caiman crocodilus and Caiman yacare from Brazilian river basins. T. grayi and T. ralphi were sister subclades. The basal subclade T. terena comprised alligatorid trypanosomes represented by Trypanosoma terena n. sp. from Ca. yacare sharing hosts and basins with the distantly genetic related T. ralphi. This subclade also included the trypanosome from Ca. crocodilus from the Orinoco basin in Venezuela and, unexpectedly, a trypanosome from the African crocodilian Osteolaemus tetraspis. The close relationship between South American and African trypanosomes is consistent with paleontological evidence of recent transoceanic dispersal of Crocodylus at the Miocene/Pliocene boundaries (4-5 mya), and host-switching of trypanosomes throughout the geological configuration of South American hydrographical basins shaping the evolutionary histories of the crocodilians and their trypanosomes.

  2. PGRP-LB is a maternally transmitted immune milk protein that influences symbiosis and parasitism in tsetse's offspring.

    Science.gov (United States)

    Wang, Jingwen; Aksoy, Serap

    2012-06-26

    Beneficial microbe functions range from host dietary supplementation to development and maintenance of host immune system. In mammals, newborn progeny are quickly colonized with a symbiotic fauna that is provisioned in mother's milk and that closely resembles that of the parent. Tsetse fly (Diptera: Glossinidae) also depends on the obligate symbiont Wigglesworthia for nutritional supplementation, optimal fecundity, and immune system development. Tsetse progeny develop one at a time in an intrauterine environment and receive nourishment and symbionts in mother's milk. We show that the host Peptidoglycan Recognition Protein (PGRP-LB) is expressed only in adults and is a major component of the milk that nourishes the developing progeny. The amidase activity associated with PGRP-LB may scavenge the symbiotic peptidoglycan and prevent the induction of tsetse's Immune Deficiency pathway that otherwise can damage the symbionts. Reduction of PGRP-LB experimentally diminishes female fecundity and damages Wigglesworthia in the milk through induction of antimicrobial peptides, including Attacin. Larvae that receive less maternal PGRP-LB give rise to adults with fewer Wigglesworthia and hyperimmune responses. Such adults also suffer dysregulated immunity, as indicated by the presence of higher trypanosome densities in parasitized adults. We show that recPGRP-LB has antimicrobial and antitrypanosomal activities that may regulate symbiosis and impact immunity. Thus, PGRP-LB plays a pivotal role in tsetse's fitness by protecting symbiosis against host-inflicted damage during development and by controlling parasite infections in adults that can otherwise reduce host fecundity.

  3. Trypanosoma brucei 29-13 strain is inducible in but not permissive for the tsetse fly vector

    Czech Academy of Sciences Publication Activity Database

    Herder, S.; Votýpka, Jan; Jirků, Milan; Rádrová, J.; Janzen, C. J.; Lukeš, Julius

    2007-01-01

    Roč. 117, č. 1 (2007), s. 111-114 ISSN 0014-4894 R&D Projects: GA MŠk(CZ) LC06009; GA MŠk 2B06129 Grant - others:MŠk(CZ) Barrande 2-06-28 Institutional research plan: CEZ:AV0Z60220518 Keywords : Trypanosoma brucei * tsetse * Glossina * GFP * Transmission * midgut infection * tetracycline Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.597, year: 2007

  4. RNA-seq de novo Assembly Reveals Differential Gene Expression in Glossina palpalis gambiensis Infected with Trypanosoma brucei gambiense vs. Non-Infected and Self-Cured Flies.

    Science.gov (United States)

    Hamidou Soumana, Illiassou; Klopp, Christophe; Ravel, Sophie; Nabihoudine, Ibouniyamine; Tchicaya, Bernadette; Parrinello, Hugues; Abate, Luc; Rialle, Stéphanie; Geiger, Anne

    2015-01-01

    Trypanosoma brucei gambiense (Tbg), causing the sleeping sickness chronic form, completes its developmental cycle within the tsetse fly vector Glossina palpalis gambiensis (Gpg) before its transmission to humans. Within the framework of an anti-vector disease control strategy, a global gene expression profiling of trypanosome infected (susceptible), non-infected, and self-cured (refractory) tsetse flies was performed, on their midguts, to determine differential genes expression resulting from in vivo trypanosomes, tsetse flies (and their microbiome) interactions. An RNAseq de novo assembly was achieved. The assembled transcripts were mapped to reference sequences for functional annotation. Twenty-four percent of the 16,936 contigs could not be annotated, possibly representing untranslated mRNA regions, or Gpg- or Tbg-specific ORFs. The remaining contigs were classified into 65 functional groups. Only a few transposable elements were present in the Gpg midgut transcriptome, which may represent active transpositions and play regulatory roles. One thousand three hundred and seventy three genes differentially expressed (DEGs) between stimulated and non-stimulated flies were identified at day-3 post-feeding; 52 and 1025 between infected and self-cured flies at 10 and 20 days post-feeding, respectively. The possible roles of several DEGs regarding fly susceptibility and refractoriness are discussed. The results provide new means to decipher fly infection mechanisms, crucial to develop anti-vector control strategies.

  5. Transcript expression analysis of putative Trypanosoma brucei GPI-anchored surface proteins during development in the tsetse and mammalian hosts.

    Directory of Open Access Journals (Sweden)

    Amy F Savage

    Full Text Available Human African Trypanosomiasis is a devastating disease caused by the parasite Trypanosoma brucei. Trypanosomes live extracellularly in both the tsetse fly and the mammal. Trypanosome surface proteins can directly interact with the host environment, allowing parasites to effectively establish and maintain infections. Glycosylphosphatidylinositol (GPI anchoring is a common posttranslational modification associated with eukaryotic surface proteins. In T. brucei, three GPI-anchored major surface proteins have been identified: variant surface glycoproteins (VSGs, procyclic acidic repetitive protein (PARP or procyclins, and brucei alanine rich proteins (BARP. The objective of this study was to select genes encoding predicted GPI-anchored proteins with unknown function(s from the T. brucei genome and characterize the expression profile of a subset during cyclical development in the tsetse and mammalian hosts. An initial in silico screen of putative T. brucei proteins by Big PI algorithm identified 163 predicted GPI-anchored proteins, 106 of which had no known functions. Application of a second GPI-anchor prediction algorithm (FragAnchor, signal peptide and trans-membrane domain prediction software resulted in the identification of 25 putative hypothetical proteins. Eighty-one gene products with hypothetical functions were analyzed for stage-regulated expression using semi-quantitative RT-PCR. The expression of most of these genes were found to be upregulated in trypanosomes infecting tsetse salivary gland and proventriculus tissues, and 38% were specifically expressed only by parasites infecting salivary gland tissues. Transcripts for all of the genes specifically expressed in salivary glands were also detected in mammalian infective metacyclic trypomastigotes, suggesting a possible role for these putative proteins in invasion and/or establishment processes in the mammalian host. These results represent the first large-scale report of the differential

  6. Success in Zanzibar: Eradication of tsetse

    International Nuclear Information System (INIS)

    Msangi, A.R.; Kiwia, N.; Malele, I.I.; Mramba, F.; Saleh, K.M.; Mussa, W.A.; Juma, K.G.; Dyck, V.A.; Vreysen, M.J.B.; Parker, A.G.; Feldmann, U.; Zhu, Z.R.; Pan, H.

    2000-01-01

    There are about 22 species of tsetse flies found nowhere else in the world except in 36 countries of sub-Saharan Africa. Tsetse flies transmit a debilitating and often fatal disease, trypanosomosis, which causes tremendous losses of livestock, and severely limits agricultural production (it reduces output of milk and meat, causes mortality, infertility and abortion in livestock, deprives the rural population of draught power and manure to improve and increase crop production). Tsetse flies also transmit human trypanosomosis, commonly known as 'sleeping sickness'. It is estimated that over 55 million people living in rural sub-Saharan Africa are at risk from this fatal disease. Tanzania's Zanzibar Island is situated 35 km off the eastern coast and comprises two main islands, Unguja and Pemba. Previous surveys revealed that out of the seven tsetse species found on mainland Tanzania, only Glossina austeni Newstead infested Unguja Island. No tsetse fly was found on the island of Pemba. The fly is responsible for the cyclical transmission of trypanosomosis in livestock, the causative agents being mainly Trypanosoma congolense and, to a lesser extent, T. vivax. It is estimated that in Zanzibar, the disease causes annual losses of US$2 million. Since fly suppression by conventional techniques has often resulted in short-term success, Tanzania has always appreciated that the long-term solution to the trypanosomosis problem is the eradication of tsetse flies in the country. In 1994, the International Atomic Energy Agency (IAEA) and the United Republic of Tanzania embarked on a project with the objective of eradicating tsetse flies from Zanzibar Island by applying the sterile insect technique (SIT) (Dyck et al. 1995, in press). Previous tsetse eradication efforts in Tanzania using SIT, enabled the establishment of a modest capacity on tsetse mass rearing in Tanga (Williamson et al. 1983). The Zanzibar tsetse project was successfully completed in 1997. The estimated cost was

  7. Quality of Sterile Male Tsetse after Long Distance Transport as Chilled, Irradiated Pupae.

    Directory of Open Access Journals (Sweden)

    Momar Talla Seck

    2015-11-01

    Full Text Available Tsetse flies transmit trypanosomes that cause human and African animal trypanosomosis, a debilitating disease of humans (sleeping sickness and livestock (nagana. An area-wide integrated pest management campaign against Glossina palpalis gambiensis has been implemented in Senegal since 2010 that includes a sterile insect technique (SIT component. The SIT can only be successful when the sterile males that are destined for release have a flight ability, survival and competitiveness that are as close as possible to that of their wild male counterparts.Tests were developed to assess the quality of G. p. gambiensis males that emerged from pupae that were produced and irradiated in Burkina Faso and Slovakia (irradiation done in Seibersdorf, Austria and transported weekly under chilled conditions to Dakar, Senegal. For each consignment a sample of 50 pupae was used for a quality control test (QC group. To assess flight ability, the pupae were put in a cylinder filtering emerged flies that were able to escape the cylinder. The survival of these flyers was thereafter monitored under stress conditions (without feeding. Remaining pupae were emerged and released in the target area of the eradication programme (RF group. The following parameter values were obtained for the QC flies: average emergence rate more than 69%, median survival of 6 days, and average flight ability of more than 35%. The quality protocol was a good proxy of fly quality, explaining a large part of the variances of the examined parameters.The quality protocol described here will allow the accurate monitoring of the quality of shipped sterile male tsetse used in operational eradication programmes in the framework of the Pan-African Tsetse and Trypanosomosis Eradication Campaign.

  8. Conflict of interest: use of pyrethroids and amidines against tsetse and ticks in zoonotic sleeping sickness endemic areas of Uganda.

    Science.gov (United States)

    Bardosh, Kevin; Waiswa, Charles; Welburn, Susan C

    2013-07-10

    Caused by trypanosomes and transmitted by tsetse flies, Human African Trypanosomiasis and bovine trypanosomiasis remain endemic across much of rural Uganda where the major reservoir of acute human infection is cattle. Following elimination of trypanosomes by mass trypanocidal treatment, it is crucial that farmers regularly apply pyrethroid-based insecticides to cattle to sustain parasite reductions, which also protect against tick-borne diseases. The private veterinary market is divided between products only effective against ticks (amidines) and those effective against both ticks and tsetse (pyrethroids). This study explored insecticide sales, demand and use in four districts of Uganda where mass cattle treatments have been undertaken by the 'Stamp Out Sleeping Sickness' programme. A mixed-methods study was undertaken in Dokolo, Kaberamaido, Serere and Soroti districts of Uganda between September 2011 and February 2012. This included: focus groups in 40 villages, a livestock keeper survey (n = 495), a veterinary drug shop questionnaire (n = 74), participatory methods in six villages and numerous semi-structured interviews. Although 70.5% of livestock keepers reportedly used insecticide each month during the rainy season, due to a variety of perceptions and practices nearly half used products only effective against ticks and not tsetse. Between 640 and 740 litres of insecticide were being sold monthly, covering an average of 53.7 cattle/km(2). Sales were roughly divided between seven pyrethroid-based products and five products only effective against ticks. In the high-risk HAT district of Kaberamaido, almost double the volume of non-tsetse effective insecticide was being sold. Factors influencing insecticide choice included: disease knowledge, brand recognition, product price, half-life and mode of product action, product availability, and dissemination of information. Stakeholders considered market restriction of non-tsetse effective products the most

  9. Trypanozoon: infectivity to humans is linked to reduced transmissibility in tsetse. II. Genetic mechanisms.

    Science.gov (United States)

    Milligan, P J; Maudlin, I; Welburn, S C

    1995-11-01

    Trypanozoon infections are less likely to mature in female tsetse than in males. Analysis of maturation data from 37 Trypanozoon isolates in Glossina m. morsitans showed that while the proportion of mature infections (salivary gland infections as a proportion of established midgut infections) varied from isolate to isolate, the proportion of mature infections in female flies was consistently smaller than the proportion in male flies. The log of the probability of maturation in females is, on average, twice the log of the probability in males (estimate of the ratio of the logged proportions is 2.09, 95% confidence interval (CI) 1.8 to 2.5). Human serum-resistant isolates were less likely to mature than human serum-sensitive isolates (ratio of logged proportions maturing was 1.5, 95% CI 1.3 to 1.8, in both male and female tsetse). Data for four other trypanosome stocks show that the probability of maturation decreases as the maturation time (the delay between the infected bloodmeal and maturation) increases. The decrease is approximately exponential with twice the half-life in male flies compared to that in female flies (estimate of the ratio of the exponential parameters is 1.97, 95% CI 0.7 to 3.3). A model is proposed to explain these observations which assumes that product(s) from an X-linked gene(s) kills or otherwise prevents migrating parasites from establishing a mature infection. Longer maturation times are associated with a heavy penalty in terms of transmissibility as measured by the vectorial capacity.

  10. Microbial symbiosis and the control of vector-borne pathogens in tsetse flies, human lice, and triatomine bugs

    Science.gov (United States)

    Sassera, Davide; Epis, Sara; Pajoro, Massimo; Bandi, Claudio

    2013-01-01

    Symbiosis is a widespread biological phenomenon, and is particularly common in arthropods. Bloodsucking insects are among the organisms that rely on beneficial bacterial symbionts to complement their unbalanced diet. This review is focused on describing symbiosis, and possible strategies for the symbiont-based control of insects and insect-borne diseases, in three bloodsucking insects of medical importance: the flies of the genus Glossina, the lice of the genus Pediculus, and triatomine bugs of the subfamily Triatominae. Glossina flies are vector of Trypanosoma brucei, the causative agent of sleeping sickness and other pathologies. They are also associated with two distinct bacterial symbionts, the primary symbiont Wigglesworthia spp., and the secondary, culturable symbiont Sodalis glossinidius. The primary symbiont of human lice, Riesia pediculicola, has been shown to be fundamental for the host, due to its capacity to synthesize B-group vitamins. An antisymbiotic approach, with antibiotic treatment targeted on the lice symbionts, could represent an alternative strategy to control these ectoparasites. In the case of triatominae bugs, the genetic modification of their symbiotic Rhodococcus bacteria, for production of anti-Trypanosoma molecules, is an example of paratransgenesis, i.e. the use of symbiotic microorganism engineered in order to reduce the vector competence of the insect host. PMID:24188239

  11. Widespread occurrence of Trypanosoma vivax in bovines of tsetse- as well as non-tsetse-infested regions of Ethiopia: a reason for concern?

    Science.gov (United States)

    Fikru, Regassa; Goddeeris, Bruno Maria; Delespaux, Vincent; Moti, Yohannes; Tadesse, Aster; Bekana, Merga; Claes, Filip; De Deken, Reginald; Büscher, Philippe

    2012-12-21

    A cross-sectional study was undertaken to assess the prevalence of bovine trypanosomosis in some tsetse-infested and tsetse-free areas of Ethiopia. From August 2010 till April 2011, a total of 1524 animals were parasitologically examined and compared by the haematocrit centrifugation technique (Woo test) and polymerase chain reaction (ITS-1 PCR). The ITS-1 PCR was more sensitive and more accurate in species identification than the Woo test. In ITS-1 PCR, an overall trypanosome prevalence of 31.0% was observed that is significantly (P<0.001) higher than in the Woo test (5.3%). Trypanosoma vivax was the predominant taxon (24.9%), followed by T. theileri (6.0%), T. congolense (2.9%) and Trypanozoon (1.6%). Mixed infections were quite common (14% of all infections). The overall prevalence of trypanosome infections in tsetse area (32.4%) was not different from non-tsetse area (30.5%) neither were the prevalences of T. vivax in both areas (respectively 22.6% and 25.7%). With these high prevalences, bovine trypanosomosis continues to hinder animal production and productivity in Ethiopia, both in tsetse-infested and non-infested parts of the country. Attempts to control African trypanosomosis should also pay attention to mechanically transmitted pathogenic trypanosomes and should adopt the most advanced molecular tests for species identification. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Response of four indigenous cattle breeds to natural tsetse and trypanosomosis challenge in the Ghibe valley of Ethiopia.

    Science.gov (United States)

    Lemecha, H; Mulatu, W; Hussein, I; Rege, E; Tekle, T; Abdicho, S; Ayalew, W

    2006-10-10

    A comparative study on the response of four indigenous cattle breeds of Ethiopia, namely Abigar, Horro, Sheko and Gurage, to natural challenge of trypanosomosis in the Tolley-Gullele area of the Ghibe valley has been undertaken from August 2000 until August 2004. Fifty female yearlings each of Horro, Sheko and Abigar and 31 of the Gurage were purchased from their natural habitats and introduced in to medium to high tsetse-trypanosomosis challenge area of the Ghibe valley. While the natural habitats of first three breeds are naturally infested with tsetse flies and trypanosomosis, that of the Gurage is known to be very minimal, if any, and hence the Gurage breed was used in this study as the known susceptible breed. During the study animal health, production performance and tsetse fly situation were monitored monthly. The Sheko breed has manifested very significantly (p<0.001) high overall average packed cell volume (PCV) values (25%) compared to that of Abigar (24%), Horro (23%) and Gurage (22%). It also had the lowest mean trypanosome prevalence rate of 9% against 23% of Horro, 26% of Abigar and 27% of Gurage, and the least number of Berenil treatments (1.36) compared to Abigar (4.0), Horro (4.6) and Gurage (6.7). While the Abigar manifested high sensitivity and frequent death to PCV depression, the Horro showed strong resilience to PCV depression and better response to Berenil treatment assistance. At this stage the Sheko breed was also found to be equal to the other breeds in its reproductive performance. These results need to be substantiated with further in-depth investigation including immune response, animal behavior and environmental influences.

  13. Updating the Northern Tsetse Limit in Burkina Faso (1949–2009: Impact of Global Change

    Directory of Open Access Journals (Sweden)

    Fabrice Courtin

    2010-04-01

    Full Text Available The northern distribution limit of tsetse flies was updated in Burkina Faso and compared to previous limits to revise the existing map of these vectors of African trypanosomiases dating from several decades ago. From 1949 to 2009, a 25- to 150-km shift has appeared toward the south. Tsetse are now discontinuously distributed in Burkina Faso with a western and an eastern tsetse belt. This range shift can be explained by a combination of decreased rainfall and increased human density. Within a context of international control, this study provides a better understanding of the factors influencing the distribution of tsetse flies.

  14. Eradicating tsetse from the Southern Rift Valley of Ethiopia

    International Nuclear Information System (INIS)

    2003-01-01

    Farming activities in Ethiopia, as in much of sub-Saharan Africa, are restricted by the presence of tsetse flies (Glossina spp.). These carry the livestock and human disease, trypanosomosis, which severely affects agricultural production and human well-being. In collaboration with the Ethiopian authorities, the International Atomic Energy Agency is sponsoring a Sterile Insect Technique (SIT) programme to eradicate tsetse from the Southern Rift Valley of Ethiopia. (IAEA)

  15. The use of antigen ELISA to monitor the effectiveness of a tsetse control campaign in the upper Didessa valley, Western Ethiopia

    International Nuclear Information System (INIS)

    Tewelde, N.; Kebede, A.; Tsegaye, A.

    1997-01-01

    Blood and serum samples were collected from a tsetse free zone in the central highlands of Ethiopia. The samples were collected to determine the specificity and establish percentage positivity cut-off points of the antigen ELISA. Blood samples collected from these areas were negative for trypanosomosis using Standard Trypanosome Detection Methods (STDM). Ag-ELISA, in contrast, detected circulating trypanosomal antigens in 7.6% of the serum samples collected. Similarly, samples were collected from a tsetse infested zone in the upper Didessa valley, western Ethiopia, to assess the sensitivity of the Ag-ELISA. STDM detected trypanosomal infections in the range of 15.8 and 16.7% of blood samples from this zone. On the other hand, Ag-ELISA, indicated the presence of circulating trypanosomal antigens in 38.6% of serum samples tested. Moreover, Ag-ELISA was used to monitor the effectiveness of a tsetse control campaign in the upper Didessa valley. There were great differences in the prevalence rates of trypanosomosis, as revealed by the STDM and Ag-ELISA, between the tsetse controlled and tsetse infested zones of the upper Didessa valley. Generally, the Ag-ELISA revealed the presence of circulating trypanosomal antigens in only 43.7% of patent infections. Nevertheless, the test detected 318 more cases which were not diagnosed by any one of the STDM used. More interestingly, Ag-ELISA indicated the widespread presence of T. brucei in the cattle sampled in all zones. (author). 11 refs, 4 tabs

  16. Determination of the prevalence of African trypanosome species in indigenous dogs of Mambwe district, eastern Zambia, by loop-mediated isothermal amplification.

    Science.gov (United States)

    Lisulo, Malimba; Sugimoto, Chihiro; Kajino, Kiichi; Hayashida, Kyouko; Mudenda, Macarthy; Moonga, Ladslav; Ndebe, Joseph; Nzala, Selestine; Namangala, Boniface

    2014-01-10

    trypanosomes from mongrels is intriguing and indicative of the risk of contracting HAT by local communities and tourists in Mambwe district. Consequently, there is a need for continuous trypanosome surveillances in animals, humans and tsetse flies using sensitive and specific tests such as LAMP.

  17. Ribosomal DNA analysis of tsetse and non-tsetse transmitted Ethiopian Trypanosoma vivax strains in view of improved molecular diagnosis.

    Science.gov (United States)

    Fikru, Regassa; Matetovici, Irina; Rogé, Stijn; Merga, Bekana; Goddeeris, Bruno Maria; Büscher, Philippe; Van Reet, Nick

    2016-04-15

    strains showed important differences and higher GC content compared to other animal trypanosomes but could not be related to their origin from tsetse-infested or tsetse-free area. The high GC content of T. vivax DNA renders accurate diagnosis of all pathogenic animal trypanosomes with one single PCR problematic. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  18. Methods to determine the transcriptomes of trypanosomes in mixtures with mammalian cells: the effects of parasite purification and selective cDNA amplification.

    Directory of Open Access Journals (Sweden)

    Julius Mulindwa

    2014-04-01

    Full Text Available Patterns of gene expression in cultured Trypanosoma brucei bloodstream and procyclic forms have been extensively characterized, and some comparisons have been made with trypanosomes grown to high parasitaemias in laboratory rodents. We do not know, however, to what extent these transcriptomes resemble those in infected Tsetse flies - or in humans or cattle, where parasitaemias are substantially lower. For clinical and field samples it is difficult to characterize parasite gene expression because of the large excess of host cell RNA. We have here examined two potential solutions to this problem for bloodstream form trypanosomes, assaying transcriptomes by high throughput cDNA sequencing (RNASeq. We first purified the parasites from blood of infected rats. We found that a red blood cell lysis procedure affected the transcriptome substantially more than purification using a DEAE cellulose column, but that too introduced significant distortions and variability. As an alternative, we specifically amplified parasite sequences from a mixture containing a 1000-fold excess of human RNA. We first purified polyadenylated RNA, then made trypanosome-specific cDNA by priming with a spliced leader primer. Finally, the cDNA was amplified using nested primers. The amplification procedure was able to produce samples in which 20% of sequence reads mapped to the trypanosome genome. Synthesis of the second cDNA strand with a spliced leader primer, followed by amplification, is sufficiently reproducible to allow comparison of different samples so long as they are all treated in the same way. However, SL priming distorted the abundances of the cDNA products and definitely cannot be used, by itself, to measure absolute mRNA levels. The amplification method might be suitable for clinical samples with low parasitaemias, and could also be adapted for other Kinetoplastids and to samples from infected vectors.

  19. Genetic diversity and population structure of the tsetse fly Glossina fuscipes fuscipes (Diptera: Glossinidae in Northern Uganda: Implications for vector control.

    Directory of Open Access Journals (Sweden)

    Robert Opiro

    2017-04-01

    Full Text Available Uganda is the only country where the chronic and acute forms of human African Trypanosomiasis (HAT or sleeping sickness both occur and are separated by < 100 km in areas north of Lake Kyoga. In Uganda, Glossina fuscipes fuscipes is the main vector of the Trypanosoma parasites responsible for these diseases as well for the animal African Trypanosomiasis (AAT, or Nagana. We used highly polymorphic microsatellite loci and a mitochondrial DNA (mtDNA marker to provide fine scale spatial resolution of genetic structure of G. f. fuscipes from 42 sampling sites from the northern region of Uganda where a merger of the two disease belts is feared. Based on microsatellite analyses, we found that G. f. fuscipes in northern Uganda are structured into three distinct genetic clusters with varying degrees of interconnectivity among them. Based on genetic assignment and spatial location, we grouped the sampling sites into four genetic units corresponding to northwestern Uganda in the Albert Nile drainage, northeastern Uganda in the Lake Kyoga drainage, western Uganda in the Victoria Nile drainage, and a transition zone between the two northern genetic clusters characterized by high level of genetic admixture. An analysis using HYBRIDLAB supported a hybrid swarm model as most consistent with tsetse genotypes in these admixed samples. Results of mtDNA analyses revealed the presence of 30 haplotypes representing three main haplogroups, whose location broadly overlaps with the microsatellite defined clusters. Migration analyses based on microsatellites point to moderate migration among the northern units located in the Albert Nile, Achwa River, Okole River, and Lake Kyoga drainages, but not between the northern units and the Victoria Nile drainage in the west. Effective population size estimates were variable with low to moderate sizes in most populations and with evidence of recent population bottlenecks, especially in the northeast unit of the Lake Kyoga drainage

  20. Consultants' Group Meeting on Tsetse Genetics in Relation to Tsetse/Trypanosomiasis Control/Eradication

    International Nuclear Information System (INIS)

    1992-01-01

    The FAO and IAEA have long recognized the need for methods for insect and pest control based upon approaches other than simply the widespread use of insecticides. Through the past several years the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture has expended a considerable amount of effort in the development of a SIT programme applicable to tsetse. Such programmes have proved to be a highly successful component of the integrated control of tsetse flies. However, the pilot programmes undertaken to date have been applied to areas of limited size and future integrated control programmes for tsetse must cover much larger regions. The Consultants' Group was cognisant of the continued need for improvements in the cost effectiveness in the mass production of tsetse, particularly for SIT programmes. The Consultants' Goup recognized also that FAO/IAEA plays an important leadership role in the development of new technologies for the control of insect pest populations, and in the transfer of such technologies to assist in the improvement of agricultural production, particularly in developing countries. In addition to research on the development of methods for insect control (emphasizing application of the Sterile Insect Technique), the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture has established and implemented five 'Co-ordinated Research Programmes' on tsetse and has, from time to time, convened groups of consultants to discuss and make recommendations on specific subjects. At least two such meetings (in July 1975 and November 1987) focused on genetic methods of insect control. The recent, rapid developments in molecular biology have stimulated interest in the application of genetic techniques to the problem of tsetse and trypanosomiasis control in Africa.

  1. The incrimination of three trypanosome species in clinically affected German shepherd dogs in Sudan.

    Science.gov (United States)

    Mossaad, Ehab; Satti, Rawan A; Fadul, Abdeen; Suganuma, Keisuke; Salim, Bashir; Elamin, E A; Musinguzi, Simon Peter; Xuan, Xuenan; Inoue, Noboru

    2017-11-01

    Canine trypanosomosisis (CT) is a common disease caused by tsetse- and non-tsetse-transmitted trypanosomes worldwide. The severity of the disease varies from acute, sub-acute to chronic with non-specific clinical signs. Here, we attempt in a cross-sectional study to assess the current situation of CT and the role of dogs in transmitting trypanosomes to other domesticated animals. The study was carried out during July 2016 on 50 caged German shepherd dogs in Khartoum State to investigate the prevalence of dog trypanosomosis using both serological (CATT/Trypanosoma evansi) and molecular (KIN-PCR, RoTat1.2 VSG-PCR and TviCatL-PCR) tests to detect possible trypanosome infections. CATT/T. evansi detected antibodies against T. evansi in 15 (30%) dogs, while parasite DNA was detected in 17 (34%) dogs by RoTat1.2 PCR. In contrast, a KIN-PCR detected the subgenus Trypanozoon, Trypanosoma congolense savannah, T. congolense Kenya and T. vivax in 36 (72%), 3 (6%), 1 (2%), and 2 (4%) dogs, respectively. However, a species-specific PCR for Trypanosoma vivax was detected 7 (14%) positive cases. We concluded that CT was caused by at least three species of trypanosomes, namely T. evansi, T. vivax and T. congolense. Trypanozoon other than T. evansi could not be ruled out since other tsetse-transmitted trypanosomes have also been detected and species-specific PCRs were not used. This study illustrates that dogs play an important role in the transmission dynamic and the epidemiology of the abovementioned trypanosome species.

  2. A landscape and climate data logistic model of tsetse distribution in Kenya.

    Directory of Open Access Journals (Sweden)

    Nathan Moore

    2010-07-01

    Full Text Available Trypanosoma spp, biologically transmitted by the tsetse fly in Africa, are a major cause of illness resulting in both high morbidity and mortality among humans, cattle, wild ungulates, and other species. However, tsetse fly distributions change rapidly due to environmental changes, and fine-scale distribution maps are few. Due to data scarcity, most presence/absence estimates in Kenya prior to 2000 are a combination of local reports, entomological knowledge, and topographic information. The availability of tsetse fly abundance data are limited, or at least have not been collected into aggregate, publicly available national datasets. Despite this limitation, other avenues exist for estimating tsetse distributions including remotely sensed data, climate information, and statistical tools.Here we present a logistic regression model of tsetse abundance. The goal of this model is to estimate the distribution of tsetse fly in Kenya in the year 2000, and to provide a method by which to anticipate their future distribution. Multiple predictor variables were tested for significance and for predictive power; ultimately, a parsimonious subset of variables was identified and used to construct the regression model with the 1973 tsetse map. These data were validated against year 2000 Food and Agriculture Organization (FAO estimates. Mapcurves Goodness-Of-Fit scores were used to evaluate the modeled fly distribution against FAO estimates and against 1973 presence/absence data, each driven by appropriate climate data.Logistic regression can be effectively used to produce a model that projects fly abundance under elevated greenhouse gas scenarios. This model identifies potential areas for tsetse abandonment and expansion.

  3. An atlas of tsetse and bovine trypanosomosis in Sudan.

    Science.gov (United States)

    Ahmed, Selma K; Rahman, Ahmed H; Hassan, Mohammed A; Salih, Sir Elkhatim M; Paone, Massimo; Cecchi, Giuliano

    2016-04-07

    After a long period of neglect, initiatives are being implemented in Sudan to control tsetse and trypanosomosis. Their planning, execution and monitoring require reliable information on the geographic distribution of the disease and its vectors. However, geo-referenced and harmonized data at the national level are lacking, despite the fact that a number of epidemiological studies were conducted over the years. The Atlas of tsetse and bovine trypanosomosis in Sudan tries to fill this gap. The present study includes both a review of historical datasets on tsetse flies and bovine trypanosomosis, as well as the results of recent, targeted field investigations. The review includes both published and unpublished datasets collected in Sudan from 1960 onwards. Targeted field investigations were conducted for trypanosomosis in Blue Nile (2011) and Gezeira States (2012), for tsetse flies in South Darfur (2012) and Blue Nile States (2009 and 2011), and for other trypanosomosis vectors in seven States (Khartoum, Gezeira, White Nile, Blue Nile, North Kordofan, Kassala and Gadarif). The latter surveys, conducted from 2010 to 2012, also enabled us to confirm the absence of tsetse flies in a number of locations. Tsetse fly infestation in Sudan appears to be limited to two relatively small areas at the south-western and south-eastern tips of the Country (South Darfur and Blue Nile State respectively). Glossina morsitans submorsitans is present in both areas, whilst G. fuscipes fuscipes is found only in the latter. In contrast, bovine trypanosomosis is widespread, its presence having being confirmed in eleven States and suspected in all the others. Both mechanical transmission by non-cyclical vectors and animal movement contribute to this broad distribution of trypanosomosis. This is especially the case for Trypanosoma vivax, which was found even in sedentary cattle at hundreds of kilometres of the tsetse belt. The Atlas provides a spatially-explicit synthesis of the current

  4. The study of trypanosome species circulating in domestic animals in two human African trypanosomiasis foci of Côte d'Ivoire identifies pigs and cattle as potential reservoirs of Trypanosoma brucei gambiense

    Science.gov (United States)

    N’Djetchi, Martial Kassi; Ilboudo, Hamidou; Koffi, Mathurin; Kaboré, Jacques; Kaboré, Justin Windingoudi; Kaba, Dramane; Courtin, Fabrice; Coulibaly, Bamoro; Fauret, Pierre; Kouakou, Lingué; Ravel, Sophie; Deborggraeve, Stijn; Solano, Philippe; De Meeûs, Thierry; Bucheton, Bruno

    2017-01-01

    Background Important control efforts have led to a significant reduction of the prevalence of human African trypanosomiasis (HAT) in Côte d’Ivoire, but the disease is still present in several foci. The existence of an animal reservoir of Trypanosoma brucei gambiense may explain disease persistence in these foci where animal breeding is an important source of income but where the prevalence of animal African trypanosomiasis (AAT) is unknown. The aim of this study was to identify the trypanosome species circulating in domestic animals in both Bonon and Sinfra HAT endemic foci. Methodology/Principal findings 552 domestic animals (goats, pigs, cattle and sheep) were included. Blood samples were tested for trypanosomes by microscopic observation, species-specific PCR for T. brucei sl, T. congolense, T. vivax and subspecies-specific PCR for T. b. gambiense and T. b. gambiense immune trypanolysis (TL). Infection rates varied significantly between animal species and were by far the highest in pigs (30%). T. brucei s.l was the most prevalent trypanosome species (13.7%) followed by T. congolense. No T. b. gambiense was identified by PCR while high TL positivity rates were observed using T. b. gambiense specific variants (up to 27.6% for pigs in the Bonon focus). Conclusion This study shows that domestic animals are highly infected by trypanosomes in the studied foci. This was particularly true for pigs, possibly due to a higher exposure of these animals to tsetse flies. Whereas T. brucei s.l. was the most prevalent species, discordant results were obtained between PCR and TL regarding T. b. gambiense identification. It is therefore crucial to develop better tools to study the epidemiological role of potential animal reservoir for T. b. gambiense. Our study illustrates the importance of “one health” approaches to reach HAT elimination and contribute to AAT control in the studied foci. PMID:29045405

  5. The study of trypanosome species circulating in domestic animals in two human African trypanosomiasis foci of Côte d'Ivoire identifies pigs and cattle as potential reservoirs of Trypanosoma brucei gambiense.

    Science.gov (United States)

    N'Djetchi, Martial Kassi; Ilboudo, Hamidou; Koffi, Mathurin; Kaboré, Jacques; Kaboré, Justin Windingoudi; Kaba, Dramane; Courtin, Fabrice; Coulibaly, Bamoro; Fauret, Pierre; Kouakou, Lingué; Ravel, Sophie; Deborggraeve, Stijn; Solano, Philippe; De Meeûs, Thierry; Bucheton, Bruno; Jamonneau, Vincent

    2017-10-01

    Important control efforts have led to a significant reduction of the prevalence of human African trypanosomiasis (HAT) in Côte d'Ivoire, but the disease is still present in several foci. The existence of an animal reservoir of Trypanosoma brucei gambiense may explain disease persistence in these foci where animal breeding is an important source of income but where the prevalence of animal African trypanosomiasis (AAT) is unknown. The aim of this study was to identify the trypanosome species circulating in domestic animals in both Bonon and Sinfra HAT endemic foci. 552 domestic animals (goats, pigs, cattle and sheep) were included. Blood samples were tested for trypanosomes by microscopic observation, species-specific PCR for T. brucei sl, T. congolense, T. vivax and subspecies-specific PCR for T. b. gambiense and T. b. gambiense immune trypanolysis (TL). Infection rates varied significantly between animal species and were by far the highest in pigs (30%). T. brucei s.l was the most prevalent trypanosome species (13.7%) followed by T. congolense. No T. b. gambiense was identified by PCR while high TL positivity rates were observed using T. b. gambiense specific variants (up to 27.6% for pigs in the Bonon focus). This study shows that domestic animals are highly infected by trypanosomes in the studied foci. This was particularly true for pigs, possibly due to a higher exposure of these animals to tsetse flies. Whereas T. brucei s.l. was the most prevalent species, discordant results were obtained between PCR and TL regarding T. b. gambiense identification. It is therefore crucial to develop better tools to study the epidemiological role of potential animal reservoir for T. b. gambiense. Our study illustrates the importance of "one health" approaches to reach HAT elimination and contribute to AAT control in the studied foci.

  6. Knowledge, attitude, and practices about tsetse control among communities neighbouring Serengeti National Park, Tanzania

    Directory of Open Access Journals (Sweden)

    Dismas L. Mwaseba

    2017-06-01

    Full Text Available Tsetse flies are vectors of blood parasite of the genus Trypanosoma, which causes African trypanosomiasis to both human beings and animals. Large losses due to nagana have been reported; and this indicates the importance of tsetse control to avoid estimated losses. This study assessed the knowledge of tsetse and control practices, attitude towards control practices against tsetse, and the actual control practices used by the local communities in Serengeti District near the Serengeti National Park (SENAPA. Data for this study were collected using various methods. An interview schedule was administered to 70 randomly selected households, 12 focus group discussions with men and women farmers, and four key informant interviews with technical staff were held. The data were analysed using largely descriptive statistics and content analysis method. The farmers had inadequate knowledge of tsetse such that they confused them with other similar flies. On the other hand, they demonstrated knowledge of tsetse control measures, and these included some, which were not among those recommended by the extension staff. While the attitude towards control methods was positive most of the farmers did not use the recommended methods largely due to the cost associated with them. This suggests that the positive attitude towards a recommendation by itself is not sufficient to influence its use. Besides, poor management of dipping facilities for tsetse control and inadequate supervision by district staff impacted on the quality of services offered. Thus enabling local community members to have clear knowledge of tsetse flies is an important starting point for mobilizing them to take appropriate control measures against tsetse. Also, district authorities need to take an active role in monitoring the performance of the dipping facilities in the district by taking up appropriate measures to ensure quality control of services offered. Moreover, there is need for the district

  7. The impact of habitat fragmentation on tsetse abundance on the plateau of eastern Zambia.

    Science.gov (United States)

    Ducheyne, E; Mweempwa, C; De Pus, C; Vernieuwe, H; De Deken, R; Hendrickx, G; Van den Bossche, P

    2009-09-01

    Tsetse-transmitted human or livestock trypanosomiasis is one of the major constraints to rural development in sub-Saharan Africa. The epidemiology of the disease is determined largely by tsetse fly density. A major factor, contributing to tsetse population density is the availability of suitable habitat. In large parts of Africa, encroachment of people and their livestock resulted in a destruction and fragmentation of such suitable habitat. To determine the effect of habitat change on tsetse density a study was initiated in a tsetse-infested zone of eastern Zambia. The study area represents a gradient of habitat change, starting from a zone with high levels of habitat destruction and ending in an area where livestock and people are almost absent. To determine the distribution and density of the fly, tsetse surveys were conducted throughout the study area in the dry and in the rainy season. Landsat ETM+ imagery covering the study area were classified into four land cover classes (munga, miombo, agriculture and settlements) and two auxiliary spectral classes (clouds and shadow) using a Gaussian Maximum Likelihood Classifier. The classes were regrouped into natural vegetation and agricultural zone. The binary images were overlaid with hexagons to obtain the spatial spectrum of spatial pattern. Hexagonal coverage was selected because of its compact and regular form. To identify scale-specific spatial patterns and associated entomological phenomena, the size of the hexagonal coverage was varied (250 and 500 m). Per coverage, total class area, mean patch size, number of patches and patch size standard deviation were used as fragmentation indices. Based on the fragmentation index values, the study zone was classified using a Partitioning Around Mediods (PAM) method. The number of classes was determined using the Wilks' lambda coefficient. To determine the impact of habitat fragmentation on tsetse abundance, the correlation between the fragmentation indices and the index

  8. Trypanosome diversity in wildlife species from the serengeti and Luangwa Valley ecosystems.

    Directory of Open Access Journals (Sweden)

    Harriet Auty

    Full Text Available BACKGROUND: The importance of wildlife as reservoirs of African trypanosomes pathogenic to man and livestock is well recognised. While new species of trypanosomes and their variants have been identified in tsetse populations, our knowledge of trypanosome species that are circulating in wildlife populations and their genetic diversity is limited. METHODOLOGY/PRINCIPAL FINDINGS: molecular phylogenetic methods were used to examine the genetic diversity and species composition of trypanosomes circulating in wildlife from two ecosystems that exhibit high host species diversity: the Serengeti in Tanzania and the Luangwa Valley in Zambia. Phylogenetic relationships were assessed by alignment of partial 18S, 5.8S and 28S trypanosomal nuclear ribosomal DNA array sequences within the Trypanosomatidae and using ITS1, 5.8S and ITS2 for more detailed analysis of the T. vivax clade. In addition to Trypanosoma brucei, T. congolense, T. simiae, T. simiae (Tsavo, T. godfreyi and T. theileri, three variants of T. vivax were identified from three different wildlife species within one ecosystem, including sequences from trypanosomes from a giraffe and a waterbuck that differed from all published sequences and from each other, and did not amplify with conventional primers for T. vivax. CONCLUSIONS/SIGNIFICANCE: Wildlife carries a wide range of trypanosome species. The failure of the diverse T. vivax in this study to amplify with conventional primers suggests that T. vivax may have been under-diagnosed in Tanzania. Since conventional species-specific primers may not amplify all trypanosomes of interest, the use of ITS PCR primers followed by sequencing is a valuable approach to investigate diversity of trypanosome infections in wildlife; amplification of sequences outside the T. brucei clade raises concerns regarding ITS primer specificity for wildlife samples if sequence confirmation is not also undertaken.

  9. Tsetse elimination: its interest and feasibility in the historical sleeping sickness focus of Loos islands, Guinea

    Directory of Open Access Journals (Sweden)

    Kagbadouno M.

    2009-03-01

    Full Text Available Guinea is the West African country which is currently the most prevalent for sleeping sickness. The littoral area is the region where most of the recent sleeping sickness cases have been described, especially the mangrove sleeping sickness foci of Dubreka and Boffa where Glossina palpalis gambiensis is the vector. Loos islands constitute a small archipelago 5 km apart from the capital, Conakry. Medical, animal, and entomological surveys were implemented in these islands in Oct-Nov 2006. No pathogenic trypanosomes were found in these surveys. The locally very high tsetse densities (up to more than 100 tsetse/trap/day linked to pig rearing, constitute a high potential risk for humans (taking into account populations movements with neighboring active sleeping sickness foci of the Guinea littoral, and the history of sleeping sickness on these islands, and for the economically important pig rearing, as well as a danger for tourism. This situation, associated to the possibility of elimination of these tsetse populations due to low possibility of reinvasion, led the National Control Program to launch a tsetse elimination project following an “area wide” strategy for the first time in West Africa, which participates in the global objective of the PATTEC (Pan African Tsetse and Trypanosomosis Eradication Campaign.

  10. A pilot study to delimit tsetse target populations in Zimbabwe.

    Directory of Open Access Journals (Sweden)

    Gerald Chikowore

    2017-05-01

    Full Text Available Tsetse (Glossina sensu stricto are cyclical vectors of human and animal trypanosomoses, that are presently targeted by the Pan African Tsetse and Trypanosomiasis Eradication Campaign (PATTEC coordinated by the African Union. In order to achieve effective control of tsetse, there is need to produce elaborate plans to guide intervention programmes. A model intended to aid in the planning of intervention programmes and assist a fuller understanding of tsetse distribution was applied, in a pilot study in the Masoka area, Mid-Zambezi valley in Zimbabwe, and targeting two savannah species, Glossina morsitans morsitans and Glossina pallidipes.The field study was conducted between March and December 2015 in 105 sites following a standardized grid sampling frame. Presence data were used to study habitat suitability of both species based on climatic and environmental data derived from MODIS and SPOT 5 satellite images. Factors influencing distribution were studied using an Ecological Niche Factor Analysis (ENFA whilst habitat suitability was predicted using a Maximum Entropy (MaxEnt model at a spatial resolution of 250 m. Area Under the Curve (AUC, an indicator of model performance, was 0.89 for G. m. morsitans and 0.96 for G. pallidipes. We then used the predicted suitable areas to calculate the probability that flies were really absent from the grid cells where they were not captured during the study based on a probability model using a risk threshold of 0.05. Apart from grid cells where G. m. morsitans and G. pallidipes were captured, there was a high probability of presence in an additional 128 km2 and 144 km2 respectively.The modelling process promised to be useful in optimizing the outputs of presence/absence surveys, allowing the definition of tsetse infested areas with improved accuracy. The methodology proposed here can be extended to all the tsetse infested parts of Zimbabwe and may also be useful for other PATTEC national initiatives in other

  11. The use of aerial spraying to eliminate tsetse from the Okavango Delta of Botswana.

    Science.gov (United States)

    Kgori, P M; Modo, S; Torr, S J

    2006-10-01

    In Botswana, 16,000 km(2) of the Okavango Delta were aerial sprayed five times with deltamethrin, applied at 0.26-0.3g/ha, to control Glossina morsitans centralis Machado (Diptera: Glossinidae) over a period of approximately 8 weeks. The northern half of the Delta (7180 km(2)) was sprayed in June-September 2001 and the southern half (8720 km(2)) in May-August 2002. A barrier (mean width approximately 10 km) of 12,000 deltamethrin-treated targets was deployed at the interface of these two blocks to prevent tsetse from invading from the southern to the northern block. Prior to spraying, the mean catches of tsetse from man fly-rounds were 44.6 round/day in the northern block and 101 in the southern. Between September 2002 and November 2005, surveys ( approximately 820 daily fly-rounds and approximately 2050 trap-days) in the northern and southern blocks failed to detect tsetse. Simulations of tsetse populations suggest that while spraying operations can reduce tsetse populations to levels that are difficult to detect by standard survey techniques, such populations will recover to densities >100 tsetse/km(2) after 1000 days, at which density there is a very high probability (>0.999) that the survey methods will catch at least one fly. Since none was caught, it is argued that tsetse have been eliminated from the Delta. The particular success of this operation in comparison to the 18 aerial spraying operations conducted in the Delta prior to 2001 is attributed to the application of an adequate dose of insecticide, the use of a GPS-based navigation system to ensure even application of insecticide, and the large size and spatial arrangement of the spray blocks coupled with the use of a barrier of targets which prevented tsetse from re-invading the northern sprayed block before the southern one was treated.

  12. The PARP promoter of Trypanosoma brucei is developmentally regulated in a chromosomal context

    DEFF Research Database (Denmark)

    Biebinger, S; Rettenmaier, S; Flaspohler, J

    1996-01-01

    African trypanosomes are extracellular protozoan parasites that are transmitted from one mammalian host to the next by tsetse flies. Bloodstream forms express variant surface glycoprotein (VSG); the tsetse fly (procyclic) forms express instead the procyclic acidic repetitive protein (PARP). PARP ...

  13. Prospects for area-wide integrated control of tsetse flies (Diptera:Glossinidae and trypanosomosis in sub-Saharan Africa Perspectivas para el control integrado abarcativo del área de moscas tse-tsé (Diptera: Glossinidae y la tripanosomiasis en el África sub-Sahariana

    Directory of Open Access Journals (Sweden)

    Marc J.B. Vreysen

    2006-07-01

    Full Text Available Countries in sub-Saharan Africa are among the least developed in the world and hunger and poverty remains widespread in most of the rural communities. Reducing hunger and chronic under nourishment through the introduction of productive livestock as a source of traction and manure for crop production, transport, milk and meat is deemed to be a fundamental first step towards better rural development. The presence of the tsetse fly in one third of the African continent and the disease trypanosomosis it transmits is considered the major barrier to the development of productive livestock. Despite the yearly administration of 35 million doses of trypanocidal drugs (at US$ 1 per dose, African farmers lose 3 million cattle every year to the disease and annual direct economic losses are estimated at US$ 600 to 1200 million. Tsetse flies mainly affect the rural poor and are rightfully considered 'a root cause of poverty ' in Africa . The most desirable way of containing the disease trypanosomosis is undoubtedly the elimination of entire populations of the vector from delimited geographical areas using an integration of various control tactics, i.e. an areawide integrated pest management (AW-IPM approach. Efficient methods to suppress or even eliminate tsetse populations have been available for the last 50 years and are mostly based on the use of insecticides or entail devices that attract and kill. Nevertheless, despite gigantic efforts in the past century, there are only a few examples where the elimination of tsetse flies has proven to be sustainable, e.g. the elimination of Glossina pallidipes Austen from South Africa in the 1950 's using mainly aerial spraying of residual insecticides or the creation of a zone free of Glossina austeni Newstead on Unguja Island of Zanzibar (1994-1997 through the integration of various control tactics including the release of sterile insects. The decentralisation of the tsetse control offices resulting in a shift from

  14. The prevalence of African animal trypanosomoses and tsetse presence in Western Senegal

    International Nuclear Information System (INIS)

    Seck, M.T.; Bouyer, J.; Sall, B.; Bengaly, Z.; Vreysen, M.J.B.

    2010-01-01

    In 2005, the Government of Senegal initiated a tsetse eradication campaign in the Niayes and La Petite Côte aiming at the removal of African Animal Trypanosomosis (AAT), which is one of the main constraints to the development of more effective cattle production systems. The target area has particular meteorological and ecological characteristics that provide great potential for animal production, but it is unfortunately still infested by the riverine tsetse species Glossina palpalis gambiensis Vanderplank (Diptera: Glossinidae). The tsetse project in Senegal has adopted an area- wide integrated pest management (AW-IPM) approach that targets the entire tsetse population within a delimited area. During the first phase of the programme, a feasibility study was conducted that included the collection of entomological, veterinary, population genetics, environmental and socio-economic baseline data. This paper presents the parasitological and serological prevalence data of AAT in cattle residing inside and outside the tsetse-infested areas of the target zone prior to the control effort. At the herd level, a mean parasitological prevalence of 2.4 % was observed, whereas a serological prevalence of 28.7 %, 4.4 %, and 0.3 % was obtained for Trypanosoma vivax, T. congolense and T. brucei brucei, respectively. The observed infection risk was 3 times higher for T. congolense and T. vivax in the tsetse-infested than in the assumed tsetse-free areas. Moreover, AAT prevalence decreased significantly with distance from the nearest tsetse captured which indicated that cyclical transmission of the parasites by tsetse was predominant over mechanical transmission by numerous other biting flies present. The importance of these results for the development of a control strategy for the planned AW-IPM campaign is discussed. (Authors) [fr

  15. Developing Product Quality Control for Standardization of Tsetse Mass Production. Working Material

    International Nuclear Information System (INIS)

    2002-01-01

    The recent Pan-African Tsetse and Trypanosomosis Eradication Campaign (PATTEC) provides a mechanism within which SIT will be one of the major components of an integrated areawide approach to the establishment of tsetse fly-free areas. Currently world-wide tsetse production is 1/40 of the projected requirement in 2006. To achieve this objective it is essential that quality control (QC) measures suitable for the expanded production be in place. Therefore, improved QC methodology has become a top priority. Improvements in QC methodology will help to ensure the attainment of these production goals and improve quality of rearing, minimize production costs and generate trained QC and production staff required to successfully produce flies and monitor their quality and suitability for release. The proposed CRP is designed to address these issues.

  16. Treating cattle to protect people? Impact of footbath insecticide treatment on tsetse density in Chad.

    Science.gov (United States)

    Ndeledje, Noël; Bouyer, Jérémy; Stachurski, Frédéric; Grimaud, Patrice; Belem, Adrien Marie Gaston; Molélé Mbaïndingatoloum, Fidèle; Bengaly, Zakaria; Oumar Alfaroukh, Idriss; Cecchi, Guiliano; Lancelot, Renaud

    2013-01-01

    In Chad, several species of tsetse flies (Genus: Glossina) transmit African animal trypanosomoses (AAT), which represents a major obstacle to cattle rearing, and sleeping sickness, which impacts public health. After the failure of past interventions to eradicate tsetse, the government of Chad is now looking for other approaches that integrate cost-effective intervention techniques, which can be applied by the stake holders to control tsetse-transmitted trypanosomoses in a sustainable manner. The present study thus attempted to assess the efficacy of restricted application of insecticides to cattle leg extremities using footbaths for controlling Glossina m. submorsitans, G. tachinoides and G. f. fuscipes in southern Chad. Two sites were included, one close to the historical human African trypanosomiasis (HAT) focus of Moundou and the other to the active foci of Bodo and Moissala. At both sites, a treated and an untreated herd were compared. In the treatment sites, cattle were treated on a regular basis using a formulation of deltamethrin 0.005% (67 to 98 cattle were treated in one of the sites and 88 to 102 in the other one). For each herd, tsetse densities were monthly monitored using 7 biconical traps set along the river and beside the cattle pen from February to December 2009. The impact of footbath treatment on tsetse populations was strong (p cattle, this technology should be used under controlled conditions, in order to avoid the development of insecticide and acaricide resistance in tsetse and tick populations, respectively.

  17. Tsetse diversity and abundance in Southern Burkina Faso in relation with the vegetation.

    Science.gov (United States)

    Rayaisse, J-B; Salou, E; Kiema, S; Akoudjin, M; Kaba, D; Kagbadouno, M; Djohan, V; Camara, M; Dayo, G-K; Courtin, F; Solano, P; Bouyer, J

    2015-09-01

    The increase of human population, combined with climatic changes, contributed to the modification of spatial distribution of tsetse flies, main vector of trypanosomiasis. In order to establish and compare tsetse presence and their relationship with vegetation, entomological survey was performed using biconical traps deployed in transects, simultaneously with phyto-sociological study, on the Comoe river at its source in the village of Moussodougou, and in the semi-protected area of Folonzo, both localities in Southern Burkina Faso. In Folonzo, the survey revealed a diversity of tsetse with 4 species occurring with apparent densities as follows: Glossina tachinoides (8.9 tsetse/trap/day); G. morsitans submorsitans (1.8 tsetse/trap/day); G. palpalis gambiensis (0.6/trap/day) and G. medicorum (0.15 tsetse/trap/day). In Moussodougou, a highly anthropized area, mainly G. p. gambiensis was caught (2.06 tsetse/trap/day), and rarely G. tachinoides. The phyto-sociological study allowed discrimination of 6 types of vegetation in both localities, with 3 concordances that are riparian forest, shrubby and woody savannah. In Moussodougou, all tsetse were caught in the riparian forest. That was also the case in Folonzo where a great proportion (95 to 99 % following the season) of G. p. gambiensis and G. tachinoides were caught in the gallery, while G. m. submorsitans was occurring as well in the gallery as in the savannah, and G. medicorum in the forest gallery. This study showed that although G. tachinoides and G.p. gambiensis are both riparian, they do not have the same preference in terms of biotope.

  18. Trypanosomes of some Fennoscandian birds

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    Gordon F. Bennett

    1994-12-01

    Full Text Available Linear measurements and derived indices of trypanosomes from species of Fennoscandian birds were compared to those reported form Trypanosoma avium, T. everetti, T. ontarioensis and T. paddae. The trypanosomes encountered in the Fennoscandian birds were identified as T. avium from Tengmalm's owl Aegolius funereus and the pied flycatcher Ficedula hypoleuca, T. everetti from the great tit Parus major and collared flycatcher F. albicollis and T. ontarioensis from the collared flycatcher; T. paddae was not seen.

  19. Tsetse Control and Gambian Sleeping Sickness; Implications for Control Strategy.

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    Inaki Tirados

    Full Text Available Gambian sleeping sickness (human African trypanosomiasis, HAT outbreaks are brought under control by case detection and treatment although it is recognised that this typically only reaches about 75% of the population. Vector control is capable of completely interrupting HAT transmission but is not used because it is considered too expensive and difficult to organise in resource-poor settings. We conducted a full scale field trial of a refined vector control technology to determine its utility in control of Gambian HAT.The major vector of Gambian HAT is the tsetse fly Glossina fuscipes which lives in the humid zone immediately adjacent to water bodies. From a series of preliminary trials we determined the number of tiny targets required to reduce G. fuscipes populations by more than 90%. Using these data for model calibration we predicted we needed a target density of 20 per linear km of river in riverine savannah to achieve >90% tsetse control. We then carried out a full scale, 500 km2 field trial covering two HAT foci in Northern Uganda to determine the efficacy of tiny targets (overall target density 5.7/km2. In 12 months, tsetse populations declined by more than 90%. As a guide we used a published HAT transmission model and calculated that a 72% reduction in tsetse population is required to stop transmission in those settings.The Ugandan census suggests population density in the HAT foci is approximately 500 per km2. The estimated cost for a single round of active case detection (excluding treatment, covering 80% of the population, is US$433,333 (WHO figures. One year of vector control organised within the country, which can completely stop HAT transmission, would cost US$42,700. The case for adding this method of vector control to case detection and treatment is strong. We outline how such a component could be organised.

  20. Treating cattle to protect people? Impact of footbath insecticide treatment on tsetse density in Chad.

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    Noël Ndeledje

    Full Text Available BACKGROUND: In Chad, several species of tsetse flies (Genus: Glossina transmit African animal trypanosomoses (AAT, which represents a major obstacle to cattle rearing, and sleeping sickness, which impacts public health. After the failure of past interventions to eradicate tsetse, the government of Chad is now looking for other approaches that integrate cost-effective intervention techniques, which can be applied by the stake holders to control tsetse-transmitted trypanosomoses in a sustainable manner. The present study thus attempted to assess the efficacy of restricted application of insecticides to cattle leg extremities using footbaths for controlling Glossina m. submorsitans, G. tachinoides and G. f. fuscipes in southern Chad. METHODOLOGY/PRINCIPAL FINDINGS: Two sites were included, one close to the historical human African trypanosomiasis (HAT focus of Moundou and the other to the active foci of Bodo and Moissala. At both sites, a treated and an untreated herd were compared. In the treatment sites, cattle were treated on a regular basis using a formulation of deltamethrin 0.005% (67 to 98 cattle were treated in one of the sites and 88 to 102 in the other one. For each herd, tsetse densities were monthly monitored using 7 biconical traps set along the river and beside the cattle pen from February to December 2009. The impact of footbath treatment on tsetse populations was strong (p < 10(-3 with a reduction of 80% in total tsetse catches by the end of the 6-month footbath treatment. CONCLUSIONS/SIGNIFICANCE: The impact of footbath treatment as a vector control tool within an integrated strategy to manage AAT and HAT is discussed in the framework of the "One Health" concept. Like other techniques based on the treatment of cattle, this technology should be used under controlled conditions, in order to avoid the development of insecticide and acaricide resistance in tsetse and tick populations, respectively.

  1. Developing photoreceptor-based models of visual attraction in riverine tsetse, for use in the engineering of more-attractive polyester fabrics for control devices.

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    Roger D Santer

    2017-03-01

    Full Text Available Riverine tsetse transmit the parasites that cause the most prevalent form of human African trypanosomiasis, Gambian HAT. In response to the imperative for cheap and efficient tsetse control, insecticide-treated 'tiny targets' have been developed through refinement of tsetse attractants based on blue fabric panels. However, modern blue polyesters used for this purpose attract many less tsetse than traditional phthalogen blue cottons. Therefore, colour engineering polyesters for improved attractiveness has great potential for tiny target development. Because flies have markedly different photoreceptor spectral sensitivities from humans, and the responses of these photoreceptors provide the inputs to their visually guided behaviours, it is essential that polyester colour engineering be guided by fly photoreceptor-based explanations of tsetse attraction. To this end, tsetse attraction to differently coloured fabrics was recently modelled using the calculated excitations elicited in a generic set of fly photoreceptors as predictors. However, electrophysiological data from tsetse indicate the potential for modified spectral sensitivities versus the generic pattern, and processing of fly photoreceptor responses within segregated achromatic and chromatic channels has long been hypothesised. Thus, I constructed photoreceptor-based models explaining the attraction of G. f. fuscipes to differently coloured tiny targets recorded in a previously published investigation, under differing assumptions about tsetse spectral sensitivities and organisation of visual processing. Models separating photoreceptor responses into achromatic and chromatic channels explained attraction better than earlier models combining weighted photoreceptor responses in a single mechanism, regardless of the spectral sensitivities assumed. However, common principles for fabric colour engineering were evident across the complete set of models examined, and were consistent with earlier

  2. Social motility in african trypanosomes.

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    Michael Oberholzer

    2010-01-01

    Full Text Available African trypanosomes are devastating human and animal pathogens that cause significant human mortality and limit economic development in sub-Saharan Africa. Studies of trypanosome biology generally consider these protozoan parasites as individual cells in suspension cultures or in animal models of infection. Here we report that the procyclic form of the African trypanosome Trypanosoma brucei engages in social behavior when cultivated on semisolid agarose surfaces. This behavior is characterized by trypanosomes assembling into multicellular communities that engage in polarized migrations across the agarose surface and cooperate to divert their movements in response to external signals. These cooperative movements are flagellum-mediated, since they do not occur in trypanin knockdown parasites that lack normal flagellum motility. We term this behavior social motility based on features shared with social motility and other types of surface-induced social behavior in bacteria. Social motility represents a novel and unexpected aspect of trypanosome biology and offers new paradigms for considering host-parasite interactions.

  3. Knowledge and attitudes of cattle owners regarding trypanosomosis control in tsetse-infested areas of Uganda

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    J.W. Magona

    2004-06-01

    Full Text Available Apilot survey using a structured questionnaire was conducted in Tororo and Busia districts of Uganda on the knowledge and attitudes of cattle owners regarding tsetse fly and trypanosomosis control, in order to understand factors that hindered their full participation. A total of 81 cattle owners was randomly selected and interviewed, of which 92.5 % were aware of tsetse flies and trypanosomosis and 87.6%recognised animal trypanosomosis as a problem in the area. Most cattle owners were aware of tsetse fly trapping (76.5 %, isometamidium chloride use (55.5 %, diminazene aceturate use (48 % and pour-on applications (18.5 %. However, knowledge did not coincide with the application of control measures. Despite the widespread awareness, tsetse fly trapping and pour-on applications were used by only a small percentage of cattle owners (7.5 % applied tsetse fly trapping while 76.5%were aware of it; 1.2%applied pour-oninsecticides while 18.5%were aware of them. Differences between awareness and application were highly significant for tsetse fly trapping (c2=67.8, d.f.=1, P<0.001 and pour-on applications (c2=10.8, d.f.=1, P<0.05, but not for isometamidium chloride use (c2 = 0.08, d.f. = 1, P = 0.77 and diminazene aceturate use (c2 = 0.00, d.f. = 1, P = 1.00. Most cattle owners (97.5 % were willing to participate in future control programmes, but preferred participating on a group basis (85.2 % rather than individually (14.8 %. The 4 most favoured control options in order of importance were: fly traps supplied by the government and maintained by cattle owners; contribution of labour by cattle owners for trap deployment; self-financing of trypanocidal drugs and self-financing of pour-on insecticide. The control options that should be selected in order to elicit full participation by cattle owners are discussed.

  4. The burden and spatial distribution of bovine African trypanosomes in small holder crop-livestock production systems in Tororo District, south-eastern Uganda.

    Science.gov (United States)

    Muhanguzi, Dennis; Picozzi, Kim; Hattendorf, Jan; Thrusfield, Michael; Kabasa, John David; Waiswa, Charles; Welburn, Susan Christina

    2014-12-23

    African animal trypanosomiasis (AAT) is considered to be one of the greatest constraints to livestock production and livestock-crop integration in most African countries. South-eastern Uganda has suffered for more than two decades from outbreaks of zoonotic Human African Trypanosomiasis (HAT), adding to the burden faced by communities from AAT. There is insufficient AAT and HAT data available (in the animal reservoir) to guide and prioritize AAT control programs that has been generated using contemporary, sensitive and specific molecular techniques. This study was undertaken to evaluate the burden that AAT presents to the small-scale cattle production systems in south-eastern Uganda. Randomised cluster sampling was used to select 14% (57/401) of all cattle containing villages across Tororo District. Blood samples were taken from all cattle in the selected villages between September-December 2011; preserved on FTA cards and analysed for different trypanosomes using a suite of molecular techniques. Generalized estimating equation and Rogen-Gladen estimator models were used to calculate apparent and true prevalences of different trypanosomes while intra cluster correlations were estimated using a 1-way mixed effect analysis of variance (ANOVA) in R statistical software version 3.0.2. The prevalence of all trypanosome species in cattle was 15.3% (95% CI; 12.2-19.1) while herd level trypanosome species prevalence varied greatly between 0-43%. Trypanosoma vivax (17.4%, 95% CI; 10.6-16.8) and Trypanosoma brucei rhodesiense (0.03%) were respectively, the most, and least prevalent trypanosome species identified. The prevalence of bovine trypanosomes in this study indicates that AAT remains a significant constraint to livestock health and livestock production. There is need to implement tsetse and trypanosomiasis control efforts across Tororo District by employing effective, cheap and sustainable tsetse and trypanosomiasis control methods that could be integrated in the

  5. Morphological and Phylogenetic Description of Trypanosoma noyesi sp. nov.: An Australian Wildlife Trypanosome within the T. cruzi Clade.

    Science.gov (United States)

    Botero, Adriana; Cooper, Crystal; Thompson, Craig K; Clode, Peta L; Rose, Karrie; Thompson, R C Andrew

    2016-11-01

    A number of trypanosome isolates from Australian marsupials are within the clade containing the human pathogen Trypanosoma cruzi. Trypanosomes within this clade are thought to have diverged from a common ancestral bat trypanosome. Here, we characterise Trypanosoma noyesi sp. nov. isolated from the critically endangered woylie (Bettongia pencillata) using phylogenetic inferences from three gene regions (18S rDNA, gGAPDH, and CytB) coupled with morphological and behavioural observations in vitro. We also investigated potential vectors and the presence of T. noyesi in the grey-headed flying fox (Pteropus poliocephalus). Phylogenetic analysis revealed T. noyesi and similar genotypes grouped at the periphery of the T. cruzi clade. T. noyesi is morphologically distinct both from other species of Australian trypanosomes and those within the T. cruzi clade. Although trypanosomes were not observed in the digestive tract of ectoparasites and biting flies collected from T. noyesi infected marsupials, tabanid and biting midges tested positive for T. noyesi DNA, indicating they are vector candidates. Tissues from flying foxes were negative for T. noyesi. This study provides novel information on the morphology and genetic variability of an Australian trypanosome within the T. cruzi clade. Copyright © 2016 The Author(s). Published by Elsevier GmbH.. All rights reserved.

  6. Patterns of development of trypanosomes and related parasites in insect hosts

    International Nuclear Information System (INIS)

    Molyneux, D.H.

    1980-01-01

    The trypanosome parasites of man and his domestic animals and the closely related Leishmania parasites pathogenic to man have widely different patterns of development in their various vector species. However, certain common features of the development of these parasites are exhibited when they develop in insects. These features include temporary storage in the crop; transformation from mammalian forms to primary multiplicative forms; avoidance of digestion by host enzymes; association with the peritrophic membrane; establishment of infection and, associated with this, attachment and colonization of surfaces; migration to different areas of gut to sites of development; formation of a reservoir of forms to ensure sufficient organisms are available for transformation to forms infective to the vertebrate host; subsequent transmission by bite or by contamination of host surfaces. The different features of development outlined above are discussed in relation to trypanosomes and related parasites. The utilization of different model systems for use in this type of study are discussed in view of difficulties in obtaining adequate numbers of infected flies (e.g. Glossina, or sandflies), and the costs and frequent problems of maintaining such colonies. Recent studies (1) on Glossina-transmitted Salivarian trypanosomes are described which indicate possible behavioural differences between infected and uninfected flies that have a bearing on epidemiology and epizootiology; (2) on the fluid mechanics of the Glossina labrum infected and uninfected with trypanosomes; and (3) on attachment of trypanosomes and Leishmania to insect gut wall surfaces. (author)

  7. Trypanosomiasis in an Australian little red flying fox (Pteropus scapulatus).

    Science.gov (United States)

    Mackie, J T; Stenner, R; Gillett, A K; Barbosa, A; Ryan, U; Irwin, P J

    2017-07-01

    An adult female Australian little red flying fox (Pteropus scapulatus) presented with icterus and anaemia. Examination of a blood smear revealed numerous trypanosomes 20.4-30.8 µm long with tapered ends. Necropsy and histological findings were consistent with trypanosome infection of lymphoid tissue and intravascular haemolysis. Sequence and phylogenetic analysis demonstrated this trypanosome species to be genetically distinct and most similar to Trypanosoma minasense and Trypanosoma rangeli (with a genetic distance of 1% at the 18S rRNA locus for both). To the authors' knowledge this is the first report of a trypanosome infection associated with clinical disease in bats. © 2017 Australian Veterinary Association.

  8. Field validation of antibody ELISA's for diagnosis of bovine trypanosomosis and monitoring the efficacy of a tsetse and trypanosomosis control campaign in the agropastoral zone of Yale, Burkina Faso

    International Nuclear Information System (INIS)

    Bengaly, Z.; Sidibe, I.; Duvallet, G.

    2000-01-01

    Four trypanosomal antibody-detection-ELISA's systems based on the use of either native or denatured crude lysate antigens prepared from in-vitro propagated T. congolense bloodstream forms and in-vitro propagated T. vivax epimastigote forms, have been validated for their diagnostic performance and their utility for monitoring the efficacy of a tsetse and trypanosomosis control program. For that purpose, 600 samples of which 34 were parasite-positive, collected at different intervals in an area where tsetse eradication was implemented, were analysed. In addition, 200 sera from non-infected cattle in tsetse-free-area were also analysed. Except the native T. vivax antigen which showed high background and unreliable data, the three other ELISA assays were found acceptable for trypanosomal antibody detection. The cut-off values determined by doubling the mean of the known negative population were slightly lower than those obtained by visual analysis. The sensitivity ranged from 91% to 100% while the specificity was between 95% and 98% depending on the assay system used. For monitoring the efficacy of the tsetse control program, the other three antigens were found suitable but only denatured T. vivax antigens showed a significant decrease of the seroprevalence of T. vivax infection between the beginning and the end of the control program. The native and denatured T. congolense assay systems suggested that T. congolense infections might occur at a chronic stage and were being controlled by the cattle. (author)

  9. Adding tsetse control to medical activities contributes to decreasing transmission of sleeping sickness in the Mandoul focus (Chad.

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    Mahamat Hissene Mahamat

    2017-07-01

    Full Text Available Gambian sleeping sickness or HAT (human African trypanosomiasis is a neglected tropical disease caused by Trypanosoma brucei gambiense transmitted by riverine species of tsetse. A global programme aims to eliminate the disease as a public health problem by 2020 and stop transmission by 2030. In the South of Chad, the Mandoul area is a persistent focus of Gambian sleeping sickness where around 100 HAT cases were still diagnosed and treated annually until 2013. Pre-2014, control of HAT relied solely on case detection and treatment, which lead to a gradual decrease in the number of cases of HAT due to annual screening of the population.Because of the persistence of transmission and detection of new cases, we assessed whether the addition of vector control to case detection and treatment could further reduce transmission and consequently, reduce annual incidence of HAT in Mandoul. In particular, we investigated the impact of deploying 'tiny targets' which attract and kill tsetse. Before tsetse control commenced, a census of the human population was conducted and their settlements mapped. A pre-intervention survey of tsetse distribution and abundance was implemented in November 2013 and 2600 targets were deployed in the riverine habitats of tsetse in early 2014, 2015 and 2016. Impact on tsetse and on the incidence of sleeping sickness was assessed through nine tsetse monitoring surveys and four medical surveys of the human population in 2014 and 2015. Mathematical modelling was used to assess the relative impact of tsetse control on incidence compared to active and passive screening.The census indicated that a population of 38674 inhabitants lived in the vicinity of the Mandoul focus. Within this focus in November 2013, the vector is Glossina fuscipes fuscipes and the mean catch of tsetse from traps was 0.7 flies/trap/day (range, 0-26. The catch of tsetse from 44 sentinel biconical traps declined after target deployment with only five tsetse being

  10. Where, when and why do tsetse contact humans? Answers from studies in a national park of Zimbabwe.

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    Stephen J Torr

    Full Text Available BACKGROUND: Sleeping sickness, also called human African trypanosomiasis, is transmitted by the tsetse, a blood-sucking fly confined to sub-Saharan Africa. The form of the disease in West and Central Africa is carried mainly by species of tsetse that inhabit riverine woodland and feed avidly on humans. In contrast, the vectors for the East and Southern African form of the disease are usually savannah species that feed mostly on wild and domestic animals and bite humans infrequently, mainly because the odours produced by humans can be repellent. Hence, it takes a long time to catch many savannah tsetse from people, which in turn means that studies of the nature of contact between savannah tsetse and humans, and the ways of minimizing it, have been largely neglected. METHODOLOGY/PRINCIPAL FINDINGS: The savannah tsetse, Glossina morsitans morsitans and G. pallidipes, were caught from men in the Mana Pools National park of Zimbabwe. Mostly the catch consisted of young G. m. morsitans, with little food reserve. Catches were increased by 4-8 times if the men were walking, not stationary, and increased about ten times more if they rode on a truck at 10 km/h. Catches were unaffected if the men used deodorant or were baited with artificial ox odour, but declined by about 95% if the men were with an ox. Surprisingly, men pursuing their normal daily activities were bitten about as much when in or near buildings as when in woodland. Catches from oxen and a standard ox-like trap were poor indices of the number and physiological state of tsetse attacking men. CONCLUSION/SIGNIFICANCE: The search for new strategies to minimize the contact between humans and savannah tsetse should focus on that occurring in buildings and vehicles. There is a need to design a man-like trap to help to provide an index of sleeping sickness risk.

  11. Water vapour and heat combine to elicit biting and biting persistence in tsetse.

    Science.gov (United States)

    Chappuis, Charles J F; Béguin, Steve; Vlimant, Michèle; Guerin, Patrick M

    2013-08-19

    Tsetse flies are obligatory blood feeders, accessing capillaries by piercing the skin of their hosts with the haustellum to suck blood. However, this behaviour presents a considerable risk as landing flies are exposed to predators as well as the host's own defense reactions such as tail flicking. Achieving a successful blood meal within the shortest time span is therefore at a premium in tsetse, so feeding until replete normally lasts less than a minute. Biting in blood sucking insects is a multi-sensory response involving a range of physical and chemical stimuli. Here we investigated the role of heat and humidity emitted from host skin on the biting responses of Glossina pallidipes, which to our knowledge has not been fully studied in tsetse before. The onset and duration of the biting response of G. pallidipes was recorded by filming movements of its haustellum in response to rapid increases in temperature and/or relative humidity (RH) following exposure of the fly to two airflows. The electrophysiological responses of hygroreceptor cells in wall-pore sensilla on the palps of G. pallidipes to drops in RH were recorded using tungsten electrodes and the ultra-structure of these sensory cells was studied by scanning and transmission electron microscopy. Both latency and proportion of tsetse biting are closely correlated to RH when accompanied by an increase of 13.1°C above ambient temperature but not for an increase of just 0.2°C. Biting persistence, as measured by the number of bites and the time spent biting, also increases with increasing RH accompanied by a 13.1°C increase in air temperature. Neurones in wall-pore sensilla on the palps respond to shifts in RH. Our results show that temperature acts synergistically with humidity to increase the rapidity and frequency of the biting response in tsetse above the levels induced by increasing temperature or humidity separately. Palp sensilla housing hygroreceptor cells, described here for the first time in tsetse

  12. The effective eradication and control strategies for tsetse and ...

    African Journals Online (AJOL)

    I conducted an extensive literature review on the effective tsetse and trypanosomiasis eradication method strategies in Africa in 2010 as i embarked on my research that coincided with the formulation of the Tsetse and Trypanosomiasis Eradication Strategy for Kenya spearheaded by Pan African Tsetse and Trypanosomiasis ...

  13. Phylogeography and Population Structure of Glossina fuscipes fuscipes in Uganda: Implications for Control of Tsetse

    Science.gov (United States)

    Beadell, Jon S.; Hyseni, Chaz; Abila, Patrick P.; Azabo, Rogers; Enyaru, John C. K.; Ouma, Johnson O.; Mohammed, Yassir O.; Okedi, Loyce M.; Aksoy, Serap; Caccone, Adalgisa

    2010-01-01

    Background Glossina fuscipes fuscipes, a riverine species of tsetse, is the main vector of both human and animal trypanosomiasis in Uganda. Successful implementation of vector control will require establishing an appropriate geographical scale for these activities. Population genetics can help to resolve this issue by characterizing the extent of linkage among apparently isolated groups of tsetse. Methodology/Principal Findings We conducted genetic analyses on mitochondrial and microsatellite data accumulated from approximately 1000 individual tsetse captured in Uganda and neighboring regions of Kenya and Sudan. Phylogeographic analyses suggested that the largest scale genetic structure in G. f. fuscipes arose from an historical event that divided two divergent mitochondrial lineages. These lineages are currently partitioned to northern and southern Uganda and co-occur only in a narrow zone of contact extending across central Uganda. Bayesian assignment tests, which provided evidence for admixture between northern and southern flies at the zone of contact and evidence for northerly gene flow across the zone of contact, indicated that this structure may be impermanent. On the other hand, microsatellite structure within the southern lineage indicated that gene flow is currently limited between populations in western and southeastern Uganda. Within regions, the average FST between populations separated by less than 100 km was less than ∼0.1. Significant tests of isolation by distance suggested that gene flow is ongoing between neighboring populations and that island populations are not uniformly more isolated than mainland populations. Conclusions/Significance Despite the presence of population structure arising from historical colonization events, our results have revealed strong signals of current gene flow within regions that should be accounted for when planning tsetse control in Uganda. Populations in southeastern Uganda appeared to receive little gene flow

  14. Tsetse immune system maturation requires the presence of obligate symbionts in larvae.

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    Brian L Weiss

    2011-05-01

    Full Text Available Beneficial microbial symbionts serve important functions within their hosts, including dietary supplementation and maintenance of immune system homeostasis. Little is known about the mechanisms that enable these bacteria to induce specific host phenotypes during development and into adulthood. Here we used the tsetse fly, Glossina morsitans, and its obligate mutualist, Wigglesworthia glossinidia, to investigate the co-evolutionary adaptations that influence the development of host physiological processes. Wigglesworthia is maternally transmitted to tsetse's intrauterine larvae through milk gland secretions. We can produce flies that lack Wigglesworthia (Gmm(Wgm- yet retain their other symbiotic microbes. Such offspring give rise to adults that exhibit a largely normal phenotype, with the exception being that they are reproductively sterile. Our results indicate that when reared under normal environmental conditions Gmm(Wgm- adults are also immuno-compromised and highly susceptible to hemocoelic E. coli infections while age-matched wild-type individuals are refractory. Adults that lack Wigglesworthia during larval development exhibit exceptionally compromised cellular and humoral immune responses following microbial challenge, including reduced expression of genes that encode antimicrobial peptides (cecropin and attacin, hemocyte-mediated processes (thioester-containing proteins 2 and 4 and prophenoloxidase, and signal-mediating molecules (inducible nitric oxide synthase. Furthermore, Gmm(Wgm- adults harbor a reduced population of sessile and circulating hemocytes, a phenomenon that likely results from a significant decrease in larval expression of serpent and lozenge, both of which are associated with the process of early hemocyte differentiation. Our results demonstrate that Wigglesworthia must be present during the development of immature progeny in order for the immune system to function properly in adult tsetse. This phenomenon provides

  15. Trypanosome transmission by Corethrella wirthi (Diptera: Chaoboridae) to the green treefrog, Hyla cinerea (Anura: Hylidae).

    Science.gov (United States)

    Johnson, R N; Young, D G; Butler, J F

    1993-09-01

    Seventy-two percent of 215 male green tree frog, Hyla cinerea (Schneider), captured in Alachua and Levy counties, FL, between April and mid-September 1978 and 1979 were infected with an undescribed Trypanosoma sp. None of the 31 female frogs captured concurrently was infected. Periodic sampling of the peripheral blood from the infected male frogs showed that the trypanosomes were present in high numbers only at night. Conspecific trypanosomes also were found in the mid and hind guts of female Corethrella wirthi Stone flies collected on or near male frogs in the field. Transmission of the parasite to uninfected frogs was demonstrated by exposure of male and female frogs to naturally infected flies and to parasites injected subdermally. This is the first report of parasite transmission by a species of Corethrella.

  16. The effect of trypanosome infection on a natural population of Glossina longipalpis Wiedemann (Diptera: Glossinidae) in Ivory Coast.

    Science.gov (United States)

    Ryan, L

    1984-12-01

    A population of Glossina longipalpis studied in the Southern Guinea savanna zone, Ivory Coast, showed marked differences between non-infected and infected females. Each fly was examined for age, reproductive condition, wear and tear, size and nutritional status. Infected flies were generally and sometimes significantly more active with lower fat reserves, residual bloodmeal and higher residual dry weight. Poorer nutritional condition may be due to energy metabolised by trypanosomes and possibly impaired feeding ability.

  17. Complex Interactions between Temperature and Relative Humidity on Water Balance of Adult Tsetse (Glossinidae, Diptera): Implications for Climate Change

    OpenAIRE

    Kleynhans, Elsje; Terblanche, John S.

    2011-01-01

    Insect water balance plays an important role in determining energy budgets, activity patterns, survival and population dynamics and, hence, geographic distribution. Tsetse (Glossina spp.) are important vectors of human and animal disease occupying a wide range of habitats in Africa and are notable for their desiccation resistance in xeric environments. Here, we measure water balance traits (water loss rate, body water content and body lipid content) in adult flies across a range of temperatur...

  18. Quantifying Heterogeneity in Host-Vector Contact: Tsetse (Glossina swynnertoni and G. pallidipes Host Choice in Serengeti National Park, Tanzania.

    Directory of Open Access Journals (Sweden)

    Harriet Auty

    Full Text Available Identifying hosts of blood-feeding insect vectors is crucial in understanding their role in disease transmission. Rhodesian human African trypanosomiasis (rHAT, also known as acute sleeping sickness is caused by Trypanosoma brucei rhodesiense and transmitted by tsetse flies. The disease is commonly associated with wilderness areas of east and southern Africa. Such areas hold a diverse range of species which form communities of hosts for disease maintenance. The relative importance of different wildlife hosts remains unclear. This study quantified tsetse feeding preferences in a wilderness area of great host species richness, Serengeti National Park, Tanzania, assessing tsetse feeding and host density contemporaneously.Glossina swynnertoni and G. pallidipes were collected from six study sites. Bloodmeal sources were identified through matching Cytochrome B sequences amplified from bloodmeals from recently fed flies to published sequences. Densities of large mammal species in each site were quantified, and feeding indices calculated to assess the relative selection or avoidance of each host species by tsetse.The host species most commonly identified in G. swynnertoni bloodmeals, warthog (94/220, buffalo (48/220 and giraffe (46/220, were found at relatively low densities (3-11/km2 and fed on up to 15 times more frequently than expected by their relative density. Wildebeest, zebra, impala and Thomson's gazelle, found at the highest densities, were never identified in bloodmeals. Commonly identified hosts for G. pallidipes were buffalo (26/46, giraffe (9/46 and elephant (5/46.This study is the first to quantify tsetse host range by molecular analysis of tsetse diet with simultaneous assessment of host density in a wilderness area. Although G. swynnertoni and G. pallidipes can feed on a range of species, they are highly selective. Many host species are rarely fed on, despite being present in areas where tsetse are abundant. These feeding patterns

  19. Complex interactions between temperature and relative humidity on water balance of adult tsetse (Glossinidae, Diptera: implications for climate change

    Directory of Open Access Journals (Sweden)

    Elsje eKleynhans

    2011-10-01

    Full Text Available Insect water balance plays an important role in determining energy budgets, activity patterns, survival and population dynamics and, hence, geographic distribution. Tsetse (Glossina spp. are important vectors of human and animal disease occupying a wide range of habitats in Africa and are notable for their desiccation resistance in xeric environments. Here, we measure water balance traits (water loss rate, body water content and body lipid content in adult flies across a range of temperature (20 – 30 °C and relative humidity (0 – 99 % combinations in four tsetse species from both xeric and mesic habitats. Water loss rates were significantly affected by measurement under different temperature and relative humidity combinations, while body water content, body lipid content and mass were less affected. Different effects of temperature and relative humidity within and among experimental conditions and species suggests cuticular permeability and saturation deficit are likely to be key factors in forecasting tsetse water balance responses to climate variability. These results provide support for mass–independent inter– and intra–specific variation in water loss rates and survival times. Therefore, water balance responses to variation in temperature and relative humidity are complex in Glossina, and this response varies within and among species, sub–groups and ecotypes in terms of both magnitude of effects and the direction of change. This complicates potential forecasting of tsetse distribution in the face of climate change.

  20. Complex Interactions between Temperature and Relative Humidity on Water Balance of Adult Tsetse (Glossinidae, Diptera): Implications for Climate Change.

    Science.gov (United States)

    Kleynhans, Elsje; Terblanche, John S

    2011-01-01

    Insect water balance plays an important role in determining energy budgets, activity patterns, survival, and population dynamics and, hence, geographic distribution. Tsetse (Glossina spp.) are important vectors of human and animal disease occupying a wide range of habitats in Africa and are notable for their desiccation resistance in xeric environments. Here, we measure water balance and related traits [water loss rate (WLR), body water content (BWC), body lipid content (BLC) and body mass] in adult flies across a range of temperature (20-30°C) and relative humidity (0-99%) combinations in four tsetse species from both xeric and mesic habitats. WLRs were significantly affected by measurement under different temperature and relative humidity combinations, while BWC, BLC, and body mass were less affected. These results provide support for mass-independent inter- and intra-specific variation in WLRs and survival times. Furthermore, water balance responses to variation in temperature and relative humidity are complex in Glossina, and this response varies within and among species, subgroups, and ecotypes in terms of both magnitude of effects and the direction of change. Different effects of temperature and relative humidity within and among experimental conditions and species suggests cuticular permeability and saturation deficit are likely to be key factors in forecasting tsetse water balance responses to climate variability. This complicates potential forecasting of tsetse distribution in the face of climate change.

  1. African animal trypanosomosis and tsetse control partnership ...

    African Journals Online (AJOL)

    Prominent clinical signs mentioned by the respondents included emaciation, rough hair coat, poor growth, anemia and loss of appetite. Majority (83%) of the respondents usually treat against trypanosomosis and other diseases. Viable option for African trypanosomes control is vector control. This control had been ...

  2. Fish trypanosomes from the Okavango Delta, Botswana.

    Science.gov (United States)

    Smit, Nico J; Van As, Jo G; Davies, Angela J

    2004-12-01

    During 2001 and 2002, blood smears from 37 of 120 fishes belonging to 10 species captured in the Okavango Delta region of Botswana, were found to harbour trypanosomes. These trypanosomes displayed differing staining properties, were morphometrically variable, and ranged in total length from 29.5 to 80.8 microm. Mixed populations of the smaller and larger trypanosomes were found in most fish examined. Despite variations in size and appearance, these specimens are tentatively identified as Trypanosoma mukasai Hoare, 1932, likely adding another 9 new hosts to those known for this parasite. It is possible that Trypanosoma clariense Pienaar, 1962, described from Clarias gariepinus in South Africa, is also a junior synonym of T. mukasai.

  3. Host range determination of tsetse fly Glossina morsitans ...

    African Journals Online (AJOL)

    ... of which warthog accounted for about 52.9 (46/87) of meals, whereas human and buffalo blood accounted for about 21.8% (19/87) and 12.6% (11/87) of the meals, respectively. Others like giraffe, goat, cattle and elephant accounted for few bloodmeals. Thus warthog appeared to be the major host for G. m. submorsitans ...

  4. THE MODULATED SOUNDS MADE BY THE TSETSE FLY ...

    African Journals Online (AJOL)

    . The females arrive later. The question is, how do they locate the host if they are more sedentary? Sound-motivation and -location is apparently fairly common in the insect world (Frings. & Frings 1958: 87-106). The purpose of the present ...

  5. The Modulated Sounds Made by the Tsetse Fly Glossina Brevipalpis ...

    African Journals Online (AJOL)

    The modulated sounds made by Glossina brevipalpis are physiologically and refiexly induced phenomena, produced by muscular vibrations in the pterothorax. The patterns and physical nature of the calls and songs were investigated acoustically, spectrographically and oscilloscopically to explore the possibility of a ...

  6. Visualization of temporal aspects of tsetse fly eradication in ...

    African Journals Online (AJOL)

    Pattern of how they are applied in time was provided in the animation representation. Further information on areas where different techniques were applied on different years is interactively visualized. Visualization of infestation changes in time was also provided by animation representation. Visualization of eradication ...

  7. Mapping the distribution of tsetse and animal trypanosomosis in ...

    African Journals Online (AJOL)

    Mapping the distribution of tsetse and animal trypanosomosis in selected districts of Uganda to facilitate targeting control measures. ... Mapping to highlight hotspots was anticipated to facilitate planning and prioritization of resources for targeting tsetse and trypanosomosis control by district departments of veterinary services ...

  8. Tsetse distribution in Tanzania: 2012 status | Daffa | Tanzania ...

    African Journals Online (AJOL)

    Results further show that the seven species of Glossina that had been recorded earlier still occur in Tanzania, although unevenly distributed due to different ecological features, climatic change, human development activities and tsetse control interventions. This paper highlights current status of tsetse distribution in ...

  9. [Ecology of Glossina palpalis VANDERPLANK, 1949 (Diptera: Glossinidae) in mangrove area of Guinea: influence of tides on tsetse densities].

    Science.gov (United States)

    Kagbadouno, S M; Salou, E; Rayaisse, J B; Courtin, F; Sanon, A; Solano, P; Camara, M

    2016-05-01

    The mangrove area on the Guinea littoral constitutes a favourable habitat for transmission of Trypanosoma brucei gambiens, the parasite causing sleeping sickness also called Human African Trypanosmosis (HAT), due the simultaneous presence of the vector (tsetse flies) and the human hosts. In order to assess the influence of the sea tides on the densities of Glossina palpalis gambiensis (Gpg), major vector of HAT in the mangrove, entomological surveys were performed using two transects, according to tides coefficient (great and small) and tide daily fluctuations (high and low). On each transect, 12 biconical traps were deployed through the mangrove to the continent. In total, up to 612 Gpg were caught, giving a density of 2.13 flies/trap/day (f/t/d). Highest captures were recorded during small tides and more tsetse were caught during the dry season than in the wet season. There were significant differences between captures when considering the different biotopes, and highest tsetse densities were recorded at the junction of the river and the channel of the mangrove (6.17±5.24); and in the channels of mangrove (3.50±3.76), during high tides of small coefficients. The results of this study may be used to improve vector control methods.

  10. Influence of nutrition on trypanosome isometamidium chloride ...

    African Journals Online (AJOL)

    Thirty six weaner wistar rats were used to study the effect of protein nutrition on trypanosome isometamidium chloride prophylaxis. Two groups of rats A and B (n = 18 per group) were maintained on 21% and 14.5% crude protein diet respectively for the twenty eight days. Thereafter, group A was sub-divided into groups A1, ...

  11. Pathogenesis of trypanosome infections in cattle

    International Nuclear Information System (INIS)

    Murray, M.; Morrison, W.I.; Emery, D.L.; Akol, G.W.O.; Masake, R.A.; Moloo, S.K.

    1980-01-01

    The potential application of radioisotopes are not discussed in this review of trypanosome pathogenesis in cattle. Initially, structural changes in the lymphoid system are characterized by marked proliferation and germinal centre formation, whereas in long-standing infections the lymphoid organs become depleted. These changes appear associated with immunodepression. Anaemia dominates the clinical disease syndrome in bovine trypanosomiasis. It develops with the onset of parasitaemia and is largely haemolytic, resulting from increased red blood cell destruction by phagocytosis. Several factors may be involved in this process including haemolysins produced by the trypanosome, immunological mechanisms, fever, disseminated intravascular coagulation and an expanded and active mononuclear phagocytic system. During this phase of the disease, cattle respond well to chemotherapy. However, in later phases of the disease, when trypanosomes cannot be detected, the anaemia sometimes persists and animals do not respond to treatment. Concerning the underlying mechanisms responsible for the anaemia, continued red cell destruction combined with some dyshaemopoiesis, associated with a defect in iron metabolism, appears responsible. Widespread tissue degeneration occurs. Organs particularly severely affected include the heart. Death in bovine trypanosomiasis is presumably due to a combination of anaemia, microcirculatory disturbances and myocardial damage. The factors incriminated in tissue damage probably vary with the species of trypanosome involved, although under natural field conditions it is common to find T. congolense, T. vivax and T. brucei in one animal. Likely pathogenic mechanisms in bovine include anoxia as a result of anaemia, microcirculatory disorders and hypersensitivity reactions

  12. Validation of an improved enzyme-linked immunosorbent assay for the diagnosis of trypanosomal antibodies in Ghanaian cattle

    International Nuclear Information System (INIS)

    Doku, C.K.; Seidu, I.B.M.

    2000-01-01

    The validation of an enzyme-linked immunosorbent assay (Ab-ELISA) for the detection of antibodies to pathogenic trypanosomes in cattle is described. Two hundred known negative sera obtained from the tsetse-free zone of Dori (Burkina Faso) were analyzed using microtitre plates pre-coated with crude antigen lysates of Trypanosoma congolense and T. vivax. A pre-test optimization was carried out and a percent positivity (PP) of 50% was chosen (specificity: >82%) for assaying field sera. A total of 440 serum samples collected from cattle in areas of known and unknown disease prevalence were assayed. For all animals the packed red cell volume (PCV) was determined and the buffy coat technique (BCT) and blood smears were examined to detect trypanosomes at the species level. A comparison of the BCT and Ab-ELISA results showed there was a much higher prevalence of antibodies to both species than the parasite prevalence as shown by the BCT (10 fold). The rate of agreement between BCT-positive and Ab-ELISA-positive samples for both species was low (<10%). No conclusion could be drawn from this finding because of the low number of known BCT positive cases that were identified. There was a better, albeit highly variable, agreement between BCT-negative and Ab-ELISA-negative samples (30-70%). Proposals for further improvement of the Ab-ELISA and prospects for the use of the assay in the monitoring of trypanosomosis control in Ghana are discussed. (author)

  13. Occurrence and Control of Multiple-drug resistant Trypanosome ...

    African Journals Online (AJOL)

    impregnated targets were erected throughout the Ghibe valley. During the subsequent 12 months a substantial decline in the apparent tsetse challenge was observed. A significant decline was also observed in both the prevalence and incidence of ...

  14. Trypanosomosis surveillance on Zanzibar island, using the trypanosomal antigen detection ELISA (enzyme-linked immunosorbent assay) technique

    International Nuclear Information System (INIS)

    Mbwambo, H.A.

    1997-01-01

    The effectiveness of trypanosomosis control programs depends greatly on prior knowledge of basic data of the epidemiological situation of the disease, which in turns depends, among others, on the use of techniques that give a fairly quick and accurate diagnosis. An antigen-detection (Ag) ELISA was first introduced into Tanzania and validated at the Animal Disease Research Institute (ADRI) through the FAO/IAEA Research Contract (RC) No. 5030/NL. Incorporation of the Ag-ELISA technique into a FAO animal disease control project (1986-1993) on Unguja island, in 1992, revealed useful information of high trypanosomosis prevalence in an area previously declared free of the disease using just stained blood smears and buffy coat examinations. This triggered further efforts into more intensive surveys of the tsetse and trypanosomosis situation on Unguja island. The present study is a continuation of previous work in an effort to confirm the practical application of Ag-ELISA in trypanosomosis control operations. Results obtained from a known tsetse and trypanosomosis-free area, on Pemba island, showed a high specificity of the test for Trypanosoma congolense, T. vivax and T. brucei. A preliminary cut-off value of 10% (Percent Positivity = PP) was used. When the PP of 10 was used on sera of trypanosomosis-endemic areas (Mangapwani, Ndijani, Dunga and Kikungwi) on Unguja island, the results reflected the 'real' trypanosomis situation in the affected area. This was most strongly felt in the Mangapwani area, where tsetse and trypanosomosis were considered under control by 1994 (no tsetse flies were caught and no samples were encountered positive by the buffy coat technique). However, it should be stressed that the buffy coat technique and the Ag-ELISA complement each other and should be used in conjunction. (author). 8 refs, 1 fig., 5 tabs

  15. Geospatial forecast model for tsetse-transmitted animal ...

    African Journals Online (AJOL)

    Results indicate that GIS model developed for parasitic diseases based on growing degree day (GDD) concept can be applied to tsetse-transmitted trypanosomosis. GIS for animal trypanosomosis was created using Food and Agriculture Organization – Crop Production System Zones (FAO-CPSZ) database and Normalized ...

  16. Olfactory responses to attractants and repellents in tsetse

    NARCIS (Netherlands)

    Voskamp, KE; Everaarts, E; Den Otter, CJ

    1999-01-01

    The aims of this study were to investigate how antennal olfactory cells of tsetse (Diptera: Glossinidae) code odour quality and how they are able to discriminate between attractive and repellent odours. For Glossina pallidipes Austen, a survey is presented of the cells' responses to attractive

  17. Fifty years of Tsetse control in Tanzania: challenges and prospects ...

    African Journals Online (AJOL)

    Even after 50 years of independence, Human African Trypanosomiasis (HAT) or Sleeping Sickness is still one of the major public health problems with about 300 cases being reported annually. Tsetse control has been sporadic and uncoordinated hence no tangible results have been accrued since independence despite ...

  18. Interferon Gamma in African Trypanosome Infections: Friends or Foes?

    Science.gov (United States)

    Wu, Hui; Liu, Gongguan; Shi, Meiqing

    2017-01-01

    African trypanosomes cause fatal infections in both humans and livestock. Interferon gamma (IFN-γ) plays an essential role in resistance to African trypanosomes. However, increasing evidence suggests that IFN-γ, when excessively synthesized, also induces immunopathology, enhancing susceptibility to the infection. Thus, production of IFN-γ must be tightly regulated during infections with African trypanosomes to ensure that a robust immune response is elicited without tissue destruction. Early studies have shown that secretion of IFN-γ is downregulated by interleukin 10 (IL-10). More recently, IL-27 has been identified as a negative regulator of IFN-γ production during African trypanosome infections. In this review, we discuss the current state of our understanding of the role of IFN-γ in African trypanosome infections. We have focused on the cellular source of IFN-γ, its beneficial and detrimental effects, and mechanisms involved in regulation of its production, highlighting some recent advances and offering some perspectives on future directions.

  19. The effect of El Nino on trypanosome infection in cattle in Dar es ...

    African Journals Online (AJOL)

    A retrospective study was carried out to assess the effect of El Nino on trypanosome infection in cattle. Trypanosome infection was monitored in free grazing dairy cattle before and after El Nino in Dar es Salaam. The study involved 49 smallholder dairy herds with a total of 570 dairy cattle. Trypanosomes were identified by ...

  20. Two genotypic groups of morphologically similar fish trypanosomes from the Okavango Delta, Botswana.

    Science.gov (United States)

    Davies, Angela J; Gibson, Wendy; Ferris, Vanessa; Basson, Linda; Smit, Nico J

    2005-09-23

    Blood smears and blood lysate samples from freshwater fishes captured in the Okavango Delta, Botswana, were examined to determine whether their trypanosomes were all Trypanosoma mukasai, a species of supposed broad host specificity and widespread existence across Africa. Trypanosomes and/or babesiosomes occurred in 20/32 blood smears, and morphometric analysis of trypanosomes from 13/32 smears showed features suggestive of T. mukasai, including nuclear indices consistently >1. In 16/32 blood lysate samples from which DNA was extracted, trypanosome DNA was detected in 12/16 by PCR (polymerase chain reaction), using trypanosome-specific ssu rRNA gene primers. Two samples positive for trypanosomes in blood smears yielded no amplifiable trypanosome DNA, but 4 samples with no detectable infection in blood smears were positive for trypanosome DNA, suggesting an overall trypanosome prevalence rate of 17/32 (53%) among fishes and demonstrating the value of PCR in trypanosome recognition. Cloning and sequencing of the 12 amplified fragments revealed 2 genotypic groups among these fish trypanosomes. Group 1 trypanosomes were from cichlids and 3 families of catfishes, Group 2 from 2 types of catfishes. Sequence comparison showed that the consensus Group 1 sequence was most similar to that of Trypanosoma cobitis, representing European fish trypanosomes of the carassii type, while the consensus Group 2 sequence showed similarity with a trypanosome sequence from another African catfish, Clarias angolensis. It was concluded that the identification of T. mukasai remains a problem, but at least 2 genotypic groups of trypanosomes occur in Okavango Delta fishes, and catfishes in this region appear to contain both types.

  1. CHEMOTHERAPY OF TRYPANOSOME AND SPIROCHETE INFECTIONS

    Science.gov (United States)

    Pearce, Louise; Brown, Wade H.

    1919-01-01

    N-PhenyIglycineamide-p-arsonic acid is an agent of marked therapeutic action in the treatment of experimental trypanosomiasis of mice, rats, and guinea pigs. It possesses an average curative range of from 0.2 to 0.3 gm. per kilo of body weight of the sodium salt against a 24 hour infection in mice and rats produced by several species of pathogenic trypanosomes. Since the lethal dose for mice is from 2 to 2.25 gm. and for rats 0.75 gm. per kilo of body weight, we have curative ratios of 1:8 and 1:3 respectively. The curative dose for guinea pigs is 0.15 gm. per kilo of body weight, thus giving a curative ratio of 1:10. The trypanocidal activity of this compound is relatively rapid in all three animal species, for the peripheral blood is cleared of organisms within 24 hours after its administration, and in addition, the lower limits of the curative range are comparatively sharply defined. Intraperitoneal, intravenous, and subcutaneous routes of administration for all practical purposes may be considered equally efficacious in Tr. brucei infections of mice both as regards the speed of action of the drug and the average curative range. The administration of the drug in therapeutic amounts in all three animal species is not followed by manifestations of organic or functional injury, but, on the contrary, the genera] physical condition of the treated animals shows an immediate and continued marked improvement. The therapeutic activity in trypanosomiasis of mice, rats, and guinea pigs as evidenced by the relative speed and sharpness of action, together with the curative ratio as expressed in fractions of the minimum lethal dose, and the absence of organic injury or functional disturbance following therapeutic doses are significant and characteristic features of the amide of N-phenylglycine-p-arsonic acid. PMID:19868370

  2. Irradiated Male Tsetse from a 40-Year-Old Colony Are Still Competitive in a Riparian Forest in Burkina Faso

    Science.gov (United States)

    Sow, Adama; Sidibé, Issa; Bengaly, Zakaria; Bancé, Augustin Z.; Sawadogo, Germain J.; Solano, Philippe; Vreysen, Marc J. B.; Lancelot, Renaud; Bouyer, Jeremy

    2012-01-01

    Background Tsetse flies are the cyclical vectors of African trypanosomosis that constitute a major constraint to development in Africa. Their control is an important component of the integrated management of these diseases, and among the techniques available, the sterile insect technique (SIT) is the sole that is efficient at low densities. The government of Burkina Faso has embarked on a tsetse eradication programme in the framework of the PATTEC, where SIT is an important component. The project plans to use flies from a Glossina palpalis gambiensis colony that has been maintained for about 40 years at the Centre International de Recherche-Développement sur l'Elevage en zone Subhumide (CIRDES). It was thus necessary to test the competitiveness of the sterile males originating from this colony. Methodology/Principal Findings During the period January–February 2010, 16,000 sterile male G. p. gambiensis were released along a tributary of the Mouhoun river. The study revealed that with a mean sterile to wild male ratio of 1.16 (s.d. 0.38), the abortion rate of the wild female flies was significantly higher than before (p = 0.026) and after (p = 0.019) the release period. The estimated competitiveness of the sterile males (Fried index) was 0.07 (s.d. 0.02), indicating that a sterile to wild male ratio of 14.4 would be necessary to obtain nearly complete induced sterility in the female population. The aggregation patterns of sterile and wild male flies were similar. The survival rate of the released sterile male flies was similar to that observed in 1983–1985 for the same colony. Conclusions/Significance We conclude that gamma sterilised male G. p. gambiensis derived from the CIRDES colony have a competitiveness that is comparable to their competitiveness obtained 35 years ago and can still be used for an area-wide integrated pest management campaign with a sterile insect component in Burkina Faso. PMID:22590652

  3. Haematology of normal and trypanosome infected Muturu cattle in ...

    African Journals Online (AJOL)

    Blood parameters of 23 Muturu cattle in a herd were studied between April and August 1998 by monthly examination of their blood samples. Fourteen of a total of 110 blood samples analysed (5 samples were unsuitable for analysis) were infected with Trypanosoma vivax. Data from the trypanosome-infected blood were ...

  4. License - Trypanosomes Database | LSDB Archive [Life Science Database Archive metadata

    Lifescience Database Archive (English)

    Full Text Available pliance with the terms and conditions of the license described below. The license s...List Contact us Trypanosomes Database License License to Use This Database Last updated : 2014/02/04 You may use this database in com

  5. The Evolution of Trypanosomes Infecting Humans and Primates

    Directory of Open Access Journals (Sweden)

    Stevens Jamie

    1998-01-01

    Full Text Available Based on phylogenetic analysis of 18S rRNA sequences and clade taxon composition, this paper adopts a biogeographical approach to understanding the evolutionary relationships of the human and primate infective trypanosomes, Trypanosoma cruzi, T. brucei, T. rangeli and T. cyclops. Results indicate that these parasites have divergent origins and fundamentally different patterns of evolution. T. cruzi is placed in a clade with T. rangeli and trypanosomes specific to bats and a kangaroo. The predominantly South American and Australian origins of parasites within this clade suggest an ancient southern super-continent origin for ancestral T. cruzi, possibly in marsupials. T. brucei clusters exclusively with mammalian, salivarian trypanosomes of African origin, suggesting an evolutionary history confined to Africa, while T. cyclops, from an Asian primate appears to have evolved separately and is placed in a clade with T. (Megatrypanum species. Relating clade taxon composition to palaeogeographic evidence, the divergence of T. brucei and T. cruzi can be dated to the mid-Cretaceous, around 100 million years before present, following the separation of Africa, South America and Euramerica. Such an estimate of divergence time is considerably more recent than those of most previous studies based on molecular clock methods. Perhaps significantly, Salivarian trypanosomes appear, from these data, to be evolving several times faster than Schizotrypanum species, a factor which may have contributed to previous anomalous estimates of divergence times.

  6. Trypanosome Letm1 protein is essential for mitochondrial potassium homeostasis

    Czech Academy of Sciences Publication Activity Database

    Hashimi, Hassan; McDonald, Lindsay M.; Stříbrná, Eva; Lukeš, Julius

    2013-01-01

    Roč. 288, č. 37 (2013), s. 26914-26925 ISSN 0021-9258 R&D Projects: GA ČR GAP305/12/2261 Institutional support: RVO:60077344 Keywords : Bioenergetics * Letm1 * Mitochondria * Potassium Transport * Translation * Trypanosome Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.600, year: 2013

  7. Evaluation of Anti-trypanosomal Properties of Four Extracts of ...

    African Journals Online (AJOL)

    JTEkanem

    2004-11-16

    Nov 16, 2004 ... on the trypanosomal parasite involved, Human. African Trypanosomiasis (HAT), exist in two potentially fatal clinical forms: a chronic form caused by Trypanosoma brucei gambiense affecting countries in west and central Africa, and an acute form, caused by Trypanosoma brucei rhodesiense in East and ...

  8. Polymerase chain reaction (PCR) detection of mixed trypanosome ...

    African Journals Online (AJOL)

    user

    2012-10-02

    Oct 2, 2012 ... kinase (KIN) and serum resistance- associated (SRA) primers, respectively for Trypanozoon group species, universal trypanosome ... Furthermore, PCR using serum resistance-associated. (SRA) gene primers which ..... PCR- based detection and typing of parasites. pp. 261-287. In: Parasitology for the 21st ...

  9. Phylogenetic and morphological characterization of trypanosomes from Brazilian armoured catfishes and leeches reveal high species diversity, mixed infections and a new fish trypanosome species.

    Science.gov (United States)

    Lemos, Moara; Fermino, Bruno R; Simas-Rodrigues, Cíntia; Hoffmann, Luísa; Silva, Rosane; Camargo, Erney P; Teixeira, Marta M G; Souto-Padrón, Thaïs

    2015-11-06

    Several Trypanosoma species transmitted by leeches infect marine and freshwater fish worldwide. To date, all South American fish trypanosome species identified have been based on unreliable morphological parameters. We recently isolated and cultured trypanosomes from the Brazilian armoured catfishes Hypostomus luetkeni and H. affinis. Here, we report the first phylogenetic analyses of South American (Brazilian) trypanosomes isolated from fish, and from leeches removed from these fish. We also analysed morphologically and morphometrically the different forms of fish, leech and cultured trypanosomes. V7V8 SSU rRNA and gGAPDH sequences were used for phylogenetic analysis of Brazilian fish and leech trypanosomes. Trypanosomes from cultures, fish blood and leech samples were also characterized morphologically and morphometrically by light and electron microscopy. In blood smears from fish high trypanosome prevalence (90-100 %) and parasitemia (0.9-1.0x10(2)) were observed. Phylogenetic relationships using SSU rRNA and gGAPDH showed that, despite relevant sequence divergence, all Brazilian fish (and derived cultures) and leech trypanosomes clustered together into a single clade. The Brazilian clade clustered with European, North American and African fish trypanosomes. Based on sequence analysis, we uncovered a new species of Brazilian fish trypanosome, Trypanosoma abeli n. sp. Trypanosoma abeli cultures contained pleomorphic epimastigotes, small trypomastigotes and rare sphaeromastigotes. Ultrastructural features of T. abeli included a cytostome-cytopharynx complex in epi- and trypomastigotes, a compact rod-like kinetoplast, lysosome-related organelles (LROs) and multivesicular bodies. Trypanosomes found in fish blood smears and leech samples were highly pleomorphic, in agreement with sequence data suggesting that catfishes and leeches often have mixed trypanosome infections. Trypanosoma abeli n. sp. is the first trypanosome from South American fishes isolated in

  10. Assessment of impacts of tsetse and trypanosomosis control measures on cattle herd composition and performance in southern region, Ethiopia.

    Science.gov (United States)

    Taye, Messele; Belihu, Kelay; Bekana, Merga; Sheferaw, Desie

    2012-10-01

    This study was conducted to assess the impact of tsetse and trypanosomosis control measures on cattle herd size and composition, herd dynamics, and milk yield in Wolaita and Gamogofa Zones, southern Ethiopia. The study showed that the average number of cattle herd size in tsetse challenged areas was significantly higher than those in tsetse-controlled areas. The number of non-pregnant dry cows, bulls and oxen were significantly higher in tsetse challenged areas than the other two study areas. The rate of cattle addition to and disposal from the herd were significantly higher in tsetse challenged areas. Cows in Southern Tsetse Eradication Project (STEP) and community tsetse controlled areas were able to give 26-27 %, 25-29 % and 17-21 % more daily milk yield at the beginning, middle and end of lactation, respectively, than those in tsetse-challenged areas. In addition, cows in STEP and community tsetse controlled areas had lactation length longer by 1.20 to 1.35 months; age at first calving was shorter by 5.30 to 5.10 months; and calving interval was shorter by 4.20 to 3.20 months than cows in tsetse-challenged area, respectively. Hence, tsetse and trypanosomosis control both by the community and project would play key role in the improvement of cattle productivity.

  11. studies on the reproductive status, catch and age compositions of ...

    African Journals Online (AJOL)

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    Insemination rates of the sampled flies were over 95% at all habitats. In any one habitat, ... fly and the disease it transmits to livestock. The on-going effort on tsetse and trypanosomes management is supplemented by the sterile insect technique, using an area wide ..... It is unlikely that artificial damage significantly affected ...

  12. Anti-trypanosomal activity of African medicinal plants: a review update.

    Science.gov (United States)

    Ibrahim, Mohammed Auwal; Mohammed, Aminu; Isah, Murtala Bindawa; Aliyu, Abubakar Babando

    2014-05-28

    African trypanosomiasis is one of the neglected tropical diseases caused by different species of trypanosomes that affect both human and livestock with devastating consequences in the continent. Most of the affected populations commonly use traditional medicinal plants for the treatment of the disease. Consequently, this prompted ethnopharmacological research activities on the anti-trypanosomal activity of a number of these African medicinal plants in order to validate their ethnomedicinal use. Furthermore, such studies could lead to the identification of chemical leads for the development of newer anti-trypanosomal agents from those plants. This review aims to provide updated information on the ethnopharmacological evidence of African medicinal plants with anti-trypanosomal activity. Literature was collected via electronic search (PubMed, Sciencedirect, Medline and Google Scholar) from published articles that report on the in vitro or in vivo anti-trypanosomal activity of plants that were collected from different parts of Africa. African medicinal plants investigated for in vitro and in vivo anti-trypanosomal activity from January 1993 to October 2013 are systematically compiled and all the in vivo studies are critically discussed. A total of 264 plant species belonging to 79 families were investigated for anti-trypanosomal activity. However, only 48 bioactive anti-trypanosomal compounds were successfully isolated in pure forms. Furthermore, some of the plants were investigated for possible ameliorative effects on the trypanosome-induced pathological changes out of which 18 plants were reported to be effective while a few others were not. In spite of interesting preclinical ethnopharmacological evidence for anti-trypanosomal activity, not a single African medicinal plant was investigated in a clinical study. Several African medicinal plants have demonstrated promising anti-trypanosomal effects but the studies on the anti-trypanosomal potentials of these plants are

  13. Database Description - Trypanosomes Database | LSDB Archive [Life Science Database Archive metadata

    Lifescience Database Archive (English)

    Full Text Available List Contact us Trypanosomes Database Database Description General information of database Database name Trypanosomes Database...stitute of Genetics Research Organization of Information and Systems Yata 1111, Mishima, Shizuoka 411-8540, JAPAN E mail: Database... classification Protein sequence databases Organism Taxonom...y Name: Trypanosoma Taxonomy ID: 5690 Taxonomy Name: Homo sapiens Taxonomy ID: 9606 Database description The Trypanosomes database... is a database providing the comprehensive information of proteins that is effective t

  14. Counterflow Dielectrophoresis for Trypanosome Enrichment and Detection in Blood

    Science.gov (United States)

    Menachery, Anoop; Kremer, Clemens; Wong, Pui E.; Carlsson, Allan; Neale, Steven L.; Barrett, Michael P.; Cooper, Jonathan M.

    2012-10-01

    Human African trypanosomiasis or sleeping sickness is a deadly disease endemic in sub-Saharan Africa, caused by single-celled protozoan parasites. Although it has been targeted for elimination by 2020, this will only be realized if diagnosis can be improved to enable identification and treatment of afflicted patients. Existing techniques of detection are restricted by their limited field-applicability, sensitivity and capacity for automation. Microfluidic-based technologies offer the potential for highly sensitive automated devices that could achieve detection at the lowest levels of parasitemia and consequently help in the elimination programme. In this work we implement an electrokinetic technique for the separation of trypanosomes from both mouse and human blood. This technique utilises differences in polarisability between the blood cells and trypanosomes to achieve separation through opposed bi-directional movement (cell counterflow). We combine this enrichment technique with an automated image analysis detection algorithm, negating the need for a human operator.

  15. Nitrofurylsemicarbazone rhenium and ruthenium complexes as anti-trypanosomal agents.

    Science.gov (United States)

    Otero, Lucía; Aguirre, Gabriela; Boiani, Lucía; Denicola, Ana; Rigol, Carolina; Olea-Azar, Claudio; Maya, Juan Diego; Morello, Antonio; González, Mercedes; Gambino, Dinorah; Cerecetto, Hugo

    2006-11-01

    Rhenium and ruthenium complexes of the type [Re(V)OCl(2)(PPh(3))L] and [Ru(II)Cl(2)(DMSO)(2)L], where L are 5-nitrofurylsemicarbazone derivatives, were prepared in an effort to obtain new anti-trypanosomal agents combining the recognized biological activity of these metals and the trypanocidal activity of the free ligands. Rhenium complexes resulted unstable in aqueous solution not allowing their use as potential drugs. On the other hand, complexation to ruthenium of the bioactive ligands lead to the lack of antiprotozoa activity even though free radical production and redox cycling induction were detected when the compounds were incubated in presence of Trypanosoma cruzi cells. The lack of anti-trypanosomal activity of ruthenium complexes could be explained on the basis of their high protein binding capacity and their high hydrophilicity.

  16. Early invasion of brain parenchyma by African trypanosomes.

    Directory of Open Access Journals (Sweden)

    Ute Frevert

    Full Text Available Human African trypanosomiasis or sleeping sickness is a vector-borne parasitic disease that has a major impact on human health and welfare in sub-Saharan countries. Based mostly on data from animal models, it is currently thought that trypanosome entry into the brain occurs by initial infection of the choroid plexus and the circumventricular organs followed days to weeks later by entry into the brain parenchyma. However, Trypanosoma brucei bloodstream forms rapidly cross human brain microvascular endothelial cells in vitro and appear to be able to enter the murine brain without inflicting cerebral injury. Using a murine model and intravital brain imaging, we show that bloodstream forms of T. b. brucei and T. b. rhodesiense enter the brain parenchyma within hours, before a significant level of microvascular inflammation is detectable. Extravascular bloodstream forms were viable as indicated by motility and cell division, and remained detectable for at least 3 days post infection suggesting the potential for parasite survival in the brain parenchyma. Vascular inflammation, as reflected by leukocyte recruitment and emigration from cortical microvessels, became apparent only with increasing parasitemia at later stages of the infection, but was not associated with neurological signs. Extravascular trypanosomes were predominantly associated with postcapillary venules suggesting that early brain infection occurs by parasite passage across the neuroimmunological blood brain barrier. Thus, trypanosomes can invade the murine brain parenchyma during the early stages of the disease before meningoencephalitis is fully established. Whether individual trypanosomes can act alone or require the interaction from a quorum of parasites remains to be shown. The significance of these findings for disease development is now testable.

  17. Characterization of Antibody-Dependent Killing of Trypanosomes by Macrophages.

    Science.gov (United States)

    1983-04-01

    werse e f08~m~ id’ Vm@ Trpnsm rhodesiense; trypanosomes; African trypanosomiasis ; protozoa, jpiiii tes macrophages; phagocytosis; antibody SEE...agglutinating antibody in the 19H im oglobulin fraction of rabbit antistrum during eaxwtntal African trypanosomiasis . .:283-292. Silverstein, S.C., R.N...species specificity in the action of complement since dog, human , guinea pig and mouse sera could be used as complement sources.4 In the presence of

  18. Effects of Trypanocidal Drugs on the Function of Trypanosomes.

    Science.gov (United States)

    1980-09-01

    W A 31 073 EFFECTS OF TRYPANOCIDAL DRUGS ON THE FUNCTION 0F1/ TRYPANOSOMES(J) COLONO STATE UNIV FORT COLLNS DEPT OF PATHOLOGY G C HILL SEP 8U DUMO 7...NAME ANO AGORESS 10. PROGRAM ELE.*J-NT, PROJEC., TL’ AREA A WORK UNIT NUMBERS Colorado State University 62770A Department of Pathology ...against all stages of the infection in both Gambian and Rhodesian sleeping sickness. It should also be incapable of inducing drug resistauice and active

  19. ASSOCIATION OF TRYPANOSOME INFECTION WITH SPERM ANTIBODIES PRODUCTION IN RED SOKOTO (MARADI GOATS

    Directory of Open Access Journals (Sweden)

    O. FAYEMI

    2006-01-01

    Full Text Available A total of 1021 randomly selected serum samples of adult male goats that had been screened for trypanosome infection were assayed for sperm antibodies using the immunoperoxidase staining technique. The result of the trypanosome screening revealed that 586(57.39% goats were positive for trypanosome infection, while 435(42.61% were negative. The assay for sperm antibodies showed that 482(47.21% animals were positive, while 539(52.79% were negative. In the group that was positive for trypanosome infection, 364(62.12% animals were positive, whereas 222(37.88% were negative for sperm antibodies (P<0.001. The group that was negative for trypanosome infection, had a significantly lower number and proportion 118(27.13% of positive compared to 317(72.87% negative for sperm antibodies. Out of a total 482 goats that were positive for sperm antibodies, a significantly higher number, 364(75.52%, were positive than 118(24.48% that were negative for trypanosome infection (P<0.001. In the group that was found negative for sperm antibodies, a significantly lower proportion, 222(41.19%, was positive compared to 317(58.81% that were negative for trypanosome infection (P<0.001. Seropositivity to sperm antibodies was positively correlated to trypanosome infection (P<0.001. Further work on the pathogenesis of sperm antibody production in trypanosome infection is advocated.

  20. Update History of This Database - Trypanosomes Database | LSDB Archive [Life Science Database Archive metadata

    Lifescience Database Archive (English)

    Full Text Available List Contact us Trypanosomes Database Update History of This Database Date Update contents 2014/05/07 The co...ntact information is corrected. The features and manner of utilization of the database are corrected. 2014/02/04 Trypanosomes Databas...e English archive site is opened. 2011/04/04 Trypanosomes Database ( http://www.tan...paku.org/tdb/ ) is opened. About This Database Database Description Download Lice...nse Update History of This Database Site Policy | Contact Us Update History of This Database - Trypanosomes Database | LSDB Archive ...

  1. Trypanosoma teixeirae: A new species belonging to the T. cruzi clade causing trypanosomosis in an Australian little red flying fox (Pteropus scapulatus).

    Science.gov (United States)

    Barbosa, Amanda D; Mackie, John T; Stenner, Robyn; Gillett, Amber; Irwin, Peter; Ryan, Una

    2016-06-15

    Little is known about the genetic diversity and pathogenicity of trypanosomes in Australian bats. Recently a novel trypanosome species was identified in an adult female little red flying fox (Pteropus scapulatus) with clinical and pathological evidence of trypanosomosis. The present study used morphology and molecular methods to demonstrate that this trypanosome is a distinct species and we propose the name Trypanosoma teixeirae sp. n. Morphological comparison showed that its circulating trypomastigotes were significantly different from those of Trypanosoma pteropi and Trypanosoma hipposideri, two species previously described from Australian bats. Genetic information was not available for T. pteropi and T. hipposideri but phylogenetic analyses at the 18S ribosomal RNA (rRNA) and glycosomal glyceraldehyde phosphate dehydrogenase (gGAPDH) loci indicated that T. teixeirae sp. n. was genetically distinct and clustered with other bat-derived trypanosome species within the Trypanosoma cruzi clade. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Laboratory investigations of insecticide impregnated materials for the control of New World screwworm flies

    International Nuclear Information System (INIS)

    Harris, E.G.; Brown, M.; Smith, S.

    1992-01-01

    In laboratory tests, New World screwworm flies were found to be at least three orders of magnitude less susceptible to the insecticides deltamethrin, alphacypermethrin and cyfluthrin than are tsetse flies. Deltamethrin was the most toxic of the three insecticides to screwworm flies. For topical application, the LD50s for deltamethrin 20% suspension concentrate were 33 ng and 25 ng for male and female screwworm flies respectively, compared with 0.04 ng for tsetse, G.m. morsitans. In various tests simulating contact of screwworm flies with cloth or netting targets impregnated with insecticide, 100% kill was only achieved with 3.2% deltamethrin and contact times of at least 10 sec, although 100% knockdown for up to 24 hours was obtained with lower concentrations. No repellent effect was observed at the higher concentrations. Cloth targets impregnated with a high dose of insecticide and baited with an attractant could be effective against NWS flies, especially if after ''knockdown'' flies are removed by predators. 1 fig., 9 tabs

  3. Automation for tsetse mass rearing for use in sterile insect technique programmes. Final report of a co-ordinated research project 1995-2001

    International Nuclear Information System (INIS)

    2003-05-01

    The rearing of tsetse flies for the sterile insect technique has been a laborious procedure in the past. The purpose of this co-ordinated research project (CRP) 'Automation for tsetse mass rearing for use in sterile insect technique programmes' was to develop appropriate semiautomated procedures to simplify the rearing, reduce the cost and standardize the product. Two main objectives were accomplished. The first was to simplify the handling of adults at emergence. This was achieved by allowing the adults to emerge directly into the production cages. Selection of the appropriate environmental conditions and timing allowed the manipulation of the emergence pattern to achieve the desired ratio of four females to one male with minimal un-emerged females remaining mixed with the male pupae. Tests demonstrated that putting the sexes together at emergence, leaving the males in the production cages, and using a ratio of 4:1 (3:1 for a few species) did not adversely affect pupal production. This has resulted in a standardized system for the self stocking of production cages. The second was to reduce the labour involved in feeding the flies. Three distinct systems were developed and tested in sequence. The first tsetse production unit (TPU 1) was a fully automated system, but the fly survival and fecundity were unacceptably low. From this a simpler TPU 2 was developed and tested, where 63 large cages were held on a frame that could be moved as a single unit to the feeding location. TPU 2 was tested in various locations, and found to satisfy the basic requirements, and the adoption of Plexiglas pupal collection slopes resolved much of the problem due to light distribution. However the cage holding frame was heavy and difficult to position on the feeding frame and the movement disturbed the flies. TPU 2 was superseded by TPU 3, in which the cages remain stationary at all times, and the blood is brought to the flies. The blood feeding system is mounted on rails to make it

  4. Sexual differences in prevalence of a new species of trypanosome infecting túngara frogs

    Directory of Open Access Journals (Sweden)

    Ximena E. Bernal

    2016-04-01

    Full Text Available Trypanosomes are a diverse group of protozoan parasites of vertebrates transmitted by a variety of hematophagous invertebrate vectors. Anuran trypanosomes and their vectors have received relatively little attention even though these parasites have been reported from frog and toad species worldwide. Blood samples collected from túngara frogs (Engystomops pustulosus, a Neotropical anuran species heavily preyed upon by eavesdropping frog-biting midges (Corethrella spp., were examined for trypanosomes. Our results revealed sexual differences in trypanosome prevalence with female frogs being rarely infected (<1%. This finding suggests this protozoan parasite may be transmitted by frog-biting midges that find their host using the mating calls produced by male frogs. Following previous anuran trypanosome studies, we examined 18S ribosomal RNA gene to characterize and establish the phylogenetic relationship of the trypanosome species found in túngara frogs. A new species of giant trypanosome, Trypanosoma tungarae n. sp., is described in this study. Overall the morphometric data revealed that the trypomastigotes of T. tungarae n. sp. are similar to other giant trypanosomes such as Trypanosoma rotatorium and Trypanosoma ranarum. Despite its slender and long cell shape, however, 18S rRNA gene sequences revealed that T. tungarae n. sp. is sister to the rounded-bodied giant trypanosome, Trypanosoma chattoni. Therefore, morphological convergence explains similar morphology among members of two non-closely related groups of trypanosomes infecting frogs. The results from this study underscore the value of coupling morphological identification with molecular characterization of anuran trypanosomes.

  5. Current tsetse control operations in Botswana and prospects for the future

    International Nuclear Information System (INIS)

    Allsopp, R.; Phillemon-Motsu, T.K.

    2000-01-01

    Several tsetse control methods have been used in Botswana over the past 70 years, ranging from bush clearing and selective game elimination, ground spraying with residual insecticides, aerial spraying with non-residual insecticides to the present odour-bait approach. Sequential aerial spraying, initially with endosulfan or mixtures of endosulfan with one of the synthetic pyrethroids, effectively controlled tsetse but did not achieve eradication. Aerial spraying was suspended in 1991 when the tsetse population had been reduced to a relatively small population along the Linyanti and Kwando rivers bordering Namibia and to an area of 4,000-5,000 km 2 in the Okavango Delta. After the 1991 aerial spraying operation the Tsetse Control Division switched to the use of odour-baited, insecticide-impregnated targets as well as localised, ground based thermal fogging. There has been no incidence of human and bovine trypanosomiasis since the mid-1980s and no significant insect population recovery since targets were introduced

  6. The interaction between nutrition and metabolism in West African dwarf goats, infected with trypanosomes

    NARCIS (Netherlands)

    Dam, van J.T.P.

    1996-01-01

    In a series of experiments the interaction between nutrition and energy- and nitrogen metabolism of West African Dwarf goats, infected with trypanosomes was studied. Animals were injected with trypanosomes, and feed intake, energy and nitrogen balance and blood metabolites and hormones were measured

  7. Application of field methods to assess isometamidium resistance of trypanosomes in cattle in western Ethiopia

    DEFF Research Database (Denmark)

    Tewelde, N.; Abebe, G.; Eisler, M.

    2004-01-01

    This study assessed the degree of isometamidium resistance of trypanosomes infecting cattle in the upper Didessa valley of western Ethiopia. An initial prevalence study was conducted to identify sites with a high risk of trypanosmosis in cattle. The trypanosome prevalence varied widely, with two...

  8. Incidence of trypanosomes in the Canada goose as revealed by bone marrow culture

    Science.gov (United States)

    Diamond, L.S.; Herman, C.M.

    1954-01-01

    1. Techniques are described for the cultural isolation of trypanosomes from avian bone marrow obtained from living birds or at autopsy. A new medium SNB-9 (saline-neopeptone-blood) is described. In addition to being a good medium for growing avian trypanosomes, it is excellent for growing trypanosomes of amphibians and mammals. 2. Evidence is presented demonstrating the superiority of (a) cultures over stained smears for detecting the presence of trypanosomes in the Canada goose, and (b) bone marrow over heart blood of this species as a source of trypanosomes for culture. 3. In April 1952, from cultures of bone marrow collected at autopsy it was demonstrated that trypanosome infection occurred in 33 (40.2%) of 82 Canada geese from the Pea Island National Wildlife Refuge. On February 17, 1953, cultures of bone marrow obtained from living birds revealed presence of trypanosomes in 12 (20.7%) of 58 geese from the same refuge. On February 26, 1953, by employing the latter method, 9 (20.4%) of 44 geese from Blackwater National Wildlife Refuge were shown to harbor the parasites. In another survey ninety-two geese from seven national wildlife refuges subjected to the biopsy technique showed evidence of infection in 13 (14.1 %) birds and indicated that trypanosome infection is widely distributed in this host.

  9. The killing of African trypanosomes by ethidium bromide.

    Directory of Open Access Journals (Sweden)

    Arnab Roy Chowdhury

    2010-12-01

    Full Text Available Introduced in the 1950s, ethidium bromide (EB is still used as an anti-trypanosomal drug for African cattle although its mechanism of killing has been unclear and controversial. EB has long been known to cause loss of the mitochondrial genome, named kinetoplast DNA (kDNA, a giant network of interlocked minicircles and maxicircles. However, the existence of viable parasites lacking kDNA (dyskinetoplastic led many to think that kDNA loss could not be the mechanism of killing. When recent studies indicated that kDNA is indeed essential in bloodstream trypanosomes and that dyskinetoplastic cells survive only if they have a compensating mutation in the nuclear genome, we investigated the effect of EB on kDNA and its replication. We here report some remarkable effects of EB. Using EM and other techniques, we found that binding of EB to network minicircles is low, probably because of their association with proteins that prevent helix unwinding. In contrast, covalently-closed minicircles that had been released from the network for replication bind EB extensively, causing them, after isolation, to become highly supertwisted and to develop regions of left-handed Z-DNA (without EB, these circles are fully relaxed. In vivo, EB causes helix distortion of free minicircles, preventing replication initiation and resulting in kDNA loss and cell death. Unexpectedly, EB also kills dyskinetoplastic trypanosomes, lacking kDNA, by inhibiting nuclear replication. Since the effect on kDNA occurs at a >10-fold lower EB concentration than that on nuclear DNA, we conclude that minicircle replication initiation is likely EB's most vulnerable target, but the effect on nuclear replication may also contribute to cell killing.

  10. Transhumance pastoralism as risk factor in the trypanosome ...

    African Journals Online (AJOL)

    Les résultats ont montré des taux d'infection à trypanosomes de 11% (C.I. = 0.0182, 0.1518) et de 17% (C.I = 0.1287, 0.2113) chez les résidents et le bétail semisédentaires respectivement, bien que la différence n'ait pas été importante du point de vue statistique (P>0.05). Les analyses de sang ont montré que les parasites ...

  11. 2008 Annual Report: Project to combat the Tsetse Fly and Trypanosomiasis in the Niayes

    International Nuclear Information System (INIS)

    2009-03-01

    The overall objective of this project is to contribute to the fight against poverty by promoting the development in the Niayes area of integrated livestock systems that can increase the incomes of local populations. This program is coordinated by the Directorate of Veterinary Services (DSV) in partnership with the Senegalese Institute for Agricultural Research (ISRA) for the research component and the Ecological Monitoring Center (CSE) for the Geographic Information System (GIS).The Center for International Cooperation in Agronomic Research for Development (CIRAD) provides scientific support to the project. Between 2007 and 2008, a feasibility study (entomological, parasitological, genetic and socio-economic studies) to characterize the area was carried out.

  12. Excreted/Secreted Proteins from Trypanosome Procyclic Strains

    Directory of Open Access Journals (Sweden)

    Celestine Michelle Atyame Nten

    2010-01-01

    Full Text Available Trypanosoma secretome was shown to be involved in parasite virulence and is suspected of interfering in parasite life-cycle steps such as establishment in the Glossina midgut, metacyclogenesis. Therefore, we attempted to identify the proteins secreted by procyclic strains of T. brucei gambiense and T. brucei brucei, responsible for human and animal trypanosomiasis, respectively. Using mass spectrometry, 427 and 483 nonredundant proteins were characterized in T. brucei brucei and T. brucei gambiense secretomes, respectively; 35% and 42% of the corresponding secretome proteins were specifically secreted by T. brucei brucei and T. brucei gambiense, respectively, while 279 proteins were common to both subspecies. The proteins were assigned to 12 functional classes. Special attention was paid to the most abundant proteases (14 families because of their potential implication in the infection process and nutrient supply. The presence of proteins usually secreted via an exosome pathway suggests that this type of process is involved in trypanosome ESP secretion. The overall results provide leads for further research to develop novel tools for blocking trypanosome transmission.

  13. STEM tomography analysis of the trypanosome transition zone.

    Science.gov (United States)

    Trépout, Sylvain; Tassin, Anne-Marie; Marco, Sergio; Bastin, Philippe

    2018-04-01

    The protist Trypanosoma brucei is an emerging model for the study of cilia and flagella. Here, we used scanning transmission electron microscopy (STEM) tomography to describe the structure of the trypanosome transition zone (TZ). At the base of the TZ, nine transition fibres irradiate from the B microtubule of each doublet towards the membrane. The TZ adopts a 9 + 0 structure throughout its length of ∼300 nm and its lumen contains an electron-dense structure. The proximal portion of the TZ has an invariant length of 150 nm and is characterised by a collarette surrounding the membrane and the presence of electron-dense material between the membrane and the doublets. The distal portion exhibits more length variation (from 55 to 235 nm) and contains typical Y-links. STEM analysis revealed a more complex organisation of the Y-links compared to what was reported by conventional transmission electron microscopy. Observation of the very early phase of flagellum assembly demonstrated that the proximal portion and the collarette are assembled early during construction. The presence of the flagella connector that maintains the tip of the new flagellum to the side of the old was confirmed and additional filamentous structures making contact with the membrane of the flagellar pocket were also detected. The structure and potential functions of the TZ in trypanosomes are discussed, as well as its mode of assembly. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Arsenophonus and Sodalis Symbionts in Louse Flies: an Analogy to the Wigglesworthia and Sodalis System in Tsetse Flies.

    Science.gov (United States)

    Nováková, Eva; Husník, Filip; Šochová, Eva; Hypša, Václav

    2015-09-01

    Symbiosis between insects and bacteria result in a variety of arrangements, genomic modifications, and metabolic interconnections. Here, we present genomic, phylogenetic, and morphological characteristics of a symbiotic system associated with Melophagus ovinus, a member of the blood-feeding family Hippoboscidae. The system comprises four unrelated bacteria representing different stages in symbiosis evolution, from typical obligate mutualists inhabiting bacteriomes to freely associated commensals and parasites. Interestingly, the whole system provides a remarkable analogy to the association between Glossina and its symbiotic bacteria. In both, the symbiotic systems are composed of an obligate symbiont and two facultative intracellular associates, Sodalis and Wolbachia. In addition, extracellular Bartonella resides in the gut of Melophagus. However, the phylogenetic origins of the two obligate mutualist symbionts differ. In Glossina, the mutualistic Wigglesworthia appears to be a relatively isolated symbiotic lineage, whereas in Melophagus, the obligate symbiont originated within the widely distributed Arsenophonus cluster. Although phylogenetically distant, the two obligate symbionts display several remarkably similar traits (e.g., transmission via the host's "milk glands" or similar pattern of genome reduction). To obtain better insight into the biology and possible role of the M. ovinus obligate symbiont, "Candidatus Arsenophonus melophagi," we performed several comparisons of its gene content based on assignments of the Cluster of Orthologous Genes (COG). Using this criterion, we show that within a set of 44 primary and secondary symbionts, "Ca. Arsenophonus melophagi" is most similar to Wigglesworthia. On the other hand, these two bacteria also display interesting differences, such as absence of flagellar genes in Arsenophonus and their presence in Wigglesworthia. This finding implies that a flagellum is not essential for bacterial transmission via milk glands. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  15. More than meets the eye: understanding Trypanosoma brucei morphology in the tsetse

    Directory of Open Access Journals (Sweden)

    Cher-Pheng eOoi

    2013-11-01

    Full Text Available T. brucei, the causative parasite for African trypanosomiasis, faces an interesting dilemma in its life cycle. It has to successfully complete its infection cycle in the tsetse vector to be able to infect other vertebrate hosts. T. brucei has to undergo multiple morphological changes as it invades the alimentary canal of the tsetse successively to finally achieve infectivity in the salivary glands. In this review, we attempt to elucidate how these morphological changes are possible for a parasite that has evolved a highly robust cell structure to survive the chemically and physically diverse environments it finds itself in. To achieve this, we juxtaposed the experimental evidence that has been collected from T. brucei forms that are cultured in vitro with the observations that have been carried out on tsetse-infective forms in vivo. Although the accumulated knowledge on T. brucei biology is by no means trivial, several outstanding questions remain for how the parasite mechanistically changes its morphology as it traverses the tsetse and how those changes are triggered. However, we conclude that with recent breakthroughs allowing for the replication of the tsetse-infection process of T. brucei in vitro, these outstanding questions can finally be addressed.

  16. The Genetics of Trypanotolerance in Cattle: A Review | Enwezor ...

    African Journals Online (AJOL)

    These include drug resistance, re-invasion of controlled areas by tsetse flies and the small population of the trypanotolerant cattle population. Hence the search for genes that will confer trypanosome-resistance and enhance productivity is imperative. Attempts to control trypanosomosis using molecular genetic techniques ...

  17. Identification of Glossina morsitans morsitans odorant binding ...

    African Journals Online (AJOL)

    Tsetse flies are vectors of trypanosome parasites, causative agents of Trypanosomiasis in humans and animals. Odorant Binding Proteins (OBPs) are critical in insect olfaction as they bind volatile odours from the environment and transport them to receptors within olfactory receptor neurons for processing providing critical ...

  18. Flying Scared

    DEFF Research Database (Denmark)

    Dal Sie, Marco; Josiassen, Alexander

    service quality expectations and fear of flying affect travellers' flight choices on long-haul flights. The study was set in Bangkok and primary data were obtained from a large sample of travelers departing from Suvarnabhumi Airport. While service quality emerged as a relevant factor, fear of flying didn......’t turn out as a variable affecting travellers’ choices....

  19. Illuminating the Prevalence of Trypanosoma brucei s.l. in Glossina Using LAMP as a Tool for Xenomonitoring.

    Directory of Open Access Journals (Sweden)

    Lucas J Cunningham

    2016-02-01

    Full Text Available As the reality of eliminating human African trypanosomiasis (HAT by 2020 draws closer, the need to detect and identify the remaining areas of transmission increases. Here, we have explored the feasibility of using commercially available LAMP kits, designed to detect the Trypanozoon group of trypanosomes, as a xenomonitoring tool to screen tsetse flies for trypanosomes to be used in future epidemiological surveys.The DNA extraction method was simplified and worked with the LAMP kits to detect a single positive fly when pooled with 19 negative flies, and the absolute lowest limit of detection that the kits were able to work at was the equivalent of 0.1 trypanosome per ml. The DNA from Trypanosoma brucei brucei could be detected six days after the fly had taken a blood meal containing dead trypanosomes, and when confronted with a range of non-target species, from both laboratory-reared flies and wild-caught flies, the kits showed no evidence of cross-reacting.We have shown that it is possible to use a simplified DNA extraction method in conjunction with the pooling of tsetse flies to decrease the time it would take to screen large numbers of flies for the presence of Trypanozoon trypanosomes. The use of commercially-available LAMP kits provides a reliable and highly sensitive tool for xenomonitoring and identifying potential sleeping sickness transmission sites.

  20. Community acceptance of tsetse control baits: a qualitative study in Arua District, North West Uganda.

    Directory of Open Access Journals (Sweden)

    Vanja Kovacic

    Full Text Available BACKGROUND: There is renewed vigour in efforts to eliminate neglected tropical diseases including sleeping sickness (human African trypanosomiasis or HAT, including attempts to develop more cost-effective methods of tsetse control. In the West Nile region of Uganda, newly designed insecticide-treated targets are being deployed over an area of ∼500 km(2. The operational area covers villages where tsetse control has not been conducted previously. The effectiveness of the targets will depend, in part, on their acceptance by the local community. METHODOLOGY/PRINCIPAL FINDINGS: We assessed knowledge, perceptions and acceptance of tsetse baits (traps, targets in villages where they had or had not been used previously. We conducted sixteen focus group discussions with male and female participants in eight villages across Arua District. Discussions were audio recorded, translated and transcribed. We used thematic analysis to compare the views of both groups and identify salient themes. CONCLUSIONS/SIGNIFICANCE: Despite the villages being less than 10 km apart, community members perceived deployed baits very differently. Villagers who had never seen traps before expressed fear, anxiety and panic when they first encountered them. This was related to associations with witchcraft and "ghosts from the river" which are traditionally linked with physical or mental illness, death and misfortune. By contrast, villagers living in areas where traps had been used previously had positive attitudes towards them and were fully aware of their purpose and benefits. The latter group reported that they had similar negative perceptions when tsetse control interventions first started a decade ago. Our results suggest that despite their proximity, acceptance of traps varies markedly between villages and this is related to the duration of experience with tsetse control programs. The success of community-based interventions against tsetse will therefore depend on early

  1. Multiple Trypanosoma infections are common amongst Glossina species in the new farming areas of Rufiji district, Tanzania

    Directory of Open Access Journals (Sweden)

    Malele Imna I

    2011-11-01

    Full Text Available Abstract Background Tsetse flies and trypanosomiasis are among several factors that constrain livestock development in Tanzania. Over the years Rufiji District was excluded from livestock production owing to tsetse fly infestation, however, a few years ago there was an influx of livestock following evictions aimed at conserving the Usangu wetlands. Methods A study was conducted to determine the efficiency of available traps for catching tsetse flies, Glossina species infesting the area, their infection rates and Trypanosoma species circulating in the area. Trapping was conducted during the semi dry season for a total of 30 days (ten days each month during the onset of the dry season of May - July 2009. Harvested flies after every 24 hours were dissected and examined under a light microscope for trypanosome infections and whole fly DNA was extracted from 82 flies and analyzed for trypanosomes by polymerase chain reaction (PCR using different sets of primers. Results The proportions of total tsetse catches per trap were in the following decreasing order S3 (33%, H-Trap (27%, Pyramidal (19%, sticky panel (11% and biconical trap (10%. Of the 1200 trapped flies, 75.6% were identified as Glossina pallidipes, 11.7% as G. brevipalpis, 9.6% as G. austeni and 3.0% G. morsitans morsitans. Dissections revealed the overall infection rate of 6.6% (13/197. Whole DNA was extracted from 82 tsetse flies and the prevalence of trypanosomes circulating in the area in descending order was 92.7% (76/82 for T. simiae; 70.7% (58/82 for T. brucei types; 48.8% (40/82 for the T. vivax types and 32.9% (27/82 for the T. congolense types as determined by PCR. All trypanosome types were found in all tsetse species analysed except for the T. congolense types, which were absent in G. m. morsitans. None of the T. brucei positive samples contained human infective trypanosomes by SRA - PCR test Conclusion All tsetse species found in Rufiji are biologically important in the

  2. The genome of the African trypanosome Trypanosoma brucei.

    Science.gov (United States)

    Berriman, Matthew; Ghedin, Elodie; Hertz-Fowler, Christiane; Blandin, Gaëlle; Renauld, Hubert; Bartholomeu, Daniella C; Lennard, Nicola J; Caler, Elisabet; Hamlin, Nancy E; Haas, Brian; Böhme, Ulrike; Hannick, Linda; Aslett, Martin A; Shallom, Joshua; Marcello, Lucio; Hou, Lihua; Wickstead, Bill; Alsmark, U Cecilia M; Arrowsmith, Claire; Atkin, Rebecca J; Barron, Andrew J; Bringaud, Frederic; Brooks, Karen; Carrington, Mark; Cherevach, Inna; Chillingworth, Tracey-Jane; Churcher, Carol; Clark, Louise N; Corton, Craig H; Cronin, Ann; Davies, Rob M; Doggett, Jonathon; Djikeng, Appolinaire; Feldblyum, Tamara; Field, Mark C; Fraser, Audrey; Goodhead, Ian; Hance, Zahra; Harper, David; Harris, Barbara R; Hauser, Heidi; Hostetler, Jessica; Ivens, Al; Jagels, Kay; Johnson, David; Johnson, Justin; Jones, Kristine; Kerhornou, Arnaud X; Koo, Hean; Larke, Natasha; Landfear, Scott; Larkin, Christopher; Leech, Vanessa; Line, Alexandra; Lord, Angela; Macleod, Annette; Mooney, Paul J; Moule, Sharon; Martin, David M A; Morgan, Gareth W; Mungall, Karen; Norbertczak, Halina; Ormond, Doug; Pai, Grace; Peacock, Chris S; Peterson, Jeremy; Quail, Michael A; Rabbinowitsch, Ester; Rajandream, Marie-Adele; Reitter, Chris; Salzberg, Steven L; Sanders, Mandy; Schobel, Seth; Sharp, Sarah; Simmonds, Mark; Simpson, Anjana J; Tallon, Luke; Turner, C Michael R; Tait, Andrew; Tivey, Adrian R; Van Aken, Susan; Walker, Danielle; Wanless, David; Wang, Shiliang; White, Brian; White, Owen; Whitehead, Sally; Woodward, John; Wortman, Jennifer; Adams, Mark D; Embley, T Martin; Gull, Keith; Ullu, Elisabetta; Barry, J David; Fairlamb, Alan H; Opperdoes, Fred; Barrell, Barclay G; Donelson, John E; Hall, Neil; Fraser, Claire M; Melville, Sara E; El-Sayed, Najib M

    2005-07-15

    African trypanosomes cause human sleeping sickness and livestock trypanosomiasis in sub-Saharan Africa. We present the sequence and analysis of the 11 megabase-sized chromosomes of Trypanosoma brucei. The 26-megabase genome contains 9068 predicted genes, including approximately 900 pseudogenes and approximately 1700 T. brucei-specific genes. Large subtelomeric arrays contain an archive of 806 variant surface glycoprotein (VSG) genes used by the parasite to evade the mammalian immune system. Most VSG genes are pseudogenes, which may be used to generate expressed mosaic genes by ectopic recombination. Comparisons of the cytoskeleton and endocytic trafficking systems with those of humans and other eukaryotic organisms reveal major differences. A comparison of metabolic pathways encoded by the genomes of T. brucei, T. cruzi, and Leishmania major reveals the least overall metabolic capability in T. brucei and the greatest in L. major. Horizontal transfer of genes of bacterial origin has contributed to some of the metabolic differences in these parasites, and a number of novel potential drug targets have been identified.

  3. Trypanin, a component of the flagellar Dynein regulatory complex, is essential in bloodstream form African trypanosomes.

    Directory of Open Access Journals (Sweden)

    Katherine S Ralston

    2006-09-01

    Full Text Available The Trypanosoma brucei flagellum is a multifunctional organelle with critical roles in motility, cellular morphogenesis, and cell division. Although motility is thought to be important throughout the trypanosome lifecycle, most studies of flagellum structure and function have been restricted to the procyclic lifecycle stage, and our knowledge of the bloodstream form flagellum is limited. We have previously shown that trypanin functions as part of a flagellar dynein regulatory system that transmits regulatory signals from the central pair apparatus and radial spokes to axonemal dyneins. Here we investigate the requirement for this dynein regulatory system in bloodstream form trypanosomes. We demonstrate that trypanin is localized to the flagellum of bloodstream form trypanosomes, in a pattern identical to that seen in procyclic cells. Surprisingly, trypanin RNA interference is lethal in the bloodstream form. These knockdown mutants fail to initiate cytokinesis, but undergo multiple rounds of organelle replication, accumulating multiple flagella, nuclei, kinetoplasts, mitochondria, and flagellum attachment zone structures. These findings suggest that normal flagellar beat is essential in bloodstream form trypanosomes and underscore the emerging concept that there is a dichotomy between trypanosome lifecycle stages with respect to factors that contribute to cell division and cell morphogenesis. This is the first time that a defined dynein regulatory complex has been shown to be essential in any organism and implicates the dynein regulatory complex and other enzymatic regulators of flagellar motility as candidate drug targets for the treatment of African sleeping sickness.

  4. Presence of trypanosome species and anemic status of dogs in Zuru, Nigeria

    Directory of Open Access Journals (Sweden)

    Rafi Rabecca Tono

    2015-10-01

    Full Text Available The aim of this research is to study the presence and prevalence of trypanosome species in local dogs between January and July, 2010 in the Zuru area of Kebbi State, Nigeria.Standard trypanosome detection methods comprising of wet blood films, thin films and microhaematocrit centrifugation technique were used to detect trypanosomes; while the degree of anemia was determined through the use of FAMACHA® eye colour chart and packed cell volume values. A total of 567 dogs were enumerated in fourteen locations within the study area out of which 192 (33.7% were randomly examined and 4 (2.08% were positive for the presence of trypanosomes. All positive samples morphologically belong to the Trypanosoma brucei group. The obtained PCV values showed that 50 (26.04% dogs were anemic, while the FAMACHA® detected anemia status of varying degrees in 104 (77% sampled dogs.These findings are significant as this is the first time that the trypanosome infection will be reported in dogs from the study area. This study establishes the presence of Trypanosoma brucei group in the study area, which is of zoonotic and economic importance.

  5. African Trypanosomes Undermine Humoral Responses and Vaccine Development: Link with Inflammatory Responses?

    Directory of Open Access Journals (Sweden)

    Benoit Stijlemans

    2017-05-01

    Full Text Available African trypanosomosis is a debilitating disease of great medical and socioeconomical importance. It is caused by strictly extracellular protozoan parasites capable of infecting all vertebrate classes including human, livestock, and game animals. To survive within their mammalian host, trypanosomes have evolved efficient immune escape mechanisms and manipulate the entire host immune response, including the humoral response. This report provides an overview of how trypanosomes initially trigger and subsequently undermine the development of an effective host antibody response. Indeed, results available to date obtained in both natural and experimental infection models show that trypanosomes impair homeostatic B-cell lymphopoiesis, B-cell maturation and survival and B-cell memory development. Data on B-cell dysfunctioning in correlation with parasite virulence and trypanosome-mediated inflammation will be discussed, as well as the impact of trypanosomosis on heterologous vaccine efficacy and diagnosis. Therefore, new strategies aiming at enhancing vaccination efficacy could benefit from a combination of (i early parasite diagnosis, (ii anti-trypanosome (drugs treatment, and (iii anti-inflammatory treatment that collectively might allow B-cell recovery and improve vaccination.

  6. Dynamics of gamete production and mating in the parasitic protist Trypanosoma brucei.

    Science.gov (United States)

    Peacock, Lori; Bailey, Mick; Gibson, Wendy

    2016-07-20

    Sexual reproduction in Plasmodium falciparum and Trypanosoma brucei occurs in the insect vector and is important in generating hybrid strains with different combinations of parental characteristics. Production of hybrid parasite genotypes depends on the likelihood of co-infection of the vector with multiple strains. In mosquitoes, existing infection with Plasmodium facilitates the establishment of a second infection, although the asynchronicity of gamete production subsequently prevents mating. In the trypanosome/tsetse system, flies become increasingly refractory to infection as they age, so the likelihood of a fly acquiring a second infection also decreases. This effectively restricts opportunities for trypanosome mating to co-infections picked up by the fly on its first feed, unless an existing infection increases the chance of successful second infection as in the Plasmodium/mosquito system. Using green and red fluorescent trypanosomes, we compared the rates of trypanosome infection and hybrid production in flies co-infected on the first feed, co-infected on a subsequent feed 18 days after emergence, or fed sequentially with each trypanosome clone 18 days apart. Infection rates were highest in the midguts and salivary glands (SG) of flies that received both trypanosome clones in their first feed, and were halved when the infected feed was delayed to day 18. In flies fed the two trypanosome clones sequentially, the second clone often failed to establish a midgut infection and consequently was not present in the SG. Nevertheless, hybrids were recovered from all three groups of infected flies. Meiotic stages and gametes were produced continuously from day 11 to 42 after the infective feed, and in sequentially infected flies, the co-occurrence of gametes led to hybrid formation. We found that a second trypanosome strain can establish infection in the tsetse SG 18 days after the first infected feed, with co-mingling of gametes and production of trypanosome hybrids

  7. Parasites in motion: flagellum-driven cell motility in African trypanosomes

    Science.gov (United States)

    Hill, Kent L.

    2011-01-01

    SUMMARY Motility of the sleeping sickness parasite, Trypanosoma brucei, impacts disease transmission and pathogenesis. Trypanosome motility is driven by a flagellum that harbors a canonical 9 + 2 axoneme, together with trypanosome-specific elaborations. Trypanosome flagellum biology and motility have been the object of intense research over the last two years. These studies have led to the discovery of a novel form of motility, termed social motility, and provided revision of long-standing models for cell propulsion. Recent work has also uncovered novel structural features and motor proteins associated with the flagellar apparatus and has identified candidate signaling molecules that are predicted to regulate flagellar motility. Together with earlier inventories of flagellar proteins from proteomic and genomic studies, the stage is now set to move forward with functional studies to elucidate molecular mechanisms and investigate parasite motility in the context of host-parasite interactions. PMID:20591724

  8. Trypanosome species, including Trypanosoma cruzi, in sylvatic and peridomestic bats of Texas, USA.

    Science.gov (United States)

    Hodo, Carolyn L; Goodwin, Chloe C; Mayes, Bonny C; Mariscal, Jacqueline A; Waldrup, Kenneth A; Hamer, Sarah A

    2016-12-01

    In contrast to other mammalian reservoirs, many bat species migrate long-distances and have the potential to introduce exotic pathogens to new areas. Bats have long been associated with blood-borne protozoal trypanosomes of the Schizotrypanum subgenus, which includes the zoonotic parasite Trypanosoma cruzi, agent of Chagas disease. Another member of the subgenus, Trypanosoma dionisii, infects bats of Europe and South America, and genetic similarities between strains from the two continents suggest transcontinental movement of this parasite via bats. Despite the known presence of diverse trypanosomes in bats of Central and South America, and the presence of T. cruzi-infected vectors and wildlife in the US, the role of bats in maintaining and dispersing trypanosomes in the US has not yet been reported. We collected hearts and blood from 8 species of insectivorous bats from 30 counties across Texas. Using PCR and DNA sequencing, we tested 593 bats for trypanosomes and found 1 bat positive for T. cruzi (0.17%), 9 for T. dionisii (1.5%), and 5 for Blastocrithidia spp. (0.8%), a group of insect trypanosomes. The T. cruzi-infected bat was carrying TcI, the strain type associated with human disease in the US. In the T. dionisii-infected bats, we detected three unique variants associated with the three infected bat species. These findings represent the first report of T. cruzi in a bat in the US, of T. dionisii in North America, and of Blastocrithidia spp. in mammals, and underscore the importance of bats in the maintenance of trypanosomes, including agents of human and animal disease, across broad geographic locales. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  9. Post-transcriptional regulation of the trypanosome heat shock response by a zinc finger protein.

    Directory of Open Access Journals (Sweden)

    Dorothea Droll

    Full Text Available In most organisms, the heat-shock response involves increased heat-shock gene transcription. In Kinetoplastid protists, however, virtually all control of gene expression is post-transcriptional. Correspondingly, Trypanosoma brucei heat-shock protein 70 (HSP70 synthesis after heat shock depends on regulation of HSP70 mRNA turnover. We here show that the T. brucei CCCH zinc finger protein ZC3H11 is a post-transcriptional regulator of trypanosome chaperone mRNAs. ZC3H11 is essential in bloodstream-form trypanosomes and for recovery of insect-form trypanosomes from heat shock. ZC3H11 binds to mRNAs encoding heat-shock protein homologues, with clear specificity for the subset of trypanosome chaperones that is required for protein refolding. In procyclic forms, ZC3H11 was required for stabilisation of target chaperone-encoding mRNAs after heat shock, and the HSP70 mRNA was also decreased upon ZC3H11 depletion in bloodstream forms. Many mRNAs bound to ZC3H11 have a consensus AUU repeat motif in the 3'-untranslated region. ZC3H11 bound preferentially to AUU repeats in vitro, and ZC3H11 regulation of HSP70 mRNA in bloodstream forms depended on its AUU repeat region. Tethering of ZC3H11 to a reporter mRNA increased reporter expression, showing that it is capable of actively stabilizing an mRNA. These results show that expression of trypanosome heat-shock genes is controlled by a specific RNA-protein interaction. They also show that heat-shock-induced chaperone expression in procyclic trypanosome enhances parasite survival at elevated temperatures.

  10. Host-Parasite Relationships and Life Histories of Trypanosomes in Australia.

    Science.gov (United States)

    Cooper, C; Clode, P L; Peacock, C; Thompson, R C A

    2017-01-01

    Trypanosomes constitute a group of flagellate protozoan parasites responsible for a number of important, yet neglected, diseases in both humans and livestock. The most significantly studied include the causative agents of African sleeping sickness (Trypanosoma brucei) and Chagas disease (Trypanosoma cruzi) in humans. Much of our knowledge about trypanosome host-parasite relationships and life histories has come from these two human pathogens. Recent investigations into the diversity and life histories of wildlife trypanosomes in Australia highlight that there exists a great degree of biological and behavioural variation within and between trypanosomes. In addition, the genetic relationships between some Australian trypanosomes show that they are unexpectedly more closely related to species outside Australia than within it. These findings have led to a growing focus on the importance of understanding parasites occurring naturally in wildlife to (1) better document parasite biodiversity, (2) determine evolutionary relationships and degree of host specificity, (3) understand host-parasite interactions and the role of parasites in the natural ecosystem and (4) identify biosecurity issues of emerging disease in both wildlife and human populations. Here we review what is known about the diversity, life histories, host-parasite interactions and evolutionary relationships of trypanosomes in Australian wildlife. In this context, we focus upon the genetic proximity of key Australian species to the pathogenic T. cruzi and discuss similarities in their biology and behaviour that present a potential risk of human disease transmission by Australian vectors and wildlife. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Anti-trypanosomal activity of pentacyclic triterpenes isolated from Austroplenckia populnea (Celastraceae).

    Science.gov (United States)

    Duarte, Lucienir Pains; Vieira Filho, Sidney Augusto; Silva, Grácia Divina de Fátima; de Sousa, José Rego; Pinto, Artur da Silveira

    2002-01-01

    Four pentacyclic triterpenes isolated from Austroplenckia populnea and four compounds of known anti T. cruzi or anti-malarial activity were tested. Of those triterpenes tested 20alpha-hydroxy-tingenone showed high activity, epikatonic acid was less active, while populnilic and populninic acids were inactive against the trypanosome of the subgenus Schizotrypanum tested. Benzonidazole, nifurtimox, ketoconazole and primaquine presented a remarkable dose-dependent inhibitory effect reaching practically to a total growth inhibition of the parasite at the end of incubation time. The trypanosome tested appear to be a suitable model for preliminary screen for anti T. (S.) cruzi compounds.

  12. Flying Cities

    DEFF Research Database (Denmark)

    Herbelin, Bruno; Lasserre, Sebastien; Ciger, Jan

    2008-01-01

    Flying Cities is an artistic installation which generates imaginary cities from the speech of its visitors. Thanks to an original interactive process analyzing people's vocal input to create 3D graphics, a tangible correspondence between speech and visuals opens new possibilities of interaction. ...... and a potential application. We believe that it could become a new medium for creativity, and a way to visually perceive a vocal performance in the context of the rehabilitation of people with reduced mobility or language impairments....

  13. Horn fly (Diptera: Muscidae) saliva targets thrombin action in hemostasis.

    Science.gov (United States)

    Cupp, M S; Zhang, D; Cupp, E W

    2000-05-01

    The horn fly, Hematobia irritans (L.), is an important pest of livestock because the adult stage of both sexes are aggressive blood-feeders. Remarkably, even though horn fly adults feed recurrently on their hosts as ectoparasites, these flies lack the ADP-responsive antiplatelet aggregation and vasodilatory antihemostatic systems described for other blood-feeding Diptera. Horn fly salivary gland extracts do interfere with the normal coagulation process as demonstrated by the recalcification time assay. Using this as a baseline, the effects of saliva on recalcification time, activated partial thromboplastin time, prothrombin time, and thrombin time were measured to determine which arm(s) of the coagulation cascade might be impacted. Factor-deficient plasma assays also were used to measure possible perturbations in clotting. Gland-free saliva delayed the recalcification time as well as the activated partial thromboplastin time, prothrombin time, and thrombin time. Saliva also further delayed clotting times of plasmas deficient in factor V, factor VIII, and factor XIII, indicating that other factors in the coagulation cascade were inhibited. Although horn fly saliva did not alter the ability of deficient plasma reconstituted with factor X to clot, it did inhibit deficient plasma reconstituted with factor II (thrombin). Antithrombin activity in saliva was confirmed by its ability to interfere with thrombin hydrolysis of fibrinogen, its normal substrate, and by its inhibition of thrombin action on a chromagenic substrate that mimics the hydrolytic site of fibrinogen. Thus, horn fly saliva contains a factor that specifically targets thrombin, a key component in the coagulation cascade. While the biochemical mechanisms of inhibition may vary, this antihemostatic characteristic is shared with other zoophilic Diptera such as black flies, Simulium spp., and tsetse, Glossina morsitans morsitans Westwood, that feed on ungulates.

  14. Drug uptake (DAPI) of trypanosomes (T. brucei) and antitrypanosomal activity in vitro, in culture and in vivo studied by microscope fluorometry, chromatogram spectrophotometry and radiotracer techniques

    International Nuclear Information System (INIS)

    Kratzer, R.D.

    1982-01-01

    The present study had the following objectives: 1) Investigation of the specific binding and location of the diamidine DAPI within trypanosomes by fluorescence microscopy. 2) Development and standardization of a microscope fluorometry technique for measuring DAPI uptake of single trypanosomes. 3) Determination of the effect of incubation media, exposure time, and drug concentration on DAPI uptake of single trypanosomes. 4) Development of a technique applicable for quantitative fluorescence chemical analysis of DAPI uptake of trypanosomes. 5) Determination of drug uptake of trypanosomes using 14 C labelled DAPI. 6) Comparison of the values obtained by the three methods. (orig./MG)

  15. Beyond Tsetse--Implications for Research and Control of Human African Trypanosomiasis Epidemics.

    Science.gov (United States)

    Welburn, Susan C; Molyneux, David H; Maudlin, Ian

    2016-03-01

    Epidemics of both forms of human African trypanosomiasis (HAT) are confined to spatially stable foci in Sub-Saharan Africa while tsetse distribution is widespread. Infection rates of Trypanosoma brucei gambiense in tsetse are extremely low and cannot account for the catastrophic epidemics of Gambian HAT (gHAT) seen over the past century. Here we examine the origins of gHAT epidemics and evidence implicating human genetics in HAT epidemiology. We discuss the role of stress causing breakdown of heritable tolerance in silent disease carriers generating gHAT outbreaks and see how peculiarities in the epidemiologies of gHAT and Rhodesian HAT (rHAT) impact on strategies for disease control. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. [Population growth and global warming: impacts on tsetse and trypanosomoses in West Africa].

    Science.gov (United States)

    Courtin, F; Sidibé, I; Rouamba, J; Jamonneau, V; Gouro, A; Solano, P

    2009-03-01

    Demographic evolution, climatic change and economical development that happened in West Africa during the XXth century had a lot of consequences on human settlement and landscape. These changes have in turn an impact on the pathogenic system of human and animal trypanosomoses. Since last century, the northern tsetse distribution limit has shifted towards the south, probably due to a decrease in rainfall combined to the impact of human pressure. Sleeping sickness (SS) foci have also shifted from the savannah areas (where there is no more SS) to the forest and mangrove areas of West Africa, but animal trypanosomoses are still present in savannah. We show a decrease of tsetse of the morsitans group as a result of an increase of human densities. On the opposite, tsetse species like Glossina palpalis adapt to high human densities and are found in the biggest urban centres of West Africa. There is a need to promote multidisciplinary studies on this demographic-climatic-vector borne disease topic, especially in Africa to be able to define future areas of presence/absence of these diseases in order to help continental plans of control that have recently begun.

  17. Fly Sings

    OpenAIRE

    Osmond, Matthew

    2015-01-01

    Fly Sings (winner of the Bitish Library's 2015 Michael Marks Poetry Illustration award) forms the first installment of a prequel to the deadman and hare stories. It concerns how hare first came to be ‘summoned to the world below’, to look for deadman.\\ud \\ud Strandline Books chapbooks are produced as signed and numbered editions of 48, printed in black inkjet on 90gsm off-white recycled paper. They sell at £8 + £2 p&p. If interested, please email Mat Osmond at

  18. Flying Cities

    DEFF Research Database (Denmark)

    Ciger, Jan

    2006-01-01

    of providing a tangible correspondence between the two spaces. This interaction mean has proved to suit the artistic expression well but it also aims at providing anyone with a pleasant and stimulating feedback from speech activity, a new medium for creativity and a way to visually perceive a vocal performance......The Flying Cities artistic installation brings to life imaginary cities made from the speech input of visitors. In this article we describe the original interactive process generating real time 3D graphics from spectators' vocal inputs. This example of cross-modal interaction has the nice property...

  19. Anti-trypanosomal activity of ethanolic bulb extract of Allium porrum ...

    African Journals Online (AJOL)

    Twenty-five male albino rats were divided into five groups and used for the study. Day 5 post-infection and establishment of parasitemia (1x106 trypanosomes/ml of blood), Group 1 was untreated while Groups 2-4 were treated with single intraperitoneal injection 50, 75 and 100 mg/kg of ethanolic extract of A. porrum ...

  20. Protein diversity in discrete structures at the distal tip of the trypanosome flagellum

    Czech Academy of Sciences Publication Activity Database

    Varga, Vladimír; Moreira-Leite, F.; Portman, N.; Gull, K.

    2017-01-01

    Roč. 114, č. 32 (2017), E6546-E6555 ISSN 0027-8424 Institutional support: RVO:68378050 Keywords : flagellar distal end * trypanosome * flagella connector * axonemal capping structure * structure immunoprecipitation Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Cell biology Impact factor: 9.661, year: 2016

  1. Diversity of bats trypanosomes in hydroeletric area of Belo Monte in Brazilian Amazonia.

    Science.gov (United States)

    da Costa, Andréa P; Nunes, Pablo Henrique; Leite, Beatriz Helena Santos; Ferreira, Juliana Isabel G da S; Tonhosolo, Renata; da Rosa, Adriana Ruckert; da Rocha, Patricio Adriano; Aires, Caroline Cotrim; Gennari, Solange Maria; Marcili, Arlei

    2016-12-01

    The Trypanosoma comprises flagellates able to infect many mammalian species and is transmitted by several groups of invertebrates. The order Chiroptera can be infected by the subgenera Herpetosoma, Schizotrypanum, Megatrypanum and Trypanozoon. In this study, we described the diversity of bats trypanosomes, inferring the phylogenetic relationships among the trypanosomes from bats caught Belo Monte Hydroeletric area (Brazilian Amazonia). Trypanosomes from bats were isolated by haemoculture, and the molecular phylogeny based on small subunit rDNA (SSU rDNA) and glycosomal-3-phosphate dehydrogenase (gGAPDH) gene sequences. Morphological characterization included light and scanning electron microscopy. A total of 157 bats were caught in the area belonging 6 Families (Emballonuridae, Furipteridae, Mormoopidae, Natalidae, Phyllostomidae and Vespertilionidae) and 34 species. The bat trypanosome prevalence, as evaluated through haemoculture, was 5,7%. Phylogenetic trees grouped the isolates in T. cruzi branch (TCI and TCbat lineage), T. cruzi marinkellei and Trypanosoma wauwau from Pteronotus parnellii. This is the first isolate from T. wauwau in Para state. The occurrence of T. cruzi in the ​​ Belo Monte Hydroeletric area (UHE Belo Monte) in Amazon/Brazil attentive to the risk of migration human population required for the works of the dam and new cities that grow in the vicinity of these businesses, but it is a zoonosis already known to the Amazon region, and the presence of unclassified Trypanosoma species, attend to the large parasitic biodiversity still unknown. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Diglycosyl diselenides alter redox homeostasis and glucose consumption of infective African trypanosomes

    Directory of Open Access Journals (Sweden)

    Jaime Franco

    2017-12-01

    Full Text Available With the aim to develop compounds able to target multiple metabolic pathways and, thus, to lower the chances of drug resistance, we investigated the anti-trypanosomal activity and selectivity of a series of symmetric diglycosyl diselenides and disulfides. Of 18 compounds tested the fully acetylated forms of di-β-D-glucopyranosyl and di-β-D-galactopyranosyl diselenides (13 and 15, respectively displayed strong growth inhibition against the bloodstream stage of African trypanosomes (EC50 0.54 μM for 13 and 1.49 μM for 15 although with rather low selectivity (SI < 10 assayed with murine macrophages. Nonacetylated versions of the same sugar diselenides proved to be, however, much less efficient or completely inactive to suppress trypanosome growth. Significantly, the galactosyl (15, and to a minor extent the glucosyl (13, derivative inhibited glucose catabolism but not its uptake. Both compounds induced redox unbalance in the pathogen. In vitro NMR analysis indicated that diglycosyl diselenides react with glutathione, under physiological conditions, via formation of selenenylsulfide bonds. Our results suggest that non-specific cellular targets as well as actors of the glucose and the redox metabolism of the parasite may be affected. These molecules are therefore promising leads for the development of novel multitarget antitrypanosomal agents. Keywords: Glutathione, Redox biosensor, Selenosugar, Trypanosome inhibition, Selenium NMR

  3. Isolation and phylogenetic relationships of bat trypanosomes from different biomes in Mato Grosso, Brazil.

    Science.gov (United States)

    Marcili, Arlei; da Costa, Andrea P; Soares, Herbert S; Acosta, Igor da C L; de Lima, Julia T R; Minervino, Antonio H H; Melo, Andréia T L; Aguiar, Daniel M; Pacheco, Richard C; Gennari, Solange M

    2013-12-01

    In the order Chiroptera, more than 30 trypanosome species belonging to the subgenera Herpetosoma, Schizotrypanum, Megatrypanum, and Trypanozoon have been described. The species Trypanosoma cruzi , Trypanosoma cruzi marinkellei, and Trypanosoma dionisii are the most common in bats and belong to the Schizotrypanum subgenus. Bats from 2 different biomes, Pantanal and Amazonia/Cerrado in the state of Mato Grosso, Brazil, were evaluated according to the presence of trypanosome parasites by means of hemoculture and PCR in primary samples (blood samples). A total of 211 bats from 20 different species were caught and the trypanosome prevalence, evaluated through hemoculture, was 9.0% (19), 15.5% (13), and 4.8% (6) in the municipalities of Confresa (Amazonia/Cerrado biome) and Poconé (Pantanal biome). Among the 123 primary samples obtained from the bats, only 3 (2.4%) were positive. Phylogenetic analysis using trypanosomatid barcoding (V7V8 region of SSU rDNA) identified all the isolates and primary samples as T. c. marinkellei. The sequences of the isolates were segregated according to the bat host genus or species and suggest that co-evolutionary patterns exist between hosts and parasites. Further studies in different Brazilian regions and biomes need to be conducted in order to gain real understanding of the diversity of trypanosomes in bats.

  4. Modeling the locomotion of the African trypanosome using multi-particle collision dynamics

    International Nuclear Information System (INIS)

    Babu, Sujin B; Stark, Holger

    2012-01-01

    The African trypanosome is a single flagellated micro-organism that causes the deadly sleeping sickness in humans and animals. We study the locomotion of a model trypanosome by modeling the spindle-shaped cell body using an elastic network of vertices with additional bending rigidity. The flagellum firmly attached to the model cell body is either straight or helical. A bending wave propagates along the flagellum and pushes the trypanosome forward in its viscous environment, which we simulate with the method of multi-particle collision dynamics. The relaxation dynamics of the model cell body due to a static bending wave reveals the sperm number from elastohydrodynamics as the relevant parameter. Characteristic cell body conformations for the helically attached flagellum resemble experimental observations. We show that the swimming velocity scales as the root of the angular frequency of the bending wave reminiscent of predictions for an actuated slender rod attached to a large viscous load. The swimming velocity for one geometry collapses on a single master curve when plotted versus the sperm number. The helically attached flagellum leads to a helical swimming path and a rotation of the model trypanosome about its long axis as observed in experiments. The simulated swimming velocity agrees with the experimental value. (paper)

  5. Anti-trypanosomal activity of cationic N-heterocyclic carbene gold(I) complexes.

    Science.gov (United States)

    Winter, Isabel; Lockhauserbäumer, Julia; Lallinger-Kube, Gertrud; Schobert, Rainer; Ersfeld, Klaus; Biersack, Bernhard

    2017-06-01

    Two gold(I) N-heterocyclic carbene complexes 1a and 1b were tested for their anti-trypanosomal activity against Trypanosoma brucei parasites. Both gold compounds exhibited excellent anti-trypanosomal activity (IC 50 =0.9-3.0nM). The effects of the gold complexes 1a and 1b on the T. b. brucei cytoskeleton were evaluated. Rapid detachment of the flagellum from the cell body occurred after treatment with the gold complexes. In addition, a quick and complete degeneration of the parasitic cytoskeleton was induced by the gold complexes, only the microtubules of the detached flagellum remained intact. Both gold compounds 1a and 1b feature selective anti-trypanosomal agents and were distinctly more active against T. b. brucei cells than against human HeLa cells. Thus, the gold complexes 1a and 1b feature promising drug candidates for the treatment of trypanosome infections such as sleeping sickness (human African Trypanosomiasis caused by Trypanosoma brucei parasites). Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Evolution of the serum resistance-associated SRA gene in African trypanosomes

    Czech Academy of Sciences Publication Activity Database

    Lai, D. H.; Wang, Q.P.; Lukeš, Julius; Lun, Z.R.

    2009-01-01

    Roč. 54, č. 7 (2009), s. 1275-1278 ISSN 1001-6538 R&D Projects: GA MŠk 2B06129 Institutional research plan: CEZ:AV0Z60220518 Keywords : SRA * SRAbc * evolution * African trypanosomes Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 0.898, year: 2009

  7. Integrity of the core mitochondrial RNA-binding complex 1/nis vital for trypanosome RNA editing

    Czech Academy of Sciences Publication Activity Database

    Huang, Zhenqiu; Faktorová, Drahomíra; Křížová, A.; Kafková, L.; Read, L. K.; Lukeš, Julius; Hashimi, Hassan

    2015-01-01

    Roč. 21, č. 12 (2015), s. 2088-2102 ISSN 1355-8382 R&D Projects: GA ČR GA15-21974S EU Projects: European Commission(XE) 289007 Institutional support: RVO:60077344 Keywords : RNA editing * mitochondrion * trypanosome Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.344, year: 2015

  8. Hemoglobin is a co-factor of human trypanosome lytic factor

    DEFF Research Database (Denmark)

    Widener, Justin; Nielsen, Marianne Jensby; Shiflett, April

    2007-01-01

    Trypanosome lytic factor (TLF) is a high-density lipoprotein (HDL) subclass providing innate protection to humans against infection by the protozoan parasite Trypanosoma brucei brucei. Two primate-specific plasma proteins, haptoglobin-related protein (Hpr) and apolipoprotein L-1 (ApoL-1), have be...

  9. Trypanosome motion represents an adaptation to the crowded environment of the vertebrate bloodstream.

    Directory of Open Access Journals (Sweden)

    Niko Heddergott

    Full Text Available Blood is a remarkable habitat: it is highly viscous, contains a dense packaging of cells and perpetually flows at velocities varying over three orders of magnitude. Only few pathogens endure the harsh physical conditions within the vertebrate bloodstream and prosper despite being constantly attacked by host antibodies. African trypanosomes are strictly extracellular blood parasites, which evade the immune response through a system of antigenic variation and incessant motility. How the flagellates actually swim in blood remains to be elucidated. Here, we show that the mode and dynamics of trypanosome locomotion are a trait of life within a crowded environment. Using high-speed fluorescence microscopy and ordered micro-pillar arrays we show that the parasites mode of motility is adapted to the density of cells in blood. Trypanosomes are pulled forward by the planar beat of the single flagellum. Hydrodynamic flow across the asymmetrically shaped cell body translates into its rotational movement. Importantly, the presence of particles with the shape, size and spacing of blood cells is required and sufficient for trypanosomes to reach maximum forward velocity. If the density of obstacles, however, is further increased to resemble collagen networks or tissue spaces, the parasites reverse their flagellar beat and consequently swim backwards, in this way avoiding getting trapped. In the absence of obstacles, this flagellar beat reversal occurs randomly resulting in irregular waveforms and apparent cell tumbling. Thus, the swimming behavior of trypanosomes is a surprising example of micro-adaptation to life at low Reynolds numbers. For a precise physical interpretation, we compare our high-resolution microscopic data to results from a simulation technique that combines the method of multi-particle collision dynamics with a triangulated surface model. The simulation produces a rotating cell body and a helical swimming path, providing a functioning

  10. Generation of a nanobody targeting the paraflagellar rod protein of trypanosomes.

    Directory of Open Access Journals (Sweden)

    Emmanuel Obishakin

    Full Text Available Trypanosomes are protozoan parasites that cause diseases in humans and livestock for which no vaccines are available. Disease eradication requires sensitive diagnostic tools and efficient treatment strategies. Immunodiagnostics based on antigen detection are preferable to antibody detection because the latter cannot differentiate between active infection and cure. Classical monoclonal antibodies are inaccessible to cryptic epitopes (based on their size-150 kDa, costly to produce and require cold chain maintenance, a condition that is difficult to achieve in trypanosomiasis endemic regions, which are mostly rural. Nanobodies are recombinant, heat-stable, small-sized (15 kDa, antigen-specific, single-domain, variable fragments derived from heavy chain-only antibodies in camelids. Because of numerous advantages over classical antibodies, we investigated the use of nanobodies for the targeting of trypanosome-specific antigens and diagnostic potential. An alpaca was immunized using lysates of Trypanosoma evansi. Using phage display and bio-panning techniques, a cross-reactive nanobody (Nb392 targeting all trypanosome species and isolates tested was selected. Imunoblotting, immunofluorescence microscopy, immunoprecipitation and mass spectrometry assays were combined to identify the target recognized. Nb392 targets paraflagellar rod protein (PFR1 of T. evansi, T. brucei, T. congolense and T. vivax. Two different RNAi mutants with defective PFR assembly (PFR2RNAi and KIF9BRNAi were used to confirm its specificity. In conclusion, using a complex protein mixture for alpaca immunization, we generated a highly specific nanobody (Nb392 that targets a conserved trypanosome protein, i.e., PFR1 in the flagella of trypanosomes. Nb392 is an excellent marker for the PFR and can be useful in the diagnosis of trypanosomiasis. In addition, as demonstrated, Nb392 can be a useful research or PFR protein isolation tool.

  11. Detection of an Unknown Trypanosoma DNA in a Phlebotomus stantoni (Diptera: Psychodidae) Collected From Southern Thailand and Records of New Sand Flies With Reinstatement of Sergentomyia hivernus Raynal & Gaschen, 1935 (Diptera: Psychodidae).

    Science.gov (United States)

    Phumee, Atchara; Tawatsin, Apiwat; Thavara, Usavadee; Pengsakul, Theerakamol; Thammapalo, Suwich; Depaquit, Jérôme; Gay, Frédérick; Siriyasatien, Padet

    2017-03-01

    Although female sand flies are best known as the vectors of Leishmania parasites and viruses, several previous reports have demonstrated that these insects can also act as vectors for the trypanosomes of bats, lizards, and snakes. In this report, we created an inventory of Phlebotomine sand flies from southern Thailand. A novel trypanosome was found in a specimen of Phlebotomus stantoni, and two sand fly species newly recorded in the country, Sergentomyia khawi and Sergentomyia hivernus, were described. PCR primer pairs specific for the internal transcribed spacer 1 (ITS1) and the small subunit ribosomal DNA (SSU rDNA) gene of trypanosomatids were used to demonstrate the presence of the parasite in the sand fly. In addition, the Cytochrome b (CytB) gene was used to identify the sand fly species. Among the 45 samples of the sand fly that were collected, seven samples were Ph. stantoni sand flies and a single sample was positive for Trypanosoma sp. through PCR analysis. This study represents the first detection of Trypanosoma sp. in a sand fly from Thailand. The ITS1 and SSU rDNA sequences indicated that this specimen is suspected to be a novel Trypanosoma species. Further studies of this suspected new Trypanosoma species, including its vertebrate hosts and pathogenic potential, are therefore necessary. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  12. Proteomics on the rims: insights into the biology of the nuclear envelope and flagellar pocket of trypanosomes.

    Science.gov (United States)

    Field, Mark C; Adung'a, Vincent; Obado, Samson; Chait, Brian T; Rout, Michael P

    2012-08-01

    Trypanosomatids represent the causative agents of major diseases in humans, livestock and plants, with inevitable suffering and economic hardship as a result. They are also evolutionarily highly divergent organisms, and the many unique aspects of trypanosome biology provide opportunities in terms of identification of drug targets, the challenge of exploiting these putative targets and, at the same time, significant scope for exploration of novel and divergent cell biology. We can estimate from genome sequences that the degree of divergence of trypanosomes from animals and fungi is extreme, with perhaps one third to one half of predicted trypanosome proteins having no known function based on homology or recognizable protein domains/architecture. Two highly important aspects of trypanosome biology are the flagellar pocket and the nuclear envelope, where in silico analysis clearly suggests great potential divergence in the proteome. The flagellar pocket is the sole site of endo- and exocytosis in trypanosomes and plays important roles in immune evasion via variant surface glycoprotein (VSG) trafficking and providing a location for sequestration of various invariant receptors. The trypanosome nuclear envelope has been largely unexplored but, by analogy with higher eukaryotes, roles in the regulation of chromatin and most significantly, in controlling VSG gene expression are expected. Here we discuss recent successful proteomics-based approaches towards characterization of the nuclear envelope and the endocytic apparatus, the identification of conserved and novel trypanosomatid-specific features, and the implications of these findings.

  13. Population genetics of Trypanosoma brucei circulating in Glossina palpalis palpalis and domestic animals of the Fontem sleeping sickness focus of Cameroon

    Science.gov (United States)

    2014-01-01

    Background Human African Trypanosomiasis is still a public health threat in Cameroon. To assess Trypanosoma brucei strains circulating in the Fontem sleeping sickness focus, we conducted a genetic structure study using microsatellites to assess genotypes circulating in both tsetse flies and domestic animals. Method For this study, pyramidal traps were set up and 2695 tsetse flies were collected and 1535 (57%) living flies were dissected and their mid-guts collected. Furthermore, blood samples were collected from 397 domestic animals (pigs, goats, sheep and dogs). DNA was extracted from midguts and blood samples, and specific primers were used to identify trypanosomes of the subgenus Trypanozoon. All positive samples were genetically characterized with seven microsatellite markers. Results Seventy five (4.7%) midguts of tsetse flies and 140 (35.2%) domestic animals were found infected by trypanosomes of the subgenus Trypanozoon. The genetic characterization of 215 Trypanozoon positive samples (75 from tsetse and 140 from animals) revealed a genetic diversity between Trypanosoma brucei circulating in tsetse and domestic animals. Of these positive samples, 87 (40.5%) single infections were used here to investigate the population genetics of Trypanosoma brucei circulating in tsetse and domestic animals. The dendrogram illustrating the genetic similarities between Trypanosoma brucei genotypes was subdivided into four clusters. The samples from tsetse belonged to the same cluster whereas the samples from domestic animals and espcially pigs were distributed in the four clusters. Conclusion Pigs appeared as the animal species harboring the highest number of different Trypanosoma brucei strains. They may play an important role in the propagation of different genotypes. The FST values revealed a sub structuration of Trypanosoma brucei according to hosts and sometimes villages. The data obtained from this study may have considerable importance for the understanding of the

  14. Aquaglyceroporin-null trypanosomes display glycerol transport defects and respiratory-inhibitor sensitivity.

    Directory of Open Access Journals (Sweden)

    Laura Jeacock

    2017-03-01

    Full Text Available Aquaglyceroporins (AQPs transport water and glycerol and play important roles in drug-uptake in pathogenic trypanosomatids. For example, AQP2 in the human-infectious African trypanosome, Trypanosoma brucei gambiense, is responsible for melarsoprol and pentamidine-uptake, and melarsoprol treatment-failure has been found to be due to AQP2-defects in these parasites. To further probe the roles of these transporters, we assembled a T. b. brucei strain lacking all three AQP-genes. Triple-null aqp1-2-3 T. b. brucei displayed only a very moderate growth defect in vitro, established infections in mice and recovered effectively from hypotonic-shock. The aqp1-2-3 trypanosomes did, however, display glycerol uptake and efflux defects. They failed to accumulate glycerol or to utilise glycerol as a carbon-source and displayed increased sensitivity to salicylhydroxamic acid (SHAM, octyl gallate or propyl gallate; these inhibitors of trypanosome alternative oxidase (TAO can increase intracellular glycerol to toxic levels. Notably, disruption of AQP2 alone generated cells with glycerol transport defects. Consistent with these findings, AQP2-defective, melarsoprol-resistant clinical isolates were sensitive to the TAO inhibitors, SHAM, propyl gallate and ascofuranone, relative to melarsoprol-sensitive reference strains. We conclude that African trypanosome AQPs are dispensable for viability and osmoregulation but they make important contributions to drug-uptake, glycerol-transport and respiratory-inhibitor sensitivity. We also discuss how the AQP-dependent inverse sensitivity to melarsoprol and respiratory inhibitors described here might be exploited.

  15. Patterns of genetic diversity and differentiation in the tsetse fly Glossina morsitans morsitans Westwood populations in East and southern Africa

    International Nuclear Information System (INIS)

    Ouma, J.O.; Marquez, J.G.; Krafsur, E.S

    2007-01-01

    Genetic diversity and differentiation within and among nine G. morsitans morsitans populations from East and southern Africa was assessed by examining variation at seven microsatellite loci and a mitochondrial locus, cytochrome oxidase (COI). Mean COI diversity within populations was 0.63 ± 0.33 and 0.81 taken over all populations. Diversities averaged over microsatellite loci were high (mean number of alleles/locus ≥7.4; mean HE ≥ 65%) in all populations. Diversities averaged across populations were greater in East Africa (mean number of alleles = 22 ± 2.6; mean he = 0.773 ± 0.033) than in southern Africa (mean number of alleles = 18.7 ± 4.0; mean he = 0.713 ± 0.072). Differentiation among all populations was highly significant (RST = 0.25, FST = 0.132). Nei’s Gij statistics were 0.09 and 0.19 within regions for microsatellites and mitochondria, respectively; between regions, Gij was 0.14 for microsatellites and 0.23 for mitochondria. GST among populations was 0.23 for microsatellite loci and 0.40 for mitochondria. The F, G and R statistics indicate highly restricted gene flow among G. m. morsitans populations separated over geographic scales of 12–917 km. (author)

  16. Flying insects and Campylobacter

    DEFF Research Database (Denmark)

    Hald, Birthe; Sommer, Helle Mølgaard; Skovgård, Henrik

    Campylobacter in flies Flies of the Muscidae family forage on all kind of faeces – various fly species have different preferences. M domestica prefer pigs, horses and cattle faeces, animals which are all known to frequently excrete Campylobacter. As a result, the insects pick up pathogenic micro...... organisms, which may collect on their bodies or survive passage through the fly gut. Campylobacter and other pathogens are then easily transferred to other surfaces, for instance peoples food – or to broiler houses where they may be swallowed by chickens or contaminate the environment. On a large material...... of several species of flies collected outside broiler houses, merely ~1% of the flies were found Campylobacter positive. However, the prevalence varied considerably with fly species, time of the year, and availability of Campylobacter sources. Influx of flies to broiler houses As the influx of flies...

  17. Global proteomic analysis in trypanosomes reveals unique proteins and conserved cellular processes impacted by arginine methylation.

    Science.gov (United States)

    Lott, Kaylen; Li, Jun; Fisk, John C; Wang, Hao; Aletta, John M; Qu, Jun; Read, Laurie K

    2013-10-08

    Arginine methylation is a common posttranslational modification with reported functions in transcription, RNA processing and translation, and DNA repair. Trypanosomes encode five protein arginine methyltransferases, suggesting that arginine methylation exerts widespread impacts on the biology of these organisms. Here, we performed a global proteomic analysis of Trypanosoma brucei to identify arginine methylated proteins and their sites of modification. Using an approach entailing two-dimensional chromatographic separation and alternating electron transfer dissociation and collision induced dissociation, we identified 1332 methylarginines in 676 proteins. The resulting data set represents the largest compilation of arginine methylated proteins in any organism to date. Functional classification revealed numerous arginine methylated proteins involved in flagellar function, RNA metabolism, DNA replication and repair, and intracellular protein trafficking. Thus, arginine methylation has the potential to impact aspects of T. brucei gene expression, cell biology, and pathogenesis. Interestingly, pathways with known methylated proteins in higher eukaryotes were identified in this study, but often different components of the pathway were methylated in trypanosomes. Methylarginines were often identified in glycine rich contexts, although exceptions to this rule were detected. Collectively, these data inform on a multitude of aspects of trypanosome biology and serve as a guide for the identification of homologous arginine methylated proteins in higher eukaryotes. T. brucei is a protozoan parasite that causes lethal African sleeping sickness in humans and nagana in livestock, thereby imposing a significant medical and economic burden on sub-Saharan Africa. The parasite encounters very different environments as it cycles between mammalian and insect hosts, and must exert cellular responses to these varying milieus. One mechanism by which all cells respond to changing

  18. The evolution of pathogenic trypanosomes A evolução dos tripanossomas patogênicos

    Directory of Open Access Journals (Sweden)

    Jamie R. Stevens

    1999-10-01

    Full Text Available In the absence of a fossil record, the evolution of protozoa has until recently largely remained a matter for speculation. However, advances in molecular methods and phylogenetic analysis are now allowing interpretation of the "history written in the genes". This review focuses on recent progress in reconstruction of trypanosome phylogeny based on molecular data from ribosomal RNA, the miniexon and protein-coding genes. Sufficient data have now been gathered to demonstrate unequivocally that trypanosomes are monophyletic; the phylogenetic trees derived can serve as a framework to reinterpret the biology, taxonomy and present day distribution of trypanosome species, providing insights into the coevolution of trypanosomes with their vertebrate hosts and vectors. Different methods of dating the divergence of trypanosome lineages give rise to radically different evolutionary scenarios and these are reviewed. In particular, the use of one such biogeographically based approach provides new insights into the coevolution of the pathogens, Trypanosoma brucei and Trypanosoma cruzi, with their human hosts and the history of the diseases with which they are associated.Os avanços recentes obtidos com os métodos moleculares e com a análise filogenética permitem atualmente interpretar a "história escrita nos genes", na ausência de um registro fóssil. A presente revisão se concentra em avanços recentes na reconstrução da filogenia dos tripanossomas, com base em dados moleculares obtidos do ARN ribossômico, do miniexon e dos genes codificadores de proteínas. Os dados já coletados demonstram inequivocamente que os tripanossomas são monofiléticos; as árvores filogenéticas derivadas podem servir como arcabouço para reinterpretar a biologia, taxonomia e distribuição atual das espécies de tripanossomas, elucidando sua co-evolução com os hospedeiros vertebrados e vetores. Diferentes métodos para datar a divergência das linhagens de

  19. Repellency of tsetse-refractory waterbuck (Kobus defassa) body odour to Glossina pallidipes (Diptera: Glossinidae): assessment of relative contribution of different classes and individual constituents.

    Science.gov (United States)

    Bett, Mathew K; Saini, Rajinder K; Hassanali, Ahmed

    2015-06-01

    Our earlier studies on the comparative behavioural responses of caged savanna tsetse (Glossina morsitans morsitans and Glossina pallidipes) on a preferred host (ox) and a non-host (waterbuck) suggested the presence of allomonal constituents on the latter. Follow up comparison of the compositions of odours of waterbuck with those of ox and buffalo led to the identification of a series of compounds (15) specific to waterbuck, including straight chain carboxylic acid (C5-C10), phenols (guaiacol and carvacrol), 2-alkanone homologues (C8-C12), geranylacetone and δ-octalactone. Behavioural studies in a windtunnel in the laboratory suggested that G. m. morsitans was repelled by a synthetic blend of waterbuck-specific constituents. In the present study, the effects of different blends of these compounds on catches of mixed sexes of G. pallidipes in attractant-baited NG2G traps were evaluated in the field. Each multicomponent class of constituents (acids, ketones and phenols) was found to reduce fly catches, but a 14-component blend of all these compounds was more effective (reduced catches by 79-85%), indicating that each of these classes of compounds contributes incrementally to the repellency of the waterbuck odour. However, subtractive assays showed some redundancy within each class of compounds, with some even demonstrating attractive properties. Addition of (RS)-δ-octalactone to the 14-component significantly increased the repellency of the resulting blend. A 5-component blend of compounds selected on the basis of their relative performance in subtractive assays (δ-octalactone, guaiacol, geranylacetone, hexanoic and pentanoic acid) showed substantial reduction in fly catches (84%) relative to the baited control. In separate sets of experiments involving an ox tethered in the middle of an incomplete ring of electric screens in the presence or absence of 15-component or 5-component blends, comparable levels in the reduction of fed flies (94 and 96%, respectively

  20. The molecular basis of livestock disease as illustrated by African trypanosomiasis

    International Nuclear Information System (INIS)

    Donelson, J.E.

    2005-01-01

    African trypanosomes are protozoan parasites, most species of which are transmitted by tsetse flies. They reside in the mammalian bloodstream and evade the immune system by periodically switching the major protein on their surface - a phenomenon called antigenic variation, mediated by gene rearrangements in the trypanosome genome. The trypanosomes eventually enter the central nervous system and cause a fatal disease, commonly called ngana in domestic cattle and sleeping sickness in humans. Two sub-species of Trypanosoma brucei infect humans (T. b. rhodesiense and T. b. gambiense) and one sub-species does not survive in humans (T. b. brucei) because it is lysed by the human-specific serum protein, apolipoprotein L-I. Wild animals in Africa have other (less well understood) molecular mechanisms of suppressing the number of African trypanosomes in the blood, and some indigenous breeds of African cattle also display a partial 'trypanotolerance' whose genetic loci have recently been mapped. (author)

  1. Study of competitiveness, survival and dispersal of a strain of sterile males from Burkina Faso in Senegal with a view to a project for the eradication of tsetse

    International Nuclear Information System (INIS)

    Pagabeleguem, Soumaila; Seck, Momar Talla; Sall, Baba; Lo, Mbargou; Vreysen, Marc; Lancelot, Renaud; Bouyer, Jeremy

    2012-01-01

    This study defines the context in which the ''project to combat the tsetse in the zone of the Niayes in Senegal'' was launched. This project has benefited from the scientific and technical support of ISRA, IAEA and CIRAD. This study defines the context in which the ''project to combat the tsetse in the zone of the Niayes in Senegal'' was launched. This project has benefited from the scientific and technical support of ISRA, IAEA, CIRAD. In the same vein, it highlights the implementation strategy and the problem on the definition of the target population, the compatibility of the tsetse to livestock from Burkina Faso (BKF strain) confirmed in experimental conditions and competitiveness of the tsetse to livestock from Burkina Faso (BKF strain) in these conditions.

  2. First fossil of an oestroid fly (Diptera: Calyptratae: Oestroidea) and the dating of oestroid divergences.

    Science.gov (United States)

    Cerretti, Pierfilippo; Stireman, John O; Pape, Thomas; O'Hara, James E; Marinho, Marco A T; Rognes, Knut; Grimaldi, David A

    2017-01-01

    Calyptrate flies include about 22,000 extant species currently classified into Hippoboscoidea (tsetse, louse, and bat flies), the muscoid grade (house flies and relatives) and the Oestroidea (blow flies, bot flies, flesh flies, and relatives). Calyptrates are abundant in nearly all terrestrial ecosystems, often playing key roles as decomposers, parasites, parasitoids, vectors of pathogens, and pollinators. For oestroids, the most diverse group within calyptrates, definitive fossils have been lacking. The first unambiguous fossil of Oestroidea is described based on a specimen discovered in amber from the Dominican Republic. The specimen was identified through digital dissection by CT scans, which provided morphological data for a cladistic analysis of its phylogenetic position among extant oestroids. The few known calyptrate fossils were used as calibration points for a molecular phylogeny (16S, 28S, CAD) to estimate the timing of major diversification events among the Oestroidea. Results indicate that: (a) the fossil belongs to the family Mesembrinellidae, and it is identified and described as Mesembrinella caenozoica sp. nov.; (b) the mesembrinellids form a sister clade to the Australian endemic Ulurumyia macalpinei (Ulurumyiidae) (McAlpine's fly), which in turn is sister to all remaining oestroids; (c) the most recent common ancestor of extant Calyptratae lived just before the K-Pg boundary (ca. 70 mya); and (d) the radiation of oestroids began in the Eocene (ca. 50 mya), with the origin of the family Mesembrinellidae dated at ca. 40 mya. These results provide new insight into the timing and rate of oestroid diversification and highlight the rapid radiation of some of the most diverse and ecologically important families of flies. ZooBank accession number-urn:lsid:zoobank.org:pub:0DC5170B-1D16-407A-889E-56EED3FE3627.

  3. Demonstration of genetic exchange during cyclical development of Leishmania in the sand fly vector.

    Science.gov (United States)

    Akopyants, Natalia S; Kimblin, Nicola; Secundino, Nagila; Patrick, Rachel; Peters, Nathan; Lawyer, Phillip; Dobson, Deborah E; Beverley, Stephen M; Sacks, David L

    2009-04-10

    Genetic exchange has not been shown to be a mechanism underlying the extensive diversity of Leishmania parasites. We report here evidence that the invertebrate stages of Leishmania are capable of having a sexual cycle consistent with a meiotic process like that described for African trypanosomes. Hybrid progeny were generated that bore full genomic complements from both parents, but kinetoplast DNA maxicircles from one parent. Mating occurred only in the sand fly vector, and hybrids were transmitted to the mammalian host by sand fly bite. Genetic exchange likely contributes to phenotypic diversity in natural populations, and analysis of hybrid progeny will be useful for positional cloning of the genes controlling traits such as virulence, tissue tropism, and drug resistance.

  4. Protease activated receptor signaling is required for African trypanosome traversal of human brain microvascular endothelial cells.

    Directory of Open Access Journals (Sweden)

    Dennis J Grab

    2009-07-01

    Full Text Available Using human brain microvascular endothelial cells (HBMECs as an in vitro model for how African trypanosomes cross the human blood-brain barrier (BBB we recently reported that the parasites cross the BBB by generating calcium activation signals in HBMECs through the activity of parasite cysteine proteases, particularly cathepsin L (brucipain. In the current study, we examined the possible role of a class of protease stimulated HBMEC G protein coupled receptors (GPCRs known as protease activated receptors (PARs that might be implicated in calcium signaling by African trypanosomes.Using RNA interference (RNAi we found that in vitro PAR-2 gene (F2RL1 expression in HBMEC monolayers could be reduced by over 95%. We also found that the ability of Trypanosoma brucei rhodesiense to cross F2RL1-silenced HBMEC monolayers was reduced (39%-49% and that HBMECs silenced for F2RL1 maintained control levels of barrier function in the presence of the parasite. Consistent with the role of PAR-2, we found that HBMEC barrier function was also maintained after blockade of Galpha(q with Pasteurella multocida toxin (PMT. PAR-2 signaling has been shown in other systems to have neuroinflammatory and neuroprotective roles and our data implicate a role for proteases (i.e. brucipain and PAR-2 in African trypanosome/HBMEC interactions. Using gene-profiling methods to interrogate candidate HBMEC pathways specifically triggered by brucipain, several pathways that potentially link some pathophysiologic processes associated with CNS HAT were identified.Together, the data support a role, in part, for GPCRs as molecular targets for parasite proteases that lead to the activation of Galpha(q-mediated calcium signaling. The consequence of these events is predicted to be increased permeability of the BBB to parasite transmigration and the initiation of neuroinflammation, events precursory to CNS disease.

  5. How Does the VSG Coat of Bloodstream Form African Trypanosomes Interact with External Proteins?

    Directory of Open Access Journals (Sweden)

    Angela Schwede

    2015-12-01

    Full Text Available Variations on the statement "the variant surface glycoprotein (VSG coat that covers the external face of the mammalian bloodstream form of Trypanosoma brucei acts a physical barrier" appear regularly in research articles and reviews. The concept of the impenetrable VSG coat is an attractive one, as it provides a clear model for understanding how a trypanosome population persists; each successive VSG protects the plasma membrane and is immunologically distinct from previous VSGs. What is the evidence that the VSG coat is an impenetrable barrier, and how do antibodies and other extracellular proteins interact with it? In this review, the nature of the extracellular surface of the bloodstream form trypanosome is described, and past experiments that investigated binding of antibodies and lectins to trypanosomes are analysed using knowledge of VSG sequence and structure that was unavailable when the experiments were performed. Epitopes for some VSG monoclonal antibodies are mapped as far as possible from previous experimental data, onto models of VSG structures. The binding of lectins to some, but not to other, VSGs is revisited with more recent knowledge of the location and nature of N-linked oligosaccharides. The conclusions are: (i Much of the variation observed in earlier experiments can be explained by the identity of the individual VSGs. (ii Much of an individual VSG is accessible to antibodies, and the barrier that prevents access to the cell surface is probably at the base of the VSG N-terminal domain, approximately 5 nm from the plasma membrane. This second conclusion highlights a gap in our understanding of how the VSG coat works, as several plasma membrane proteins with large extracellular domains are very unlikely to be hidden from host antibodies by VSG.

  6. Trypanosome lytic factor, an antimicrobial high-density lipoprotein, ameliorates Leishmania infection.

    Directory of Open Access Journals (Sweden)

    Marie Samanovic

    2009-01-01

    Full Text Available Innate immunity is the first line of defense against invading microorganisms. Trypanosome Lytic Factor (TLF is a minor sub-fraction of human high-density lipoprotein that provides innate immunity by completely protecting humans from infection by most species of African trypanosomes, which belong to the Kinetoplastida order. Herein, we demonstrate the broader protective effects of human TLF, which inhibits intracellular infection by Leishmania, a kinetoplastid that replicates in phagolysosomes of macrophages. We show that TLF accumulates within the parasitophorous vacuole of macrophages in vitro and reduces the number of Leishmania metacyclic promastigotes, but not amastigotes. We do not detect any activation of the macrophages by TLF in the presence or absence of Leishmania, and therefore propose that TLF directly damages the parasite in the acidic parasitophorous vacuole. To investigate the physiological relevance of this observation, we have reconstituted lytic activity in vivo by generating mice that express the two main protein components of TLFs: human apolipoprotein L-I and haptoglobin-related protein. Both proteins are expressed in mice at levels equivalent to those found in humans and circulate within high-density lipoproteins. We find that TLF mice can ameliorate an infection with Leishmania by significantly reducing the pathogen burden. In contrast, TLF mice were not protected against infection by the kinetoplastid Trypanosoma cruzi, which infects many cell types and transiently passes through a phagolysosome. We conclude that TLF not only determines species specificity for African trypanosomes, but can also ameliorate an infection with Leishmania, while having no effect on T. cruzi. We propose that TLFs are a component of the innate immune system that can limit infections by their ability to selectively damage pathogens in phagolysosomes within the reticuloendothelial system.

  7. The trypanosome transcriptome is remodelled during differentiation but displays limited responsiveness within life stages

    Directory of Open Access Journals (Sweden)

    Sergeenko Tatiana

    2008-06-01

    Full Text Available Abstract Background Trypanosomatids utilise polycistronic transcription for production of the vast majority of protein-coding mRNAs, which operates in the absence of gene-specific promoters. Resolution of nascent transcripts by polyadenylation and trans-splicing, together with specific rates of mRNA turnover, serve to generate steady state transcript levels that can differ in abundance across several orders of magnitude and can be developmentally regulated. We used a targeted oligonucleotide microarray, representing the strongly developmentally-regulated T. brucei membrane trafficking system and ~10% of the Trypanosoma brucei genome, to investigate both between-stage, or differentiation-dependent, transcriptome changes and within-stage flexibility in response to various challenges. Results 6% of the gene cohort are developmentally regulated, including several small GTPases, SNAREs, vesicle coat factors and protein kinases both consistent with and extending previous data. Therefore substantial differentiation-dependent remodeling of the trypanosome transcriptome is associated with membrane transport. Both the microarray and qRT-PCR were then used to analyse transcriptome changes resulting from specific gene over-expression, knockdown, altered culture conditions and chemical stress. Firstly, manipulation of Rab5 expression results in co-ordinate changes to clathrin protein expression levels and endocytotic activity, but no detectable changes to steady-state mRNA levels, which indicates that the effect is mediated post-transcriptionally. Secondly, knockdown of clathrin or the variant surface glycoprotein failed to perturb transcription. Thirdly, exposure to dithiothreitol or tunicamycin revealed no evidence for a classical unfolded protein response, mediated in higher eukaryotes by transcriptional changes. Finally, altered serum levels invoked little transcriptome alteration beyond changes to expression of ESAG6/7, the transferrin receptor

  8. Trypanosomosis: a priority disease in tsetse-challenged areas of Burkina Faso.

    Science.gov (United States)

    Soudré, Albert; Ouédraogo-Koné, Salifou; Wurzinger, Maria; Müller, Simone; Hanotte, Olivier; Ouédraogo, Anicet Georges; Sölkner, Johann

    2013-02-01

    Trypanosomosis is an important disease affecting humans as well as animals. It remains a big constraint to livestock productions in tropical areas. The objective of this study was to assess the importance of trypanosomosis among cattle diseases in Burkina Faso, mainly in tsetse-challenged areas, and to capture information on how farmers apply available methods for controlling the disease. A survey has been carried out in 29 villages of Burkina Faso in three regions (north, southwest, and west regions). One hundred and thirty-four cattle breeders were interviewed individually with a questionnaire. The results indicate that among the 16 diseases mentioned by cattle breeders, trypanosomosis is the most important one in tsetse-challenged areas. Overall, 76.12 % of the breeders mentioned it as the most important disease, while 54.55 % of the farmers in the southwest region and 70.91 % of the farmers in the west region ranked it as a priority disease. Chemoprophylaxis/chemotherapy is widely used as a control method. Isometamidium chloride and diminazene aceturate were used by 53.49 and 46.52 % of the responders, respectively. Among farmers, 85.55 % ranked diminazene aceturate as the less efficient while 14.45 % ranked isometamidium chloride as the most efficient trypanocid. Trypanocidal drug quality and drug resistance were raised as a major concern by 30.77 and 50 % of the respondents, respectively. According to them, zebu cattle are more susceptible to trypanosomosis than taurine Baoule cattle and their crosses with zebu, emphasizing that crossing susceptible breeds with trypanotolerant ones, could be used as part of an integrated control strategy.

  9. Pathogenesis and pathology of African trypanosomosis in Baoulé, N'Dama/Baoulé cross bred and Zebu cattle in Burkina Faso. 1. Clinical performance under high natural tsetse challenge.

    Science.gov (United States)

    Clausen, P H; Sidibé, I; Bassinga, A; Richard, X; Bauer, B; Pohlit, H

    1993-06-01

    The pathogenesis and pathology of African animal trypanosomosis (AAT) in Baoulé, N'Dama/Baoulé-cross-bred and Zebu cattle was studied from 1987 to 1991 in a series of experiments conducted under natural and artificial conditions of challenge at the Centre de Recherches sur les Trypanosomoses Animales (CRTA) in Burkina Faso. This first paper reports on the clinical performance of 64 Baoulé, 10 N'Dama/Baoulé-cross-bred and 20 Zebu cattle, which were transferred to the pastoral zone of Satiri, 50 km northeast of Bobo-Dioulasso, a zone infested with Glossina palpalis gambiensis, G. morsitans submorsitans and G. tachinoides. Prior to the experiment, the cattle had been raised in a fly proof stable and at the CRTA breeding station, an area of extremely low incidence of trypanosomosis or had been exposed at least once to natural trypanosome challenge in an area of high Glossina density. The cattle were monitored daily for clinical performance. Blood samples were collected twice weekly and examined on the spot for packed red cell volume (PCV) and parasitaemia. In the blood of 98% of the cattle trypanosomes (Trypanosoma vivax, T. congolense) were detected. Significant inter- and intrabreed differences with respect to the clinical performance were recorded. Regarding general health, the humpless Baoulé and N'Dama/Baoulé cross-bred cattle (Bos taurus) proved to be superior to the humped Zebu cattle (B. indicus) under this high challenge. Previous exposure to natural challenge had a positive effect on survival for both Baoulé and Zebu cattle. The phenotypic variation in response to trypanosomosis was small in Baoulé previously exposed and large in Baoulé previously not exposed.(ABSTRACT TRUNCATED AT 250 WORDS)

  10. Horn Fly, (L.), Overwintering

    OpenAIRE

    Allan T. Showler; Weste L.A. Osbrink; Kimberly H. Lohmeyer

    2014-01-01

    The horn fly, Haematobia irritans irritans (L.), is an ectoparasitic blood feeder mainly on cattle. Its cosmopolitan distribution extends from boreal and grassland regions in northern and southern latitudes to the tropics. Stress and blood loss from horn flies can reduce cattle weight gain and milk production. Horn flies show substantial plasticity in their response to winter. Populations in warmer, lower latitudes have been reported to overwinter in a state of dormancy, but most overwinter a...

  11. Determinants of Human African Trypanosomiasis Elimination via Paratransgenesis.

    Science.gov (United States)

    Gilbert, Jennifer A; Medlock, Jan; Townsend, Jeffrey P; Aksoy, Serap; Ndeffo Mbah, Martial; Galvani, Alison P

    2016-03-01

    Human African trypanosomiasis (HAT), transmitted by tsetse flies, has historically infected hundreds of thousands of individuals annually in sub-Saharan Africa. Over the last decade, concerted control efforts have reduced reported cases to below 10,000 annually, bringing complete elimination within reach. A potential technology to eliminate HAT involves rendering the flies resistant to trypanosome infection. This approach can be achieved through the introduction of transgenic Sodalis symbiotic bacteria that have been modified to produce a trypanocide, and propagated via Wolbachia symbionts, which confer a reproductive advantage to the paratransgenic tsetse. However, the population dynamics of these symbionts within tsetse flies have not yet been evaluated. Specifically, the key factors that determine the effectiveness of paratransgenesis have yet to be quantified. To identify the impact of these determinants on T.b. gambiense and T.b. rhodesiense transmission, we developed a mathematical model of trypanosome transmission that incorporates tsetse and symbiont population dynamics. We found that fecundity and mortality penalties associated with Wolbachia or recombinant Sodalis colonization, probabilities of vertical transmission, and tsetse migration rates are fundamental to the feasibility of HAT elimination. For example, we determined that HAT elimination could be sustained over 25 years when Wolbachia colonization minimally impacted fecundity or mortality, and when the probability of recombinant Sodalis vertical transmission exceeded 99.9%. We also found that for a narrow range of recombinant Sodalis vertical transmission probability (99.9-90.6% for T.b. gambiense and 99.9-85.8% for T.b. rhodesiense), cumulative HAT incidence was reduced between 30% and 1% for T.b. gambiense and between 21% and 3% for T.b. rhodesiense, although elimination was not predicted. Our findings indicate that fitness and mortality penalties associated with paratransgenic symbionts, as well

  12. Determinants of Human African Trypanosomiasis Elimination via Paratransgenesis.

    Directory of Open Access Journals (Sweden)

    Jennifer A Gilbert

    2016-03-01

    Full Text Available Human African trypanosomiasis (HAT, transmitted by tsetse flies, has historically infected hundreds of thousands of individuals annually in sub-Saharan Africa. Over the last decade, concerted control efforts have reduced reported cases to below 10,000 annually, bringing complete elimination within reach. A potential technology to eliminate HAT involves rendering the flies resistant to trypanosome infection. This approach can be achieved through the introduction of transgenic Sodalis symbiotic bacteria that have been modified to produce a trypanocide, and propagated via Wolbachia symbionts, which confer a reproductive advantage to the paratransgenic tsetse. However, the population dynamics of these symbionts within tsetse flies have not yet been evaluated. Specifically, the key factors that determine the effectiveness of paratransgenesis have yet to be quantified. To identify the impact of these determinants on T.b. gambiense and T.b. rhodesiense transmission, we developed a mathematical model of trypanosome transmission that incorporates tsetse and symbiont population dynamics. We found that fecundity and mortality penalties associated with Wolbachia or recombinant Sodalis colonization, probabilities of vertical transmission, and tsetse migration rates are fundamental to the feasibility of HAT elimination. For example, we determined that HAT elimination could be sustained over 25 years when Wolbachia colonization minimally impacted fecundity or mortality, and when the probability of recombinant Sodalis vertical transmission exceeded 99.9%. We also found that for a narrow range of recombinant Sodalis vertical transmission probability (99.9-90.6% for T.b. gambiense and 99.9-85.8% for T.b. rhodesiense, cumulative HAT incidence was reduced between 30% and 1% for T.b. gambiense and between 21% and 3% for T.b. rhodesiense, although elimination was not predicted. Our findings indicate that fitness and mortality penalties associated with paratransgenic

  13. Formation Flying Concept Issues

    Directory of Open Access Journals (Sweden)

    M. V. Palkin

    2015-01-01

    Full Text Available The term “formation flying” implies coordinated movement of at least two satellites on coplanar and non-coplanar orbits with a maximum distance between them being much less than the length of the orbit. Peculiarities of formation flying concept also include:- automatic coordination of satellites;- sub-group specialization of formation flying satellites;- equipment and data exchange technology unification in each specialized group or subgroup.Formation flying satellites can be classified according to the configuration stability level (order (array, cluster («swarm», intergroup specialization rules («central satellite», «leader», «slave», manoeuvrability («active» and «passive» satellites.Tasks of formation flying include:- experiments with payload, distributed in formation flying satellites;- various near-earth space and earth-surface research;- super-sized aperture antenna development;- land-based telescope calibration;- «space advertisement» (earth-surface observable satellite compositions of a logotype, word, etc.;- orbital satellite maintenance, etc.Main issues of formation flying satellite system design are:- development of an autonomous satellite group manoeuvring technology;- providing a sufficient characteristic velocity of formation flying satellites;- ballistic and navigation maintenance for satellite formation flying;- technical and economic assessment of formation flying orbital delivery and deployment;- standardization, unification, miniaturization and integration of equipment;- intergroup and intersatellite function redistribution.

  14. Catechol pyrazolinones as trypanocidals: fragment-based design, synthesis, and pharmacological evaluation of nanomolar inhibitors of trypanosomal phosphodiesterase b1

    NARCIS (Netherlands)

    Orrling, K.M.; Jansen, C.J.W.; Vu, X.L.; Balmer, V.; Bregy, P.; Shanmugham, A.; England, P.; Bailey, D.; Cos, P.; Maes, L.; Adams, E.; van den Bogaart, E.; Chatelain, E.; Ioset, J.R.; van de Stolpe, A.; Zorg, S.; Veerman, J.; Seebeck, T.; Sterk, G.J.; de Esch, I.J.P.; Leurs, R.

    2012-01-01

    Trypanosomal phosphodiesterases B1 and B2 (TbrPDEB1 and TbrPDEB2) play an important role in the life cycle of Trypanosoma brucei, the causative parasite of human African trypanosomiasis (HAT), also known as African sleeping sickness. We used homology modeling and docking studies to guide fragment

  15. Studies on the infection rates and transmission characteristics of pathogenic trypanosomes in laboratory reared Glossina species as part of the SIT programme. Part of a coordinated programme on use of radiation and isotopes to develop diets for mass rearing hematophagous insects for sterile insect releases and to study disease transmission by these vectors

    International Nuclear Information System (INIS)

    Moloo, S.K.

    1985-02-01

    The releases of sterile male tsetse in tsetse control programmes will potentially increase the trypanosomiasis risk in the affected area. Hence appropriate measures should be integrated in any SIR method of tsetse control campaign in order to provide adequate protection to man and his livestock

  16. The Fly Printer - Extended

    DEFF Research Database (Denmark)

    Beloff, Laura; Klaus, Malena

    2016-01-01

    points to a divide between the engineered and the organic and shows a human aspiration for control of information and of biological species. Frustratingly, the work does not allow control over the flies and the printing surface; the flies decide whether it is suitable to print on the paper...

  17. Horn Fly, (L., Overwintering

    Directory of Open Access Journals (Sweden)

    Allan T. Showler

    2014-01-01

    Full Text Available The horn fly, Haematobia irritans irritans (L., is an ectoparasitic blood feeder mainly on cattle. Its cosmopolitan distribution extends from boreal and grassland regions in northern and southern latitudes to the tropics. Stress and blood loss from horn flies can reduce cattle weight gain and milk production. Horn flies show substantial plasticity in their response to winter. Populations in warmer, lower latitudes have been reported to overwinter in a state of dormancy, but most overwinter as active adults in normal or reduced numbers. As latitudes increase, winters are generally colder, and correspondingly, larger percentages of horn fly populations become dormant as pharate adults (a post-pupal, pre-emergent stage or die. Reports on the effect of elevation on horn fly dormancy at high elevations were contradictory. When it occurs, dormancy takes place beneath cattle dung pats and in the underlying soil. The horn fly's mode of dormancy is commonly called diapause, but the collective research on horn fly diapause (behavioral and biochemical is not conclusive. Understanding the horn fly's overwintering behaviors can lead to development of pre-dormancy insecticide spray strategies in colder latitudes while other strategies must be determined for warmer regions.

  18. Mineralogy of fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Moon Young; Park, Suk Whan [Korea Inst. of Geology Mining and Materials, Taejon (Korea, Republic of); Lee, Moo Seung [Chonbuk National University, Chonju (Korea, Republic of)

    1995-12-01

    This study is focused on mineralogical and chemical characteristics of coal fly ash collected from Boreong, Honam, Samcheonpo, Gunsan, Seocheon power plants. Mineralogical and chemical characters of fly ashes are clarified by experimental studies, using x-ray diffractometer, scanning electron microscope, differential thermal analyzer, grain size analyzer and chemical analysis. The results of this study can be summarized as follows; The coal fly ashes from the all power plants are mainly consisted with mullite and quartz, and minor quantity of hematite. In particular, fly ash from the Honam power plant is converted into the anorthite under the 1200 degree. According to the result grain size analysis, most of the fly ashes are under the 200 mesh except 66% of fly ashes from the Boreong and Honam, 54% from Seocheon, 83% from Gunsan and 31% from Samcheonpo power plants. The unburned carbon contents are decreased in the small grain size of fly ashes. Under the 200 mesh grain size of Honam fly ashes shows particularly less than 1% content of unburned carbon. Chemical components of fly ashes are found to be 49-80% of SiO{sub 2} and Al{sub 2}O{sub 3} contents in the bituminous and anthracite coal ash are 49-69% and 75-80%, respectively. The Fe{sub 2}O{sub 3} and CaO concentrations in the bituminous coal ash are higher than anthracite coal ash. The trace elements such as Pb and Zn are higher anthracite coal ash than bituminous coal ash, which is mainly due to the grain size characteristic. The fly ash from Honam power plant with high CaO content can be used potassium silicate fertilizer and raw materials for cements after separation of 200 mesh. Anorthite are formed after 1200 degree heating of bituminous coal ash, which can be utilized as aggregate and bricks. (author). 21 refs., 32 figs., 7 tabs.

  19. Growth and differentiation on a trypanosome of the subgenus Schizotrypanum from the bat Phyllostomus hastatus

    Directory of Open Access Journals (Sweden)

    Sônia I. Hamanaka

    1993-12-01

    Full Text Available The effects of temperature, pH, osmolarity and aeration on the growth and differentiation of a trypanosome ofthe subgenus Schizotrypanum isolatedfrom the bat Phyllostomus hastatus were studied. In general, the growth characteristics ofthe flagellate were similar to those of Trypanosoma (Schizotrypanum cruzi. However, the parasite did not growth at 33 or 37C. Increase in the osmolarity and aeration promoted growth at 33C. Significant metacyclogenesis was detected only in the growth condition where maximal growth occured (28C, pH 7.3, 380m0s/kg, in tissue cullure flasks, at the end ofthe exponential growth phase. The begining of the metacyclogenesis process was coincident with most glucose utilization and lowest pH. During metacyclogenesis both culture medium pH and osmolarity increased steadly.

  20. Factors affecting the efficiency of the sterile insect release method for tsetse

    International Nuclear Information System (INIS)

    Curtis, C.F.

    1980-01-01

    Data are reviewed on the levels of sterility, survival and competitiveness of Glossina males after irradiation with various gamma-ray doses delivered in air or nitrogen. A simple population model helps in the choice of the optimum dose. Field studies of mating competitiveness require a measure of the ratio of sterile to fertile males and of sterile to fertile matings, and both ratio estimates will be subject to sampling error. Data on multiple mating of female Glossina are reviewed. There is some degree of precedence for sperm from the first mating but sterile sperm are fully competitive for fertilization and, following the early death of an embryo, the timing of the next ovulation is only advanced to a slight extent. Thus in an isolated population the occurrence or non-occurrence of female polygamy would be of almost no consequence. Where mated females were immigrating into the release area female polygamy would be advantageous. The low recovery potential of tsetse populations is the main reason for thinking them suitable for control by the introduction of sterility. In trying to measure this recovery potential it is important to distinguish it from natural seasonal increase. If natural population fluctuations are studied to detect density dependent effects it is important not to confuse cause with effect. Non-isolation of the 'target' population is almost certainly the most serious obstacle to practical application of the sterile insect release method, and a steady 'rolling forward' of the release area may be a possible solution. (author)

  1. Freshwater fish trypanosomes: definition of two types, host control by antibodies and lack of antigenic variation.

    Science.gov (United States)

    Overath, P; Haag, J; Mameza, M G; Lischke, A

    1999-12-01

    Haemoflagellates of the genus Trypanosoma are prevalent in freshwater fishes and are transmitted by leeches as vectors. As demonstrated by sequence comparisons of nuclear small subunit rRNA genes, trypanosomes isolated from several fish species at different localities can be divided into at least 2 closely related types, designated Type A and Type B. A clone derived from a Type A isolate from carp (Cyprinus carpio) was used to study the anti-parasite immune response in specified pathogen-free outbred carp. Infection leads to an initial rise in parasitaemia in the blood followed by a sharp decline in all fish (acute phase). Thereafter, in some carp, parasites become undetectable both in the blood and in internal organs while, in others, low numbers can be found in the blood for up to 1 year (chronic phase). Fish that have controlled an acute infection with the clone are not only protected against an homologous challenge infection, but also against the infection with parasite lines derived from carp in the chronic phase of infection. Passive immunization experiments with IgM purified from serum of recovered carp indicate that the infection is controlled by antibodies. The anti-parasite antibody level in recovered carp remains high for many months although the parasitaemia is controlled at very low levels and the half life of IgM, t1/2 = 22.5 days, is comparatively short. The effective control of trypanosomes in laboratory infections is in contrast to the high prevalence in natural and farmed freshwater fish populations.

  2. Is there a classical nonsense-mediated decay pathway in trypanosomes?

    Directory of Open Access Journals (Sweden)

    Praveen Delhi

    Full Text Available In many eukaryotes, messenger RNAs with premature termination codons are destroyed by a process called "nonsense-mediated decay", which requires the RNA helicase Upf1 and also, usually, an interacting factor, Upf2. Recognition of premature termination codons may rely on their distance from either a splice site or the polyadenylation site, and long 3'-untranslated regions can trigger mRNA decay. The protist Trypanosoma brucei relies heavily on mRNA degradation to determine mRNA levels, and 3'-untranslated regions play a major role in control of mRNA decay. We show here that trypanosomes have a homologue of Upf1, TbUPF1, which interacts with TbUPF2 and (in an RNA-dependent fashion with poly(A binding protein 1, PABP1. Introduction of a premature termination codon in either an endogenous gene or a reporter gene decreased mRNA abundance, as expected for nonsense-mediated decay, but a dependence of this effect on TbUPF1 could not be demonstrated, and depletion of TbUPF1 by over 95% had no effect on parasite growth or the mRNA transcriptome. Further investigations of the reporter mRNA revealed that increases in open reading frame length tended to increase mRNA abundance. In contrast, inhibition of translation, either using 5'-secondary structures or by lengthening the 5'-untranslated region, usually decreased reporter mRNA abundance. Meanwhile, changing the length of the 3'-untranslated region had no consistent effect on mRNA abundance. We suggest that in trypanosomes, translation per se may inhibit mRNA decay, and interactions with multiple RNA-binding proteins preclude degradation based on 3'-untranslated region length alone.

  3. Deforestation does not affect the prevalence of a common trypanosome in African birds.

    Science.gov (United States)

    Valkiūnas, Gediminas; Iezhova, Tatjana A; Sehgal, Ravinder N M

    2016-10-01

    In spite of numerous reports of avian Trypanosoma spp. in birds throughout the world, patterns of the distribution and prevalence of these blood parasites remains insufficiently understood. It is clear that spatial heterogeneity influences parameters of parasite distributions in natural populations, but data regarding avian trypanosomes are scarce. Using microscopy and molecular diagnostic methods, we analysed the variation of prevalence of avian Trypanosoma parasites in two widespread African bird species, the yellow-whiskered greenbul Andropadus latirostris and the olive sunbird Cyanomitra olivacea. In all, 353 birds were captured in pristine forests and agroforest sites in Cameroon and Ghana. Overall, the prevalence of avian trypanosomes was 51.3%. Five morphospecies were reported (Trypanosoma everetti, T. anguiformis, T. avium, T. naviformis, T. ontarioensis). Trypanosoma everetti predominated, representing 98% of all Trypanosoma spp. reports, and it was present in both avian hosts. The prevalence of T. everetti was significantly less in the yellow-whiskered greenbul (19%) than olive sunbird (83%), and the same pattern of prevalence was reported in these avian hosts at different study sites. We found no interaction between sites and the prevalence of T. everetti. For both avian hosts, the prevalence did not differ significantly between pristine forests and agroforests. This indicates the same pattern of transmission at sites with different levels of deforestation and suggests that spatial heterogeneity related to deforestation does not affect the prevalence of avian Trypanosoma infections. It is likely that host-related factors, but not environmental conditions favour or reduce these parasite infections in forests of sub-Saharan Africa. Microscopic and PCR-based diagnostics showed the same sensitivity in diagnostics of T. everetti. We discuss the implications of these findings for the epidemiology of avian trypanosomiasis in natural populations. Copyright

  4. Cytosolic peroxidases protect the lysosome of bloodstream African trypanosomes from iron-mediated membrane damage.

    Directory of Open Access Journals (Sweden)

    Corinna Hiller

    2014-04-01

    Full Text Available African trypanosomes express three virtually identical non-selenium glutathione peroxidase (Px-type enzymes which preferably detoxify lipid-derived hydroperoxides. As shown previously, bloodstream Trypanosoma brucei lacking the mitochondrial Px III display only a weak and transient proliferation defect whereas parasites that lack the cytosolic Px I and Px II undergo extremely fast lipid peroxidation and cell lysis. The phenotype can completely be rescued by supplementing the medium with the α-tocopherol derivative Trolox. The mechanism underlying the rapid cell death remained however elusive. Here we show that the lysosome is the origin of the cellular injury. Feeding the px I-II knockout parasites with Alexa Fluor-conjugated dextran or LysoTracker in the presence of Trolox yielded a discrete lysosomal staining. Yet upon withdrawal of the antioxidant, the signal became progressively spread over the whole cell body and was completely lost, respectively. T. brucei acquire iron by endocytosis of host transferrin. Supplementing the medium with iron or transferrin induced, whereas the iron chelator deferoxamine and apo-transferrin attenuated lysis of the px I-II knockout cells. Immunofluorescence microscopy with MitoTracker and antibodies against the lysosomal marker protein p67 revealed that disintegration of the lysosome precedes mitochondrial damage. In vivo experiments confirmed the negligible role of the mitochondrial peroxidase: Mice infected with px III knockout cells displayed only a slightly delayed disease development compared to wild-type parasites. Our data demonstrate that in bloodstream African trypanosomes, the lysosome, not the mitochondrion, is the primary site of oxidative damage and cytosolic trypanothione/tryparedoxin-dependent peroxidases protect the lysosome from iron-induced membrane peroxidation. This process appears to be closely linked to the high endocytic rate and distinct iron acquisition mechanisms of the infective

  5. Flying insects and Campylobacter

    DEFF Research Database (Denmark)

    Hald, Birthe; Sommer, Helle Mølgaard; Skovgård, Henrik

    organisms, which may collect on their bodies or survive passage through the fly gut. Campylobacter and other pathogens are then easily transferred to other surfaces, for instance peoples food – or to broiler houses where they may be swallowed by chickens or contaminate the environment. On a large material...... period was rather short, as even high doses of Campylobacter remained viable for less than 24 hours in flies, when they were incubated at temperatures from 20 ºC and higher. Lower temperatures are less- or irrelevant, as flies become slow or immobile below 15-20 ºC....

  6. Autonomous Martian flying rover

    Science.gov (United States)

    1990-01-01

    A remotely programmable, autonomous flying rover is proposed to extensively survey the Martian surface environment. A Mach .3, solar powered, modified flying wing could cover roughly a 2000 mile range during Martian daylight hours. Multiple craft launched from an orbiting mother ship could provide near-global coverage. Each craft is envisioned to fly at about 1 km above the surface and measure atmospheric composition, pressure and temperature, map surface topography, and remotely penetrate the near subsurface looking for water (ice) and perhaps evidence of life. Data collected are relayed to Earth via the orbiting mother ship. Near surface guidance and control capability is an adaptation of current cruise missile technology. A solar powered aircraft designed to fly in the low temperature, low density, carbon dioxide Martian atmosphere near the surface appears feasible.

  7. Fruit fly eradication: Argentina

    International Nuclear Information System (INIS)

    2003-01-01

    Fruit exports account for 9% of Argentina's total agricultural exports and generate annually close to $450 million. This could be increased but for fruit flies that cause damage equivalent to 15% to 20% of present production value of fruit and also deny export access to countries imposing quarantine barriers. The Department of Technical Co-operation is sponsoring a programme, with technical support from the Joint FAO/IAEA Division, to eradicate the Mediterranean fruit fly using the Sterile Insect Technique (SIT). (IAEA)

  8. The LAMP-like protein p67 plays an essential role in the lysosome of African trypanosomes.

    Science.gov (United States)

    Peck, Ronald F; Shiflett, April M; Schwartz, Kevin J; McCann, Amanda; Hajduk, Stephen L; Bangs, James D

    2008-05-01

    RNAi knockdown was employed to study the function of p67, a lysosome-associated membrane protein (LAMP)-like type I transmembrane lysosomal glycoprotein in African trypanosomes. Conditional induction of p67 dsRNA resulted in specific approximately 90% reductions in de novo p67 synthesis in both mammalian bloodstream and procyclic insect-stage parasites. Bloodstream cell growth was severely retarded with extensive death after > 24 h of induction. Biosynthetic trafficking of residual p67, and of the soluble lysosomal protease trypanopain, were unimpaired. Endocytosis of tomato lectin, a surrogate receptor-mediated cargo, was only mildly impaired (approximately 20%), but proper lysosomal targeting was unaffected. p67 ablation had dramatic effects on lysosomal morphology with gross enlargement (four- to fivefold) and internal membrane profiles reminiscent of autophagic vacuoles. Ablation of p67 expression rendered bloodstream trypanosomes refractory to lysis by human trypanolytic factor (TLF), a lysosomally activated host innate immune mediator. Similar effects on lysosomal morphology and TLF sensitivity were also obtained by two pharmacological agents that neutralize lysosomal pH--chloroquine and bafilomycin A1. Surprisingly, however, lysosomal pH was not affected in ablated cells suggesting that other physiological alterations must account for increased resistance to TLF. These results indicate p67 plays an essential role in maintenance of normal lysosomal structure and physiology in bloodstream-stage African trypanosomes.

  9. Population Genetics as a Tool to Select Tsetse Control Strategies: Suppression or Eradication of Glossina palpalis gambiensis in the Niayes of Senegal

    International Nuclear Information System (INIS)

    Solano, Philippe; Kaba, Dramane; Ravel, Sophie; Sall, Baba; Mathu Ndung'u, Joseph

    2010-01-01

    The Government of Senegal has initiated the ''Projet de lutte contre les glossines dans les Niayes'' to remove the trypanosomosis problem from this area in a sustainable way. Due to past failures to sustainably eradicate Glossina palpalis gambiensis from the Niayes area, controversies remain as to the best strategy implement, i.e. ''eradication'' versus ''supression''.To inform this debate, we used population genetics to measure genetic differentiation between G. palpalis gambiensis from the Niayes and those from the southern tsetse belt (Missira).Three different markers (microsatellite DNA, mitochondrial CO1 DNA, and geometric morphometrics of the wings) were used on 153 individuals and revealed that the G. p. gambiensis populations of the Niayes were genetically isolated from the nearest proximate known population of Missira. The genetic differentiation measured between these two areas (h=0.12 using microsatellites) was equivalent to a between-taxa differentiation. We also demonstrated that within the Niayes, the population from Dakar Hann was isolated from the others and had probably experienced a bottleneck.The information presented in this paper leads to the recommendation that an eradication strategy for the Niayes populations is advisable. This kind of study may be repeated in other habitats and for other tsetse species to help decision on appropriate tsetse control strategies and find other possible discontinuities in tsetse distribution.

  10. Improving anti-trypanosomal activity of alkamides isolated from Achillea fragrantissima.

    Science.gov (United States)

    Skaf, Joseph; Hamarsheh, Omar; Berninger, Michael; Balasubramanian, Srikkanth; Oelschlaeger, Tobias A; Holzgrabe, Ulrike

    2018-03-01

    In previous studies the aerial parts of Achillea fragrantissima were found to have substantial antileishmanial and antitrypanosomal activity. A bioassay-guided fractionation of a dichloromethane extract yielded the isolation of the essential anti-trypanosomal compounds of the plant. Seven sesquiterpene lactones (including Achillolide-A), two flavonoids, chrysosplenol-D and chrysosplenetine, and four alkamides (including pellitorine) were identified. This is the first report for the isolation of the sesquiterpene lactones 3 and 4, chrysosplenetine and the group of alkamides from this plant. Bioevaluation against Trypanosoma brucei brucei TC221 (T.b brucei) using the Alamar-Blue assay revealed the novel alkamide 13 to have an IC 50 value of 40.37μM. A compound library, derived from the alkamide pellitorine (10), was synthesized and bioevaluated in order to find even more active substances. The most active compounds 26 and 27 showed activities in submicromolar concentrations and selectivity indices of 20.1 and 45.6, respectively, towards macrophage cell line J774.1. Toxicity of 26 and 27 was assessed using the greater wax moth Galleria mellonella larvae as an in vivo model. No significant toxicity was observed for the concentration range of 1.25-20mM. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. TAC102 Is a Novel Component of the Mitochondrial Genome Segregation Machinery in Trypanosomes.

    Directory of Open Access Journals (Sweden)

    Roman Trikin

    2016-05-01

    Full Text Available Trypanosomes show an intriguing organization of their mitochondrial DNA into a catenated network, the kinetoplast DNA (kDNA. While more than 30 proteins involved in kDNA replication have been described, only few components of kDNA segregation machinery are currently known. Electron microscopy studies identified a high-order structure, the tripartite attachment complex (TAC, linking the basal body of the flagellum via the mitochondrial membranes to the kDNA. Here we describe TAC102, a novel core component of the TAC, which is essential for proper kDNA segregation during cell division. Loss of TAC102 leads to mitochondrial genome missegregation but has no impact on proper organelle biogenesis and segregation. The protein is present throughout the cell cycle and is assembled into the newly developing TAC only after the pro-basal body has matured indicating a hierarchy in the assembly process. Furthermore, we provide evidence that the TAC is replicated de novo rather than using a semi-conservative mechanism. Lastly, we demonstrate that TAC102 lacks an N-terminal mitochondrial targeting sequence and requires sequences in the C-terminal part of the protein for its proper localization.

  12. Uptake of NO-releasing drugs by the P2 nucleoside transporter in trypanosomes

    Directory of Open Access Journals (Sweden)

    L. Soulère

    1999-11-01

    Full Text Available Nitric oxide (NO· has been identified as a principal regulatory molecule of the immune system and the major cytotoxic mediator of activated immune cells. NO· can also react rapidly with a variety of biological species, particularly with the superoxide radical anion O2·- at almost diffusion-limited rates to form peroxynitrite anion (ONOO-. ONOO- and its proton-catalyzed decomposition products are capable of oxidizing a great diversity of biomolecules and can act as a source of toxic hydroxyl radicals. As a consequence, a strategy for the development of molecules with potential trypanocidal activities could be developed to increase the concentration of nitric oxide in the parasites through NO·-releasing compounds. In this way, the rate of formation of peroxynitrite from NO· and O2·- would be faster than the rate of dismutation of superoxide radicals by superoxide dismutases which constitute the primary antioxidant enzymatic defense system in trypanosomes. The adenosine transport systems of parasitic protozoa, which are also in certain cases implicated in the selective uptake of active drugs such as melarsoprol or pentamidine, could be exploited to specifically target these NO·-releasing compounds inside the parasites. In this work, we present the synthesis, characterization and biological evaluation of a series of molecules that contain both a group which would specifically target these drugs inside the parasites via the purine transporter, and an NO·-donor group that would exert a specific pharmacological effect by increasing NO level, and thus the peroxynitrite concentration inside the parasite.

  13. Morphological Features of Trypanosomes from Squirrel Monkeys from the Brazilian Amazon

    Directory of Open Access Journals (Sweden)

    Mariangela Ziccardi

    1998-01-01

    Full Text Available A morphometric analysis of blood trypomastigotes identified as Trypanosoma minasense, T. saimirii, and T. rangeli harbored by squirrel monkeys from the Brazilian Amazon was performed. Additionally, morphological and biological comparative analyses were conducted of T. saimirii-like and T. rangeli development forms from haemoculture and xenodiagnosis. Illustrations are given of blood trypomastigotes as well as of developing flagellates in triatomine and axenic culture. Mean values of blood trypomastigotes of T. saimirii differ statistically from those of T. rangeli in only two out of ten morphological characters measured, and ranges overlapped. The developing forms of T. saimrii-like parasites were essentially identical in both xenodiagnosis and haemoculture to those of T. rangeli. Trypanosomes confirmed as T. rangeli were transmitted to mice by the bites of the great majority of triatomines that fed on T. saimirii-like infected monkeys. We conclude that, based on morphology and on the development in triatomine bugs and haemoculture, T. saimirii should not be considered a distinct species. We therefore propose T. saimirii to be a junior synonym of T. rangeli

  14. Blue and Black Cloth Targets: Effects of Size, Shape, and Color on Stable Fly (Diptera: Muscidae) Attraction.

    Science.gov (United States)

    Hogsette, Jerome A; Foil, Lane D

    2018-04-02

    Stable fly management is challenging because of the fly's dispersal behavior and its tendency to remain on the host only while feeding. Optically attractive traps have been used to survey and sometimes reduce adult populations. Insecticide-treated blue and black cloth targets developed for tsetse fly management in Africa were found to be attractive to stable flies in the United States, and various evaluations were conducted in Louisiana and Florida. Tests using untreated targets were designed to answer questions about configuration, size, and color relative to efficacy and stability in high winds. Studies with electric grid targets and with targets paired with Olson traps showed cloth target color attraction in the following decreasing order: black > blue-black > blue. A solid black target is easier to make than a blue-black target because no sewing is involved. Attraction was not affected when flat 1-m2 targets were formed into cylinders, despite the limited view of the blue and black colors together. There was no reduction in attraction when the 1-m2 cylindrical targets were compared with smaller (63 × 30 cm high) cylindrical targets. In addition, there was no difference in attraction between the small blue-black, blue, and black targets. Significance of findings and implications of potential uses for treated targets are discussed. Target attraction was indicated by the numbers of stable flies captured on an Olson sticky trap placed 30 cm from the target. Although this system is adequate for field research, it greatly underestimates the actual numbers of stable flies attracted to treated targets.

  15. Can E. coli fly?

    DEFF Research Database (Denmark)

    Lindeberg, Yrja Lisa; Egedal, Karen; Hossain, Zenat Zebin

    2018-01-01

    OBJECTIVE: To investigate the transmission of fecal bacteria by flies to food under natural settings. METHODS: Over a period of two months paired (exposed and non-exposed) containers with cooked rice were placed on the ground in kitchen areas in an urban slum area in Dhaka, Bangladesh, and the nu......OBJECTIVE: To investigate the transmission of fecal bacteria by flies to food under natural settings. METHODS: Over a period of two months paired (exposed and non-exposed) containers with cooked rice were placed on the ground in kitchen areas in an urban slum area in Dhaka, Bangladesh...

  16. The use of yellow fluorescent hybrids to indicate mating in Trypanosoma brucei

    Directory of Open Access Journals (Sweden)

    Ferris Vanessa

    2008-02-01

    Full Text Available Abstract Background Trypanosoma brucei undergoes genetic exchange in its insect vector, the tsetse fly, by an unknown mechanism. The difficulties of working with this experimental system of genetic exchange have hampered investigation, particularly because the trypanosome life cycle stages involved cannot be cultured in vitro and therefore must be examined in the insect. Searching for small numbers of hybrid trypanosomes directly in the fly has become possible through the incorporation of fluorescent reporter genes, and we have previously carried out a successful cross using a reporter-repressor strategy. However, we could not be certain that all fluorescent trypanosomes observed in that cross were hybrids, due to mutations of the repressor leading to spontaneous fluorescence, and we have therefore developed an alternative strategy. Results To visualize the production of hybrids in the fly, parental trypanosome clones were transfected with a gene encoding Green Fluorescent Protein (GFP or Red Fluorescent Protein (RFP. Co-infection of flies with red and green fluorescent parental trypanosomes produced yellow fluorescent hybrids, which were easily visualized in the fly salivary glands. Yellow trypanosomes were not seen in midgut or proventricular samples and first appeared in the glands as epimastigotes as early as 13 days after fly infection. Cloned progeny originating from individual salivary glands had yellow, red, green or no fluorescence and were confirmed as hybrids by microsatellite, molecular karyotype and kinetoplast (mitochondrial DNA analyses. Hybrid clones showed biparental inheritance of both nuclear and kinetoplast genomes. While segregation and reassortment of the reporter genes and microsatellite alleles were consistent with Mendelian inheritance, flow cytometry measurement of DNA content revealed both diploid and polyploid trypanosomes among the hybrid progeny clones. Conclusion The strategy of using production of yellow hybrids

  17. Physiology Flies with Time.

    Science.gov (United States)

    Sehgal, Amita

    2017-11-30

    The 2017 Nobel Prize in Medicine or Physiology has been awarded to Jeffrey Hall, Michael Rosbash, and Michael Young for elucidating molecular mechanisms of the circadian clock. From studies beginning in fruit flies, we now know that circadian regulation pervades most biological processes and has strong ties to human health and disease. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Turbulence and Flying Machines

    Indian Academy of Sciences (India)

    cluding section. What Makes Flight Possible. It is obvious to most of us today that a body in flight must obey. Newton's laws of motion. Leonardo da Vinci in the early 1500's had already realised that "a bird flies according to mathematical .... Here x is the distance from the leading edge along the wing surface. In a majority of ...

  19. Use of isotopes for research and control of vectors of animal diseases, host-pathogen relationships and the environmental impact of control procedures

    International Nuclear Information System (INIS)

    1979-01-01

    pathogenesis of trypanosome infections in the bovine and the third on the sterile insect technique: current and future. Significant contributions were presented on bovine anaplasmosis, on the immunologic properties of babesias, on cattle protection from bovine babesiosis by the inoculation of irradiated piroplasms, on host specific immunization, on immunologic response in trypanosome infected animals, on chemotherapy against Babesia parasites, on the pathophysiology of trypanosome infections in different breeds of cattle, on patterns of trypanosome development in insect hosts and on the role of biologically active substances in the pathogenesis and immunology of trypanosomiasis. In the latter portion of the symposium, devoted to the SIT, papers on recent advances in studies of the dynamics and behaviour of tsetse fly populations and on factors affecting the efficiency of the sterile insect release method for tsetse flies were presented. Considerable progress was reported in the in vitro mass-rearing of the tsetse flies using freeze-dried blood, which will aid and enhance sterile insect programmes using tsetse flies. Finally, the results of successful experiments in Upper Volta and Tanzania were reported on the eradication or control of tsetse fly field populations by the use of the sterile insect technique. (author)

  20. Report of the workshop on strategic planning of area-wide tsetse and trypanosomiasis control in West Africa

    International Nuclear Information System (INIS)

    2002-01-01

    Tsetse-transmitted trypanosomiasis is a disease unique to Africa affecting both humans and animals. This disease occurs in about 10 million km 2 in 37 sub-Saharan countries corresponding approximately to one-third of Africa's total land area, and threatens an estimated 50 million people, 48 million cattle and a countless population of other domestic animal species. Trypanosomiasis has a severe impact on African agriculture; estimated annual losses in cattle production alone are in the range of 1.0-1.2 billion dollars. To this, we have to add the indirect negative effects engendered by trypanosomiasis on total crop production. The disease influences where people decide to live, how they manage their livestock and the intensity of crop agriculture. The combined effects result in changes in land use, environment and affect human welfare and increase the vulnerability of agricultural activity. FAO has identified the reinforcement of agriculture as a key element in the fight against poverty and the improvement of food security in developing countries. The need to reduce poverty is particularly felt in tsetse infested areas of sub-Saharan Africa. In this region half of the population suffers from food insecurity. Approximately 85% of the poor are located in rural areas and more than 80% of the population depends on agricultural production for their livelihood. In order to respond to the need in the fight against tsetse and trypanosomiasis (T and T) in people as well as livestock, the Programme Against African Trypanosomiasis (PAAT) was endorsed in November 1997 by the FAO Conference. The Programme seeks to combine the forces of FAO, IAEA, OAU/IBAR and WHO in order to: promote and co-ordinate international alliances and efforts assisting in harmonised interventions against T and T; effectively combat the disease in Africa; and delineate the polity framework, strategies and guiding pest management principles. This workshop was primarily concerned with the development of

  1. An annotated checklist of the horse flies, deer flies, and yellow flies (Diptera: Tabanidae) of Florida

    Science.gov (United States)

    The family Tabanidae includes the horse flies, deer flies, and yellow flies and is considered a significant pest of livestock throughout the United States, including Florida. Tabanids can easily become a major pest of man, especially salt marsh species which are known to readily feed on humans and o...

  2. The ecotopes and evolution of triatomine bugs (triatominae and their associated trypanosomes

    Directory of Open Access Journals (Sweden)

    Gaunt Michael

    2000-01-01

    Full Text Available Triatomine bug species such as Microtriatoma trinidadensis, Eratyrus mucronatus, Belminus herreri, Panstrongylus lignarius, and Triatoma tibiamaculata are exquisitely adapted to specialist niches. This suggests a long evolutionary history, as well as the recent dramatic spread a few eclectic, domiciliated triatomine species. Virtually all species of the genus Rhodnius are primarily associated with palms. The genus Panstrongylus is predominantly associated with burrows and tree cavities and the genus Triatoma with terrestrial rocky habitats or rodent burrows. Two major sub-divisions have been defined within the species Trypanosoma cruzi, as T. cruzi 1 (Z1 and T. cruzi 2 (Z2. The affinities of a third group (Z3 are uncertain. Host and habitat associations lead us to propose that T. cruzi 1 (Z1 has evolved in an arboreal, palm tree habitat with the triatomine tribe Rhodniini, in association with the opossum Didelphis. Similarly we propose that T. cruzi (Z2 and Z3 evolved in a terrestrial habitat in burrows and in rocky locations with the triatomine tribe Triatomini, in association with edentates, and/or possibly ground dwelling marsupials. Both sub-divisions of T. cruzi may have been contemporary in South America up to 65 million years ago. Alternatively, T. cruzi 2 (Z2 may have evolved more recently from T. cruzi 1 (Z1 by host transfers into rodents, edentates, and primates. We have constructed a molecular phylogeny of haematophagous vectors, including triatomine bugs, which suggests that faecal transmission of trypanosomes may be the ancestral route. A molecular clock phylogeny suggests that Rhodnius and Triatoma diverged before the arrival, about 40 million years ago, of bats and rodents into South America.

  3. Genome of the avirulent human-infective trypanosome--Trypanosoma rangeli.

    Directory of Open Access Journals (Sweden)

    Patrícia Hermes Stoco

    2014-09-01

    Full Text Available Trypanosoma rangeli is a hemoflagellate protozoan parasite infecting humans and other wild and domestic mammals across Central and South America. It does not cause human disease, but it can be mistaken for the etiologic agent of Chagas disease, Trypanosoma cruzi. We have sequenced the T. rangeli genome to provide new tools for elucidating the distinct and intriguing biology of this species and the key pathways related to interaction with its arthropod and mammalian hosts.The T. rangeli haploid genome is ∼ 24 Mb in length, and is the smallest and least repetitive trypanosomatid genome sequenced thus far. This parasite genome has shorter subtelomeric sequences compared to those of T. cruzi and T. brucei; displays intraspecific karyotype variability and lacks minichromosomes. Of the predicted 7,613 protein coding sequences, functional annotations could be determined for 2,415, while 5,043 are hypothetical proteins, some with evidence of protein expression. 7,101 genes (93% are shared with other trypanosomatids that infect humans. An ortholog of the dcl2 gene involved in the T. brucei RNAi pathway was found in T. rangeli, but the RNAi machinery is non-functional since the other genes in this pathway are pseudogenized. T. rangeli is highly susceptible to oxidative stress, a phenotype that may be explained by a smaller number of anti-oxidant defense enzymes and heat-shock proteins.Phylogenetic comparison of nuclear and mitochondrial genes indicates that T. rangeli and T. cruzi are equidistant from T. brucei. In addition to revealing new aspects of trypanosome co-evolution within the vertebrate and invertebrate hosts, comparative genomic analysis with pathogenic trypanosomatids provides valuable new information that can be further explored with the aim of developing better diagnostic tools and/or therapeutic targets.

  4. WAYS OF ACQUIRING FLYING PHOBIA.

    Science.gov (United States)

    Schindler, Bettina; Vriends, Noortje; Margraf, Jürgen; Stieglitz, Rolf-Dieter

    2016-02-01

    The few studies that have explored how flying phobia is acquired have produced contradictory results. We hypothesized that classical conditioning plays a role in acquiring flying phobia and investigated if vicarious (model) learning, informational learning through media, and experiencing stressful life events at the time of onset of phobia also play a role. Thirty patients with flying phobia and thirty healthy controls matched on age, sex, and education were interviewed with the Mini-DIPS, the short German version of the Anxiety Disorders Interview Schedule (DSM-IV diagnostic criteria) and the Fear-of-Flying History Interview. Fifty Percent of patients with flying phobia and 53% of healthy controls reported frightening events in the air. There was no significant difference between the two samples. Thus there were not more classical conditioning events for patients with flying phobia. There also was no significant difference between the two samples for vicarious (model) learning: 37% of flying phobia patients and 23% of healthy controls felt influenced by model learning. The influence of informational learning through media was significantly higher for the clinical sample (70%) than for the control group (37%). Patients with flying phobia experienced significantly more stressful life events in the period of their frightening flight experience (60%) than healthy controls (19%). Frightening experiences while flying are quite common, but not everybody develops a flying phobia. Stressful life events and other factors might enhance conditionability. Informational learning through negative media reports probably reinforces the development of flying phobia. Clinical implications are discussed. © 2015 Wiley Periodicals, Inc.

  5. Restricted application of insecticides: a promising tsetse control technique, but what do the farmers think of it?

    Directory of Open Access Journals (Sweden)

    Fanny Bouyer

    2011-08-01

    Full Text Available BACKGROUND: Restricted application of insecticides to cattle is a cheap and safe farmer-based method to control tsetse. In Western Africa, it is applied using a footbath, mainly to control nagana and the tick Amblyomma variegatum. In Eastern and Southern Africa, it might help controlling the human disease, i.e., Rhodesian sleeping sickness as well. The efficiency of this new control method against ticks, tsetse and trypanosomoses has been demonstrated earlier. The invention, co-built by researchers and farmers ten years ago, became an innovation in Burkina Faso through its diffusion by two development projects. METHODOLOGY/PRINCIPAL FINDINGS: In this research, we studied the process and level of adoption in 72 farmers inhabiting the peri-urban areas of Ouagadougou and Bobo-Dioulasso. Variables describing the livestock farming system, the implementation and perception of the method and the knowledge of the epidemiological system were used to discriminate three clusters of cattle farmers that were then compared using indicators of adoption. The first cluster corresponded to modern farmers who adopted the technique very well. The more traditional farmers were discriminated into two clusters, one of which showed a good adoption rate, whereas the second failed to adopt the method. The economic benefit and the farmers' knowledge of the epidemiological system appeared to have a low impact on the early adoption process whereas some modern practices, as well as social factors appeared critical. The quality of technical support provided to the farmers had also a great influence. Cattle farmers' innovation-risk appraisal was analyzed using Rogers' adoption criteria which highlighted individual variations in risk perceptions and benefits, as well as the prominent role of the socio-technical network of cattle farmers. CONCLUSIONS/SIGNIFICANCE: Results are discussed to highlight the factors that should be taken into consideration, to move discoveries from

  6. Bats, Trypanosomes, and Triatomines in Ecuador: New Insights into the Diversity, Transmission, and Origins of Trypanosoma cruzi and Chagas Disease.

    Science.gov (United States)

    Pinto, C Miguel; Ocaña-Mayorga, Sofía; Tapia, Elicio E; Lobos, Simón E; Zurita, Alejandra P; Aguirre-Villacís, Fernanda; MacDonald, Amber; Villacís, Anita G; Lima, Luciana; Teixeira, Marta M G; Grijalva, Mario J; Perkins, Susan L

    2015-01-01

    The generalist parasite Trypanosoma cruzi has two phylogenetic lineages associated almost exclusively with bats-Trypanosoma cruzi Tcbat and the subspecies T. c. marinkellei. We present new information on the genetic variation, geographic distribution, host associations, and potential vectors of these lineages. We conducted field surveys of bats and triatomines in southern Ecuador, a country endemic for Chagas disease, and screened for trypanosomes by microscopy and PCR. We identified parasites at species and genotype levels through phylogenetic approaches based on 18S ribosomal RNA (18S rRNA) and cytochrome b (cytb) genes and conducted a comparison of nucleotide diversity of the cytb gene. We document for the first time T. cruzi Tcbat and T. c. marinkellei in Ecuador, expanding their distribution in South America to the western side of the Andes. In addition, we found the triatomines Cavernicola pilosa and Triatoma dispar sharing shelters with bats. The comparisons of nucleotide diversity revealed a higher diversity for T. c. marinkellei than any of the T. c. cruzi genotypes associated with Chagas disease. Findings from this study increased both the number of host species and known geographical ranges of both parasites and suggest potential vectors for these two trypanosomes associated with bats in rural areas of southern Ecuador. The higher nucleotide diversity of T. c. marinkellei supports a long evolutionary relationship between T. cruzi and bats, implying that bats are the original hosts of this important parasite.

  7. Nuclear pore complex evolution: a trypanosome Mlp analogue functions in chromosomal segregation but lacks transcriptional barrier activity.

    Science.gov (United States)

    Holden, Jennifer M; Koreny, Ludek; Obado, Samson; Ratushny, Alexander V; Chen, Wei-Ming; Chiang, Jung-Hsien; Kelly, Steven; Chait, Brian T; Aitchison, John D; Rout, Michael P; Field, Mark C

    2014-05-01

    The nuclear pore complex (NPC) has dual roles in nucleocytoplasmic transport and chromatin organization. In many eukaryotes the coiled-coil Mlp/Tpr proteins of the NPC nuclear basket have specific functions in interactions with chromatin and defining specialized regions of active transcription, whereas Mlp2 associates with the mitotic spindle/NPC in a cell cycle-dependent manner. We previously identified two putative Mlp-related proteins in African trypanosomes, TbNup110 and TbNup92, the latter of which associates with the spindle. We now provide evidence for independent ancestry for TbNup92/TbNup110 and Mlp/Tpr proteins. However, TbNup92 is required for correct chromosome segregation, with knockout cells exhibiting microaneuploidy and lowered fidelity of telomere segregation. Further, TbNup92 is intimately associated with the mitotic spindle and spindle anchor site but apparently has minimal roles in control of gene transcription, indicating that TbNup92 lacks major barrier activity. TbNup92 therefore acts as a functional analogue of Mlp/Tpr proteins, and, together with the lamina analogue NUP-1, represents a cohort of novel proteins operating at the nuclear periphery of trypanosomes, uncovering complex evolutionary trajectories for the NPC and nuclear lamina.

  8. Pest Control on the "Fly"

    Science.gov (United States)

    2002-01-01

    FlyCracker(R), a non-toxic and environmentally safe pesticide, can be used to treat and control fly problems in closed environments such as milking sheds, cattle barns and hutches, equine stables, swine pens, poultry plants, food-packing plants, and even restaurants, as well as in some outdoor animal husbandry environments. The product can be applied safely in the presence of animals and humans, and was recently permitted for use on organic farms as livestock production aids. FlyCracker's carbohydrate technology kills fly larvae within 24 hours. By killing larvae before they reach the adult stages, FlyCracker eradicates another potential breeding population. Because the process is physical-not chemical-flies and other insects never develop resistance to the treatment, giving way to unlimited use of product, while still keeping the same powerful effect.

  9. Trypanosoma culicavium sp nov., an avian trypanosome transmitted by Culex mosquitoes

    Czech Academy of Sciences Publication Activity Database

    Votýpka, Jan; Szabová, J.; Rádrová, J.; Zídková, J.; Svobodová, M.

    2012-01-01

    Roč. 62, MAR (2012), s. 745-754 ISSN 1466-5026 R&D Projects: GA MŠk(CZ) LC06009; GA ČR GD206/09/H026 Institutional support: RVO:60077344 Keywords : ORNITHOMYIA-AVICULARIA * BITING MIDGES * RIBOSOMAL-RNA * BLACK FLIES * AVIUM * TRANSMISSION * KINETOPLASTIDA * PARASITE * DIPTERA * VECTOR Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.112, year: 2012

  10. Sand fly-borne viruses

    OpenAIRE

    Nedvědová Cvanová, Lucie

    2015-01-01

    Sand flies (Diptera: Psychodidae) are important vectors of protozoan, bacterial and viral patogens causing diseases in humans and domestic animals. This thesis summarizes the current knowledge on sand fly-born viruses, their distribution in the World, infection symptoms and life cycle in the nature. These viruses are transmitted by sand flies of genera Phlebotomus, Lutzomyia and Sergentomyia and they can be found on every continent except for Antarctica. They belong into four families, Bunyav...

  11. Utilization of Coal Fly Ash

    Science.gov (United States)

    1992-01-01

    T1 Thallium Br Bromine U Uranium C Carbon V Vanadium Ca Calcium W Tungsten Cd Cadmium Zn Zinc Ce Cerium Cl Chlorine Co Cobalt Cr Chromium Cu Copper...2933 (1987). £ 46 I A 3 Christensen, J., L. Kryger, and N. Pind, "The Determination of Traces of Cadmium, Lead, and Thallium in Fly Ash by...Elements and Radioactivity in Fly Ashes, Adsorption of Elements by Cabbage Grown in Fly Ash-Soil Mixtures," Environmental Science and Technology, v.11

  12. Phylogenetic analysis of freshwater fish trypanosomes from Europe using ssu rRNA gene sequences and random amplification of polymorphic DNA

    Czech Academy of Sciences Publication Activity Database

    Gibson, W. C.; Lom, Jiří; Pecková, Hana; Ferris, V. R.; Hamilton, P. B.

    2005-01-01

    Roč. 130, č. 4 (2005), s. 405-412 ISSN 0031-1820 Institutional research plan: CEZ:AV0Z60220518 Keywords : trypanosomes * freshwater fish * phylogeny Subject RIV: EA - Cell Biology Impact factor: 1.703, year: 2005

  13. Synthesis and evaluation of analogs of the phenylpyridazinone NPD-001 as potent trypanosomal TbrPDEB1 phosphodiesterase inhibitors and in vitro trypanocidals.

    NARCIS (Netherlands)

    Veerman, J.; van den Bergh, T.; Orrling, K.M.; Jansen, C.J.W.; Cos, P.; Maes, L.; Chatelain, E.; Ioset, J.R.; Edink, E.S.E.; Tenor, H.; Seebeck, T.; de Esch, I.J.P.; Leurs, R.; Sterk, G.J.

    2016-01-01

    Trypanosomal phosphodiesterases B1 and B2 (TbrPDEB1 and TbrPDEB2) play an important role in the life cycle of Trypanosoma brucei, the causative parasite of human African trypanosomiasis (HAT), also known as African sleeping sickness. Knock down of both enzymes leads to cell cycle arrest and is

  14. Mass rearing methods for fruit fly

    International Nuclear Information System (INIS)

    Dominguez Gordillo, J.C.

    1999-01-01

    The most common rearing methods used for mass rearing of fruit flies, with emphasis on those of economic importance in Mexico such as Anastrepha ludens (the Mexican fruit fly). Anastrepha obliqua (the mango and plum fruit fly) and the exotic fruit fly Ceratitis capitata (the Mediterranean fruit fly) are described here. (author)

  15. Trypanosomosis prevalence in cattle on Mafia Island (Tanzania).

    Science.gov (United States)

    Goossens, B; Mbwambo, H; Msangi, A; Geysen, D; Vreysen, M

    2006-06-30

    During two consecutive surveys (February and August/Sept 2002), a total of 970 cattle from the cattle population of Mafia Island (United Republic of Tanzania) were blood-sampled. All blood samples were microscopically screened for the presence of trypanosomes and a portion of these were checked for antibodies with an Ab-ELISA and for the presence of trypanosomal DNA with PCR. Microscopic evidence of trypanosomes of the congolense group (sub-genus Nannomonas) was found in 0.8% of the animals (8/970) and in two cases the species identified was confirmed by PCR as Trypanosoma congolense savannah type. Non-pathogenic Trypanosoma theileri were detected in 3.2% (31/970) of the samples using the Dark Ground-Buffy Coat (DG-BC) technique. For survey 1 (S1), detection of antibodies (Ab-ELISA) against pathogenic trypanosomes indicated a seroprevalence of 14.2% (68/480). Of the samples, either DG positive or with a PCV lower then 25, examined by PCR, a total of 8.4% (5/59) (selected from 970 samples), were found positive for T. congolense. The low prevalence of pathogenic trypanosomes on Mafia Island is intriguing, especially in view of the omnipresence of the tsetse fly Glossina brevipalpis. Although the presence of detected trypanosomal antibodies does not necessarily indicate a current infection, the combination of serological/parasitological examinations and the results of the PCR do support this low prevalence of trypanosomosis in cattle. Despite the low prevalence, pathogenic trypanosomes are present on Mafia Island and possible reasons for this low infection rate, taking account of the relation between Glossina species present, transmission risk and trypanosomes found in cattle, are discussed also in view of a future appropriate intervention strategy.

  16. Fly ash quality and utilization

    Energy Technology Data Exchange (ETDEWEB)

    Barta, L.E.; Lachner, L.; Wenzel, G.B. [Inst. for Energy, Budapest (Hungary); Beer, M.J. [Massachusetts Inst. of Technology, Cambridge, MA (United States)

    1995-12-01

    The quality of fly ash is of considerable importance to fly ash utilizers. The fly ash puzzolanic activity is one of the most important properties that determines the role of fly ash as a binding agent in the cementing process. The puzzolanic activity, however is a function of fly ash particle size and chemical composition. These parameters are closely related to the process of fly ash formation in pulverized coal fired furnaces. In turn, it is essential to understand the transformation of mineral matter during coal combustion. Due to the particle-to-particle variation of coal properties and the random coalescence of mineral particles, the properties of fly ash particles e.g. size, SiO{sub 2} content, viscosity can change considerably from particle to particle. These variations can be described by the use of the probability theory. Since the mean values of these randomly changing parameters are not sufficient to describe the behavior of individual fly ash particles during the formation of concrete, therefore it is necessary to investigate the distribution of these variables. Examples of these variations were examined by the Computer Controlled Scanning Electron Microscopy (CCSEM) for particle size and chemical composition for Texas lignite and Eagel Butte mineral matter and fly ash. The effect of combustion on the variations of these properties for both the fly ash and mineral matter were studied by using a laminar flow reactor. It is shown in our paper, that there are significant variations (about 40-50% around the mean values) of the above-listed properties for both coal samples. By comparing the particle size and chemical composition distributions of the mineral matter and fly ash, it was possible to conclude that for the Texas lignite mineral matter, the combustion did not effect significantly the distribution of these properties, however, for the Eagel Butte coal the combustion had a major impact on these mineral matter parameters.

  17. The Flying University

    Science.gov (United States)

    Friesen, Catherine

    The Flying University is solo theater performance framed as an academic lecture about Marie Curie and her discovery of radium, delivered to a group of women who have gathered in secret to further their education. As the lecture proceeds, the professor brings in her own research based on a study of Esther Horsch (1905-1991) who lived on a farm in central Illinois. She introduces data from Esther's journals, personal memories, and dreams about Esther's life. The professor's investigation of radium plays at the intersections of magical and mundane, decay and the transformation of life, and the place of ambition in these two women's lives. The intention of this piece is to explore these themes, which are full of mystery, through the traces of the daily lives of Mme. Curie and Esther. Their words and photos are used as roots from which to imagine the things that echo beyond their familiar work; elemental and also fantastically radiant. The Flying University was written and performed by Catherine Friesen April 27-29, 2012 in the Center for Performance Experiment at Hamilton College as part of the University of South Carolina MFA Acting Class of 2013 showcase, Pieces of Eight.

  18. Physics of flying

    Science.gov (United States)

    Vetrone, Jim

    2015-05-01

    Column editor's note: As the school year comes to a close, it is important to start thinking about next year. One area that you want to consider is field trips. Many institutions require that teachers plan for a field trip well in advance. Keeping that in mind, I asked Jim Vetrone to write an article about the fantastic field trip he takes his AP Physics students on. I had the awesome opportunity to attend a professional development day that Jim arranged at iFLY in the Chicago suburbs. The experience of "flying" in a wind tunnel was fabulous. Equally fun was watching the other physics teachers come up with experiments to have the professional "flyers" perform in the tube. I could envision my students being similarly excited about the experience and about the development of their own experiments. After I returned to school, I immediately began the process of trying to get this field trip approved for the 2015-16 school year. I suggest that you start your process as well if you hope to try a new field trip next year. The key to getting the approval, in my experience, is submitting a proposal early that includes supporting documentation from sources. Often I use NGSS or state standards as justifications for my field trips. I have also quoted College Board expectations for AP Physics 1 and 2 in my documents when requesting an unusual field trip.

  19. Learning from the Fruit Fly

    Science.gov (United States)

    Bierema, Andrea; Schwartz, Renee

    2016-01-01

    The fruit fly ("Drosophila melanogaster") is an ideal subject for studying inheritance patterns, Mendel's laws, meiosis, Punnett squares, and other aspects of genetics. Much of what we know about genetics dates to evolutionary biologist Thomas Hunt Morgan's work with mutated fruit flies in the early 1900s. Many genetic laboratories…

  20. In vitro activity of 2-pyridinecarboxylic acid against trypanosomes of the subgenus Schizotrypanum isolated from the bat Phyllostomus hastatus - doi: 10.4025/actascibiolsci.v33i4.6482 In vitro activity of 2-pyridinecarboxylic acid against trypanosomes of the subgenus Schizotrypanum isolated from the bat Phyllostomus hastatus - doi: 10.4025/actascibiolsci.v33i4.6482

    Directory of Open Access Journals (Sweden)

    Sueli Fumie Yamada-Ogatta

    2011-09-01

    Full Text Available The effect of 2-pyridinecarboxylic acid (picolinic acid on trypanosomes of the subgenus Schizotrypanum isolated from the bat Phyllostomus hastatus was determined in this study. Picolinic acid, at 50 µg mL-1, inhibited epimastigote growth by 99% after 12 days incubation. In addition, trypomastigote motility decreased by 50% after 6h and completely after 24h in the presence of 50 µg mL-1 picolinic acid. The 50% cytotoxic concentration on HEp-2 cell line was 275 µg mL-1 after 4 days incubation. Altogether, these results indicate higher toxicity against trypanosomes. The inhibitory effect of picolinic acid on epimastigote growth can be partially reversed by nicotinic acid and L-tryptophan, suggesting a competitive inhibition. Furthermore, two anti-Trypanosoma (Schizotrypanum cruzi drugs were also evaluated with regard to bat trypanosome growth. Benznidazole, at 50 µg mL-1, inhibited epimastigote growth by 90% after 12 days incubation. Nifurtimox, at the same concentration, caused 96% growth inhibition after four days incubation. Corroborating a previous study, bat trypanosomes are a good model for screening new trypanocidal compounds. Moreover, they can be used to study many biological processes common to human pathogenic trypanosomatids.The effect of 2-pyridinecarboxylic acid (picolinic acid on trypanosomes of the subgenus Schizotrypanum isolated from the bat Phyllostomus hastatus was determined in this study. Picolinic acid, at 50 µg mL-1, inhibited epimastigote growth by 99% after 12 days incubation. In addition, trypomastigote motility decreased by 50% after 6h and completely after 24h in the presence of 50 µg mL-1 picolinic acid. The 50% cytotoxic concentration on HEp-2 cell line was 275 µg mL-1 after 4 days incubation. Altogether, these results indicate higher toxicity against trypanosomes. The inhibitory effect of picolinic acid on epimastigote growth can be partially reversed by nicotinic acid and L-tryptophan, suggesting a

  1. First Detection of Leishmania tropica DNA and Trypanosoma Species in Sergentomyia Sand Flies (Diptera: Psychodidae) from an Outbreak Area of Cutaneous Leishmaniasis in Ghana

    Science.gov (United States)

    Nzelu, Chukwunonso O.; Kato, Hirotomo; Puplampu, Naiki; Desewu, Kwame; Odoom, Shirley; Wilson, Michael D.; Sakurai, Tatsuya; Katakura, Ken; Boakye, Daniel A.

    2014-01-01

    Background Leishmania major and an uncharacterized species have been reported from human patients in a cutaneous leishmaniasis (CL) outbreak area in Ghana. Reports from the area indicate the presence of anthropophilic Sergentomyia species that were found with Leishmania DNA. Methodology/Principal Findings In this study, we analyzed the Leishmania DNA positive sand fly pools by PCR-RFLP and ITS1 gene sequencing. The trypanosome was determined using the SSU rRNA gene sequence. We observed DNA of L. major, L. tropica and Trypanosoma species to be associated with the sand fly infections. This study provides the first detection of L. tropica DNA and Trypanosoma species as well as the confirmation of L. major DNA within Sergentomyia sand flies in Ghana and suggests that S. ingrami and S. hamoni are possible vectors of CL in the study area. Conclusions/Significance The detection of L. tropica DNA in this CL focus is a novel finding in Ghana as well as West Africa. In addition, the unexpected infection of Trypanosoma DNA within S. africana africana indicates that more attention is necessary when identifying parasitic organisms by PCR within sand fly vectors in Ghana and other areas where leishmaniasis is endemic. PMID:24516676

  2. In vitro drug susceptibility of two strains of the wildlife trypanosome, Trypanosoma copemani: A comparison with Trypanosoma cruzi.

    Science.gov (United States)

    Botero, Adriana; Keatley, Sarah; Peacock, Christopher; Thompson, R C Andrew

    2017-04-01

    Trypanosomes are blood protozoan parasites that are capable of producing illness in the vertebrate host. Within Australia, several native Trypanosoma species have been described infecting wildlife. However, only Trypanosoma copemani has been associated with pathological lesions in wildlife hosts and more recently has been associated with the drastic decline of the critically endangered woylie (Bettongia penicillata). The impact that some trypanosomes have on the health of the vertebrate host has led to the development of numerous drug compounds that could inhibit the growth or kill the parasite. This study investigated and compared the in vitro susceptibility of two strains of T. copemani (G1 and G2) and one strain of Trypanosoma cruzi (10R26) against drugs that are known to show trypanocidal activity (benznidazole, posaconazole, miltefosine and melarsoprol) and against four lead compounds, two fenarimols and two pyridine derivatives (EPL-BS1937, EPL-BS2391, EPL-BS0967, and EPL-BS1246), that have been developed primarily against T.cruzi. The in vitro cytotoxicity of all drugs against L6 rat myoblast cells was also assessed. Results showed that both strains of T. copemani were more susceptible to all drugs and lead compounds than T. cruzi, with all IC50 values in the low and sub-μM range for both species. Melarsoprol and miltefosine exhibited the highest drug activity against both T. copemani and T. cruzi, but they also showed the highest toxicity in L6 cells. Interestingly, both fenarimol and pyridine derivative compounds were more active against T. copemani and T. cruzi than the reference drugs benznidazole and posaconazole. T. copemani strains exhibited differences in susceptibility to all drugs demonstrating once again considerable differences in their biological behaviour. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  3. Trypanosoma (Megatrypanum) melophagium in the sheep ked Melophagus ovinus from organic farms in Croatia: phylogenetic inferences support restriction to sheep and sheep keds and close relationship with trypanosomes from other ruminant species.

    Science.gov (United States)

    Martinković, Franjo; Matanović, Krešimir; Rodrigues, Adriana C; Garcia, Herakles A; Teixeira, Marta M G

    2012-01-01

    Trypanosoma (Megatrypanum) melophagium is a parasite of sheep transmitted by sheep keds, the sheep-restricted ectoparasite Melophagus ovinus (Diptera: Hippoboscidae). Sheep keds were 100% prevalent in sheep from five organic farms in Croatia, Southeastern Europe, whereas trypanosomes morphologically compatible with T. melophagium were 86% prevalent in the guts of the sheep keds. Multilocus phylogenetic analyses using sequences of small subunit rRNA, glycosomal glyceraldehyde-3-phosphate dehydrogenase, spliced leader, and internal transcribed spacer 1 of the rDNA distinguished T. melophagium from all allied trypanosomes from other ruminant species and placed the trypanosome in the subgenus Megatrypanum. Trypanosomes from sheep keds from Croatia and Scotland, the only available isolates for comparison, shared identical sequences. All biologic and phylogenetic inferences support the restriction of T. melophagium to sheep and, especially, to the sheep keds. The comparison of trypanosomes from sheep, cattle, and deer from the same country, which was never achieved before this work, strongly supported the host-restricted specificity of trypanosomes of the subgenus Megatrypanum. Our findings indicate that with the expansion of organic farms, both sheep keds and T. melophagium may re-emerge as parasitic infections of sheep. © 2011 The Author(s) Journal of Eukaryotic Microbiology © 2011 International Society of Protistologists.

  4. Roll Control in Fruit Flies

    OpenAIRE

    Beatus, Tsevi; Guckenheimer, John M.; Cohen, Itai

    2014-01-01

    Due to aerodynamic instabilities, stabilizing flapping flight requires ever-present fast corrective actions. Here we investigate how flies control body roll angle, their most susceptible degree of freedom. We glue a magnet to each fly, apply a short magnetic pulse that rolls it in mid-air, and film the corrective maneuver. Flies correct perturbations of up to $100^{\\circ}$ within $30\\pm7\\mathrm{ms}$ by applying a stroke-amplitude asymmetry that is well described by a linear PI controller. The...

  5. Quantitative proteomics on the fly

    NARCIS (Netherlands)

    Gouw, J.W.|info:eu-repo/dai/nl/304837377

    2009-01-01

    The development of multicellular organisms is characterized by complex processes that progressively transform essentially a single cell into a creature with complicated structures and highly specialized functions. The fruit fly Drosophila melanogaster provides an excellent model system to

  6. Evolution, Fruit Flies and Gerontology

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 11. Evolution, Fruit Flies and Gerontology Evolutionary Biology Helps Unravel the Mysteries of Ageing. Amitabh Joshi. General Article Volume 1 Issue 11 November 1996 pp 51-63 ...

  7. Integrated management of fruit flies

    International Nuclear Information System (INIS)

    1983-01-01

    This film introduces species of fruit-flies and their reproduction cycle and suggests various methods for controlling insect pests (insect traps, treatment of infested fruits, chemical, legal, and biological control -sterile male technique

  8. Mechanism of Trypanosoma brucei gambiense resistance to human serum

    DEFF Research Database (Denmark)

    Uzureau, Pierrick; Uzureau, Sophie; Lecordier, Laurence

    2013-01-01

    The African parasite Trypanosoma brucei gambiense accounts for 97% of human sleeping sickness cases. T. b. gambiense resists the specific human innate immunity acting against several other tsetse-fly-transmitted trypanosome species such as T. b. brucei, the causative agent of nagana disease...... in cattle. Human immunity to some African trypanosomes is due to two serum complexes designated trypanolytic factors (TLF-1 and -2), which both contain haptoglobin-related protein (HPR) and apolipoprotein LI (APOL1). Whereas HPR association with haemoglobin (Hb) allows TLF-1 binding and uptake via......GP), which prevents APOL1 toxicity and induces stiffening of membranes upon interaction with lipids. Two additional features contribute to resistance to TLFs: reduction of sensitivity to APOL1 requiring cysteine protease activity, and TbHpHbR inactivation due to a L210S substitution. According...

  9. Review on the Molecular Tools for the Understanding of the Epidemiology of Animal Trypanosomosis in West Africa

    Directory of Open Access Journals (Sweden)

    Duvallet G

    1999-01-01

    Full Text Available The epidemiology of animal trypanosomosis around Bobo-Dioulasso (Burkina Faso, West Africa benefited a lot in the last years from the progress of molecular tools. The two most used molecular techniques were the polymerase chain reaction for the diagnosis of the disease in cattle and the characterization of the trypanosomes in the host and the vector on one hand, and the microsatellite DNA polymorphism in tsetse flies to study the intraspecific genetic variability of the vector on the other hand. The results obtained in the Sideradougou area during a recent two year survey with these techniques, associated with many other georeferenced informations concerning vector and cattle distribution, natural environment, landuse, ground occupation, livestock management, were combined in a Geographical Information System. This new approach of a complex pathogenic system led to a better evaluation of the risk of trypanosome transmission.

  10. Dewatered sewage biosolids provide a productive larval habitat for stable flies and house flies (Diptera: Muscidae).

    Science.gov (United States)

    Doud, C W; Taylor, D B; Zurek, L

    2012-03-01

    Species diversity and seasonal abundance of muscoid flies (Diptera: Muscidae) developing in biosolid cake (dewatered biosolids) stored at a wastewater treatment facility in northeastern Kansas were evaluated. Emergence traps were deployed 19 May through 20 October 2009 (22 wk) and 27 May through 18 November 2010 (25 wk). In total, 11,349 muscoid flies were collected emerging from the biosolid cake. Stable flies (Stomoxys calcitrans (L.)) and house flies (Musca domestica (L.)), represented 80 and 18% of the muscoid flies, respectively. An estimated 550 stable flies and 220 house flies per square-meter of surface area developed in the biosolid cake annually producing 450,000 stable flies and 175,000 house flies. Stable fly emergence was seasonally bimodal with a primary peak in mid-July and a secondary peak in late August. House fly emergence peaked with the first stable fly emergence peak and then declined gradually for the remainder of the year. House flies tended to emerge from the biosolid cake sooner after its deposition than did stable flies. In addition, house fly emergence was concentrated around midsummer whereas stable fly emergence began earlier in the spring and continued later into the fall. Biosolid age and temperature were the most important parameters affecting emergence for house flies and stable flies, whereas precipitation was not important for either species. This study highlights the importance of biosolid cake as a larval developmental habitat for stable flies and house flies.

  11. Fly ash. Quality recycling material

    Energy Technology Data Exchange (ETDEWEB)

    Blomster, D.; Leisio, C.

    1996-11-01

    Imatran Voima`s coal-fired power plants not only generate power and heat but also produce fly ash which is suitable raw material for recycling. This material for recycling is produced in the flue gas cleaning process. It is economical and, thanks to close quality control, is suitable for use as a raw material in the building materials industry, in asphalt production, and in earthworks. Structures made from fly ash are also safe from an environmental point of view. (orig.)

  12. Evidence for viable and stable triploid Trypanosoma congolense parasites.

    Science.gov (United States)

    Tihon, Eliane; Imamura, Hideo; Dujardin, Jean-Claude; Van Den Abbeele, Jan

    2017-10-10

    Recent whole genome sequencing (WGS) analysis identified a viable triploid strain of Trypanosoma congolense. This triploid strain BANANCL2 was a clone of the field isolate BANAN/83/CRTRA/64 that was collected from cattle in Burkina Faso in 1983. We demonstrated the viability and stability of triploidy throughout the complete life-cycle of the parasite by infecting tsetse flies with the triploid clone BANANCL2. Proboscis-positive tsetse flies efficiently transmitted the parasites to mice resulting in systemic infections. WGS of the parasites was performed at all life-cycle stages, and a method based on a block alternative allele frequency spectrum was developed to efficiently detect the ploidy profiles of samples with low read depth. This approach confirmed the triploid profile of parasites throughout their life-cycle in the tsetse fly and the mammalian host, demonstrating that triploidy is present at all stages and is stable over time. The presence of viable field-isolated triploid parasites indicates another possible layer of genetic diversity in natural T. congolense populations. The comparison between triploid and diploid parasites provides a unique model system to study the impact of chromosome copy number variations in African trypanosomes. In addition, the consequences of triploidy can be further investigated using this stable triploid model.

  13. Trypanosomosis in The Gambia: prevalence in working horses and donkeys detected by whole genome amplification and PCR, and evidence for interactions between trypanosome species

    Directory of Open Access Journals (Sweden)

    Jallow Jibril

    2008-02-01

    Full Text Available Abstract Background The Gambia has an increasing population of equidae largely used for agriculture and transportation. A review of cases at The Gambian Horse and Donkey Trust (GHDT indicated that a common reason for presentation is a poorly defined medical condition often attributed to trypanosomosis. There are few reports describing the prevalence or the range of clinical signs associated with infection with different species of trypanosomes in horses and donkeys, but given the importance of these animals, the role of trypanosomosis requires investigation. Results In total 241 animals from the Central River Division in The Gambia (183 horses and 58 donkeys were screened using Whole Genome Amplification (WGA followed by trypanosome species identification using polymerase chain reaction (PCR. The results indicated overall trypanosome prevalence of 91%; with an infection rate of 31% for Trypanosoma congolense Savannah, 87% for Trypanosoma vivax and 18% for Trypanosoma brucei sp. Multiple species were present in 43% of infections. Microscopy had a good specificity (100% and positive predictive value (100% for trypanosome detection, but the sensitivity (20% and negative predictive value (10.5% were low relative to PCR-based diagnosis. Infection with T congolense showed the greatest negative effect on packed cell volume (PCV, while infection with T. brucei sp also had a significant, although lesser, negative effect on PCV. In addition, cases positive by microscopy were associated with significantly lower PCV. However, concurrent infection with T. vivax appeared to cause less effect on PCV, compared to animals infected with T. congolense alone. Conclusion The prevalence of Trypanosomosis was high in both horses and donkeys. Infection with T. congolense appeared to have the greatest clinical significance, while T. vivax infection may be of limited clinical significance in this population. Indeed, there is evidence of T. vivax co-infection ameliorating

  14. Ticks, Lyme disease spirochetes, trypanosomes, and antibody to encephalitis viruses in wild birds from coastal Georgia and South Carolina.

    Science.gov (United States)

    Durden, L A; McLean, R G; Oliver, J H; Ubico, S R; James, A M

    1997-12-01

    Ticks and blood samples were collected from wild birds mist-netted on St. Catherine's Island, Georgia, and at the Wedge Plantation in coastal South Carolina in 1994 and 1995. Immature stages of 5 species of ixodid ticks were recovered from 10 of 148 (7%) birds belonging to 6 species in Georgia, whereas 6 ixodid species were recovered from 45 of 259 (17%) birds representing 10 avian species in South Carolina. Borrelia burgdorferi sensu lato was isolated from 27 of 120 (23%) screened ticks (Ixodes scapularis and Ixodes minor) recovered from South Carolina birds, but from none of 16 screened ticks removed from Georgia birds. This spirochete was also isolated from 1 of 97 (1%) birds in South Carolina. In 1995, neither eastern equine encephalitis (EEE) virus nor St. Louis encephalitis (SLE) virus was isolated from any of 218 bird sera screened, but serum neutralizing antibodies were found to EEE virus in 4 of 121 (3%) sera and to SLE virus in 2 of 121 (2%) sera from South Carolina. No antibody to either virus was detected in 51 avian sera screened from Georgia. Trypanosomes (probably Trypanosoma avium) were isolated from 1 of 51 (2%) birds from Georgia and from 13 of 97 (13%) birds from South Carolina. Our data suggest that some wild birds may be reservoir hosts for the Lyme disease spirochete and for encephalitis viruses in coastal Georgia and South Carolina and that migrating birds can disperse immature ticks infected with B. burgdorferi.

  15. Trisomy and chromosome size changes in hybrid trypanosomes from a genetic cross between Trypanosoma brucei rhodesiense and T. b. brucei.

    Science.gov (United States)

    Gibson, W; Garside, L; Bailey, M

    1992-04-01

    Further analysis of hybrid clones from an experimental cross of Trypanosoma brucei rhodesiense 058 and T. b. brucei 196 shows 2 of the hybrid clones to have DNA contents about 1.5 times parental values. This represents over 40,000 kb of extra DNA. Comparison of the molecular karyotypes of parental and progeny trypanosomes shows that the bulk of the extra DNA constitutes chromosomes greater than 1 Mb in size, although a small proportion can be accounted for by an increased number of mini-chromosomes. The 2 hybrid clones have 3 alleles at several loci for housekeeping genes as shown by RFLP and isoenzyme analysis. Trisomy of the chromosome carrying phosphoglycerate kinase and tubulin genes and that carrying the phospholipase C gene was demonstrated by analysis of molecular karyotypes. These chromosomes appear prone to substantial size alterations associated with genetic exchange. Our results for one of the hybrid clones are completely consistent with it being triploid and the product of fusion of haploid and diploid nuclei.

  16. Ommatidia of blow fly, house fly, and flesh fly: implication of their vision efficiency.

    Science.gov (United States)

    Sukontason, Kabkaew L; Chaiwong, Tarinee; Piangjai, Somsak; Upakut, Sorawit; Moophayak, Kittikhun; Sukontason, Kom

    2008-06-01

    This work aims to elucidate the number of ommatidia or facets (the outwardly visible units of each ommatidium) for compound eyes in blow flies [Chrysomya megacephala (F.), Chrysomya rufifacies (Macquart), Chrysomya nigripes (Aubertin), Lucilia cuprina (Wiedemann)], house flies (Musca domestica L.), and flesh flies (Liosarcophaga dux Thomson) by manual counts of the corneal spreads. The head of the fly in each species was soaked in 20% potassium hydroxide solution at room temperature for 7 days, and the clear compound eye was dissected into six small parts, each of which was placed onto a slide and flattened using a coverslip. Images of each part were obtained using a microscope connected to a computer. The printed images of each part were magnified, and the total number of ommatidia per eye was manually counted. For males, the mean number of ommatidia was statistically different among all flies examined: L. dux (6,032) > C. rufifacies (5,356) > C. nigripes (4,798) > C. megacephala (4,376) > L. cuprina (3,665) > M. domestica (3,484). Likewise, the mean number of facets in females was statistically different: L. dux (6,086) > C. megacephala (5,641) > C. rufifacies (5,208) > C. nigripes (4,774) > L. cuprina (3,608) > M. domestica (3433). Scanning electron microscopy analysis of adult flies revealed the sexual dimorphism in the compound eye. Male C. megacephala had large ommatidia in the upper two thirds part and small ommatidia in the lower one third part, whereas only small ommatidia were detected in females. Dense postulate appearance was detected in the external surface of the corneal lens of the ommatidia of C. megacephala, C. rufifacies, and C. nigripes, while a mix of dense postulate appearance and variable groove array length was detected in L. cuprina and M. domestica. The probable functions of ommatidia are discussed with reference to other literature.

  17. Flying in Nightmares - A Neglected Phenomenon

    OpenAIRE

    Schönhammer, Rainer

    2000-01-01

    It is widely supposed in the scientific and popular literature on dreams that flying in dreams is of mostly delightful character. Domhoff (1996) recently emphasised the highly positive feelings experienced in flying dreams although he mentions a turn to apprehension later in the dream ("crashing", "coming down"). In my research (an interview-sample of flying dreams) I met flying experiences in contexts of nightmares which are seldom mentioned and never thoroughly discussed in interdiscipli...

  18. Evolution, Fruit Flies and Gerontology

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 11. Evolution, Fruit Flies and Gerontology Evolutionary Biology Helps Unravel the ... Author Affiliations. Amitabh Joshi1. Animal Behaviour Unit Jawaharlal Nehru Centre for Advanced Scientific Research Jakkur P.O. Bangalore 560 064, India ...

  19. Dielectric properties of fly ash

    Indian Academy of Sciences (India)

    Unknown

    Fly ash (FA) is a coal product generated from coal fired thermal power stations. ... million tons during 2001–2010 AD (Muraka et al 1987;. Satyanarayan and Pushpalata 1991). Disposal of FA and bottom ash are today's burning problems as they have .... Muraka I P, Boyd R H and Harbert H P 1987 Solid waste disposal and ...

  20. To Fly in the Sky.

    Science.gov (United States)

    Brodie, Carolyn S.

    1995-01-01

    Suggests activities for students that focus on airplanes, famous pilots, and travel. Provides a list of suggested titles with the following topics: history of flight and airplanes; airplanes and flying information; paper and model airplanes; Charles Lindbergh; Amelia Earhart; the Wright Brothers; videos; and picture books. (AEF)

  1. Genetic control of fruit flies

    International Nuclear Information System (INIS)

    Walder, J.M.M.

    1987-01-01

    The sterile-insect technique for control of fruit-flies is studied. A brief historic of the technique is presented, as well as a short description of the methodology. Other aspects are discussed: causes of sterility in insects and the principles of insect population suppression by sterile-insect technique. (M.A.C.)

  2. FLY ASH: AN ALTERNATIVE TO POWDERED ACTIVATED ...

    African Journals Online (AJOL)

    Preferred Customer

    fly ash were measured through N2 adsorption at 77 K using a TRISTAR-3000 surface area and porosity analyzer (Micromeritics). Surface morphology of fly ash was characterized by a SM-. 6700F field emission scanning electron microscope. Table 2. Chemical composition of fly ash. Oxide of metal. Percentage composition.

  3. Evaluation of fly ash quality control tools.

    Science.gov (United States)

    2010-06-30

    Many entities currently use fly ash in portland cement concrete (PCC) pavements and structures. Although the body of knowledge is : great concerning the use of fly ash, several projects per year are subject to poor performance where fly ash is named ...

  4. Flies and Campylobacter infection of broiler flocks

    DEFF Research Database (Denmark)

    Hald, Birthe; Skovgård, Henrik; Bang, Dang Duong

    2004-01-01

    A total of 8.2% of flies caught outside a broiler house in Denmark had the potential to transmit Campylobacter jejuni to chickens, and hundreds of flies per day passed through the ventilation system into the broiler house. Our study suggests that flies may be an important source of Campylobacter ...... infection of broiler flocks in summer....

  5. Managing the horn fly (Diptera: Muscidae) using an electric walk-through fly trap.

    Science.gov (United States)

    Watson, D W; Stringham, S M; Denning, S S; Washburn, S P; Poore, M H; Meier, A

    2002-10-01

    An electric walk-through fly trap was evaluated for the management of the horn fly, Hematobia irritans (L.), on dairy cattle in North Carolina over 2 yr. The trap relies on black lights and electrocution grids to attract and kill flies that are brushed from the cattle passing through. During the first season, horn fly densities were reduced from >1,400 to flies per animal. Horn fly density averaged 269.2 +/- 25.8 on cattle using the walk-through fly trap twice daily, and 400.2 +/- 43.5 on the control group during the first year. The second year, seasonal mean horn fly density was 177.3 +/- 10.8 on cattle using the walk-through fly trap compared with 321.1 +/- 15.8 on the control group. No insecticides were used to control horn flies during this 2-yr study.

  6. Zoonotic trypanosomes in South East Asia: Attempts to control Trypanosoma lewisi using human and animal trypanocidal drugs.

    Science.gov (United States)

    Desquesnes, Marc; Yangtara, Sarawut; Kunphukhieo, Pawinee; Jittapalapong, Sathaporn; Herder, Stéphane

    2016-10-01

    Beside typical human trypanosomes responsible of sleeping sickness in Africa and Chagas disease in Latin America, there is a growing number of reported atypical human infections due to Trypanosoma evansi, a livestock parasite, or Trypanosoma lewisi, a rat parasite, especially in Asia. Drugs available for the treatment of T. brucei ssp. in humans are obviously of choice for the control of T. evansi because it is derived from T. brucei. However, concerning T. lewisi, there is an urgent need to determine the efficacy of trypanocidal drugs for the treatment in humans. In a recent study, pentamidine and fexinidazole were shown to have the best efficacy against one stock of T. lewisi in rats. In the present study suramin, pentamidine, eflornitine, nifurtimox, benznidazole and fexinidazole, were evaluated at low and high doses, in single day administration to normal rats experimentally infected with a stock of T. lewisi recently isolated in Thailand. Because none of these treatments was efficient, a trial was made with the most promising trypanocide identified in a previous study, fexinidazole 100mg/kg, in 5 daily administrations. Results observed were unclear. To confirm the efficacy of fexinidazole, a mixed infection protocol was set up in cyclophosphamide immunosuppressed rats. Animals were infected successively by T. lewisi and T. evansi, and received 10 daily PO administrations of 200mg/kg fexinidazole. Drastic effects were observed against T. evansi which was cleared from the rat's blood within 24 to 48h; however, the treatment did not affect T. lewisi which remained in high number in the blood until the end of the experiment. This mixed infection/treatment protocol clearly demonstrated the efficacy of fexinidazole against T. evansi and its inefficacy against T. lewisi. Since animal trypanocides were also recently shown to be inefficient, other protocols as well as other T. lewisi stocks should be investigated in further studies. Copyright © 2016. Published by

  7. Crovirin, a snake venom cysteine-rich secretory protein (CRISP with promising activity against Trypanosomes and Leishmania.

    Directory of Open Access Journals (Sweden)

    Camila M Adade

    2014-10-01

    Full Text Available The neglected human diseases caused by trypanosomatids are currently treated with toxic therapy with limited efficacy. In search for novel anti-trypanosomatid agents, we showed previously that the Crotalus viridis viridis (Cvv snake venom was active against infective forms of Trypanosoma cruzi. Here, we describe the purification of crovirin, a cysteine-rich secretory protein (CRISP from Cvv venom with promising activity against trypanosomes and Leishmania.Crude venom extract was loaded onto a reverse phase analytical (C8 column using a high performance liquid chromatographer. A linear gradient of water/acetonitrile with 0.1% trifluoroacetic acid was used. The peak containing the isolated protein (confirmed by SDS-PAGE and mass spectrometry was collected and its protein content was measured. T. cruzi trypomastigotes and amastigotes, L. amazonensis promastigotes and amastigotes and T. brucei rhodesiense procyclic and bloodstream trypomastigotes were challenged with crovirin, whose toxicity was tested against LLC-MK2 cells, peritoneal macrophages and isolated murine extensor digitorum longus muscle. We purified a single protein from Cvv venom corresponding, according to Nano-LC MS/MS sequencing, to a CRISP of 24,893.64 Da, henceforth referred to as crovirin. Human infective trypanosomatid forms, including intracellular amastigotes, were sensitive to crovirin, with low IC50 or LD50 values (1.10-2.38 µg/ml. A considerably higher concentration (20 µg/ml of crovirin was required to elicit only limited toxicity on mammalian cells.This is the first report of CRISP anti-protozoal activity, and suggests that other members of this family might have potential as drugs or drug leads for the development of novel agents against trypanosomatid-borne neglected diseases.

  8. Trypanosoma rangeli (Tejera, 1920 isolated from a sylvatic rodent (Echimys dasythrix in Santa Catarina island, Santa Catarina state: first report of this trypanosome in southern Brazil

    Directory of Open Access Journals (Sweden)

    M. Steindel

    1991-03-01

    Full Text Available A trypanosome strain isolated from a sylvatic rodent (Echimys dasythrix from Santa Catarina Island (Santa Catarina State, Brazil was characterized by the following methods: experimental transmission and development in invertebrate hosts, morphometry, cross protection, complement sensitivity, lectin agglutination and isoenzyme profiles. Comparasions were made with standard Trypanosoma cruzi and T. rangeli strains. All methods except isoenzyne analysis led to the identification of the isolate as T. rangeli. The isoenzyme differences found could be explained on the basis of polymorphism. Therefore this is the first report of T. rangeli in southern Brazil, increasing the geographical distribution of this parasite.

  9. Spatial distribution of Glossina sp. and Trypanosoma sp. in south-western Ethiopia.

    Science.gov (United States)

    Duguma, Reta; Tasew, Senbeta; Olani, Abebe; Damena, Delesa; Alemu, Dereje; Mulatu, Tesfaye; Alemayehu, Yoseph; Yohannes, Moti; Bekana, Merga; Hoppenheit, Antje; Abatih, Emmanuel; Habtewold, Tibebu; Delespaux, Vincent; Duchateau, Luc

    2015-08-19

    Accurate information on the distribution of the tsetse fly is of paramount importance to better control animal trypanosomosis. Entomological and parasitological surveys were conducted in the tsetse belt of south-western Ethiopia to describe the prevalence of trypanosomosis (PoT), the abundance of tsetse flies (AT) and to evaluate the association with potential risk factors. The study was conducted between 2009 and 2012. The parasitological survey data were analysed by a random effects logistic regression model, whereas the entomological survey data were analysed by a Poisson regression model. The percentage of animals with trypanosomosis was regressed on the tsetse fly count using a random effects logistic regression model. The following six risk factors were evaluated for PoT (i) altitude: significant and inverse correlation with trypanosomosis, (ii) annual variation of PoT: no significant difference between years, (iii) regional state: compared to Benishangul-Gumuz (18.0%), the three remaining regional states showed significantly lower PoT, (iv) river system: the PoT differed significantly between the river systems, (iv) sex: male animals (11.0%) were more affected than females (9.0%), and finally (vi) age at sampling: no difference between the considered classes. Observed trypanosome species were T. congolense (76.0%), T. vivax (18.1%), T. b. brucei (3.6%), and mixed T. congolense/vivax (2.4%). The first four risk factors listed above were also evaluated for AT, and all have a significant effect on AT. In the multivariable model only altitude was retained with AT decreasing with increasing altitude. Four different Glossina species were identified i.e. G. tachinoides (52.0%), G. pallidipes (26.0%), G.morsitans submorsitans (15.0%) and G. fuscipes fuscipes (7.0 %). Significant differences in catches/trap/day between districts were observed for each species. No association could be found between the tsetse fly counts and trypanosomosis prevalence. Trypanosomosis

  10. Strength Properties of Processed Fly Ash Concrete

    Directory of Open Access Journals (Sweden)

    Sivakumar Anandan

    2015-07-01

    Full Text Available The present paper reports on the mechanical treatment of fly ash for improving the delayed reactivity of fly ash with the hydration product of cement. Grinding of fly ash was carried out in a ball mill for different time durations and processing time was optimized for maximum fineness. Concrete mixes were prepared using various proportions of processed and unprocessed fly ash replacement in cement (25% and 50%. The influence of steel fiber addition on the mechanical properties of the concrete was studied for different curing periods. The test results on pozzolanic activity and lime reactivity indicate that the processed fly ash exhibited a higher strength gain than the unprocessed fly ash, with a maximum increase in compressive strength of up to 12%. Improved pozzolanic properties were noticed due to the increase in fineness of the fly ash particles.

  11. Automated Surveillance of Fruit Flies

    Science.gov (United States)

    Potamitis, Ilyas; Rigakis, Iraklis; Tatlas, Nicolaos-Alexandros

    2017-01-01

    Insects of the Diptera order of the Tephritidae family cause costly, annual crop losses worldwide. Monitoring traps are important components of integrated pest management programs used against fruit flies. Here we report the modification of typical, low-cost plastic traps for fruit flies by adding the necessary optoelectronic sensors to monitor the entrance of the trap in order to detect, time-stamp, GPS tag, and identify the species of incoming insects from the optoacoustic spectrum analysis of their wingbeat. We propose that the incorporation of automated streaming of insect counts, environmental parameters and GPS coordinates into informative visualization of collective behavior will finally enable better decision making across spatial and temporal scales, as well as administrative levels. The device presented is at product level of maturity as it has solved many pending issues presented in a previously reported study. PMID:28075346

  12. Automated Surveillance of Fruit Flies

    Directory of Open Access Journals (Sweden)

    Ilyas Potamitis

    2017-01-01

    Full Text Available Insects of the Diptera order of the Tephritidae family cause costly, annual crop losses worldwide. Monitoring traps are important components of integrated pest management programs used against fruit flies. Here we report the modification of typical, low-cost plastic traps for fruit flies by adding the necessary optoelectronic sensors to monitor the entrance of the trap in order to detect, time-stamp, GPS tag, and identify the species of incoming insects from the optoacoustic spectrum analysis of their wingbeat. We propose that the incorporation of automated streaming of insect counts, environmental parameters and GPS coordinates into informative visualization of collective behavior will finally enable better decision making across spatial and temporal scales, as well as administrative levels. The device presented is at product level of maturity as it has solved many pending issues presented in a previously reported study.

  13. Automated Surveillance of Fruit Flies.

    Science.gov (United States)

    Potamitis, Ilyas; Rigakis, Iraklis; Tatlas, Nicolaos-Alexandros

    2017-01-08

    Insects of the Diptera order of the Tephritidae family cause costly, annual crop losses worldwide. Monitoring traps are important components of integrated pest management programs used against fruit flies. Here we report the modification of typical, low-cost plastic traps for fruit flies by adding the necessary optoelectronic sensors to monitor the entrance of the trap in order to detect, time-stamp, GPS tag, and identify the species of incoming insects from the optoacoustic spectrum analysis of their wingbeat. We propose that the incorporation of automated streaming of insect counts, environmental parameters and GPS coordinates into informative visualization of collective behavior will finally enable better decision making across spatial and temporal scales, as well as administrative levels. The device presented is at product level of maturity as it has solved many pending issues presented in a previously reported study.

  14. Geopolymer Mortar with Fly Ash

    Directory of Open Access Journals (Sweden)

    Saloma

    2016-01-01

    Full Text Available The cement industry accounts for about 7% of all CO2 emissions caused by humans. Therefore, it is necessary to find another material in order to support sustainable material. An alternative way is replacing cement material with alternative material as fly ash. Fly ash as binder need to be added alkaline activator in the form of sodium silicate (Na2SiO3 or potassium silicate (K2SiO3 and sodium hydroxide (NaOH or potassium hydroxide (KOH. The purpose of this research is to analyze the effect of activator liquid concentration on geopolymer mortar properties and to know the value of compressive strength. Molarity variation of NaOH are 8, 12, 14, and 16 M with ratio of Na2SiO3/NaOH = 1.0. Ratio of sand/fly ash = 2.75 and ratio of activator/fly ash = 0.8. The cube-shaped specimen 50 × 50 × 50 mm is cured by steam curing with a temperature of 60°C for 48 hours. The experimental result of fresh mortar reported that the molarity of NaOH affect the slump flow and setting time, higher of NaOH produces the smaller value of slump and the faster time of setting. The experimental of density results reported that the increase of specific gravity when the molarity of NaOH increased. The experimental results of the compressive strength are showed that the maximum compressive strength of geopolymer mortar 14 M is 10.06 MPa and the lowest compressive strength produced by geopolymer mortar 8 M is 3.95 MPa. Testing the compressive strength of geopolymer mortar 16 M produces compressive strength lower than 14 M geopolymer mortar is 9.16 MPa.

  15. Electrodialytic treatment of fly ash

    DEFF Research Database (Denmark)

    Jensen, Pernille Erland; Pedersen, Anne Juul; Kirkelund, Gunvor Marie

    Heavy metals are removed from the fly ashes by an electrodialytic treatment with the aim of up-grading the ashes for reuse in stead of disposal in landfill.A great potential for upgrading of bio- and waste incineration ashes by electrodialytic treatment exists. In the future, the applicability...... of the treated products for reuse in construction or farming sectors should be explored further, as should the possibility of recycling of valuable, extracted elements in the metallurgical industry....

  16. Notes on flying and dying.

    Science.gov (United States)

    Meyer, B C

    1983-07-01

    Focused on selected details in the lives and creative works of Samuel Johnson, Edgar Allan Poe, and Houdini, this paper explores a seeming antinomy between claustrophobic annihilation and aviation. At first glance the latter appears as an antidote to the threat of entrapment and death. On a deeper level the distinction fades as the impression arises that in the examples cited, flying may represent an unconscious expression of a wish for death and ultimate reunion.

  17. Identifying glass compositions in fly ash

    Directory of Open Access Journals (Sweden)

    Katherine eAughenbaugh

    2016-01-01

    Full Text Available In this study, four Class F fly ashes were studied with a scanning electron microscope; the glassy phases were identified and their compositions quantified using point compositional analysis with k-means clustering and multispectral image analysis. The results showed that while the bulk oxide contents of the fly ashes were different, the four fly ashes had somewhat similar glassy phase compositions. Aluminosilicate glasses (AS, calcium aluminosilicate glasses (CAS, a mixed glass, and, in one case, a high iron glass were identified in the fly ashes. Quartz and iron crystalline phases were identified in each fly ash as well. The compositions of the three main glasses identified, AS, CAS, and mixed glass, were relatively similar in each ash. The amounts of each glass were varied by fly ash, with the highest calcium fly ash containing the most of calcium-containing glass. Some of the glasses were identified as intermixed in individual particles, particularly the calcium-containing glasses. Finally, the smallest particles in the fly ashes, with the most surface area available to react in alkaline solution, such as when mixed with portland cement or in alkali-activated fly ash, were not different in composition than the large particles, with each of the glasses represented. The method used in the study may be applied to a fly ash of interest for use as a cementing material in order to understand its potential for reactivity.

  18. In vivo imaging of trypanosome-brain interactions and development of a rapid screening test for drugs against CNS stage trypanosomiasis.

    Directory of Open Access Journals (Sweden)

    Elmarie Myburgh

    Full Text Available HUMAN AFRICAN TRYPANOSOMIASIS (HAT MANIFESTS IN TWO STAGES OF DISEASE: firstly, haemolymphatic, and secondly, an encephalitic phase involving the central nervous system (CNS. New drugs to treat the second-stage disease are urgently needed, yet testing of novel drug candidates is a slow process because the established animal model relies on detecting parasitemia in the blood as late as 180 days after treatment. To expedite compound screening, we have modified the GVR35 strain of Trypanosoma brucei brucei to express luciferase, and have monitored parasite distribution in infected mice following treatment with trypanocidal compounds using serial, non-invasive, bioluminescence imaging. Parasites were detected in the brains of infected mice following treatment with diminazene, a drug which cures stage 1 but not stage 2 disease. Intravital multi-photon microscopy revealed that trypanosomes enter the brain meninges as early as day 5 post-infection but can be killed by diminazene, whereas those that cross the blood-brain barrier and enter the parenchyma by day 21 survived treatment and later caused bloodstream recrudescence. In contrast, all bioluminescent parasites were permanently eliminated by treatment with melarsoprol and DB829, compounds known to cure stage 2 disease. We show that this use of imaging reduces by two thirds the time taken to assess drug efficacy and provides a dual-modal imaging platform for monitoring trypanosome infection in different areas of the brain.

  19. Anti-trypanosomal activity of pentacyclic triterpenes isolated from Austroplenckia populnea (Celastraceae Atividade anti-tripanosomicida de triterpenes pentacíclicos isolados de Austroplenckia populnea (Celastraceae

    Directory of Open Access Journals (Sweden)

    Lucienir Pains DUARTE

    2002-04-01

    Full Text Available Four pentacyclic triterpenes isolated from Austroplenckia populnea and four compounds of known anti T. cruzi or anti-malarial activity were tested. Of those triterpenes tested 20alpha-hydroxy-tingenone showed high activity, epikatonic acid was less active, while populnilic and populninic acids were inactive against the trypanosome of the subgenus Schizotrypanum tested. Benzonidazole, nifurtimox, ketoconazole and primaquine presented a remarkable dose-dependent inhibitory effect reaching practically to a total growth inhibition of the parasite at the end of incubation time. The trypanosome tested appear to be a suitable model for preliminary screen for anti T. (S. cruzi compounds.Foram testados quatro triterpenos pentacíclicos isolados de Austroplenckia populnea e quatro compostos de conhecida atividade anti-T. cruzi ou anti-malárica. Dos triterpenos testados 20alfa-hidroxi-tingenona mostrou atividade elevada, ácido epicatônico foi menos ativo, enquanto ácido populnílico e populnínico foram inativos contra o tripanossoma do subgênero Schizotrypanum testado. Benzonidazole, nifurtimox, cetoconazole e primaquina apresentaram efeito inibitório dose-dependente atingindo praticamente a inibição total do crescimento do parasita no final do tempo de incubação. O tripanossoma testado mostrou ser um modelo adequado para uma seleção preliminar de compostos anti. T. (S. cruzi.

  20. Evaluating paratransgenesis as a potential control strategy for African trypanosomiasis.

    Science.gov (United States)

    Medlock, Jan; Atkins, Katherine E; Thomas, David N; Aksoy, Serap; Galvani, Alison P

    2013-01-01

    Genetic-modification strategies are currently being developed to reduce the transmission of vector-borne diseases, including African trypanosomiasis. For tsetse, the vector of African trypanosomiasis, a paratransgenic strategy is being considered: this approach involves modification of the commensal symbiotic bacteria Sodalis to express trypanosome-resistance-conferring products. Modified Sodalis can then be driven into the tsetse population by cytoplasmic incompatibility (CI) from Wolbachia bacteria. To evaluate the effectiveness of this paratransgenic strategy in controlling African trypanosomiasis, we developed a three-species mathematical model of trypanosomiasis transmission among tsetse, humans, and animal reservoir hosts. Using empirical estimates of CI parameters, we found that paratransgenic tsetse have the potential to eliminate trypanosomiasis, provided that any extra mortality caused by Wolbachia colonization is low, that the paratransgene is effective at protecting against trypanosome transmission, and that the target tsetse species comprises a large majority of the tsetse population in the release location.

  1. Possibilities of utilizing power plant fly ashes

    Directory of Open Access Journals (Sweden)

    Mezencevová Andrea

    2003-09-01

    Full Text Available The burning of fossil fuels in industrial power stations plays a significant role in the production of thermal and electrical energy. Modern thermal power plants are producing large amounts of solid waste, mainly fly ashes. The disposal of power plant waste is a large environmental problem at the present time. In this paper, possibilities of utilization of power plant fly ashes in industry, especially in civil engineering, are presented. The fly ash is a heterogeneous material with various physical, chemical and mineralogical properties, depending on the mineralogical composition of burned coal and on the used combustion technology. The utilization of fly ashes is determined of their properties. The fineness, specific surface area, particle shape, density, hardness, freeze-thaw resistance, etc. are decisive. The building trade is a branch of industry, which employs fly ash in large quantities for several decades.The best utilization of fluid fly ashes is mainly in the production of cement and concrete, due to the excellent pozzolanic and cementitious properties of this waste. In the concrete processing, the fly ash is utilized as a replacement of the fine aggregate (fine filler or a partial replacement for cement (active admixture. In addition to economic and ecological benefits, the use of fly ash in concrete improves its workability and durability, increases compressive and flexural strength, reduces segregation, bleeding, shrinkage, heat evolution and permeability and enhances sulfate resistance of concrete.The aim of current research is to search for new technologies for the fly ash utilization. The very interesting are biotechnological methods to recovery useful components of fly ashes and unconventional methods of modification of fly ash properties such as hydrothermal zeolitization and mechanochemical modification of its properties. Mechanochemistry deals with physico - chemical transformations and chemical reactions of solids induced by

  2. Composites Based on Fly Ash and Clay

    International Nuclear Information System (INIS)

    Fidancevska, E.; Jovanov, V.; Angusheva, B.; Srebrenkoska, V.

    2014-01-01

    Fly ash is a waste generated from the coal combustion during the production of electricity in the thermal power plants. It presents industrial by-product containing Technologically Enhanced Natural Occurring Radioactive Materials (TENORM) with the great potential for valorisation. Fly ash is successfully utilized in cement and concrete industry, also in ceramics industry as component for manufacturing bricks and tiles, and recently there are many investigations for production of glass-ceramics from fly ash. Although the utilization of fly ash in construction and civil engineering is dominant, the development of new alternative application for its further exploitation into new products is needed. This work presents the possibility for fly ash utilization for fabricating dense composites based on clay and fly ash with the potential to be used in construction industry

  3. An essential nuclear protein in trypanosomes is a component of mRNA transcription/export pathway.

    Directory of Open Access Journals (Sweden)

    Mariana Serpeloni

    decrease of translation levels, reinforcing that Trypanosoma-Sub2 (Tryp-Sub2 is a component of mRNA transcription/export pathway in trypanosomes.

  4. Structural characterization reveals a novel bilobed architecture for the ectodomains of insect stage expressed Trypanosoma brucei PSSA-2 and Trypanosoma congolense ISA.

    Science.gov (United States)

    Ramaswamy, Raghavendran; Goomeshi Nobary, Sarah; Eyford, Brett A; Pearson, Terry W; Boulanger, Martin J

    2016-12-01

    African trypanosomiasis, caused by parasites of the genus Trypanosoma, is a complex of devastating vector-borne diseases of humans and livestock in sub-Saharan Africa. Central to the pathogenesis of African trypanosomes is their transmission by the arthropod vector, Glossina spp. (tsetse fly). Intriguingly, the efficiency of parasite transmission through the vector is reduced following depletion of Trypanosoma brucei Procyclic-Specific Surface Antigen-2 (TbPSSA-2). To investigate the underlying molecular mechanism of TbPSSA-2, we determined the crystal structures of its ectodomain and that of its homolog T. congolense Insect Stage Antigen (TcISA) to resolutions of 1.65 Å and 2.45 Å, respectively using single wavelength anomalous dispersion. Both proteins adopt a novel bilobed architecture with the individual lobes displaying rotational flexibility around the central tether that suggest a potential mechanism for coordinating a binding partner. In support of this hypothesis, electron density consistent with a bound peptide was observed in the inter-lob cleft of a TcISA monomer. These first reported structures of insect stage transmembrane proteins expressed by African trypanosomes provide potentially valuable insight into the interface between parasite and tsetse vector. © 2016 The Protein Society.

  5. Passive Baited Sequential Filth Fly Trap.

    Science.gov (United States)

    Aldridge, Robert L; Britch, Seth C; Snelling, Melissa; Gutierez, Arturo; White, Gregory; Linthicum, Kenneth J

    2015-09-01

    Filth fly control measures may be optimized with a better understanding of fly population dynamics measured throughout the day. We describe the modification of a commercial motorized sequential mosquito trap to accept liquid odorous bait and leverage a classic inverted-cone design to passively confine flies in 8 modified collection bottles corresponding to 8 intervals. Efficacy trials in a hot-arid desert environment indicate no significant difference (P  =  0.896) between the modified sequential trap and a Rid-Max® fly trap.

  6. Use Of Fly Iarvae In Space Agriculture

    Science.gov (United States)

    Katayama, Naomi; Mitsuhashi, Jun; Hachiya, Natumi; Miyashita, Sachiko; Hotta, Atuko

    The concept of space agriculture is full use of biological and ecological components ot drive materials recycle loop. In an ecological system, producers, consumers and decomposers are its member. At limited resources acailable for space agriculture, full use of members' function is required to avoid food shortage and catastrophe.Fly is categrized to a decomposer at its eating excreta and rotten materials. However, is it could be edible, certainly it is eaten in several food culture of the world, it functions as a converter of inedible biomass ot edible substance. This conversion enhances the efficiency of usage of resource that will be attributed to space agriculture. In this context, we examine the value of melon fly, Dacus cucurbitae, as a candidate fly species ofr human food. Nutrients in 100g of melon fly larvae were protein 12g, lipid 4.6g Fe 4.74mg, Ca 275mg, Zn 6.37mg, Mn 4.00mg. Amino acids compositon in 100g of larvae was glutamic acid 1.43g and aspartic acid 1.12g. Because of high contents of these amino acids taste of fly larva might be good. Life time of adult melon fly is one to two month, and lays more than 1,000 eggs in total during the life. Larvae hatch after one to two days, and metamorphose after 8 to 15 days to pupae. Srxual maturity is reached after 22 days the earliest from it egg. Sixteen generations could be succeeded in a year for melon fly at maximum. The rate of proliferation of fly is quite high compared to silkworm that can have 8.7 generations per year. The wide food habit of fly, compared to mulberry leaf for silkworm, is another advantage to choose fly for entomophage. Rearing technology of melon fly is well established, since large scaled production of sterile male fly has been conducted in order ot exterminate melon fly in the field. Feeding substance for melon fly larvae in production line is a mixture of wheat, bran, raw sugar, olara, beer yeast, tissue paper, and additive chemicals. A 1 kg of feed substance can be converted to

  7. Emittance growth due to Tevatron flying wires

    Energy Technology Data Exchange (ETDEWEB)

    Syphers, M; Eddy, Nathan

    2004-06-01

    During Tevatron injection, Flying Wires have been used to measure the transverse beam size after each transfer from the Main Injector in order to deduce the transverse emittances of the proton and antiproton beams. This amounts to 36 + 9 = 45 flies of each of 3 wire systems, with an individual wire passing through each beam bunch twice during a single ''fly''. below they estimate the emittance growth induced by the interaction of the wires with the particles during these measurements. Changes of emittance from Flying Wire measurements conducted during three recent stores are compared with the estimations.

  8. Formation Flying and Deformable Instruments

    International Nuclear Information System (INIS)

    Rio, Yvon

    2009-01-01

    Astronomers have always attempted to build very stable instruments. They fight all that can cause mechanical deformation or image motion. This has led to well established technologies (autoguide, active optics, thermal control, tip/tilt correction), as well as observing methods based on the use of controlled motion (scanning, micro scanning, shift and add, chopping and nodding). Formation flying disturbs this practice. It is neither possible to reduce the relative motion to very small amplitudes, nor to control it at will. Some impacts on Simbol-X instrument design, and operation are presented.

  9. Sensitizing pigment in the fly

    International Nuclear Information System (INIS)

    Vogt, K.; Kirschfeld, K.

    1983-01-01

    The sensitizing pigment hypothesis for the high UV sensitivity in fly photoreceptors (R1-6) is further substantiated by measurements of the polarisation sensitivity in the UV. The quantum yield of the energy transfer from sensitizing pigment to rhodopsin was estimated by electrophysiological measurements of the UV sensitivity and the rhabdomeric absorptance (at 490 nm) in individual receptor cells. The transfer efficiency is >=0.75 in receptors with an absorptance in the rhabdomeres of 0.55-0.95. This result suggests that the sensitizing pigment is bound in some way to the rhodopsin. A ratio of two molecules of sensitizing pigment per one rhodopsin is proposed. (orig.)

  10. Flying Qualities (Qualites de Vol)

    Science.gov (United States)

    1991-02-01

    de Vol Electriques . Experience de IAirbus A320 par J.Farineau et X.Lc tron MIL-STD- 1797 is Not a Cookbook 7 by D).B.Lcggctt and G.TIBlack Flying...Gideslip excursion in the dutc-h-roll mocl and the ILajoi- corsequence is its non~-osc& Ilatory behaviour. When dipole cancellation does nct occur laterai...single dipole pair in the each axis are near optima, interaxis closed-loop pilot-vehicle system (with crosstalk is minimized, etc. Just as the Izero

  11. Trypanosoma brucei Infection in a herd of sedentary cattle in Danja ...

    African Journals Online (AJOL)

    However, with forestations, strict laws on bush burning and global warming, tsetse flies seems to be moving back into this hitherto declared tsetse - free zone. Several reports of the incidence of tsetse flies in this zone have been received by the Clinical And Ambulatory Services Unit of the Veterinary Teaching Hospital of the ...

  12. Cementing Efficiency of Low Calcium Fly Ash in Fly Ash Concretes

    OpenAIRE

    T. D. Gunneswara Rao; Mudimby Andal

    2014-01-01

    Research on the utilization of fly ash will no longer refer the fly ash as a waste material of thermal power plants. Use of fly ash in concrete making, makes the concrete economical as well as durable. The fly ash is being added to the concrete in three ways namely, as partial replacement to cement, as partial replacement to fine aggregates and as admixture. Addition of fly ash to the concrete in any one of the form mentioned above, makes the concrete more workable and durable than the conven...

  13. A fly larva (Syrphidae: Ocyptamus that preys on adult flies

    Directory of Open Access Journals (Sweden)

    Onanchi Ureña

    2010-12-01

    Full Text Available Predatory syrphid larvae feed on relatively immobile prey, but here we report the first case (as far as we are aware of obligatory predation on very mobile prey. Larvae of an undescribed species of Ocyptamus (Diptera: Syrphidae were found in whitefly (Hemiptera: Aleyrodidae aggregations on the undersides of citrus leaves. However, instead of preying on the whitefly nymphs (as would be expected, the larvae preyed on adult flies (Diptera that were attracted to the honeydew. In the laboratory, larvae captured significantly more flies on whitefly infested leaves than on washed leaves, and generally abandoned leaves that lacked whiteflies. Most cases of successful prey capture involved flies that probed the anterior part of the larva’s body with its proboscis (as if it were honeydew. The syrphid larva lashed out at the fly and entangled it in sticky oral secretion. The prey did not recover when they were removed from the larva, suggesting that this new predatory species also employs venom to subdue its prey. Although the larvae consumed some honeydew, they were unable to complete their development on this diet. Two parasitoids were reared from Ocyptamus puparia, Proaspicera sp. (Hymenoptera: Figitidae and Paracarotomus sp. (Hymenoptera: Pteromalidae, both of which are endoparasitic koinobionts. Rev. Biol. Trop. 58 (4: 1157-1163. Epub 2010 December 01.Las larvas depredadoras de Syrphidae se alimentan de presas relativamente inmóviles, pero aquí reportamos el primer caso (hasta ahora conocido de la depredación obligatoria en presas muy móviles. Se encontraron las larvas de una especie no descrita de Ocyptamus (Diptera: Syrphidae juntas con ninfas de mosca blanca (Hemiptera: Aleyrodidae en el envés de las hojas de cítricos. Sin embargo, en vez de alimentarse de las ninfas de mosca blanca (como debería esperarse, las larvas se alimentaron de moscas adultas (Diptera que fueron atraídas a las excreciones azucaradas de la mosca blanca. En el

  14. Oblique-Flying-Wing Supersonic Transport Airplane

    Science.gov (United States)

    Van Der Velden, Alexander J. M.

    1992-01-01

    Oblique-flying-wing supersonic airplane proposed as possible alternative to B747B (or equivalent). Tranports passengers and cargo as fast as twice speed of sound at same cost as current subsonic transports. Flies at same holding speeds as present supersonic transports but requires only half takeoff distance.

  15. Seasonal fluctuations of phlebotomines sand fly populations ...

    African Journals Online (AJOL)

    Seasonal fluctuations of phlebotomines sand fly populations (Diptera: Psychodidae) in the Moulay Yacoub province, centre Morocco: Effect of ecological factors. ... Sand flies were collected twice a month between April 2011 and March 2012, using sticky traps and CDC light traps. 3675 specimens were collected (78.3% ...

  16. Low back pain and low level flying

    NARCIS (Netherlands)

    J.C.F.M. Aghina

    1989-01-01

    textabstractLow level flying is a very good tactical possibility to carry out a mission unseen by a hostile radarsystem. Nowadays, Western Europe in general and the Federal Republic of Germany in particular, decreased . the permissions to low level flying in assigned regions. That's why the

  17. Zeolite from fly ash: synthesis and characterization

    Indian Academy of Sciences (India)

    Unknown

    disposal or to minimize the environmental impact. One of the approaches is the conversion of fly ash to zeolites, which have wide applications in ion exchange, as mole- cular sieves, catalysts, and adsorbents (Breck 1974). The present study is concerned with the synthesis of zeolite from coal fly ash and its characterization ...

  18. Activity of Bacillus thuringiensis isolates against immature horn fly and stable fly (Diptera: Muscidae).

    Science.gov (United States)

    Lysyk, T J; Kalischuk-Tymensen, L D; Rochon, K; Selinger, L B

    2010-06-01

    We screened 85 isolates of Bacillus thuringiensis (Berliner), making up 57 different subspecies, and two isolates of Bacillus sphaericus (Meyer and Neide) for activity against immature horn flies, Haematobia irritans (L.), and stable flies, Stomoxys calcitrans (L.). The majority of B. thuringiensis and the B. sphaericus isolates had little or no activity against horn fly and stable fly. Approximately 87% of the isolates caused fly larvae and 64% caused stable fly, 95% of the isolates caused fly and stable fly immatures. These isolates were B. t. tolworthi 4L3, B. t. darmstadiensis 4M1, B. t. thompsoni 401, B. t. thuringiensis HD2, and B. t. kurstaki HD945. The LD50 values ranged from 2.2 to 7.9 x 10(6) spores per g manure for horn fly and from 6.3 to 35 x 10(6) spores per g media for stable fly. These were consistently more toxic compared with the B. t. israelensis isolates examined. All had DNA that hybridized with cry1Aa, cry1Ab, and cry1Ac toxin probes, three hybridized with a cry1B probe, and two hybridized with a cry2A probe. These may have potential for use in integrated management of pest flies.

  19. Area-wide control of fruit flies and other insect pests. Joint proceedings of the international conference on area-wide control of insect pests and the fifth international symposium on fruit flies of economic importance

    International Nuclear Information System (INIS)

    Tan, Keng-Hong

    2000-01-01

    With the world population attaining the six billion mark, the urgency of increasing quality food production and reducing the spread of diseases transmitted by insects, without affecting our fragile environment, will be of paramount importance. Losses currently experienced in agricultural production, due to insect pests and through diseases transmitted by insect vectors, are very high especially in developing and poor countries. Many insect pests and vectors are of economic importance, and several such as fruit flies, mosquitoes and tsetse flies have attracted international concerns. Most pests are traditionally controlled through heavy reliance on pesticides which can cause environmental pollution, pesticide resistance, and pest resurgence. The control, management or eradication of insect pests and vectors with minimal adverse impact on our food quality, environment, health and well-being should be of great concern to many agriculturists, biological and physical scientists as well as to national and international agencies responsible for pest control. Steps taken by the various concerned agencies to improve and implement the area-wide control will hopefully lead us into the next millennium free from major insect pests and vectors while at the same time protect our precarious global environment. This volume is the culmination of proceedings conducted in two recent international meetings, FAO/IAEA International Conference on Area-Wide Control of Insect Pests, 28 May - 2 June 1998, and the Fifth International Symposium on Fruit Flies of Economic Importance, 1-5 June 1998, held in Penang, Malaysia. Over three hundred papers (both oral contributions and posters) were presented at the two meetings. The manuscripts submitted by authors are divided according to broad topics into eighteen sections originally defined by the organisers as corresponding to the sessions of the meetings. The organisers identified one to several individuals in each of the sessions to deliver an

  20. Distribution of horn flies on individual cows as a percentage of the total horn fly population.

    Science.gov (United States)

    Pruett, J H; Steelman, C D; Miller, J A; Pound, J M; George, J E

    2003-10-20

    Twenty-three mixed-breed herd cows were phenotyped for their ability to serve as a suitable host for Haematobia irritans, the horn fly. Based upon consistent observations within the lower quartile or upper quartile of individual fly counts, four cows were phenotyped as low carriers and five cows were phenotyped as high carriers of horn flies. The cows designated as low carriers consistently carried levels of flies below the economic threshold. However, during a period of fly population explosion, low carriers harbored flies well above the economic threshold. Although the number of flies counted on these low carrying cattle increased as the population increased, the relative percentage of the population that they carried changed very little. A hypothesis is proposed to explain this observation, and future studies are suggested.

  1. Stable Fly, (L., Dispersal and Governing Factors

    Directory of Open Access Journals (Sweden)

    Allan T. Showler

    2015-01-01

    Full Text Available Although the movement of stable fly, Stomoxys calcitrans (L., has been studied, its extent and significance has been uncertain. On a local scale (13 km is mainly wind-driven by weather fronts that carry stable flies from inland farm areas for up to 225 km to beaches of northwestern Florida and Lake Superior. Stable flies can reproduce for a short time each year in washed-up sea grass, but the beaches are not conducive to establishment. Such movement is passive and does not appear to be advantageous to stable fly's survival. On a regional scale, stable flies exhibit little genetic differentiation, and on the global scale, while there might be more than one “lineage”, the species is nevertheless considered to be panmictic. Population expansion across much of the globe likely occurred from the late Pleistocene to the early Holocene in association with the spread of domesticated nomad livestock and particularly with more sedentary, penned livestock.

  2. Epidemiology of animal trypanosomosis in the Niayes region of Senegal

    International Nuclear Information System (INIS)

    Seye, M.; Diaite, A.; Ndiaye, T.D.; Diouf, A.

    2000-01-01

    A study was performed in the Niayes region of Senegal to verify the return of tsetse and animal trypanosomosis 25 years after successful eradication of the disease and the vector from the region. Entomological investigations using tsetse traps demonstrated that a large part of the study area has been reinvaded by tsetse flies. Parasitological investigations of blood samples collected from cattle from the region showed rather high prevalence levels of Trypanosoma vivax, but did not indicate the presence of T. congolense or T. brucei. A serological survey of cattle using ELISA tests to detect antibodies directed against T. congolense and T. vivax showed high antibody prevalence levels for the two trypanosome species. Finally, the study permitted to establish the presence of antibodies directed against T. congolense and T. vivax in serum samples collected from the field using ELISA tests developed by the International Atomic Energy Agency (IAEA) in Vienna. The specificity of each of the two tests was found to be 95%. It is suggested that the two serological tests are used in combination with parasitological techniques in the diagnosis and epidemiology of bovine trypanosomosis. (author)

  3. PGRP-LB is a maternally transmitted immune milk protein that influences symbiosis and parasitism in tsetse’s offspring

    Science.gov (United States)

    Wang, Jingwen; Aksoy, Serap

    2012-01-01

    Beneficial microbe functions range from host dietary supplementation to development and maintenance of host immune system. In mammals, newborn progeny are quickly colonized with a symbiotic fauna that is provisioned in mother’s milk and that closely resembles that of the parent. Tsetse fly (Diptera: Glossinidae) also depends on the obligate symbiont Wigglesworthia for nutritional supplementation, optimal fecundity, and immune system development. Tsetse progeny develop one at a time in an intrauterine environment and receive nourishment and symbionts in mother’s milk. We show that the host Peptidoglycan Recognition Protein (PGRP-LB) is expressed only in adults and is a major component of the milk that nourishes the developing progeny. The amidase activity associated with PGRP-LB may scavenge the symbiotic peptidoglycan and prevent the induction of tsetse's Immune Deficiency pathway that otherwise can damage the symbionts. Reduction of PGRP-LB experimentally diminishes female fecundity and damages Wigglesworthia in the milk through induction of antimicrobial peptides, including Attacin. Larvae that receive less maternal PGRP-LB give rise to adults with fewer Wigglesworthia and hyperimmune responses. Such adults also suffer dysregulated immunity, as indicated by the presence of higher trypanosome densities in parasitized adults. We show that recPGRP-LB has antimicrobial and antitrypanosomal activities that may regulate symbiosis and impact immunity. Thus, PGRP-LB plays a pivotal role in tsetse’s fitness by protecting symbiosis against host-inflicted damage during development and by controlling parasite infections in adults that can otherwise reduce host fecundity. PMID:22689989

  4. Electrodialytic removal of heavy metals from fly ashes

    DEFF Research Database (Denmark)

    Pedersen, Anne Juul

    2002-01-01

    The aim of the Ph.D. work was to develop the electrodialytic remediation method for removal of heavy metals from fly ashes. The work was focused on two types of fly ashes: fly ashes from wood combustion and fly ashes from municipal solid waste incineration.......The aim of the Ph.D. work was to develop the electrodialytic remediation method for removal of heavy metals from fly ashes. The work was focused on two types of fly ashes: fly ashes from wood combustion and fly ashes from municipal solid waste incineration....

  5. Anti-trypanosomal activity of 1,2,3,4,6-penta-O-galloyl-β -D-glucose isolated from Plectranthus barbatus Andrews (Lamiaceae

    Directory of Open Access Journals (Sweden)

    Roberta T. dos Santos

    2012-01-01

    Full Text Available MeOH extract from the leaves of Plectranthus barbatus Andrews (Lamiaceae, showed in vitro anti-trypanosomal activity. The bioassay-guided fractionation resulted in the isolation of a gallic acid derivative, identified as 1,2,3,4,6-penta-O-galloyl-β-D-glucose (PGG, after thorough NMR and MS spectral analysis. Finally, this compound was tested against trypomastigote forms of T. cruzi and displayed an EC50 value of 67 µM, at least 6.6-fold more effective than the standard drug benznidazole. This is the first occurrence of PGG in the Plectranthus genus and the first anti-parasitic activity described for PGG in the literature.

  6. Anti-trypanosomal activity of 1,2,3,4,6-penta-O-galloyl-? -D-glucose isolated from Plectranthus barbatus Andrews (Lamiaceae)

    International Nuclear Information System (INIS)

    Santos, Roberta T. dos; Hiramoto, Liliane L.; Lago, Joao Henrique G.; Sartorelli, Patricia

    2012-01-01

    MeOH extract from the leaves of Plectranthus barbatus Andrews (Lamiaceae), showed in vitro anti-trypanosomal activity. The bioassay-guided fractionation resulted in the isolation of a gallic acid derivative, identified as 1,2,3,4,6-penta-O-galloyl-β-D-glucose (PGG), after thorough NMR and MS spectral analysis. Finally, this compound was tested against trypomastigote forms of T. cruzi and displayed an EC 50 value of 67 μM, at least 6.6-fold more effective than the standard drug benznidazole. This is the first occurrence of PGG in the Plectranthus genus and the first anti-parasitic activity described for PGG in the literature (author)

  7. Anti-trypanosomal activity of 1,2,3,4,6-penta-O-galloyl-? -D-glucose isolated from Plectranthus barbatus Andrews (Lamiaceae)

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Roberta T. dos; Hiramoto, Liliane L.; Lago, Joao Henrique G.; Sartorelli, Patricia [Universidade Federal de Sao Paulo (UNIFESP), Diadema, SP (Brazil). Inst. de Ciencias Ambientais, Quimicas e Farmaceuticas; Tempone, Andre G.; Pinto, Erika G. [Instituto Adolfo Lutz, Sao Paulo, SP (Brazil). Dept. de Parasitologia; Lorenzi, Harri, E-mail: psartorelli@unifesp.br [Instituto Plantarum de Estudos da Flora, Nova Odessa, SP (Brazil)

    2012-07-01

    MeOH extract from the leaves of Plectranthus barbatus Andrews (Lamiaceae), showed in vitro anti-trypanosomal activity. The bioassay-guided fractionation resulted in the isolation of a gallic acid derivative, identified as 1,2,3,4,6-penta-O-galloyl-{beta}-D-glucose (PGG), after thorough NMR and MS spectral analysis. Finally, this compound was tested against trypomastigote forms of T. cruzi and displayed an EC{sub 50} value of 67 {mu}M, at least 6.6-fold more effective than the standard drug benznidazole. This is the first occurrence of PGG in the Plectranthus genus and the first anti-parasitic activity described for PGG in the literature (author)

  8. Fly Photoreceptors Encode Phase Congruency.

    Directory of Open Access Journals (Sweden)

    Uwe Friederich

    Full Text Available More than five decades ago it was postulated that sensory neurons detect and selectively enhance behaviourally relevant features of natural signals. Although we now know that sensory neurons are tuned to efficiently encode natural stimuli, until now it was not clear what statistical features of the stimuli they encode and how. Here we reverse-engineer the neural code of Drosophila photoreceptors and show for the first time that photoreceptors exploit nonlinear dynamics to selectively enhance and encode phase-related features of temporal stimuli, such as local phase congruency, which are invariant to changes in illumination and contrast. We demonstrate that to mitigate for the inherent sensitivity to noise of the local phase congruency measure, the nonlinear coding mechanisms of the fly photoreceptors are tuned to suppress random phase signals, which explains why photoreceptor responses to naturalistic stimuli are significantly different from their responses to white noise stimuli.

  9. Fly Photoreceptors Encode Phase Congruency.

    Science.gov (United States)

    Friederich, Uwe; Billings, Stephen A; Hardie, Roger C; Juusola, Mikko; Coca, Daniel

    2016-01-01

    More than five decades ago it was postulated that sensory neurons detect and selectively enhance behaviourally relevant features of natural signals. Although we now know that sensory neurons are tuned to efficiently encode natural stimuli, until now it was not clear what statistical features of the stimuli they encode and how. Here we reverse-engineer the neural code of Drosophila photoreceptors and show for the first time that photoreceptors exploit nonlinear dynamics to selectively enhance and encode phase-related features of temporal stimuli, such as local phase congruency, which are invariant to changes in illumination and contrast. We demonstrate that to mitigate for the inherent sensitivity to noise of the local phase congruency measure, the nonlinear coding mechanisms of the fly photoreceptors are tuned to suppress random phase signals, which explains why photoreceptor responses to naturalistic stimuli are significantly different from their responses to white noise stimuli.

  10. Repertoire, Genealogy and Genomic Organization of Cruzipain and Homologous Genes in Trypanosoma cruzi, T. cruzi-Like and Other Trypanosome Species

    Science.gov (United States)

    Lima, Luciana; Ortiz, Paola A.; da Silva, Flávia Maia; Alves, João Marcelo P.; Serrano, Myrna G.; Cortez, Alane P.; Alfieri, Silvia C.; Buck, Gregory A.; Teixeira, Marta M. G.

    2012-01-01

    Trypanosoma cruzi, the agent of Chagas disease, is a complex of genetically diverse isolates highly phylogenetically related to T. cruzi-like species, Trypanosoma cruzi marinkellei and Trypanosoma dionisii, all sharing morphology of blood and culture forms and development within cells. However, they differ in hosts, vectors and pathogenicity: T. cruzi is a human pathogen infective to virtually all mammals whilst the other two species are non-pathogenic and bat restricted. Previous studies suggest that variations in expression levels and genetic diversity of cruzipain, the major isoform of cathepsin L-like (CATL) enzymes of T. cruzi, correlate with levels of cellular invasion, differentiation, virulence and pathogenicity of distinct strains. In this study, we compared 80 sequences of genes encoding cruzipain from 25 T. cruzi isolates representative of all discrete typing units (DTUs TcI-TcVI) and the new genotype Tcbat and 10 sequences of homologous genes from other species. The catalytic domain repertoires diverged according to DTUs and trypanosome species. Relatively homogeneous sequences are found within and among isolates of the same DTU except TcV and TcVI, which displayed sequences unique or identical to those of TcII and TcIII, supporting their origin from the hybridization between these two DTUs. In network genealogies, sequences from T. cruzi clustered tightly together and closer to T. c. marinkellei than to T. dionisii and largely differed from homologues of T. rangeli and T. b. brucei. Here, analysis of isolates representative of the overall biological and genetic diversity of T. cruzi and closest T. cruzi-like species evidenced DTU- and species-specific polymorphisms corroborating phylogenetic relationships inferred with other genes. Comparison of both phylogenetically close and distant trypanosomes is valuable to understand host-parasite interactions, virulence and pathogenicity. Our findings corroborate cruzipain as valuable target for drugs, vaccine

  11. Prevalence of trypanosomosis in cattle in Burkina Faso

    International Nuclear Information System (INIS)

    Bengaly, Z.M.

    1997-01-01

    The specificity of the Antigen ELISA was determined by examining 320 bovine serum samples from a tsetse free area and found to be high for the three trypanosome species pathogenic to cattle. By using parasitological techniques in conjunction with the Ag-ELISA it was possible to greatly increase the number of animals found positive for trypanosomes in a tsetse endemic area. For example T. brucei was detected in a region where it had not been encountered previously. The Ag-ELISA will be used to monitor the efficacy of past on-going tsetse control programs. (author). 3 refs, 1 fig., 4 tabs

  12. Treatment of fly ash for use in concrete

    Science.gov (United States)

    Boxley, Chett; Akash, Akash; Zhao, Qiang

    2013-01-08

    A process for treating fly ash to render it highly usable as a concrete additive. A quantity of fly ash is obtained that contains carbon and which is considered unusable fly ash for concrete based upon foam index testing. The fly ash is mixed with an activator solution sufficient to initiate a geopolymerization reaction and for a geopolymerized fly ash. The geopolymerized fly ash is granulated. The geopolymerized fly ash is considered usable fly ash for concrete according to foam index testing. The geopolymerized fly ash may have a foam index less than 35% of the foam index of the untreated fly ash, and in some cases less than 10% of the foam index of the untreated fly ash. The activator solution may contain an alkali metal hydroxide, carbonate, silicate, aluminate, or mixtures thereof.

  13. Treatment of fly ash for use in concrete

    Science.gov (United States)

    Boxley, Chett [Park City, UT

    2012-05-15

    A process for treating fly ash to render it highly usable as a concrete additive. A quantity of fly ash is obtained that contains carbon and which is considered unusable fly ash for concrete based upon foam index testing. The fly ash is mixed with a quantity of spray dryer ash (SDA) and water to initiate a geopolymerization reaction and form a geopolymerized fly ash. The geopolymerized fly ash is granulated. The geopolymerized fly ash is considered usable fly ash for concrete according to foam index testing. The geopolymerized fly ash may have a foam index less than 40%, and in some cases less than 20%, of the foam index of the untreated fly ash. An optional alkaline activator may be mixed with the fly ash and SDA to facilitate the geopolymerization reaction. The alkaline activator may contain an alkali metal hydroxide, carbonate, silicate, aluminate, or mixtures thereof.

  14. Sand Flies and Their Control Methods.

    Science.gov (United States)

    Çetin, Hüseyin; Özbel, Yusuf

    2017-06-01

    The main aim of managing arthropod vectors that carry the disease agents is interrupting the infection cycle. Therefore, the management of the disease implies that all precautions related to all elements (i.e., human, arthropod vector, and reservoir) in the infection cycle need to be taken. There are important points that need to be considered while dealing with sand flies (Diptera: Psychodidae: Phlebotominae), which in many regions worldwide, particularly in tropical and subtropical areas, are vectors of diseases such as leishmaniasis and sand fly fever and are the arthropods of the infection cycle. Because the larval control of the sand flies is very difficult and almost impossible, the management is mainly conducted for the adults. The most effective strategy for reducing both sand fly fever and leishmaniasis is managing sand flies, particularly in areas where humans are located. In this review, the morphology, biology, and taxonomy of sand flies; the integrated fighting and management methods such as insecticide-impregnated bed nets and use of curtains, zooprophylaxis, indoor and outdoor residual applications, larvicides, repellents, and insecticide-impregnated dog collars; and data regarding many issues such as insecticide resistance in sand flies have been emphasized on in the review.

  15. Simulating the complex cell design of Trypanosoma brucei and its motility.

    Directory of Open Access Journals (Sweden)

    Davod Alizadehrad

    2015-01-01

    Full Text Available The flagellate Trypanosoma brucei, which causes the sleeping sickness when infecting a mammalian host, goes through an intricate life cycle. It has a rather complex propulsion mechanism and swims in diverse microenvironments. These continuously exert selective pressure, to which the trypanosome adjusts with its architecture and behavior. As a result, the trypanosome assumes a diversity of complex morphotypes during its life cycle. However, although cell biology has detailed form and function of most of them, experimental data on the dynamic behavior and development of most morphotypes is lacking. Here we show that simulation science can predict intermediate cell designs by conducting specific and controlled modifications of an accurate, nature-inspired cell model, which we developed using information from live cell analyses. The cell models account for several important characteristics of the real trypanosomal morphotypes, such as the geometry and elastic properties of the cell body, and their swimming mechanism using an eukaryotic flagellum. We introduce an elastic network model for the cell body, including bending rigidity and simulate swimming in a fluid environment, using the mesoscale simulation technique called multi-particle collision dynamics. The in silico trypanosome of the bloodstream form displays the characteristic in vivo rotational and translational motility pattern that is crucial for survival and virulence in the vertebrate host. Moreover, our model accurately simulates the trypanosome's tumbling and backward motion. We show that the distinctive course of the attached flagellum around the cell body is one important aspect to produce the observed swimming behavior in a viscous fluid, and also required to reach the maximal swimming velocity. Changing details of the flagellar attachment generates less efficient swimmers. We also simulate different morphotypes that occur during the parasite's development in the tsetse fly, and

  16. Heavy metals in MSW incineration fly ashes

    DEFF Research Database (Denmark)

    Ferreira, Celia; Ribeiro, Alexandra B.; Ottosen, Lisbeth M.

    2003-01-01

    is characterized regarding its physical-chemical properties: pH, solubility, chemical composition, and leaching, amongst others. Results indicate a high alkalinity and the presence of large amounts of calcium, chlorides, sulfates, carbonates, sodium and potassium. Metal concentrations in fly ash are: 6,2 g....../kg for zinc, 2,4 g/kg for lead, 1,7 g/kg for iron, and 7,9 g/kg for magnesium. Copper, manganese, chromium and cadmium are also present with 546, 338, 104 and 91 mg/kg of fly ash, respectively. These results are extremely important in subsequent studies on the treatment of fly ash....

  17. Controlling roll perturbations in fruit flies

    OpenAIRE

    Beatus, Tsevi; Guckenheimer, John M.; Cohen, Itai

    2015-01-01

    Owing to aerodynamic instabilities, stable flapping flight requires ever-present fast corrective actions. Here, we investigate how flies control perturbations along their body roll angle, which is unstable and their most sensitive degree of freedom. We glue a magnet to each fly and apply a short magnetic pulse that rolls it in mid-air. Fast video shows flies correct perturbations up to 100° within 30 ± 7 ms by applying a stroke-amplitude asymmetry that is well described by a linear proportion...

  18. Evidence for Sticky-Trap Avoidance by Stable Fly, Stomoxys calcitrans (Diptera: Muscidae), in Response to Trapped Flies.

    Science.gov (United States)

    Beresford, D V; Sutcliffe, J F

    2017-09-01

    Populations of stable flies, Stomoxys calcitrans, and other filth flies are often sampled using sticky traps. We wanted to know whether flies already caught on sticky traps might inhibit to some extent subsequent flies from being caught. To test this, we recorded the number of stable flies landing on white plastic corrugated panels (Coroplast®), which were prepared according to 4 treatments: 12 live stable flies glued to the surface, 12 live house flies (Musca domestica) glued to the surface, 12 black dots, and no treatment. From 160 observations, we found that fewer stable flies landed on panels with either attached stable flies (129) or house flies (133) compared with the number landing on panels with black dots (259) and/or with no treatment (210). This apparent inhibitory effect of trapped flies may explain published trap-catch patterns from field studies.

  19. Prospective medical evaluation of 7 dogs presented with fly biting.

    Science.gov (United States)

    Frank, Diane; Bélanger, Marie C; Bécuwe-Bonnet, Véronique; Parent, Joane

    2012-12-01

    Fly biting describes a syndrome in which dogs appear to be watching something and then snapping at it. Medical work-up of fly biting in dogs has never been reported. The aims of this case series were to characterize fly biting and perform a complete medical evaluation of dogs displaying fly biting.

  20. Prospective medical evaluation of 7 dogs presented with fly biting

    OpenAIRE

    Frank, Diane; Bélanger, Marie C.; Bécuwe-Bonnet, Véronique; Parent, Joane

    2012-01-01

    Fly biting describes a syndrome in which dogs appear to be watching something and then snapping at it. Medical work-up of fly biting in dogs has never been reported. The aims of this case series were to characterize fly biting and perform a complete medical evaluation of dogs displaying fly biting.

  1. Student life - Fly on the wall approach.

    Science.gov (United States)

    White, Sarah; Coghlan, Phoebe

    2015-08-26

    Imagine your grandmother was in hospital. How would you expect her to be treated? Would the nurse or doctor smile and ask her how she's feeling? Imagine what you would see if you were a fly on the wall.

  2. Controlling roll perturbations in fruit flies.

    Science.gov (United States)

    Beatus, Tsevi; Guckenheimer, John M; Cohen, Itai

    2015-04-06

    Owing to aerodynamic instabilities, stable flapping flight requires ever-present fast corrective actions. Here, we investigate how flies control perturbations along their body roll angle, which is unstable and their most sensitive degree of freedom. We glue a magnet to each fly and apply a short magnetic pulse that rolls it in mid-air. Fast video shows flies correct perturbations up to 100° within 30 ± 7 ms by applying a stroke-amplitude asymmetry that is well described by a linear proportional-integral controller. For more aggressive perturbations, we show evidence for nonlinear and hierarchical control mechanisms. Flies respond to roll perturbations within 5 ms, making this correction reflex one of the fastest in the animal kingdom. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  3. Evaluation of a commercial vacuum fly trap for controlling flies on organic dairy farms.

    Science.gov (United States)

    Kienitz, M J; Heins, B J; Moon, R D

    2018-02-28

    The objective of this study was to evaluate the efficacy of a commercial vacuum fly trap (CowVac, Spalding Laboratories, Reno, NV) in on-farm organic dairy production systems to control horn flies, stable flies, and face flies. As cows walk through the trap, flies are brushed off the face, flank, and back with hanging flaps and blown off the belly, udder, and legs from one side, and then vacuumed from the air into a chamber from vacuum inlets opposite the blower and above the cow. The study included 8 organic dairy farms during the summer of 2015 in Minnesota, and herds ranged from 30 to 350 cows in size. The farms were divided into pairs by location; during the first period of the summer (June to July), the trap was set up on 1 farm, whereas during the second period of the summer (August to September) the trap was sent to its paired farm. Farms were visited once per week to collect and count flies from the trap as well as count and record flies on cows. Bulk tank milk, fat, and protein production and somatic cell count were collected on farms during the entire study period. Data were analyzed using the GLM procedure of SAS (version 9.3, SAS Institute Inc., Cary, NC). Independent variables for analyses were the fixed effects of farm, trap presence, housing scenario, and summer period. Horn fly numbers on cows were lower by 44% on farm in the presence of a trap (11.4 vs. 20.5 flies/cow-side) compared with the absence of a trap. Stable fly (5.4 vs. 7.1 flies/leg) and face fly (1.0 vs. 1.0 flies/cow) numbers were similar on farm whether the trap was present or absent on farms, respectively. Milk production was similar for farms with the trap (15.5 kg/d) compared to without (15.3 kg/d) the trap. Bulk tank milk, milk components, and somatic cell count were statistically similar in the presence and absence of the trap, so potential benefits of the trap for those measures were not evident at low fly populations observed during the study. The presence of a trap on farm

  4. The fly's eye camera system

    Science.gov (United States)

    Mészáros, L.; Pál, A.; Csépány, G.; Jaskó, A.; Vida, K.; Oláh, K.; Mezö, G.

    2014-12-01

    We introduce the Fly's Eye Camera System, an all-sky monitoring device intended to perform time domain astronomy. This camera system design will provide complementary data sets for other synoptic sky surveys such as LSST or Pan-STARRS. The effective field of view is obtained by 19 cameras arranged in a spherical mosaic form. These individual cameras of the device stand on a hexapod mount that is fully capable of achieving sidereal tracking for the subsequent exposures. This platform has many advantages. First of all it requires only one type of moving component and does not include unique parts. Hence this design not only eliminates problems implied by unique elements, but the redundancy of the hexapod allows smooth operations even if one or two of the legs are stuck. In addition, it can calibrate itself by observed stars independently from both the geographical location (including northen and southern hemisphere) and the polar alignment of the full mount. All mechanical elements and electronics are designed within the confines of our institute Konkoly Observatory. Currently, our instrument is in testing phase with an operating hexapod and reduced number of cameras.

  5. Leaching of saltstones containing fly ash

    International Nuclear Information System (INIS)

    Barnes, M.W.; Roy, D.M.; Langton, C.A.

    1985-01-01

    Two types of fly ash were incorporated in saltstones designed for potential encapsulation of Savannah River Plant low level defense waste. These fly ashes have some cementitious properties while at the same time their presence in substitution for cement slows early hydration. Class C fly ash has a high calcium content and is considered cementitious; Class F fly ash has a low calcium content and is not classified as cementitious. Leach tests were performed and physical properties were measured for saltstones containing each class, to see the differences in the effect of the fly ashes. The four waste ions nitrate, nitrite, sodium and sulfate were shown to leach by diffusion. Effective diffusivities were determined for these ions. Data for nitrate, the most important species from the environmental point of view, are shown in Table A. Saltstones made with Class C fly ash have substantially lower leach rates than those made with Class F fly ash. The leach rates, and therefore the square roots of the effective diffusivities, have been found to be proportional to the pore surface area per unit volume (or the ratio of pore volume to pore radius), to the fraction of waste containing solution, and to the inverse of the fraction of calcium in the saltstone. Rates and diffusivities are not proportional to the water to cement ratio, because this number depends on whether the fly ash is counted as cementitious, as in Class C cement, or not cementitious, as in Class F cement. In fact the relatively small amount of calcium in Class F cement contributes to the cementitious properties overall, though not so much as Class C cement. 4 refs., 2 figs., 6 tabs

  6. Studies on mating competition of irradiated melon flies

    International Nuclear Information System (INIS)

    Limohpasmanee, W.

    1994-01-01

    Mating competition is the key factor for fruit flies control by using sterile insect technique project. Mass rearing and irradiation can reduce the mating competition of fruit flies. This experiment has purpose to evaluate the mating competition of the irradiated melon fly. The results show that mating competition values of irradiated melon flies were 0.36 and 0.24 when they mated with normal and irradiated females. Both normal male and female can mate more frequency than irradiated flies. (Z=1.322, P<0.05; Z=1.851, P<0.05). The results show that quality of mass rearing and irradiated melon fly was lower than the normal flies. So that quality of irradiated fly must be improved and the number of released flies as less must be higher than natural flies 6 time

  7. Transformations through Proximity Flying: A Phenomenological Investigation

    Directory of Open Access Journals (Sweden)

    Maria Holmbom

    2017-10-01

    Full Text Available Participation in extreme sports has been linked to personal transformations in everyday life. Descriptions of lived experience resulting from transformative experiences are limited. Proximity flying, a relatively new discipline involving BASE jumping with a wingsuit where participants fly close to solid structures, is arguably one of the most extreme of extreme sports. The aim of this paper, part of a larger phenomenological study on the lived experience of proximity flying, is to explicate the ways in which participating in proximity flying influences the everyday lives of participants. Interpretative phenomenological analysis was used to explicate the lived experience of six proximity pilots. An analysis of interview transcripts revealed three significant themes describing the lived experience of participants. First, experiences of change were described as positive and skills developed through proximity flying were transferable into everyday life. Second, transformative experiences were considered fundamental to participants’ perspectives on life. Third, experience of transformation influenced their sense of personal identity and facilitated flourishing in other aspects of everyday life. Participants were clear that their experiences in proximity flying facilitated a profound process of transformation which manifest as changes in everyday capabilities and behaviors, values and sense of identity.

  8. The Mexican Fruit Fly Eradication Programme

    International Nuclear Information System (INIS)

    Reyes F, Jesus; Santiago M, Guillermo; Hernandez M, Porfirio

    2000-01-01

    The goal of the Mexican Fruit Fly Eradication Programme is to control, suppress or eradicate from Mexico four species of fruit flies of economic and quarantine importance (Anastrepha ludens Loew, A. obliqua Macquart, A. serpentina Wied. and A. striata Schiner). These pests cause damage amounting to US$710 million per year. In addition to this cost, there are other expenses from pest control actions and the loss of international markets, because fruit importing countries have established stringent quarantine measures to restrict the entry of these pests. For purposes of the programme's implementation, Mexico was divided into three working zones, defined by agro-ecological characteristics, the number of fruit fly species present and the size of fruit growing regions. In addition, a cost:benefit analysis was carried out which indicated that the rate of return, in a 12-year time frame, might be as much as 33:1 in Northern Mexico, and 17:1 in the rest of the country, for an area over 100,000 hectares. Eradication technology involves: 1) surveys of pest populations by trapping and host fruit harvesting to monitor the presence and density of fruit flies, 2) reduction of pest populations applying cultural practices and using selective bait sprays, 3) mass release of sterile flies and augmentative release of parasitoids to eliminate populations and, 4) enforcement of quarantine measures to protect fruit fly free areas

  9. 76 FR 18419 - Movement of Hass Avocados From Areas Where Mediterranean Fruit Fly or South American Fruit Fly Exist

    Science.gov (United States)

    2011-04-04

    ... commented that Hass avocados attached to trees are not hosts for the guava fruit fly (A. striata), or the... respect to Mediterranean fruit fly and South American fruit fly; we did, however, acknowledge that guava... proposed restrictions related to the movement of Hass avocados from areas where the guava fruit fly is...

  10. The evaluation of GM6-based ELISA and ICT as diagnostic methods on a Mongolian farm with an outbreak of non-tsetse transmitted horse trypanosomosis.

    Science.gov (United States)

    Davaasuren, Batdorj; Amgalanbaatar, Tovuu; Musinguzi, Simon Peter; Suganuma, Keisuke; Otgonsuren, Davaajav; Mossaad, Ehab; Narantsatsral, Sandagdorj; Battur, Banzragch; Battsetseg, Badgar; Xuan, Xuenan; Inoue, Noboru

    2017-09-15

    Trypanosoma equiperdum, which is the etiological agent of dourine, spreads through sexual intercourse in equines. Dourine (T. equiperdum) has been reported in Mongolia, where it is considered an economically important disease of horses. T. evansi has also been reported in Mongolian domestic animals. The objective of this study was to evaluate the potential application of recombinant T. evansi GM6 (rTeGM6-4r)-based diagnostic methods on a farm with an outbreak of non-tsetse transmitted horse trypanosomosis. Ninety-seven percent homology was found between the amino acid sequences of T. equiperdum GM6 and the GM6 of another Trypanozoon, which also shared the same cellular localization. This finding suggests the utility of rTeGM6-4r-based serodiagnostic methods for epidemiological studies and the diagnosis of both surra and dourine in Equidae. Fifty blood samples were examined from a herd of horses. The diagnostic value of an rTeGM6-4r-based ELISA and an rTeGM6-4r-based immunochromatographic test (ICT) were measured in comparison to a T. evansi crude antigen-based ELISA, which is a diagnostic method recommended by the OIE. However, this is not a perfect diagnostic method for trypanosomosis. Positive serum samples were detected in 46%, 42% and 28% of the tested horses using an rTeGM6-4r-based ELISA, crude antigen-based ELISA and rTeGM6-4r-based ICT, respectively. The sensitivity of rTeGM6-based ELISA was 81%, the specificity was 79%, and the agreement was moderate. We conclude that rTeGM6-4r-based ELISA and ICT represent alternative options for baseline epidemiological studies and the on-site diagnosis of horse trypanosomoses in the field, respectively. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Attractant for vinegar fly, Drosophila busckii, and cluster fly, Pollenia rudis (Diptera: Drosophilidae et Calliphoridae).

    Science.gov (United States)

    Buda, Vincas; Radziute, Sandra; Lutovinovas, Erikas

    2009-01-01

    A field test carried out in an industrial greenhouse in Lithuania revealed the attractiveness of synthetic methyl salicylate (MeSa) to two dipteran species: the vinegar fly, Drosophila busckii (Drosophilidae), and the cluster fly, Pollenia rudis (Calliphoridae). The attractant for the former fly species was especially effective, as sticky traps containing 0.25 ml of MeSa captured (814 +/- 55) D. busckii flies/trap on average compared to (12 +/- 4) flies/trap in control traps. The mean capture of P. rudis [(42 +/- 4) flies/trap] was significantly higher in MeSa-baited traps compared to the control traps [(13 +/- 4) flies/trap]. The presence of MeSa in emissions of many fruits suitable for D. busckii feeding allows to attribute this attractant to kairomones. In case of P. rudis, MeSa should be attributed to synomones (compounds beneficial for both receiver and sender), because adult flies feeding on flowers act as pollinators. This is the first report on the field-active attractant for D. busckii and the second for P. rudis.

  12. Using detergent to enhance detection sensitivity of African trypanosomes in human CSF and blood by loop-mediated isothermal amplification (LAMP.

    Directory of Open Access Journals (Sweden)

    Dennis J Grab

    2011-08-01

    Full Text Available The loop-mediated isothermal amplification (LAMP assay, with its advantages of simplicity, rapidity and cost effectiveness, has evolved as one of the most sensitive and specific methods for the detection of a broad range of pathogenic microorganisms including African trypanosomes. While many LAMP-based assays are sufficiently sensitive to detect DNA well below the amount present in a single parasite, the detection limit of the assay is restricted by the number of parasites present in the volume of sample assayed; i.e. 1 per µL or 10(3 per mL. We hypothesized that clinical sensitivities that mimic analytical limits based on parasite DNA could be approached or even obtained by simply adding detergent to the samples prior to LAMP assay.For proof of principle we used two different LAMP assays capable of detecting 0.1 fg genomic DNA (0.001 parasite. The assay was tested on dilution series of intact bloodstream form Trypanosoma brucei rhodesiense in human cerebrospinal fluid (CSF or blood with or without the addition of the detergent Triton X-100 and 60 min incubation at ambient temperature. With human CSF and in the absence of detergent, the LAMP detection limit for live intact parasites using 1 µL of CSF as the source of template was at best 10(3 parasites/mL. Remarkably, detergent enhanced LAMP assay reaches sensitivity about 100 to 1000-fold lower; i.e. 10 to 1 parasite/mL. Similar detergent-mediated increases in LAMP assay analytical sensitivity were also found using DNA extracted from filter paper cards containing blood pretreated with detergent before card spotting or blood samples spotted on detergent pretreated cards.This simple procedure for the enhanced detection of live African trypanosomes in biological fluids by LAMP paves the way for the adaptation of LAMP for the economical and sensitive diagnosis of other protozoan parasites and microorganisms that cause diseases that plague the developing world.

  13. Using Detergent to Enhance Detection Sensitivity of African Trypanosomes in Human CSF and Blood by Loop-Mediated Isothermal Amplification (LAMP)

    Science.gov (United States)

    Grab, Dennis J.; Nikolskaia, Olga V.; Inoue, Noboru; Thekisoe, Oriel M. M.; Morrison, Liam J.; Gibson, Wendy; Dumler, J. Stephen

    2011-01-01

    Background The loop-mediated isothermal amplification (LAMP) assay, with its advantages of simplicity, rapidity and cost effectiveness, has evolved as one of the most sensitive and specific methods for the detection of a broad range of pathogenic microorganisms including African trypanosomes. While many LAMP-based assays are sufficiently sensitive to detect DNA well below the amount present in a single parasite, the detection limit of the assay is restricted by the number of parasites present in the volume of sample assayed; i.e. 1 per µL or 103 per mL. We hypothesized that clinical sensitivities that mimic analytical limits based on parasite DNA could be approached or even obtained by simply adding detergent to the samples prior to LAMP assay. Methodology/Principal Findings For proof of principle we used two different LAMP assays capable of detecting 0.1 fg genomic DNA (0.001 parasite). The assay was tested on dilution series of intact bloodstream form Trypanosoma brucei rhodesiense in human cerebrospinal fluid (CSF) or blood with or without the addition of the detergent Triton X-100 and 60 min incubation at ambient temperature. With human CSF and in the absence of detergent, the LAMP detection limit for live intact parasites using 1 µL of CSF as the source of template was at best 103 parasites/mL. Remarkably, detergent enhanced LAMP assay reaches sensitivity about 100 to 1000-fold lower; i.e. 10 to 1 parasite/mL. Similar detergent-mediated increases in LAMP assay analytical sensitivity were also found using DNA extracted from filter paper cards containing blood pretreated with detergent before card spotting or blood samples spotted on detergent pretreated cards. Conclusions/Significance This simple procedure for the enhanced detection of live African trypanosomes in biological fluids by LAMP paves the way for the adaptation of LAMP for the economical and sensitive diagnosis of other protozoan parasites and microorganisms that cause diseases that plague the

  14. Retention of Escherichia coli by house fly and stable fly (Diptera: Muscidae) during pupal metamorphosis and eclosion.

    Science.gov (United States)

    Rochon, K; Lysyk, T J; Selinger, L B

    2005-05-01

    Populations of Escherichia coli obtained by feeding larval house flies, Musca domestica L. and stable flies, Stomoxys calcitrans (L.), persisted through the pupal stage. The abundance of E. coli in house fly pupae increased initially then declined before adult emergence. Abundance of E. coli in stable fly pupae increased through pupal development and remained high. Infected stable fly pupal cases typically contained more E. coli than house fly pupal cases. A greater proportion of emerging adult house flies were infected with E. coli compared with stable flies; however, the abundance of E. coli on infected flies was similar between species. Adult flies contained 0.04-0.19% of the E. coli in the pupal cases. The proportion of infected house fly adults and the amount of E. coli on the infected flies were related to the levels of E. coli in the pupal cases; however, these relationships did not occur with the stable fly. Results suggest that retention of E. coli from larval to adult house flies could play a role in the transmission and spread of E. coli, whereas stable fly adults probably play a minor role in E. coli spread. However, pupae of both species have potential to act as reservoirs for E. coli.

  15. An overview of quarantine for fruit flies

    International Nuclear Information System (INIS)

    Frampton, E.R.

    2000-01-01

    What is meant by 'quarantine for fruit flies'? The Collins dictionary describes 'quarantine' as a period of isolation or detention, especially of persons or animals arriving from abroad, to prevent the spread of disease. In providing an overview of quarantine for fruit flies, a broader definition needs to be applied, that is, the combination of activities required to maintain the fruit fly status of a particular geographical area - perhaps better referred to as a 'quarantine system'. Familiarity with New Zealand's quarantine system for fruit flies (Diptera: Tephritidae) provides a useful basis for subsequent comparison with other countries' systems where some fruit fly species may be present. But, why have 'quarantine for fruit flies'? The multivoltine life history of many species. combined with a relatively long-lived adult stage and highly fecund females, results in a high potential for rapid population increase (Bateman 1979, Fletcher 1987). These factors and the close association of fruit flies with harvested fruit or vegetables explain the high quarantine profile of these insects. However, there is no international requirement for a country to have a quarantine system and unless there are natural quarantine barriers (e.g., mountain range, oceans, deserts) that can be utilised, effective quarantine by an individual country may be an impossible task. The implementation of a successful quarantine system is very expensive and therefore, it would be expected that any benefits attained outweigh the costs (Ivess 1998). Ivess (1998) listed the following benefits from the implementation of an effective quarantine system: minimising production costs (including post harvest treatments), maintaining competitive advantages for market access due to the ongoing freedom from particular pests of quarantine significance, an environment free from many pests harmful to plant health, the maintenance of ecosystems

  16. Investigation of gliding flight by flying fish

    Science.gov (United States)

    Park, Hyungmin; Jeon, Woo-Pyung; Choi, Haecheon

    2006-11-01

    The most successful flight capability of fish is observed in the flying fish. Furthermore, despite the difference between two medium (air and water), the flying fish is well evolved to have an excellent gliding performance as well as fast swimming capability. In this study, flying fish's morphological adaptation to gliding flight is experimentally investigated using dry-mounted darkedged-wing flying fish, Cypselurus Hiraii. Specifically, we examine the effects of the pectoral and pelvic fins on the aerodynamic performance considering (i) both pectoral and pelvic fins, (ii) pectoral fins only, and (iii) body only with both fins folded. Varying the attack angle, we measure the lift, drag and pitching moment at the free-stream velocity of 12m/s for each case. Case (i) has higher lift-to-drag ratio (i.e. longer gliding distance) and more enhanced longitudinal static stability than case (ii). However, the lift coefficient is smaller for case (i) than for case (ii), indicating that the pelvic fins are not so beneficial for wing loading. The gliding performance of flying fish is compared with those of other fliers and is found to be similar to those of insects such as the butterfly and fruitfly.

  17. Reconstructing the behavior of walking fruit flies

    Science.gov (United States)

    Berman, Gordon; Bialek, William; Shaevitz, Joshua

    2010-03-01

    Over the past century, the fruit fly Drosophila melanogaster has arisen as almost a lingua franca in the study of animal behavior, having been utilized to study questions in fields as diverse as sleep deprivation, aging, and drug abuse, amongst many others. Accordingly, much is known about what can be done to manipulate these organisms genetically, behaviorally, and physiologically. Most of the behavioral work on this system to this point has been experiments where the flies in question have been given a choice between some discrete set of pre-defined behaviors. Our aim, however, is simply to spend some time with a cadre of flies, using techniques from nonlinear dynamics, statistical physics, and machine learning in an attempt to reconstruct and gain understanding into their behavior. More specifically, we use a multi-camera set-up combined with a motion tracking stage in order to obtain long time-series of walking fruit flies moving about a glass plate. This experimental system serves as a test-bed for analytical, statistical, and computational techniques for studying animal behavior. In particular, we attempt to reconstruct the natural modes of behavior for a fruit fly through a data-driven approach in a manner inspired by recent work in C. elegans and cockroaches.

  18. Preliminary Study of Fly Ash Ceramic Process

    International Nuclear Information System (INIS)

    Herry-Poernomo; Djoko-Sardjono, Ign.

    2000-01-01

    Preliminary study of ceramic production process from two components ofwhich are fly ash and feldspar has been done. Aluminosilicate substancecontained in the fly ash is a basic material a former ceramic body, if itfired at the temperature of 1000 o C forms mullite (3Al 2 O 3 .2SiO 2 ). Mulliteis a refractory material which is very stable at the temperature changing.This experiment studies the ceramic production process of two componentsnamely fly ash with particle size of o C.Steps of processes are making paste of fly ash and feldspar, making of greenpellets, and firing of pellets, physical analysis of ceramic including volumedecrease, lost ignition, porosity, density, water sorption, compressivestrength. The experiment result at firing temperature of 1000 o C were shownthat best composition at the weight ratio of fly ash to feldspar are 60/40and 50/50. It physical characteristic respectively are decrease of volume0.54 and 0.69 %, lost ignition = 11.98 and 11.78 %, porosity = 0.159 and0.155, density = 2.05 and 2.06 g/cm 3 , water sorption = 18.96 and 18.36 %,compressive strength = 24.82 and 24.79 kN/mm 2 . (author)

  19. Entomopathogenic Fungi in Flies Associated with Pastured Cattle in Denmark

    DEFF Research Database (Denmark)

    Steenberg, Tove; Jespersen, Jørgen B.; Jensen, Karl-Martin Vagn

    2001-01-01

    Cattle flies, including Musca autumnalis, Haematobia irritans, and Hydrotaea irritans, are pests of pastured cattle. A 2-year study of the natural occurrence of entomopathogenic fungi in adult cattle flies and other flies associated with pastures showed that the four species included in the Entom......Cattle flies, including Musca autumnalis, Haematobia irritans, and Hydrotaea irritans, are pests of pastured cattle. A 2-year study of the natural occurrence of entomopathogenic fungi in adult cattle flies and other flies associated with pastures showed that the four species included...

  20. Ecotype evolution in Glossina palpalis subspecies, major vectors of sleeping sickness.

    Directory of Open Access Journals (Sweden)

    Thierry De Meeûs

    2015-03-01

    Full Text Available The role of environmental factors in driving adaptive trajectories of living organisms is still being debated. This is even more important to understand when dealing with important neglected diseases and their vectors.In this paper, we analysed genetic divergence, computed from seven microsatellite loci, of 614 tsetse flies (Glossina palpalis gambiensis and Glossina palpalis palpalis, major vectors of animal and human trypanosomes from 28 sites of West and Central Africa. We found that the two subspecies are so divergent that they deserve the species status. Controlling for geographic and time distances that separate these samples, which have a significant effect, we found that G. p. gambiensis from different landscapes (Niayes of Senegal, savannah and coastal environments were significantly genetically different and thus represent different ecotypes or subspecies. We also confirm that G. p. palpalis from Ivory Coast, Cameroon and DRC are strongly divergent.These results provide an opportunity to examine whether new tsetse fly ecotypes might display different behaviour, dispersal patterns, host preferences and vectorial capacities. This work also urges a revision of taxonomic status of Glossina palpalis subspecies and highlights again how fast ecological divergence can be, especially in host-parasite-vector systems.

  1. Fly ash utilization to ecology purpose products

    Energy Technology Data Exchange (ETDEWEB)

    Sasae, T.; Kinugawa, M. (En-Tech Research Institute Inc. (Japan))

    1993-01-01

    Fly ash contains many elements necessary for plant growth. En-Tech Research Institute has a 100 ton/month fly ash granulation plant which produces 0.5-10mm diameter granules which are used in the cultivation of approximately 15,000 Onsidumu and Denpharae orchids in a 3,000 m[sup 2] greenhouse and as a soil improver for a 1,600m[sup 2] test lawn. The granules are also used as agricultural chemical adsorbents for drainage of the test lawn. Orchids cultivated using the fly ash granules are shipped to market as cut flowers regularly. There they fetch the same price or a higher price than orchids cultivated in the usual way. Good results have also been achieved with the soil improvement test and the adsorption test. Tests to obtain design data are being carried out on two golf courses in the Kumamoto Prefecture. 8 figs., 10 tabs., 7 photos.

  2. Seasonal abundance of stable flies and filth fly pupal parasitoids (Hymenoptera: Pteromalidae) at Florida equine facilities.

    Science.gov (United States)

    Pitzer, Jimmy B; Kaufman, Phillip E; Hogsette, Jerome A; Geden, Christopher J; Tenbroeck, Saundra H

    2011-06-01

    Beginning in November 2007 and continuing until December 2009, weekly stable fly, Stomoxys calcitrans (L.), surveillance was conducted at four equine facilities near Ocala, FL, by using alsynite sticky traps for adults and by searching immature developmental sites for pupae. Adult stable fly trap captures were highly variable throughout the year, ranging from 0 to 1,400 flies per trap per farm. The greatest adult stable fly activity was observed during the spring months of March and April, with weekly three-trap means of 121 and 136 flies per farm, respectively. The importance of cultural control measures was most apparent on the only farm with no reported insecticide use and the lowest stable fly trap captures, where an intense daily sanitation and composting program was conducted. A survey of on-site filth fly pupae revealed that 99.9% of all parasitoids recovered were Spalangia spp., consisting of Spalangia cameroni Perkins (56.5%), Spalangia nigroaenea Curtis (34.0%), Spalangia endius Walker (5.8%), and Spalangia nigra Latreille (3.7%). The implications of these findings are discussed.

  3. Cuticular hydrocarbons of buffalo fly, Haematobia exigua, and chemotaxonomic differentiation from horn fly, H. irritans.

    Science.gov (United States)

    Urech, Rudolf; Brown, Geoffrey W; Moore, Christopher J; Green, Peter E

    2005-10-01

    We determined the quantity and chemical composition of cuticular hydrocarbons of different strains, sexes, and ages of buffalo flies, Haematobia exigua. The quantity of cuticular hydrocarbons increased from less than 1 microg/fly for newly emerged flies to over 11 microg/fly in 13-d-old flies. The hydrocarbon chain length varied from C(21) to C(29), with unbranched alkanes and monounsaturated alkenes the major components. Newly emerged flies contained almost exclusively C(27) hydrocarbons. Increasing age was accompanied by the appearance of hydrocarbons with shorter carbon chains and an increase in the proportion of alkenes. 11-Tricosene and 7-tricosene were the most abundant hydrocarbons in mature H. exigua. Cuticular hydrocarbons of H. exigua are distinctly different from those of horn flies, Haematobia irritans. The most noticeable differences were in the C(23) alkenes, with the major isomers 11- and 7-tricosene in H. exigua and (Z)-9- and (Z)-5-tricosene in H. irritans, respectively. Cuticular hydrocarbon analysis provides a reliable method to differentiate the two species, which are morphologically difficult to separate. The differences in cuticular hydrocarbons also support their recognition as separate species, H. exigua and H. irritans, rather than as subspecies.

  4. The Hungry Fly: Hydrodynamics of feeding in the common house fly

    Science.gov (United States)

    Prakash, Manu; Steele, Miles

    2010-11-01

    A large number of insect species feed primarily on a fluid diet. To do so, they must overcome the numerous challenges that arise in the design of high-efficiency, miniature pumps. Although the morphology of insect feeding structures has been described for decades, their dynamics remain largely unknown even in the most well studied species (e.g. fruit fly). Here, we use invivo imaging and microsurgery to elucidate the design principles of feeding structures of the common house fly. Using high-resolution X-ray microscopy, we record invivo flow of sucrose solutions through the body over many hours during fly feeding. Borrowing from microsurgery techniques common in neurophysiology, we are able to perturb the pump to a stall position and thus evaluate function under load conditions. Furthermore, fluid viscosity-dependent feedback is observed for optimal pump performance. As the gut of the fly starts to fill up, feedback from the stretch receptors in the cuticle dictates the effective flow rate. Finally, via comparative analysis between the house fly, blow fly, fruit fly and bumble bees, we highlight the common design principles and the role of interfacial phenomena in feeding.

  5. Mercury release from fly ashes and hydrated fly ash cement pastes

    Science.gov (United States)

    Du, Wen; Zhang, Chao-yang; Kong, Xiang-ming; Zhuo, Yu-qun; Zhu, Zhen-wu

    2018-04-01

    The large-scale usage of fly ash in cement and concrete introduces mercury (Hg) into concrete structures and a risk of secondary emission of Hg from the structures during long-term service was evaluated. Three fly ashes were collected from coal-fired power plants and three blend cements were prepared by mixing Ordinary Portland cement (OPC) with the same amount of fly ash. The releasing behaviors of Hg0 from the fly ash and the powdered hydrated cement pastes (HCP) were measured by a self-developed Hg measurement system, where an air-blowing part and Hg collection part were involved. The Hg release of fly ashes at room temperature varied from 25.84 to 39.69 ng/g fly ash during 90-days period of air-blowing experiment. In contrast, the Hg release of the HCPs were in a range of 8.51-18.48 ng/g HCP. It is found that the Hg release ratios of HCPs were almost the same as those of the pure fly ashes, suggesting that the hydration products of the HCP have little immobilization effect on Hg0. Increasing temperature and moisture content markedly promote the Hg release.

  6. Radiation sterilization facility for melon fly