Browsing by Author "Ndungu, K."
Now showing 1 - 8 of 8
- Results Per Page
- Sort Options
Item Clinical and pathological characterizati~ of Blood stream forms and cerebrospinal fluid T. b. rhodesiense trypailosomes iSolated from a patient using rabbits.(2009) Ndungu, K.; Kagira, J.M.; Ouma J.M.; Bett, B.; Gitonga, P.; KARI -Trypanosomiasis Research Centre, P.O. Box 362, Kikuyu, KenyaClinical and pathological characterisation of blood stream (BSF) and cerebrospinal fluid (CSF) forms of Trypanosoma brucei rhodesiense trypanosome isolated from a sleeping sickness patient were investigated in rabbits. The study aimed at investigating whether there is any significant difference in clinical and pathological presentation in rabbits infected by the two forms of trypanosomes. Each form of parasite was inoculated into five rabbits at 104 trypanosomes/rnl while five rabbits were used as un-infected controls. Parasitaemia development, body temperature, packed cell volume (PCV), body weight, food and water intake, heartbeat and respiration were monitored daily for 30 days post infection when the experiment was terminated. Pathological changes were evaluated following euthanasia. All the infected rabbits became parasitaemic 6 days post infection (dpi) and the parasitaemia levels were significantly higher (p=O.Ol) for the BSF than the CSF infected rabbits. No significant difference was observed in heartbeat, respiration, food and water intake as well as PCv. However, CSF infected rabbits had a significantly (p=O.Ol) higher body temperature and weights than BSF infected rabbits. There was no major difference in the clinical manifestation of the disease caused by the two forms of parasite. However, temporary paralysis was observed around the left side of the neck in one rabbit infected with CSF trypanosomes whereas mucoid stool with the presence of amoeba cysts were observed in the rabbits infected with the BSF trypanosomes. The spleen weights of CSF infected rabbits was heavier (3.59 ± 1.13 grams) than the BSF infected rabbits (2.92± 0.78 grams). The proportions of monocytes were significantly higher (pItem A comparative study in direct cryopreservative efficacy between Triladly and EDTA saline glucose 10% glycerol cryopreservative media for human and non-human infective trypanosomes(2009) Ndungu, K.; Gitonga, P.; Mulinge, M.; Kangethe, J.; Kibugu, J. K.; Munga, L. K.; Maina, N.; Kagira, J. M.; Ngae, G. N.; Murilla, G.; Kenya Trypanosomiasis Research Institute; Tryponosomiasis Research Centre-KARI, Jomo Kenyatta University of Agricultural & Technology, National Agricultural Centre - KARIThe efficacy of Triladyl®, a commercial cryomedium for bull semen, in the cryopreservation of both human and animal infective trypanosomes as compared to EDT a Saline Glucose (ESG) 10% glycerol was evaluated in the current study. Cryopreserved Trypanosoma brucei rhodesiense, T. evansi, T. b. brucei and T. congolense were first propagated in irradiated mice. At the peak of parasitemia, parasites were harvested by cardiac puncture and 106,105,104103,102 and 10 dilutions made using whole blood bled from clean mice. These dilutions were divided into two equal portions of 0.5 ml each and cryopreserved in both ESG 10% glycerol and neat Triladly®. The procedure was also repeated with T. congolense and T. vivax species of trypanosomes directly Isolated from naturally infected cattle. After 1 month of cryopreservation, 0.4 ml each portion of this dilution was injected intraperitonially into irradiated Swiss white mice. Results on pre-patent period (PPP) and progression of parasitemia showed no difference in the recovery of samples cryopreserved using the 2 media. However, mice injected with T. b. brucei cryopreserved in the 2 media showed highly significantly (p < 0.01 by t-test) lower PPP when compared to the other species of trypanosomes which had no significant difference. However, the PPP in mice injected with trypanosomes cryopreserved in ESG 10% glycerol was significantly lower (p < 0.05 by t-test) when compared to those cryopreserved in Triladyl®. The interaction between media and species was highly significant indicating therefore that the difference in cryopreservation between the two media varies from one species of trypanosome to the other. The interaction between dose and species was also highly significant (p < 0.01 by t-test) implying therefore that the effect of the inoculum dose varied from one species to the other leading to the conclusion therefore that although Triladyl® appears as good a cryopreservative medium as ESG 10% glycerol, the choice will be determined by the species of trypanosome.Item Detection of Trypanosoma brucei rhodesiense in animals from sleeping sickness foci in East Africa using the serum resistance associated (SRA) gene(2004) Njiru, Z. K.; Ndungu, J. M.; Ndungu, K.; Matete, G.; gibson, C. W.; Kenya Trypanosomiasis Research Institute (KETRI), P.O. Box 362, Kikuyu, Kenya School of Biological Sciences, University of Bristol, Woodland Road, Bristol BS8 1UG, UKThe human serum resistance associated (SRA) gene has been found exclusively in Trypanosoma brucei rhodesiense, allowing the unequivocal detection of this pathogen in reservoir hosts and the tsetse vector without recourse to laborious strain characterisation procedures. We investigated the presence of the SRA gene in 264 T. brucei ssp. isolates from humans, domestic animals and Glossina pallidipes from foci of human trypanosomiasis in Kenya and Uganda. The SRA gene was present in all isolates that were resistant to human serum, and absent from all serum sensitive isolates tested. Further, the gene was present in all isolates that had previously been shown to be identical to human infective trypanosomes by isoenzyme characterisation. The SRA gene was detected in isolates from cattle, sheep, pigs, dog, reedbuck, hyena and G. pallidipes from sleeping sickness foci, but was not found in Trypanosoma evansi or in Trypanosoma brucei gambiense isolates. The present study indicates that the SRA gene may be invaluable in detecting and differentiating T. brucei rhodesiense from other T. brucei ssp. in reservoir hosts and tsetse.Item Effect of Tillage, Liming, and Cropping Systems on Maize Yields in Different Agroecological Zones in Kenya(East African Agricultural and Forestry Journal, 2023) Githunguri, C.M.; Esilaba, A.O.; Okoti, M.; Mutuma, E.; Miriti, J.; Nyongesa, D.; Thuranira, E.; Koech, M.; Mutoko, C.; Ndungu, K.; Ooro, P.; Ketiem, P.; Mwangi, H.; Woyengo, V.; Odendo, M.; Ashiono, G.; Kenya Agricultural and Livestock Research Organization(KALRO)Negative effects induced by climate change have contributed to reduced global yields of maize. There is therefore need to endow farmers with innovative and transformative climate smart agriculture technologies to urgently address food insecurity and the realities of climate change in cereal growing regions of Kenya. Technologies have been generated for improved maize and beans production and their impact has not been fully felt. In this study, technologies and innovations on tillage, liming and cropping systems that can improve maize and beans production were evaluated and demonstrated to farmers in different agro-ecological zones in Kenya with the aim of enhancing their adoption. Trials were established at KALRO-Njoro, KALRO-Kakamega, KALRO-Kitale, Baraton University, and Mabanga Agricultural Training Centre, in Nakuru, Kakamega, Trans-Nzoia, Nandi, and Bungoma Counties, respectively. The tillage treatments evaluated included conventional, tied ridges, minimum and zero tillage planted in plots applied with 2 t/ha of lime or without lime. The cropping systems evaluated were maize intercropped with beans or sole cropped maize. A split-split plot design with four replications was used. Results indicated that conventional, tied ridges, and minimum tillage produced higher (P<0.05) yields than the zero tillage with or without lime irrespective of the cropping system in Nakuru, Nandi and Trans-Nzoia Counties. In Nandi, Kakamega and Bungoma Counties, there were no differences (P>0.05) between the four tillage systems.Item The efficacy of Triladyl 50% in cryopreservation of low concentration pathogenic trypanosomes(2010) Ndungu, K.; Gitonga, P; Kagira, J.; Kibugu, J.; Mulinge, M.; Kangethe, J.; Ngae, G. N.; Kenya Trypanosomiasis Research Institute; Trypanosomiasis Research Centre-KARI, Jomo Kenyatta University of Agriculture and Technology, KARI Agricultural Research Center- MugugaThe efficacy of a bull cryopreservation medium Triladyl in preservation of the various pathogenic trypanosomes was evaluated against the commonly used glycerol ethylenediamine tetraacetic acid (EDT A) sahne glucose (ESG). Trypanosoma brucei rhodesiense, T. evansi, T. b, brucel and T. congolense were first propagated in Swiss White mice. At peak of parasitemia, blood was collected from the mice by cardiac puncture and I x 102 trypanosomes/ml dilution made. This dilution was then divided into 2 equal portions which were cryopreserved in either ESG 10% glycerol or Triladyl® 50%. After 1 month of cryopreservation, 2 mediated mice were intraperitoneally administered with 0.2 ml of the cryopreserved sample and then monitored for parasitemia development. Triladyl cryopreserved T ,evansi and ESG-cryopreserved T. congolense had shorter although not significant prepatent period (PPP) compared to their counterparts in the alternate medium. The peak parasitemia was significantly higher for Triladyl®-cryopreserved T evansi Trypanosomes compared to that preserved in ESG. The parasitemia pattern for T. evansi, T. b. brucei and T. congolense were characterized by 1 wave while T. b. rhodesiense had 2 waves. For T b, brucei, T. b rhodesiense and T. congolense the number of days taken to develop peak parasitemia were shortest for ESG cryopreserved trypanosomes and this was opposite for T. evansi. In conclusion, Triladyl® can be used as an alternative cry preservative medium for trypanosomes and would be the cry preservative medium of choice for T. evansi trypanosomes based on the PPP, peak parasitaemia and days to peak parasitaemia.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.Item Infectra-kit: A device for restraining mice and confining tsetse flies during trypanosome infection transmission experiments(2013) Ndungu, K.; Kibugu, J. K.; Gitonga, P. K; Thuita, J. K.; Auma, J.E.; Gitonga, S. K.; Ngae, G. N.; Murilla, G. A.; Kenya Trypanosomiasis Research Institute; Kenya Agricultural Research Institute (KARI), KenyaChemical(anaesthesia) and manual techniques are commonly used to restrain mice during vector mediated parasite transmission experiments in laboratory. Chemical restrain may interfere with natural fly vector-mouse interactions and therfore potentially affect the outcome of transmission experiments. Conversely, manual restraint is labour-intensive and exposes laboratory animals to excessive restraining- related discomfort. We report development of a mouse restraining device (infectra-kit)that allows essential transmission studies to be carried out with animal human manipilation and without the need for anaesthesia. Infectra- kit can be used as a single unit for restraining one mouse or as eight- assmbled units, thus significantly improving effeciency of a single operator in comparision to manual restraint. The kit was validated by comparing feeding success in tsetse flies fed on mice restrained usning infectra-kit(group 1 )to those manually restrained (group II). The mean +SE% feeding sucess was 75.0+8.2% for tsestse flies in Groups I and II respectively. Statistical analysis using two sample, test showed no significant difference between the two groups at p< 0.05, indicating that infectra -kit as restraining device was as good as the conventional manual restraint method. The main benefits of using infectra-kit for transmission studies therfore include reduction of man- hours and animal restrainining-related discomfort, which is an important consideration when working with zoonotic parasites.Item Pathogenicity of bloodstream and cerebrospinal fluid forms of Trypanosoma brucei rhodesiense in Swiss White Mice(2008) Ndungu, K.; Ngotho, M.; Kinyua, J.; Kagira, J.; Guya, S.; Ndungu, J.; Murilla, G.; Kenya Trypanosomiasis Research InstituteTrypanosoma brucei rhodesiense (T.b.r.), the causative agent of the East African form of human African trypanosomiasis (HAT), is capable of crossing the blood brain barrier and invade the central nervous system (CNS). However, it is not clear whether bloodstream forms (BSF) of T.b.rhodesiense differ in biological characteristics from the cerebrospinal fluid (CSF) forms. The present study was carried out to compare the pathogenicity of CSF and BSF of T.b. rhodesiense parasites in Swiss white mice following intraperitoneal inoculation with 106 trypanosomes. The parasites were tested for presence of the serum resistance associated (SRA) gene. Parasitaemia, body weight, packed cell volume (PCV) and survival of the mice was monitored daily until the experiment was terminated. Data was analyzed using general linear model. Both forms of parasite were positive for the SRA gene, and there was no significant difference in progression of parasitaemia, PCV values or survival of the mice. However, the weights of BSF infected mice initially dropped faster than those of CSF infected mice (P<0.001). Key words: Trypanosoma brucei rhodesiense, bloodstream and CSF forms, pathogenicity, and mice.
