Browsing by Author "Muchiri, M.W."
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Item Comparative evaluation of anticoagulatory activity of ethylenediamine tetra-acetic acid (EDTA) and heparin for haematological analysis(2010) Kibugi, J.K.; Muchiri, M.W.; Mbugua, N.; Mwangi, J.N.; Thuita, J.K.; Kenya Trypanosomiasis Research Institute; Kenya Research Institute Trypanosomiasis Research Centre(KARI - TRC), Kenya Socio Economics and Biromantic DivisionSample collection for haematological analysis requires use of anticoagulant, the two commonly used in trypanosomiasis research being ethylenediamine tetra-acetic acid and heparin. Since these are known to have different modes of action (Lewis, 200 I), it is important to ascertain whether they can be used alternatively. Further, Swiss White mouse has been used in research involving disease pathogenesis and trials of new drugs (Kibugu et al., 2009, Thuita et al., 2008). Since handling methods are important for accurate haematological results, appropriate blood sampling and processing techniques need to be employed. The small body size of the mouse is probably a limitation to blood sample collection. The aim of the present study was to evaluate the anticoagulatory efficacy of ethylenediamine tetra-acetic acid and heparin for electronic cell counting, and develop a suitable blood handling procedure for laboratory mice.Item Comparative pathogenicity of Trypanosoma brucei rhodesiense strains in Swiss white mice and Mastomys natalensis rats(Kenya Agricultural Research Institute, 1927) Muchiri, M.W.; Ndung'u, K.; Kibugu, J.K.; Thuita, J.K.; Gitonga, P.K.; Ngae, G.N.; Mdachi, R.E.; Kagira, J.M.; Kenya Agricultural and Livestock Research Organization (KALRO), Biotechnology Research Institute (BioRI), P. O. Box 362, Kikuyu, Кепуа; Jomo Kenyatta University of Agriculture and Technology, P.O. Box 62000-00200, Kenya; Kenya Food Crop Research Institute, P. O. Box 30148, Nairobi, KenyaWe evaluated Mastomys natelensis rat as an animal model for Rhodesian sleeping sickness, Parasitaemia, clinical and pathological characteristics induced by T. b. rhodesiense isolates, KETRI 3439, 3622 and 3637 were compared in Mastomys rats and Swiss white mice. Each isolate was intra-peritonially injected in mice and rat groups (n-12) at 1x 10º trypanosomes/0.2 ml. Pre-patent period (PP) range for KETRI 3439 and KETRI 3622-groups was 3-6 days for mice and 4-5 days for rats while for KETRI 3637-infected mice. and rats was 5-9 and 4-12 days, respectively. Pairwise comparison between PP of mice and rats separately infected with either isolate showed no significant difference (p>0.05). The PP's of KETRI 3637-infected mice were significantly (p>0.01) longer than those infected with KETRI 3439 or KETRI 3622, a trend also observed in rats. The second parasitaemic wave was more prominent in mice. Clinical signs included body weakness, dyspnoea, peri-orbital oedema and extreme emaciation which were more common in rats. Survival time for KETRI 3439 and 3622-infected groups was significantly (p<0.05) longer in mice than rats but similar in KETRI 3637-infected groups. Inflammatory lesions were more severe in rats than mice. All mice and KETRI 3622-infected rats had splenomegaly, organ congestion with rats additionally showing prominent lymphadenopathy. KETRI 3439-infected rats showed hemorrhagic pneumonia, enteritis with moderate splenomegaly and lymphadenopathy. KETRI 3637-infected rats had the most severe lesions characterized by prominent splenomegaly, lymphadenopathy, hepatomegaly, enlarged adrenal glands, organ congestion, generalized oedemas, gastroenteritis, pneumonia and brain congestion. KETRI 3637- infected Mastomys is a suitable model for studying pathophysiology of HAT.Item Effect of aflatoxin Bl on the therapeutic efficacy of suramin in Trypanosoma brucei rhodesiense-infected mice(2011) Kibugu, J.K.; Mdachi, R.E.; Kagira, J.M.; Muchiri, M.W.; Makumi, J.N.; Ngeranwa, J.J.N.; Auma, J.E.; Ngae, G.N.; Kenya Trypanosomiasis Research Institute; Kenya Agricultural Research Institute(KARI), Trypanosomiasis Research Centre (TRC), Kikuyu Kenya, Kenyatta University Department of Biochemistry and Biotechnology, Nairobi, Kenya, KARI, Agricultural Centre-MugugaThrough immuno-suppression, aflatoxins could affect drug and vaccine efficacy. Such effects have not been evaluated in treatment of many diseases including trypanosomiasis. We assessed the effect of aflatoxin B 1 on the efficacy of suramin, the drug used for treatment of early stage sleeping sickness, in a murine model. Mice were fed daily on a diet containing 0.50 mg aflatoxin/kg body weight or a placebo. They were infected with Trypanosoma brucei rhodesiense on day 7 post-aflatoxin exposure and then treated with one of 6 different doses of suramin (4.0, 4.5, 5.0, 5.5, 6.0 and 6.5 mg/kg body weight) at the onset of parasitemia. The mice were fed on aflatoxin diet for 30 days and the curative dose values (CD 50, 75. and 90) computed and compared using a logistic linear regression model. Aflatoxin B 1 induced transient protection of the host against T. b. rhodesiense infection and a consistent increase in suramin CD values in the mice suggesting reduced drug efficacy. Aflatoxicosis hindered curative treatment of T. b. rhodesiense infection in mice, and may contribute to reduced efficacy of suramin during treatment of sleeping sickness in man.Item Improved protocol for aseptic collection and handling procedures of bovine blood diet in areas with special contamination challenges for use in tsetse rearing(2010) Mwangangi, D.M.; Kiragu, J.M.; Muchiri, M.W.; Kibugu, J.K.; Mumba, A.M.; Kenya Agricultural Research Institute–Trypanosomiasis Research Centre (KARI-TRC), PO Box 362, Kikuyu, KenyaImportation of blood to support tsetse feeding in Africa is costly and marred by delays, quarantine restrictions and other logistic problems,l while chemical contamination is likely to be encountered in tsetse diet from drug residues arising from treatment of animal diseases in Africa. Further, blood diet collection procedures are not standardized risking the health of the donor animals. We established a blood collection procedure of bovine blood for in vitro tsetse feeding in areas with special contamination challenges that is safe for both donor animals and tsetse flies. Six Orma Baran steers (registered at the Kenya Stud Book, Boran Cattle Breeders Society 2009, Kenya) aged between 12 and 16 months supplied from Kenya Agricultural Research Institute-Trypanosomiasis Research Centre (KARI-TRC), delivered on foot, ,thoroughly. washed with water using a soft brush (PVC, LG Harris and Co (EA) Ltd, Nairobi, Kenya) to remove possible pesticide contamination, dewormed with 10% albendazole and acclimatized for one week before collection of blood could start. The criteria for the selection of steers were healthy looking animals above six months of age and animals recently exposed to treatment, especially antibiotics, were excluded The animals were confined in a well-ventilated, fly-proof barn house partitioned into eight metallic cubicles each measuring 3 x 4.3 x 2.5 (height) m with concrete floor and wood chippings provided as bedding material.Item Improved protocol for aseptic collection and handling procedures of bovine blood diet in areas with special contamination challenges for use in tsetse rearing(2010) Kibugu, J.K.; Kiragu, J.M.; Mumba, A.M.; Mwangangi, D.M.; Muchiri, M.W.; Kenya Trypanosomiasis Research Institute; Kenya Agricultural Research Institute–Trypanosomiasis Research Centre (KARI-TRC)Importation of blood to support tsetse feeding in Africa is costly and marred by delays, quarantine restrictions and other logistic problems while chemical contamination is likely to be encountered in tsetse diet from drug residues arising from treatment of animal diseases in Africa. Further, blood diet collection procedures are not standardized risking the health of the donor animals. We established a blood collection procedure of bovine blood for in vit7'O tsetse feeding in areas with special contamination challenges that is safe for both donor animals and tsetse flies. Six Orma Boran steers (registered at the Kenya Stud Book, Boran Cattle Breeders Society 2009, Kenya) aged between 12 and 16 months supplied from Kenya Agricultural Research Institute-Trypanosomiasis Research Centre (KARI-TRC), delivered on foot, thoroughly washed with water using a soft brush (PVC, LG Harris and Co (EA) Ltd, Nairobi, Kenya) to remove possible pesticide contamination, de-wormed with 10% albendazole and acclimatized for one week before collection of blood could start. The criteria for the selection of steers were healthy looking animals above six months of age and animals recently exposed to treatment, especially antibiotics, were excluded.Item Improved survival of laboratory-reared tsetse flies Glossina morsitans morsitans (Diptera: Glossinidae) through use of homidium bromide-treated blood diet(2010) Kibugu, J.K.; Mwangi, J.N.; Kiragu, J.M.; Muchiri, M.W.; Ndungu, K.; Mdachi, R.E.; Kenya Trypanosomiasis Research Institute; Kenya Agricultural Research Institute (KARI), Trypanosomiasis Research Centre, Social Economics and Biometrics Division, KARIHomidium bromide is a broad-spectrum anti-microbial trypanocide likely to be encountered as a violative residue in blood collected from abattoirs destined for feeding laboratory-reared tsetse colonies. We investigated its effects on longevity of laboratory reared Glossina morsitans morsitans Westwood. Four steers were intra-muscularly administered with 1 mg homidium bromide/kg of body weight and blood was aseptically collected from them between 15 and 30 min post-administration. This blood was defibrinated, analysed for homidium levels, screened for bacterial contamination, frozen and warmed to 37"C before feeding to tsetse flies. Teneral male (l00) and female (220) G. m. morsitans flies were fed on homidiurn-treated diet, and control flies (99 males and 187 females) on untreated blood diet and their survival monitored for 163 days. Homidium, at 266.15ng/ml blood diet, significantly (P <0.05) improved fly survival. We concluded that homidium bromide has a beneficial effect on tsetse, probably attributable to its antimicrobial activity against unfavourable microbes mediated by the drug, and could be used as a tsetse diet additive.
