Publications by authors named "George W Lubega"

East Coast fever (ECF) is a tick-borne disease of cattle that hinders the development of the livestock industry in eastern, central and southern Africa. The 'Muguga cocktail' live vaccine, delivered by an infection and treatment method (ITM), remains the only immunisation strategy of controlling ECF. However, there are challenges of the live vaccine inducing ECF carrier status in immunised animals and the possibility of lack of protection from parasite strains that are antigenically different from the vaccine strains.

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The integrated control of East Coast fever (ECF) by early diagnosis and treatment involving acquired immunity induced by natural infection in Ankole cattle was assessed. A longitudinal study was carried out in Kiruhura district, southwestern Uganda for six months on 244 Ankole breed of cattle from 18 herds under natural tick challenge and relaxed tick control measures. Calves aged three to six months old were recruited and monitored daily by farmers for detection of ECF clinical symptoms.

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Background: Plasmodium falciparum is the most deadly and leading cause of morbidity and mortality in Africa. About 90% of all malaria deaths in the world today occur in Sub-Saharan Africa especially in children aged < 5 years. In 2018, it was reported that there were 228 million malaria cases that resulted in 405,000 deaths from 91 countries.

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Theileria parva is a tick-transmitted apicomplexan protozoan parasite that infects lymphocytes of cattle and African Cape buffalo (Syncerus caffer), causing a frequently fatal disease of cattle in eastern, central and southern Africa. A live vaccination procedure, known as infection and treatment method (ITM), the most frequently used version of which comprises the Muguga, Serengeti-transformed and Kiambu 5 stocks of T. parva, delivered as a trivalent cocktail, is generally effective.

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Trypanosoma brucei are extracellular hemoflagellate protozoan parasites and one of the causative agents of a devastating zoonotic disease called African Trypanosomiasis. In humans, the disease is caused by Trypanosoma brucei rhodensiense and Trypanosoma brucei gambiense, which cross the blood brain barrier (BBB) causing neurological disorders which culminate in death if untreated. In some domestic animals and laboratory rodents, Trypanosoma brucei brucei causes a disease similar to that in humans.

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Diagnosis of human African trypanosomiasis (HAT) using molecular tests should ideally achieve high sensitivity without compromising specificity. This study compared 2 simplified tests, nucleic acid sequence-based amplification (NASBA) combined with oligochromatography (OC) and loop-mediated isothermal amplification (LAMP), executed on 181 blood samples from 65 Trypanosoma brucei gambiense HAT patients, 86 controls, and 30 serological suspects from Uganda. Basing on the composite reference standard, the diagnostic sensitivity and specificity of NASBA were 93.

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Animal African trypanosomiasis (AAT) also known as Nagana is a devastating disease among domestic animals in large parts of Sub-Saharan Africa causing loses in milk and meat production as well as traction power. However, there is currently no commercial vaccine against AAT. The parasites have also developed resistance to some of the drugs in use.

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The prevalence and pathogenic effects of trypanosomosis were determined in cattle, goats and pigs reared in Kasese, Jinja and Rakai districts, Uganda; presence of trypanosomes was detected by buffy coat technique (BCT). The overall prevalence of trypanosomosis in cattle was 7.6% (144/1,891), 0.

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Background: We investigated several adjuvants for their effects on the humoral immune response in both mice and cattle using the central domain of congopain (C2), the major cysteine protease of Trypanosoma congolense, as a model for developing a vaccine against animal trypanosomosis. The magnitude and sustainability of the immune response against C2 and the occurrence of a booster effect of infection, an indirect measure of the presence of memory cells, were determined by ELISA, while spectrofluorometry was used to determine and measure the presence of enzyme-inhibiting antibodies.

Results: Mice immunized with recombinant C2 in TiterMax™, Adjuphos™, purified saponin Quil A™ or Gerbu™ showed the best response according to the evaluation criteria and the latter three were chosen for the cattle vaccination study.

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During 2006-2007, transmitted human immunodeficiency virus (HIV) drug resistance (TDR) among drug-naive women with newly diagnosed HIV infection and likely to be recently infected when attending antenatal clinics in Entebbe was found to be <5% with use of the World Health Organization (WHO) survey method. Using the same method, we attempted to classify TDR among women who seroconverted during 2008-2010 and who were identified from a cohort of recently infected sex workers in Kampala, Uganda. TDR mutations were identified using the 2009 WHO TDR mutations list.

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Wildlife, especially Cape buffalo (Syncerus caffer), are thought to act as a reservoir for many of the important tick-borne pathogens of cattle. In this study, we have determined the prevalence of the most significant tick-borne haemoparasites in wildlife (buffalo, impala, eland and bushbuck) as well as in cattle grazing inside and neighbouring Lake Mburo National Park (LMNP) in Uganda. A high percentage of buffalo were carriers of Theileria parva, Theileria mutans, Theileria velifera, Theileria buffeli and Theileria sp.

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Background: The polymerase chain reaction (PCR) and nucleic acid sequence-based amplification (NASBA) have been recently modified by coupling to oligochromatography (OC) for easy and fast visualisation of products. In this study we evaluate the sensitivity and specificity of the PCR-OC and NASBA-OC for diagnosis of Trypanosoma brucei gambiense and Trypanosoma brucei rhodesiense human African trypanosomiasis (HAT).

Methodology And Results: Both tests were evaluated in a case-control design on 143 HAT patients and 187 endemic controls from the Democratic Republic of Congo (DRC) and Uganda.

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Objective: To evaluate the repeatability and reproducibility of four simplified molecular assays for the diagnosis of Trypanosoma brucei spp. or Leishmania ssp. in a multicentre ring trial with seven participating laboratories.

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Molecular tools, such as real-time nucleic acid sequence-based amplification (NASBA) and PCR, have been developed to detect Trypanosoma brucei parasites in blood for the diagnosis of human African trypanosomiasis (HAT). Despite good sensitivity, these techniques are not implemented in HAT control programs due to the high cost of the equipment, which is unaffordable for laboratories in developing countries where HAT is endemic. In this study, a simplified technique, oligochromatography (OC), was developed for the detection of amplification products of T.

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Currently, the conventional diagnosis of human African trypanosomiasis (HAT) is by microscopic demonstration of trypomastigotes in blood, lymph, and/or cerebrospinal fluid. However, microscopic diagnosis of HAT is not sensitive enough and may give false-negative results, thus, denying the patient the necessary treatment of the otherwise fatal disease. For this reason, a highly sensitive technique needs to be developed to enhance case findings.

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Objective: To assess the application of allele-specific PCR (AS-PCR) as a fast, cheap and reliable method for detecting mutant TbAT1 associated with melarsoprol relapse in Trypanosoma brucei gambiense isolates from northwest Uganda.

Methods: A total of 105 trypanosome isolates were analysed using SfaN1 restriction fragment length polymorphism (RFLP) and AS-PCR, the former used as the gold standard. Sensitivity, specificity, positive and negative predictive values of AS-PCR as well as agreement between the tests were determined.

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The alpha- and beta-tubulin genes from Onchocerca volvulus were individually expressed for the first time in Escherichia coli (DH5alpha). The recombinant tubulins were purified, renatured and reconstituted into oligomers, probably dimers, which were competent to bind three classical tubulin ligands: mebendazole (MBZ), taxol (TAX) and vinblastine (VBN). A new charcoal-dependent binding assay allowed accurate discrimination between specific and non-specific ligand binding in crude cell extracts.

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We previously observed that trypanosome tubulin immunizes mice against infection by this parasite. Here we describe the direct effect of anti-tubulin antibodies on trypanosomes, using rabbit antibodies to renatured (nTbTub) or SDS-PAGE denatured (dTbTub) Trypanosoma brucei tubulin. We also evaluate antibodies to synthetic tubulin peptides (STP) and rat brain tubulin (RbTub).

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Pig production has increased significantly in the Eastern and Southern Africa (ESA) region during the past decade, especially in rural, resource-poor, smallholder communities. Concurrent with the increase in smallholder pig keeping and pork consumption, there have been increasing reports of porcine cysticercosis in the ESA region. This article reviews the findings concerning the presence and impact of porcine cysticercosis in seven of the ESA countries.

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Tubulin from Trypanosoma brucei was purified to near homogeneity using a protocol which involved treatment with urea with subsequent renaturation and was then used to immunize mice. Renatured tubulin further purified by SDS-PAGE (denatured), synthetic tubulin peptides (STP), and rat brain tubulin (RbTub) were also used. Immunized mice were challenged with T.

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Carboxyl methylation of the C-terminal prenylated cysteine, which occurs in most farnesylated and geranylgeranylated proteins, is a reversible step and is implicated in the regulation of membrane binding and cellular functions of prenylated proteins such as GTPases. The gene coding for prenylated-protein carboxyl methyltransferase (PPMT) of the protozoan parasite Trypanosoma brucei has been cloned and expressed in the baculovirus/Sf9 cell system. The protein of 245 amino acids has 24-28% sequence identity to the orthologues from other species including human and Saccharomyces cerevisiae.

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Tubulin ligands known to be toxic to certain organisms or cells were tested for their ability to inhibit proliferation of trypanosomes in culture. Tubulin was purified from Trypanosoma brucei brucei or rat brain by poly-L-lysine affinity chromatography and used in binding studies in order to compare the binding of [3H]mebendazole to trypanosome and mammalian tubulin. All the compounds tested in culture inhibited trypanosome proliferation in a concentration-dependent manner.

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