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- Kenya (11)
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- Trypanosoma congolense (6)
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- Rhipicephalus appendiculatus (4)
- Sleeping sickness (4)
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- East Africa (3)
- Rickettsia (3)
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- Trypanosoma vivax (3)
- Trypsin (3)
- Tsetse fly (3)
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- Amblyomma gemma (2)
- Animal trypanosomosis (2)
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Articles 91 - 120 of 128
Full-Text Articles in Diseases
Functional Characterization And Protein-Protein Interactions Of Trypanosome Splicing Factors U2af35, U2af65 And Sf1, Martin P. Vazquez, David Mualem, Natalia Bercovich, Michael Zeev Stern, Benson Nyambega, Omer Barda, Dan Masiga, Sachin Kumar Gupta, Shulamit Michaeli, Mariano J. Levin
Functional Characterization And Protein-Protein Interactions Of Trypanosome Splicing Factors U2af35, U2af65 And Sf1, Martin P. Vazquez, David Mualem, Natalia Bercovich, Michael Zeev Stern, Benson Nyambega, Omer Barda, Dan Masiga, Sachin Kumar Gupta, Shulamit Michaeli, Mariano J. Levin
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Early in the assembly of the spliceosome of eukaryotes the branch-point binding protein (BBP, also called SF1) recognizes the branch point sequence, whereas the heterodimer U2AF consisting of a 65 and a 35 kDa subunit, contacts the polypyrimidine tract and the AG splice site, respectively. Herein, we identified, cloned and expressed the Trypanosoma cruzi and Trypanosoma brucei U2AF35, U2AF65 and SF1. Trypanosomatid U2AF65 strongly diverged from yeast and human homologues. On the contrary, trypanosomatid SF1 was conserved but lacked the C-terminal sequence present in the mammalian protein. Yeast two hybrid approaches were used to assess their interactions. The interaction between …
The Use Of A Semiochemical Bait To Enhance Exposure Of Amblyomma Variegatum (Acari: Ixodidae) To Metarhizium Anisopliae (Ascomycota: Hypocreales), F. Nchu, N. K. Maniania, A. Touré, A. Hassanali, J. N. Eloff
The Use Of A Semiochemical Bait To Enhance Exposure Of Amblyomma Variegatum (Acari: Ixodidae) To Metarhizium Anisopliae (Ascomycota: Hypocreales), F. Nchu, N. K. Maniania, A. Touré, A. Hassanali, J. N. Eloff
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Experiments were conducted to explore the use of a semiochemical bait to enhance exposure of Amblyomma variegatum Fabricius (Acari: Ixodidae) to different formulations of the entomopathogenic fungus Metarhizium anisopliae (Metsch.) Sorok. (Ascomycota: Hypocreales). Initially, the relative efficacies of attraction-aggregation-attachment pheromone (AAAP), made up of o-nitrophenol, methyl salicylate and nonanoic acid in the ratio 2:1:8, 1-octen-3-ol and butyric acid, were evaluated in an olfactometer. Only AAAP and 1-octen-3-ol were found to elicit attractive responses to the tick. Simultaneous release of 1-octen-3-ol and AAAP together with CO2 from a trap in semifield plots attracted up to 94.0 ± 6% of adult ticks …
Trypanosoma Brucei Rhodesiense Transmitted By A Single Tsetse Fly Bite In Vervet Monkeys As A Model Of Human African Trypanosomiasis, John K. Thuita, John M. Kagira, David Mwangangi, Enock Matovu, C. M.R. Turner, Daniel Masiga
Trypanosoma Brucei Rhodesiense Transmitted By A Single Tsetse Fly Bite In Vervet Monkeys As A Model Of Human African Trypanosomiasis, John K. Thuita, John M. Kagira, David Mwangangi, Enock Matovu, C. M.R. Turner, Daniel Masiga
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We have investigated the pathogenicity of tsetse (Glossina pollidipes)-transmitted cloned strains of Trypanosoma brucei rhodesiense in velvet monkeys. Tsetse files 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. …
Eco-Social Analysis Of An East African Agro-Pastoral System: Management Of Tsetse And Bovine Trypanosomiasis, Johann Baumgärtner, Gianni Gilioli, Getachew Tikubet, Andrew Paul Gutierrez
Eco-Social Analysis Of An East African Agro-Pastoral System: Management Of Tsetse And Bovine Trypanosomiasis, Johann Baumgärtner, Gianni Gilioli, Getachew Tikubet, Andrew Paul Gutierrez
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A key constraint for development of many East African agro-pastoral communities is African animal trypanosomiasis or nagana caused by Trypanosoma spp. and vectored by species of tsetse flies (Glossina spp.). Suppression of trypanosomiasis through trapping of tsetse fly populations was conducted from 1995 to 2005 at and near Luke, Southwest Ethiopia. Odor baited mass trapping technology was used to suppress adult fly populations to very low levels while tryponocidal drugs were used to treat trypanosome infections in cattle. Data on ecological, economic and social variables were collected and analyzed in the context of eco-social dynamics in the community. The bio-economic …
The Glossina Proteolytic Lectin (Gpl) Gene Is Expressed Only In Members Of Glossina Species, M. W. Burugu, B. N. Mbatia, E. O. Osir, E. U. Kenya, L. U. Abubakar
The Glossina Proteolytic Lectin (Gpl) Gene Is Expressed Only In Members Of Glossina Species, M. W. Burugu, B. N. Mbatia, E. O. Osir, E. U. Kenya, L. U. Abubakar
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Differentiation of bloodstream-form trypanosomes into procyclics in tsetse flies (Diptera: Glossinidae) is a crucial step in the establishment of midgut infections. A number of factors have been implicated in the transformation process, including enzymes and lectins or lectin-like molecules. Recently, Glossina proteolytic lectin (Gpl) gene, which encodes a protein with both lectin and trypsin activities has been shown to stimulate transformation of bloodstream-form trypanosomes into procyclics in vitro. Using RT-PCR, we show that the induction of Gpl gene expression by blood meal occurs only in Glossina fuscipes fuscipes Newstead, Glossina austeni Newstead, Glossina pallidipes Austen, and not in the Anopheles …
Livestock Farmers' Perception And Epidemiology Of Bovine Trypanosomosis In Kwale District, Kenya, S. O. Ohaga, E. D. Kokwaro, I. O. Ndiege, A. Hassanali, R. K. Saini
Livestock Farmers' Perception And Epidemiology Of Bovine Trypanosomosis In Kwale District, Kenya, S. O. Ohaga, E. D. Kokwaro, I. O. Ndiege, A. Hassanali, R. K. Saini
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We did cross-sectional surveys in Kwale District, Kenya to determine the epidemiology of bovine trypanosomosis and livestock owners' perceptions of the disease. The surveys involved relative importance of trypanosomosis, examination of the current disease constraints, current control practices and drug-use patterns. Informal meetings were held with farmers and cattle census undertaken. Tsetse-fly densities and trypanosomosis prevalences in cattle were determined. A total of 132 farmers were interviewed. Trypanosomosis, anaplasmosis, East Coast fever, foot-and-mouth diseases were reported to be the major constraints to livestock production. Trypanosomosis was the most important compared to other diseases. Chemotherapy was the most widely used method …
Performance Of A Prototype Baited-Trap In Attracting And Infecting The Tick Amblyomma Variegatum (Acari: Ixodidae) In Field Experiments, R. O. Maranga, A. Hassanali, G. P. Kaaya, J. M. Mueke
Performance Of A Prototype Baited-Trap In Attracting And Infecting The Tick Amblyomma Variegatum (Acari: Ixodidae) In Field Experiments, R. O. Maranga, A. Hassanali, G. P. Kaaya, J. M. Mueke
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Investigations were commenced to study the potential use of the fungi, Beauveria bassiana, Metarhizium anisopliae, and the attraction-aggregation- attachment pheromone (AAAP) for the control of Ambloyomma variegatum as an environmentally friendly technology. The objective of the study was to develop and test a device, which could be used for pheromone and carbon dioxide delivery and infection of ticks with the fungi in an attempt to control the tick populations in the vegetation. Using a pheromone-baited device treated with the fungi mixture, 79% of the ticks released were attracted and exposed to the fungi and of these, 78% died during incubation …
Molecular Characterization Of A Tsetse Fly Midgut Proteolytic Lectin That Mediates Differentiation Of African Trypanosomes, Laila U. Abubakar, Wallace D. Bulimo, Francis J. Mulaa, Ellie O. Osir
Molecular Characterization Of A Tsetse Fly Midgut Proteolytic Lectin That Mediates Differentiation Of African Trypanosomes, Laila U. Abubakar, Wallace D. Bulimo, Francis J. Mulaa, Ellie O. Osir
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Differentiation of bloodstream-form trypanosomes into procyclic (midgut) forms is an important first step in the establishment of an infection within the tsetse fly. This complex process is mediated by a wide variety of factors, including those associated with the vector itself, the trypanosomes and the bloodmeal. As part of an on-going project in our laboratory, we recently isolated and characterized a bloodmeal-induced molecule with both lectin and trypsin activities from midguts of the tsetse fly, Glossina longipennis [Osir, E.O., Abubakar, L., Imbuga, M.O., 1995. Purification and characterization of a midgut lectin-trypsin complex from the tsetse fly, Glossina longipennis. Parasitol. Res. …
Protein-Protein Interaction Map Of The Trypanosoma Cruzi Ribosomal P Protein Complex, Maximiliano Juri Ayub, Cristian R. Smulski, Benson Nyambega, Natalia Bercovich, Dan Masiga, Martín P. Vazquez, Carlos F. Aguilar, Mariano J. Levin
Protein-Protein Interaction Map Of The Trypanosoma Cruzi Ribosomal P Protein Complex, Maximiliano Juri Ayub, Cristian R. Smulski, Benson Nyambega, Natalia Bercovich, Dan Masiga, Martín P. Vazquez, Carlos F. Aguilar, Mariano J. Levin
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The large subunit of the eukaryotic ribosome possesses a long and protruding stalk formed by the ribosomal P proteins. Four out of five ribosomal P proteins of Trypanosoma cruzi, TcP0, TcP1α, TcP2α, and TcP2β had been previously characterized. Data mining of the T. cruzi genome data base allowed the identification of the fifth member of this protein group, a novel P1 protein, named P1β. To gain insight into the assembly of the stalk, a yeast two-hybrid based protein interaction map was generated. A parasite specific profile of interactions amongst the ribosomal P proteins of T. cruzi was evident. The TcP0 …
Detection Of Trypanosomes In Small Ruminants And Pigs In Western Kenya: Important Reservoirs In The Epidemiology Of Sleeping Sickness?, Musa O. Ng'ayo, Zablon K. Njiru, Eucharia U. Kenya, Geoffrey M. Muluvi, Ellie O. Osir, Daniel K. Masiga
Detection Of Trypanosomes In Small Ruminants And Pigs In Western Kenya: Important Reservoirs In The Epidemiology Of Sleeping Sickness?, Musa O. Ng'ayo, Zablon K. Njiru, Eucharia U. Kenya, Geoffrey M. Muluvi, Ellie O. Osir, Daniel K. Masiga
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Background: Trypanosomosis is a major impediment to livestock farming in sub-Saharan Africa and limits the full potential of agricultural development in the 36 countries where it is endemic. In man, sleeping sickness is fatal if untreated and causes severe morbidity. This study was undertaken in western Kenya, an area that is endemic for both human and livestock trypanosomosis. While trypanosomosis in livestock is present at high levels of endemicity, sleeping sickness occurs at low levels over long periods, interspersed with epidemics, underscoring the complexity of the disease epidemiology. In this study, we sought to investigate the prevalence of trypanosomes in …
Effects Of Combining The Fungi Beauveria Bassiana And Metarhiziumanisopliae On The Mortality Of The Tick Amblyomma Variegatum (Ixodidae) In Relation To Seasonal Changes, R. O. Maranga, G. P. Kaaya, J. M. Mueke, A. Hassanali
Effects Of Combining The Fungi Beauveria Bassiana And Metarhiziumanisopliae On The Mortality Of The Tick Amblyomma Variegatum (Ixodidae) In Relation To Seasonal Changes, R. O. Maranga, G. P. Kaaya, J. M. Mueke, A. Hassanali
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The effect of formulation, fungal concentration, type and seasonal changes on the mortality of the tick Amblyomma variegatum was investigated. A previous study demonstrated high pathogenicity of strains of the fungi Beauveria bassiana and Metarhizium anisopliae against the ticks Rhipicephalus appendiculatus and Amblyomma variegatum (Kaaya et al. J Invertebr Pathol 1996; 67: 15-20). The present study was undertaken to explore possible additive or synergistic effects of the two fungi on A. variegatum. The effects of oil and water formulations at different concentrations of each fungus and combination of the two on the mortality of A. variegatum in the laboratory and …
Evidence For The Involvement Of A Tsetse Midgut Lectin-Trypsin Complex In Differentiation Of Bloodstream-Form Trypanosomes, L. U. Abubakar, G. Zimba, C. Wells, F. Mulaa, E. O. Osir
Evidence For The Involvement Of A Tsetse Midgut Lectin-Trypsin Complex In Differentiation Of Bloodstream-Form Trypanosomes, L. U. Abubakar, G. Zimba, C. Wells, F. Mulaa, E. O. Osir
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We have previously described a bloodmeal-induced molecule (lectin-trypsin complex) from the midgut of the tsetse fly, Glossina longipennis, with both lectin and trypsin activities (Osir et al., 1995). In this paper, we report on the isolation of a similar molecule from the midguts of Glossina fuscipes fuscipes and provide direct evidence for its involvement in the development of African trypanosomes. The molecule (native Mr ∼65,700) has two non-covalently linked subunits, Mr ∼28,800 and Mr ∼35,700. The native molecule was found to be capable of inducing differentiation of bloodstream-form trypanosomes into procyclic (midgut forms) in vitro. In the assays, specific antibodies …
Characterization Of Protective Antigens From The Midgut Of Amblyomma Variegatum Ticks, J. K. Kinyua, E. O. Osir, D. O. Ogoyi, E. K. Nguu
Characterization Of Protective Antigens From The Midgut Of Amblyomma Variegatum Ticks, J. K. Kinyua, E. O. Osir, D. O. Ogoyi, E. K. Nguu
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Separation of midgut membrane proteins from the tick, Ambylomma variegatum, using a non-ionic detergent (Triton X-114), resulted in two protein fractions, namely DET (detergent) and AQ (aqueous). In immunoblotting analysis with polyclonal antibodies against these fractions, 4 proteins (Mr ∼ 27,000, 67,000, 86,000 and 95,000,) and 2 proteins (Mr ∼ 54,000 and 67,000) were detected in the DET and AQ fractions, respectively. Three of the DET fraction proteins Mr ∼ 27,000, 67,000 and 95,000 were glycosylated since they bound to the lectin, concanavalin A. In 2-dimensional gel electrophoresis, the AQ and DET fraction proteins were found to be acidic in …
Protein Polymorphism In Two Populations Of The Brown Ear Tick, Rhipicephalus Appendiculatus Neumann (Acari: Ixodidae), F. N. Baliraine, E. O. Osir, S. B. Obuya', F. J. Mulaa
Protein Polymorphism In Two Populations Of The Brown Ear Tick, Rhipicephalus Appendiculatus Neumann (Acari: Ixodidae), F. N. Baliraine, E. O. Osir, S. B. Obuya', F. J. Mulaa
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Two-dimensional gel electrophoresis was used to compare the protein profiles of two geographically isolated populations of the tick Rliipiccplmlus appcndiciilalus Neumann (Acnri: Ixodidne) in Kenya. Most of the protein spots were common to both populations, but a number were specific to each population. Since proteins are encoded by genes, the presence of populationspecific proteins suggests that there.may be genetic differences between the two populations. It is proposed that some of these population-specific proteins might be related to the differences in susceptibility of the ticks to Thcikria pawn infection. ©2000ICIPE.
Isolation Of Trypanosoma Brucei From The Monitor Lizard (Varanus Niloticus) In An Endemic Focus Of Rhodesian Sleeping Sickness In Kenya, Zipporah Njagu, Steve Mihok, Elizabeth Kokwaro, Didier Verloo
Isolation Of Trypanosoma Brucei From The Monitor Lizard (Varanus Niloticus) In An Endemic Focus Of Rhodesian Sleeping Sickness In Kenya, Zipporah Njagu, Steve Mihok, Elizabeth Kokwaro, Didier Verloo
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Monitor lizards were sampled along the shores of Lake Victoria to detect natural infections of potentially human-infective trypanosomes. In an area with endemic rhodesian sleeping sickness, one of 19 lizards was infected (Busia, Kenya). Six of ten lizards also showed indirect evidence of infection with Trypanosoma brucei (antibody ELISA). In an area with no recent history of human disease (Rusinga Island), no parasites were found and no antibodies to T. brucei were detected. The isolate was identified as T. brucei through xenodiagnosis (completion of the life cycle in the salivary glands of tsetse), and through molecular techniques (positive reactions with …
Trypanosome Infection Rate In Cattle At Nguruman, Kenya, R. A. Tarimo-Nesbitt, T. K. Golder, R. D. Dransfield, M. F. Chaudhury, R. Brightwell
Trypanosome Infection Rate In Cattle At Nguruman, Kenya, R. A. Tarimo-Nesbitt, T. K. Golder, R. D. Dransfield, M. F. Chaudhury, R. Brightwell
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Trypanosome infection rate in cattle at Nguruman was investigated in a study conducted in 1984-1986. Shifting pastoralism significantly reduced trypanosome infections in cattle. The cattle were more heavily infected with Trypanosoma congolense (16.5%) than Trypanosoma vivax (4.95%) and Trypanosoma brucei (0.19%). Trypanosoma theileri was observed only once among the cattle examined. Mixed trypanosome infections in cattle were observed to be 2.75% and 0.014% for T. congolense/T. vivax and T. congolense/T. brucei, respectively. The duration of infection in the cattle was 55 days for T. congolense and 79 days for T. vivax. High infections in cattle were observed 2 months after …
Development, Reproductive Capacity And Survival Of Amblyomma Variegatum And Boophilus Decoloratus In Relation To Host Resistance And Climatic Factors Under Field Conditions, G. Solomon, G. P. Kaaya
Development, Reproductive Capacity And Survival Of Amblyomma Variegatum And Boophilus Decoloratus In Relation To Host Resistance And Climatic Factors Under Field Conditions, G. Solomon, G. P. Kaaya
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To determine the developmental periods, fecundity and survival of Amblyomma variegatum and Boophilus decoloratus and the effect of host resistance, a study was carried out in the field at Abemossa ranch in Ethiopia using three breeds of cattle: Arssi, Baran and Baran X Friesian crossbreed. The investigation took place between October 1991 and September 1992. The developmental periods of both tick species were recorded. The hatching periods of larvae, engorgement, larvo-nymphal and nympho-adult moulting periods during various climatic seasons in shaded and dry areas were also recorded. While the engorgement periods recorded on the animal were relatively constant for each …
Gynandropsis Gynandra Essential Oil And Its Constituents As Tick (Rhipicephalus Appendiculatus) Repellents, W. Lwande, A. J. Ndakala, A. Hassanali, L. Moreka, E. Nyandat, M. Ndungu, H. Amiani, P. M. Gitu, M. M. Malonza, D. K. Punyua
Gynandropsis Gynandra Essential Oil And Its Constituents As Tick (Rhipicephalus Appendiculatus) Repellents, W. Lwande, A. J. Ndakala, A. Hassanali, L. Moreka, E. Nyandat, M. Ndungu, H. Amiani, P. M. Gitu, M. M. Malonza, D. K. Punyua
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The repellency of the essential oil of the previously reported anti- tick pasture shrub Gynandropsis gynandra and identified constituents of the oil were evaluated against the livestock tick, Rhipicephalus appendiculatus. In a tick-climbing repellency bioassay, the oil of G. gynandra exhibited a repellency effect which at the highest treatment levels was higher than that of the commercial arthropod repellent N,N-diethyltoluamide. Twenty eight compounds were identified in the G. gynandra oil by GC, GC-MS and coinjection with authentic samples. Carvacrol was found to occur in largest quantity (29.2%), followed by trans-phytol (24.0%), linalool (13.3%), trans-2- methylcyclopentanol (7.2%) and β-caryophyllene (4.4%). m-Cymene, …
Repellence Of The Tick Rhipicephalus Appendiculatus By The Grass Melinis Minutiflora, Esther N. Mwangi, S. Essuman, G. P. Kaaya, E. Nyandat, D. Munyinyi, M. G. Kimondo
Repellence Of The Tick Rhipicephalus Appendiculatus By The Grass Melinis Minutiflora, Esther N. Mwangi, S. Essuman, G. P. Kaaya, E. Nyandat, D. Munyinyi, M. G. Kimondo
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In a study to develop anti-tick pastures, the climbing behaviour of Rhipicephalus appendiculatus on Melinis minutiflora (molasses grass) was investigated. Experiments were done with cut green stems of grass, grass dried in the shade, grass dried in sunshine, grass washed in solvent and grass growing in a study plot. In all cases a common pasture grass, Pennisetum clandestinum (Kikuyu grass), was used as control. All instars of the tick avoided climbing on the green M. minutiflora whereas most larvae, nymphs and adults climbed on the control green P. clandestinum grass. More ticks climbed on the stems dried in the sunshine …
Repellent And Acaricidal Properties Of Ocimum Suave Against Rhipicephalus Appendiculatus Ticks, Esther N. Mwangi, Ahmed Hassanali, Suliman Essuman, Edward Myandat, Lambert Moreka, Mark Kimondo
Repellent And Acaricidal Properties Of Ocimum Suave Against Rhipicephalus Appendiculatus Ticks, Esther N. Mwangi, Ahmed Hassanali, Suliman Essuman, Edward Myandat, Lambert Moreka, Mark Kimondo
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An oil extracted from the leaves of a tropical shrub Ocimum suave was found to repel as well as kill all stages of the tick Rhipicephalus appendiculatus. In an in vitro bioassay for the larvae, the LC50 of the oil in liquid paraffin was 0.024%. A 10% solution was found to kill all immatures and more than 70% of adults feeding on rabbits. Rabbits were protected for 5 days against attaching larvae using a 10% solution. Preliminary experiments undertaken with cattle kept in the field suggest that the oil may have potential in tick control, and a role in integrated …
Optimization Of The In Vitro Feeding Of Rhipicephalus Appendiculatus Nymphae For The Transmission Of Theileria Parva, S. M. Waladde, S. N. Mwaura, G. N. Njihia, F. N. Mwakima
Optimization Of The In Vitro Feeding Of Rhipicephalus Appendiculatus Nymphae For The Transmission Of Theileria Parva, S. M. Waladde, S. N. Mwaura, G. N. Njihia, F. N. Mwakima
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An apparatus for artificial feeding of Rhipicephalus appendiculatus nymphae was modified to improve feeding performance. Heparinized blood was supplied above a treated artificial membrane while the ticks attached below on its undersurface. The feeding apparatus was incubated at 37 °C in an atmosphere of 3% CO2 concentration and a relative humidity of 75–80 °0. Under these conditions, 91 °0 of the engorged nymphae attained a mean weight of 6–11 mg, and an average of 93 °0 of those nymphae moulted into adults. When this system was used to feed nymphal ticks on blood infected with Theileria parva piroplasms, the mean …
Dynamics Of Host Blood Effects In Glossina Morsitans Sspp. Infected With Trypanosoma Congolense And T. Brucei, Reardon O. Olubayo, Steve Mihok, Eli Munyoki, Leonard H. Otieno
Dynamics Of Host Blood Effects In Glossina Morsitans Sspp. Infected With Trypanosoma Congolense And T. Brucei, Reardon O. Olubayo, Steve Mihok, Eli Munyoki, Leonard H. Otieno
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The pattern of infection in Glossina morsitans morsitans and G. m. centralis membrane-fed on eland, buffalo or goat blood mixed with Trypanosoma congolense or T. brucei was studied from day 1 to day 10. Tsetse were initially permissive vectors, with most flies harbouring infections of 104-105 parasites on day 3. However, after a second blood meal on day 3, flies cleared many infections with G. m. morsitans clearing more infections than G. m. centralis. Infective feeds of goat blood consistently increased final infection rates by limiting the number of infections lost between days 3 and 6. In further experiments with …
Detection Of Trypanosome Infections In The Saliva Of Tsetse Flies And Buffy-Coat Samples From Antigenaemic But Aparasitaemic Cattle, P. A.O. Majiwa, R. Thatthi, S. K. Moloo, J. H.P. Nyeko
Detection Of Trypanosome Infections In The Saliva Of Tsetse Flies And Buffy-Coat Samples From Antigenaemic But Aparasitaemic Cattle, P. A.O. Majiwa, R. Thatthi, S. K. Moloo, J. H.P. Nyeko
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Relatively simple protocols employing non-radioactive DNA probes have been used for the detection of African trypano-somes in the blood of mammalian hosts and the saliva of live tsetse flies. In combination with the polymerase chain reaction (PCR), the protocols revealed trypanosomes in buffy-coat samples from antigenaemic but aparasitaemic cattle and in the saliva of live, infected tsetse flies. Furthermore, the protocols were used to demonstrate concurrent natural infections of single tsetse flies with different species of African trypanosomes. © 1994, Cambridge University Press. All rights reserved.
Isolation Of Trypanosoma Spp. From Wild Tsetse Flies Through Procyclic Expansion In Glossina Morsitans Centralis, Steve Mihok, Eli N. Munyoki, Freddie Masaninga, Paul N. Ndegwa, Reardon O. Olubayo
Isolation Of Trypanosoma Spp. From Wild Tsetse Flies Through Procyclic Expansion In Glossina Morsitans Centralis, Steve Mihok, Eli N. Munyoki, Freddie Masaninga, Paul N. Ndegwa, Reardon O. Olubayo
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Procyclic trypanosomes from wild tsetse flies were membrane-fed to Glossina morsitans centralis in order to develop an optimal technique for propagating field isolates. A 70% success rate was achieved in isolating Trypanosoma simiae and a variety of genotypes of T. congolense originating from G. pallidipes, G. brevipalpis and G. swynnertoni. Parasites matured into forms infective for mammals, and could be maintained by passage of gut forms to new groups of flies. In experiments with laboratory stocks, we also passaged immature gut infections of T. congolense and T. brucei from various tsetse species to G. m. centralis. The optimal technique was …
Trypanosoma Simiae In The White Rhinoceros (Ceratotherium Simum) And The Dromedary Camel (Camelus Dromedarius), Steve Mihok, Erich Zweygarth, Eli N. Munyoki, John Wambua, Richard Kock
Trypanosoma Simiae In The White Rhinoceros (Ceratotherium Simum) And The Dromedary Camel (Camelus Dromedarius), Steve Mihok, Erich Zweygarth, Eli N. Munyoki, John Wambua, Richard Kock
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Trypanosoma simiae was identified as the cause of a disease outbreak in dromedary camels (Camelus dromedarius) introduced to Tsavo East National Park, confirming the susceptibility of camels to this pathogen. T. simiae was also isolated from a new host, the white rhinoceros (Ceratotherium simum) through xenodiagnosis with a susceptible tsetse species (Glossina morsitans centralis). A white rhinoceros showed some evidence of anaemia and lymphopaenia when harbouring T. simiae, but did not suffer any long-term health effects. © 1994.
Trypanosoma (Nannomonas) Congolense: Molecular Characterization Of A New Genotype From Tsavo, Kenya, P. A.O. Majiwa, M. Maina, J. N. Waitumbi, S. Mihok, E. Zweygarth
Trypanosoma (Nannomonas) Congolense: Molecular Characterization Of A New Genotype From Tsavo, Kenya, P. A.O. Majiwa, M. Maina, J. N. Waitumbi, S. Mihok, E. Zweygarth
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Trypanosoma (Nannomonas) congolense comprises morphologically identical but genetically heterogeneous parasites infective to livestock and other mammalian hosts; three different genotypes of this parasite have been described previously. Restriction enzyme fragment length polymorphisms (RFLPs) in both kinetoplast DNA minicircle and nuclear DNA sequences, and randomly amplified polymorphic deoxyribonucleic acid (RAPD) patterns have been used here to demonstrate the existence of another type of T. (N.) congolense that is genotypically distinct from those that have so far been characterized at the molecular level. A highly repetitive, tandemly arranged DNA sequence and oligonucleotide primers, for use in polymerase chain reaction (PCR) amplification are …
Experimental Immunity Against Trypanosomiasis In Rabbits, Curtis Powell
Experimental Immunity Against Trypanosomiasis In Rabbits, Curtis Powell
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Rabbits were immunized with specially prepared subcellular fractions of a cloned Trypanosoma brucei brucei stock 427. One fraction was found to be highly immunoprophylactic in rabbits exposed to the vector fly genus Glossina m. morsitans (tsetse flies) infected with EATRO Trypanosoma brucei brucei 1969. The most immunoprotective fraction IPFA from T. b. brucei 427 gave 75% protection to animals challenged by EATRO T. b. brucei 1969. IPFA also showed the highest IgG antibody titre against the heterologous and homologous strains. In in vitro studies, the sera from these immunized rabbits killed different strains of parasites, T. b. brucei strains 1969 …
The Influence Of Host Blood On Infection Rates In Glossina Morsitans Sspp. Infected With Trypanosoma Congolense, T. Brucei And T. Simiae, S. Mihok, R. O. Olubayo, N. Darji, E. Zweygarth
The Influence Of Host Blood On Infection Rates In Glossina Morsitans Sspp. Infected With Trypanosoma Congolense, T. Brucei And T. Simiae, S. Mihok, R. O. Olubayo, N. Darji, E. Zweygarth
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Trypanosoma congolense, T. brucei and T. simiae isolated from wild-caught Glossina pallidipes were fed to laboratory-reared G. morsitans centralis and G. m. morsitans to determine the effect of host blood at the time of the infective feed on infection rates. Bloodstream forms of trypanosomes were membrane-fed to flies either neat, or mixed with blood from cows, goats, pigs, buffalo, eland, waterbuck and oryx. The use of different bloods for the infective feed resulted in differences in infection rates that were repeatable for both tsetse subspecies and most parasite stocks. Goat, and to a lesser extent, pig blood facilitated infection, producing …
The Role Of Host Management In Tick Population Changes On Rusinga Island, Kenya, D. K. Punyua, S. M. Hassan
The Role Of Host Management In Tick Population Changes On Rusinga Island, Kenya, D. K. Punyua, S. M. Hassan
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Contrary to patterns described elsewhere, tick numbers on Rusinga Island cattle drop markedly after the onset of the rainy season. One possible explanation is that this is related to seasonal differences in host behaviour since cattle grazing on the island are restricted during the crop-growing season (the rainy season) and free grazing afterwards. In a field experiment, cattle were divided into two groups, free grazing and restricted, for 2 months each during the rainy season and during the dry season, and the number of ticks infesting each group was compared. In both seasons, the free-grazing group carried more ticks than …
Inhibitory Effect Of Trypanosoma Brucei Brucei On Glossina Morsitans Midgut Trypsin In Vitro, M. O. Imbuga, E. O. Osir, V. L. Labongo
Inhibitory Effect Of Trypanosoma Brucei Brucei On Glossina Morsitans Midgut Trypsin In Vitro, M. O. Imbuga, E. O. Osir, V. L. Labongo
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The ability of Trypanosoma brucei brucei to inhibit trypsin or trypsin-like enzymes in crude midgut homogenates of Glossina morsitans morsitans was studied in vitro. The isolated parasites caused a concentration-dependent decrease in midgut trypsin activity. Furthermore, trypanosomes lysed by repeated freeze-thawing had a similar effect on trypsin activity. In both cases, the inhibition by either intact or lysed parasites was partial as revealed by Dixon plots. Similarly, trypanosome membrane proteins stoichiometrically inhibited trypsin activity, suggesting that the enzyme interacts specifically with a moiety on the parasite surface. The Km and Ki values obtained in this case were 35 μm and …