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Ethnobotanical Survey of Phytotherapeutic Management of Diabetes and Hypertension Diseases in Mpigi District, Uganda.
(East African Journal of Science, Technology and Innovation, 2024-12-13) Nnko, Silas Sangito; Kaddumukasa, Martha ; Sekagya, Yahaya H. K; Kyayesimira, Juliet
Diabetes and hypertension are escalating global health challenges, affecting over 500 million and 1.3 billion people respectively, and significantly contributing to mortality, especially in less developed regions. The prevalence of these diseases is rapidly increasing underscoring the urgent need for effective prevention, management, and treatment strategies. Various allopathic medicines have been produced but with low curative efficiency and side effects. On the other hand, medicinal plants have been a key alternative form of treatment for human ailments including diabetes and hypertension. Despite their importance, the majority of them have not been studied and documented. This study was conducted to assess the use of medicinal plants in the management of diabetes and hypertension diseases in the Mpigi district, Uganda. Semi-structured interviews were conducted with traditional herbalists followed by field visits for taxonomic classification of the plants. Data was analysed using Atlas.ti software and IBM SPSS Statistics 29 was used to calculate frequencies. Fifty-four herbalists were interviewed, and 64% of them had an experience of more than 6 years in treating diabetes and hypertension. One hundred and twenty plant species were mentioned to be used by herbalists to manage diabetes and hypertension. Forty-seven percent (47%) of these plants treat diabetes, 24% treat hypertension and 29% treat both diabetes and hypertension. These plants were distributed to 52 different families, key among them include Asteraceae, Solanaceae, and Euphorbiaceae. The most frequently used parts included leaves (38.7%) and bark (20.6%). Highly mentioned plants included Tithonia diversifolius, Aloe vera, Catharanthus roseus, Kigelia africana, Prunus africana, Momordica foetida, and Centella asiatica. Key threats and conservation strategies were also mentioned. It is concluded that traditional healing knowledge still plays a key role in managing human ailments and therefore these findings are key for the management of diabetes and hypertension and for future research in drug development.
Isolation, characterization and genome analysis of the orphan phage Kintu infecting Xanthomonas vasicola pv. musacearum
(BMC Microbiology, 2024-11-18) Nakayinga, Ritah; Ntulume, Ibrahim; Wagemans, Jeroen; Vallino, Marta; Kanaabi, Reagan; Kajubi, Ali; Kwetegyeka, Justus
Background Xanthomonas vasicola pv. musacearum is responsible for the widespread Banana Xanthomonas Wilt in banana cultivation regions across the globe. Biocontrol measures for disease management remain limited amidst increasing antimicrobial resistance and unsustainable conventional agricultural practices. The purpose of this study is to explore a viable alternative or adjunct strategy through the use of bacteriophages for disease management. Results Kintu was isolated from sewage and displayed clear and circular plaques measuring 3 mm. Based on transmission electron microscopy, Kintu displays siphovirus characteristics, including an icosahedral head and a non-contractile tail. Kintu infects 78% (22 out of 28) Ugandan Xvm strains, has an optimal multiplicity of infection of 1, a 10 min adsorption and latent period, a 35 min burst period, and a burst size of 15 particles per bacterium. Phage titers remain stable for two and half months (75 days) in SM buffer at -20 oC and − 40 oC but decrease significantly (p ≤ 0.0001) at 4 oC. Kintu is active at pH 3 and 11, maintains viability at temperatures between 25 oC and 120 oC and tolerates UV irradiation for up to 2 min and 20 s. Kintu inhibits Xvm growth at MOI ratios of 0.1, 1 and 10. The genome is a double stranded DNA molecule that consists of 48,985 base pairs and a G + C content of 51.71%. Antibiotic resistance genes or genes associated with a lysogenic life cycle are absent. There is limited sequence similarity of Kintu with other phages, making it a novel phage belonging to an unclassified genus of the class Caudoviricetes. Conclusion Kintu is a novel bacteriophage that infects and lyses Xanthomonas vasicola pv. musacearum, the causative agent for Banana Xanthomonas Wilt. Its stability across diverse temperatures and pH conditions highlights its potential as a biocontrol agent for managing the disease.
Soil Moisture Content Suitability for Coffee Growing under Climate Change Scenarios in Uganda
(2024-11-13) Kobusinge, Judith; Twesigye, Charles K.; Kagezi, Godfrey H.; Ssembajwe, Ronald; Arinaitwe, Geofrey
Background: Previous studies have looked at suitability of Arabica coffee with less emphasis on Robusta coffee. Secondly, they looked at coffee suitability in terms of temperature and rainfall. Methods: This study examined the effect of climate change on soil moisture content for coffee growing in Uganda, using historical (1990-2022) and projected (2025-2050) data from Terraclimate and eight Global Climate Models (GCMs). Soil moisture was analyzed in relation to coffee crop moisture thresholds at the root zone to simulate historical and future coffee suitability under two scenarios: Shared Socio-economic Pathways (SSPs) 245 and 585. Results: Soil moisture content in Uganda was characterized by high variability in highland areas during the March to May season among years. Furthermore, there were both decreasing and increasing trends averaging at ±1mm/Month. The future was on the other hand dominated by increasing trends over the western region and eastern-northern regions under SSP245 and SSP585 respectively averaging at 0.2mm/Month. Suitability analysis for 1990-2022 revealed that 71% of Uganda was highly suitable for coffee, while future predictions indicated an increase in suitable areas to 74% under SSP245 and 81% under SSP585. Conclusion: Generally, the higher moisture content associated with climate change will result in increased suitability of coffee by 10%, however, characterized by shifting area suitability especially for the mid-northern and south western regions where a reduction and gain in suitability is expected, respectively. This study highly the importance of identification and adaptation of site-specific soil moisture conservation practices, especially in the unsuitable areas.
Quantification of fine particulate matter and carbon monoxide from households cooking with fixed mud charcoal stoves in Awindiri ward, Arua municipality, Uganda
(International Journal of Environmental Science and Technology, 2024-11-14) Muhwezi, G.; Ruhangariyo, D.; Kyayesimira, J.; Andama, M.
Globally, there is an increasing awareness of indoor air pollution and its resultant impacts. Indoor air pollution is a risk factor for multiple conditions that increases human mortality rates. There are limited studies on indoor air pollution in Arua, Uganda. This study quantified carbon monoxide and particulate matter (PM2.5) from households cooking with fixed mud charcoal stoves in Awindiri suburb, Arua Municipality. Fine particulate matter and carbon monoxide concentrations were measured for 24 h in kitchens. The results indicate that the average 24-h carbon monoxide (157.2 ± 86.2) ppm and fine particulate matter (473.3 ± 406.4) µgm−3 values obtained from households were both significantly (P < 0.001) higher than the recommended World Health Organisation levels. High fine particulate matter and carbon monoxide levels may be attributed to the inefficient fixed mud charcoal stove, poor ventilation, kitchen congestion, and long hours of cooking. High levels of fine particulate matter and carbon monoxide in the households could lead to serious long-term health effects on the occupants.
Effect of Land Use Activities on Water Quality and Vegetation Cover Change in Nsooba - Lubigi Wetland System, Kampala City
(East African Journal of Biophysical and Computational Sciences, 2024-10-07) Twesigye, Charles K.; Igunga, Kennedy; Nakayinga, Ritah
An assessment of the effect of land use activities on water quality and vegetation cover change in Nsooba - Lubingi Wetland System in Kampala city was conducted between July and October 2020. In order to achieve the set objectives, twelve locations were selected from the Nsooba - Lubingi Catchment. The physico-chemical characteristics of water along the catchment area were determined by standard analytical methods. The average values for Total Dissolved Solids across all the land-use types of wetland, built up areas and agriculture were lower than the National Standard (750 mg/l). A similar pattern of the land-use was observed for the parameters Total phosphorous, Biological oxygen demand, Chemical oxygen demand, Total suspended solids and Total organic carbon, where the observed average values were all below the National Standards of 10 mg/l, 50mg/l, 70mg/l, 50mg/l and 50mg/l, respectively. The Total Nitrogen average value for built-up areas (11.27 mg/l) was higher than the national standard of 10 mg/l while the remaining land use types of wetland (8.05mg/l) and agriculture (5.96mg/l) were below that of the recommended standard. GIS and Remote sensing techniques were used to analyze highresolution satellite imagery captured during 1998, 2008 and 2018. Wetland coverage declined by approximately 5 hectares (47.2% to 14.58%) from 1998 to 2018. Although most of the measured parameters were below the National standard specified by the Uganda National Environmental Management Authority apart from Total Nitrogen for built-up areas, there is need for close monitoring of the water quality in Nsooba - Lubingi catchment to ensure public health safety. The increased built-up environment in the Nsooba - Lubigi wetland affects ecosystems services of the wetland. The buffer zones for flood control and sewage treatment have been turned into built-up environment. The results from this study suggest a need to protect the Nsooba - Lubingi catchment for its important ecosystems services of flood control and sewage treatment.
Genetic diversity of Nile tilapia (Oreochromis niloticus, L. 1758) in native and introduced populations in East Africa
(Journal of Wildlife and Biodiversity, 2024-04-03) Charles, K.Twesigye; Francis, W. Nsubuga; Richard, Raja; Paul, Kato
Freshwater fish in East African Lakes are under severe threat due to the recently discovered oil and gas in the Albertine Region and overfishing across the entire East African Region. The threats, primarily caused by overfishing, are a matter of declining fish populations and a potential reduction in genetic diversity in the surviving populations due to genetic drift. This study, therefore, is of utmost importance as it assessed genetic diversity in seven populations, including five from native and two from introduced populations. The assessment of genetic diversity in Oreochromis niloticus was conducted using molecular markers in 128 samples. The results showed a moderate genetic variation between native and introduced populations at mitochondrial and microsatellite loci. The potential effects of overfishing, fish introductions, and new threats from cage farming on the genetic diversity and ecological integrity of wildlife species are discussed, highlighting the need for immediate action.
Ethnomedicinal uses and nutritional composition of yams (Dioscorea hispida Dennst.) In Kitholhu, Kasese District, Uganda
(Springer, 2024-05) Makeo, Onani; Okot, Amito Patricia; Isabirye, Isaac; Omara, Timothy; Walugembe, Joel
Yams (Dioscorea species) are traditionally valued as famine foods and medicinal lianas in countries such as Uganda, Indonesia, Ethiopia, Sudan, Thailand and Singapore. However, little information exists on the traditional medicinal uses and nutritional composition of yams in Uganda, despite them being cultivated and considered to have medicinal benefits in Eastern and Western Uganda. This study was sought to document the ethnobotanical knowledge and assess the nutritional composition of Dioscorea hispida Dennst. (D. hispida) in Kasese District of Western Uganda. An ethnobotanical survey was carried out from November 2022 to May 2023 in Kitholhu subcounty, a flood-prone area in Kasese District to assess the indigenous knowledge on the medicinal uses of D. hispida. Using semi-structured questionnaires, a total of 47 respondents selected using snow ball technique were interviewed. The proximate composition (moisture, ash, crude fat, protein, crude fiber and total carbohydrate contents) of sampled D. hispida tubers were analyzed. The ethnobotanical data obtained was analyzed using descriptive statistics while nutritional data was subjected to a one-way analysis of variance at P < 0.05. Up to 83% of the respondents cultivate D. hispida, with 94% of these indicating that the tuber is used in traditional management of typhoid, diabetes mellitus, malaria, yellow fever, intestinal inflammation, cancer, peptic ulcers and hypertension, among other ailments. Proximate analysis indicated that D. hispida samples from Kitholhu had 72.29 ± 0.38% moisture, 6.08 ± 0.15% crude fiber, 1.24 ± 0.05% crude fat, 3.05 ± 0.03% ash, 5.65 ± 0.29% proteins and 11.67 ± 0.52% carbohydrates. Our results suggest that there is rich ethnobotanical knowledge on the use of D. hispida for the treatment of ailments among the local communities of Kitholhu. Thus, D. hispida is a famine and medicinal plant that needs to be considered for conservation to enhance food security in Kitholhu and Uganda as a whole. Further studies are required to assess D. hispida for its claimed bioactivities against the reported diseases and conditions.
Mosquito-borne diseases and their control strategies: an overview focused on green synthesized plant-based metallic nanoparticles
(Insects, 2023-02-23) Hudson, Onen; Miryam, M. Luzala; Stephen, Kigozi; Rebecca, M. Sikumbili; Claude-Josué, K. Muanga; Eunice, N. Zola; Sébastien, N. Wendji; Aristote, B. Buya; Aiste, Balciunaitiene; Jonas, Viškelis; Martha, A. Kaddumukasa; Patrick, B. Memvanga
Mosquitoes act as vectors of pathogens that cause most life-threatening diseases, such as malaria, Dengue, Chikungunya, Yellow fever, Zika, West Nile, Lymphatic filariasis, etc. To reduce the transmission of these mosquito-borne diseases in humans, several chemical, biological, mechanical, and pharmaceutical methods of control are used. However, these different strategies are facing important and timely challenges that include the rapid spread of highly invasive mosquitoes worldwide, the development of resistance in several mosquito species, and the recent outbreaks of novel arthropod-borne viruses (e.g., Dengue, Rift Valley fever, tick-borne encephalitis, West Nile, yellow fever, etc.). Therefore, the development of novel and effective methods of control is urgently needed to manage mosquito vectors. Adapting the principles of nanobiotechnology to mosquito vector control is one of the current approaches. As a single-step, eco-friendly, and biodegradable method that does not require the use of toxic chemicals, the green synthesis of nanoparticles using active toxic agents from plant extracts available since ancient times exhibits antagonistic responses and broad-spectrum target-specific activities against different species of vector mosquitoes. In this article, the current state of knowledge on the different mosquito control strategies in general, and on repellent and mosquitocidal plant-mediated synthesis of nanoparticles in particular, has been reviewed. By doing so, this review may open new doors for research on mosquito-borne diseases.
Microsatellite-based analysis reveals Aedes aegypti populations in the Kingdom of Saudi Arabia result from colonization by both the ancestral African and the global domestic forms
(Evolutionary Applications, 2024-01-24) Abadi, M. Mashlawi; Hussain, Alqahtani; Sara, A. Abuelmaali; Andrea, Gloria-Soria; Jassada, Saingamsook; Martha, Kaddumukasa; Ahmad, Hassn Ghzwani; Ahmed, A. Abdulhaq; Hesham, M. Al-Mekhlafi; Catherine, Walton
The Aedes aegypti (Linnaeus, 1762) mosquito is the main vector of dengue, chi- kungunya and Zika and is well established today all over the world. The species comprises two forms: the ancestral form found throughout Africa and a global do- mestic form that spread to the rest of the tropics and subtropics. In Saudi Arabia, A. aegypti has been known in the southwest since 1956, and previous genetic studies clustered A. aegypti from Saudi Arabia with the global domestic form. The purpose of this study was to assess the genetic structure of A. aegypti in Saudi Arabia and determine their geographic origin. Genetic data for 17 microsatellites were col- lected for A. aegypti ranging from the southwestern highlands of Saudi Arabia on the border of Yemen to the north-west in Madinah region as well as from Thailand and Uganda populations (as representatives of the ancestral African and global domestic forms, respectively). The low but significant level of genetic structur- ing in Saudi Arabia was consistent with long-distance dispersal capability possibly through road connectivity and human activities, that is, passive dispersal. There are two main genetic groupings in Saudi Arabia, one of which clusters with the Ugandan population and the other with the Thailand population with many Saudi Arabian individuals having mixed ancestry. The hypothesis of genetic admixture of the ancestral African and global domestic forms in Saudi Arabia was supported by approximate Bayesian computational analyses. The extent of admixture varied across Saudi Arabia. African ancestry was highest in the highland area of the Jazan region followed by the lowland Jazan and Sahil regions. Conversely, the western (Makkah, Jeddah and Madinah) and Najran populations corresponded to the global domesticated form. Given potential differences between the forms in transmission capability, ecology and behaviour, the findings here should be taken into account in vector control efforts in Saudi Arabia.
Molecular analysis of knockdown resistance (kdr) mutations in the voltage‑gated sodium channel gene of Aedes aegypti populations from Saudi Arabia
(BMC Parasites & Vectors, 2022) Abadi, M. Mashlawi; Ashwaq, M. Al‑Nazawi; Elsiddig, M. Noureldin; Hussain, Alqahtani; Jazem, A. Mahyoub; Jassada, Saingamsook; Mustapha, Debboun; Martha, Kaddumukasa; Hesham, M. Al‑Mekhlafi; Catherine, Walton
Background: The Aedes aegypti mosquito is the primary vector for dengue, chikungunya, yellow fever and Zika viruses worldwide. The first record of Ae. aegypti in southwestern Saudi Arabia was in 1956. However, the first outbreak and cases of dengue fever were reported in 1994, and cases have increased in recent years. Vector control for Ae. aegypti mainly uses pyrethroid insecticides in outdoor and indoor space spraying. The constant use of pyrethroids has exerted intense selection pressure for developing target-site mutations in the voltage-gated sodium channel (vgsc) gene in Ae. Aegypti against pyrethroids—mutations that have led to knockdown resistance (kdr). Methods: Aedes aegypti field populations from five regions (Jazan, Sahil, Makkah, Jeddah and Madinah) of southwestern Saudi Arabia were genotyped for known kdr mutations in domains IIS6 and IIIS6 of the vgsc gene using polymerase chain reaction (PCR) amplification and sequencing. We estimated the frequency of kdr mutations and genotypes from Saudi Arabia as well as from other countries, Thailand, Myanmar (Southeast Asia) and Uganda (East Africa). We constructed haplotype networks to infer the evolutionary relationships of these gene regions. Results: The three known kdr mutations, S989P, V1016G (IIS6) and F1534C (IIIS6), were detected in all five regions of Saudi Arabia. Interestingly, the triple homozygous wild genotype was reported for the first time in two individuals from the highlands of the Jazan region and one from the Al-Quoz, Sahil region. Overall, nine genotypes comprising four haplotypes were observed in southwestern Saudi Arabia. The median-joining haplotype networks of eight populations from Saudi Arabia, Southeast Asia and East Africa for both the IIS6 and IIIS6 domains revealed that haplotype diversity was highest in Uganda and in the Jazan and Sahil regions of Saudi Arabia, whereas haplotype diversity was low in the Jeddah, Makkah and Madinah regions. Median-joining haplotype networks of both domains indicated selection acting on the kdr-mutation containing haplotypes in Saudi Arabia. Conclusions: The presence of wild type haplotypes without any of the three kdr mutations, i.e. that are fully susceptible, in Saudi Arabia indicates that further consideration should be given to insecticide resistance management strategies that could restore pyrethroid sensitivity to the populations of Ae. aegypti in Saudi Arabia as part of an integrative vector control strategy.
Potential of moisture conservation practices to improve soil properties and nutrient status of Robusta coffee plant
(Agronomy, 2023-04) Judith, Kobusinge; Geofrey, Gabiri; Godfrey H., Kagezi; Godfrey, Sseremba; Alice, Nakitende; Geofrey, Arinaitwe; Charles K., Twesigye
Soil moisture conservation practices (SMCPs) have been adopted in Uganda to adapt to the effects of climate variability. However, limited information exists on how conservation measures influence the physico-chemical properties of soil and coffee leaf nutrient concentrations. Thus, we determined the effects of selected SMCPs on the soil physio-chemical properties and leaf nutrient concentrations in Robusta coffee in a randomized incomplete block design, replicated three times, in Kituza, Uganda. Soil samples were collected from 0 to 20 cm and 20 to 40 cm depths, and analyzed in the laboratory following standard procedures for selected physio-chemical properties. Coffee leaf samples were picked from each treatment (open sun coffee (COSS), coffee cover crop, Desmodium intortum (CCS), coffee mulch, Miscanthidium violoceum (CMS), and coffee A. coriaria (ACS)). Bulk density was significantly (p < 0.001) the highest under ACS (1.61 gcm−3) and lowest under CCS (1.29 gcm−3), and it significantly (p < 0.001) increased with depth. The soil organic matter was higher than the optimum range of 1–3% at the 0–20 cm depth across different SMCPs, but within the optimum range at the 20–40 cm depth. Leaf nitrogen was significantly the highest under ACS (3.19%) and lowest under COSS (2.30%). Overall, the findings suggest that SMCPs improve the soil physio-chemical attributes and leaf nutrients for sustainable coffee productivity. However, ACS improved the leaf plant nutrition better compared to other SMCPs.
Genetically engineered East African highland bananas –proximate analysis and effect of cooking on the enhanced provitamin A levels
(African Journal of Food, Agriculture, Nutrition and Development, 2020-12) Walugembe, J.; Buah, S.; Runo, S.; Ateka, E.; Kubiriba, J.; Tushemereirwe, W.
Micronutrient deficiency is a major challenge in the developing world. This is mainly attributed to over-reliance on starchy staples foods such as cassava, rice and banana among others, which are deficient in micronutrients such as vitamin A and iron. Strategies put in place to provide a solution to micronutrient deficiencies such as dietary supplementation of vitamin A and food fortification have not been successful in the developing world due to high costs and unreliable supply chains (food and medical). Biofortification of the easily accessible staple foods could help reduce this problem associated with micronutrient deficiency. On this account, the Biofortification project in Uganda under the National Banana Program developed transgenic East African Highland Bananas (EAHBs) (M9 and Nakitembe) with enhanced levels of provitamin A (PVA) using the Fe’i banana-derived phytoene synthase 2a (MtPsy2a) gene. To determine the nutritional quality of the transgenic bananas, an analysis of the proximate composition of the biofortified East African Highland Bananas was carried out. The effect of cooking on retention of provitamin A carotenoids (pVAC), was assessed using two cooking methods; boiling and steaming (most common methods of preparing cooking banana meals in Uganda). It was observed that there were no significant (P≤0.05) differences in moisture content (P=0.4287), carbohydrate (P=0.3966), crude fat (P=0.4051), crude fiber (P=0.3214), protein (P=0.0858) and ash content (P=0.1336) between transgenic and non-transformed bananas. It was found that steaming, as a cooking method allowed for retention of more provitamin A carotenoids compared to boiling. Comparison of the cultivars on their retention of provitamin A carotenoids, results indicated that Nakitembe was superior to M9. Genetic engineering of bananas by biofortification has no effect on major food components in EAHBs (M9 and Nakitembe) and, therefore, genetically modified M9 and Nakitembe are substantially equivalent to the non-transgenic controls and the biofortified bananas can provide the necessary nutrients even after cooking. This data will inform subsequent steps for the commercialization of biofortified EAHBs.
Indigenous knowledge and antibacterial activity of selected herbs used locally to treat common cold in Central Uganda
(Journal of Medicinal Plants Research, 2016-08) Walugembe, Joel; Iramiot, Jacob S.; Katuura, Esther
The study documented the medicinal plants used in the treatment of influenza and common cough and established efficacy of some plants locally used against bacteria causing upper respiratory tract infections in Uganda. It involved an ethnobotanical survey and laboratory experimental investigation to determine the bioactivity against selected bacteria that cause upper respiratory tract infections. Data on medicinal indigenous knowledge was collected with the aid of questionnaires, direct observations, key informant interviews and field excursions and voucher specimen collection. The plants were identified by a botanist at Makerere University Herbarium (MHU), Department of Biological Sciences and voucher specimen were deposited in the herbarium. Methanol and diethyl ether extracts of the commonly used plants were screened for antibacterial activity against Streptococcus pneumonia and Klebsiella pneumonia using agar well diffusion and agar well dilution methods. Ethno botanical survey showed that 43 plants were commonly used and the most commonly used plant was Momordica feotida. Three out of four extracts assayed had activity against S. pneumonia and K. pneumonia, while one showed activity against K. pneumoniae. Hence, plants extracts showed broad spectrum antimicrobial activity. There is need for further development and standardization of products to treat respiratory diseases at household level in the study area.
Xanthomonas bacteriophages: a review of their biology and biocontrol applications in agriculture
(BMC Microbiology, 2021-10-25) Nakayinga, Ritah; Makumi, Angela; Tumuhaise, Venansio; Tinzaara, William
Phytopathogenic bacteria are economically important because they affect crop yields and threaten the livelihoods of farmers worldwide. The genus Xanthomonas is particularly significant because it is associated with some plant diseases that cause tremendous loss in yields of globally essential crops. Current management practices are ineffective, unsustainable and harmful to natural ecosystems. Bacteriophage (phage) biocontrol for plant disease management has been of particular interest from the early nineteenth century to date. Xanthomonas phage research for plant disease management continues to demonstrate promising results under laboratory and field conditions. AgriPhage has developed phage products for the control of Xanthomonas campestris pv. vesicatoria and Xanthomonas citri subsp. citri. These are causative agents for tomato, pepper spot and speck disease as well as citrus canker disease. Phage-mediated biocontrol is becoming a viable option because phages occur naturally and are safe for disease control and management. Thorough knowledge of biological characteristics of Xanthomonas phages is vital for developing effective biocontrol products. This review covers Xanthomonas phage research highlighting aspects of their ecology, biology and biocontrol applications.
Analysis of the 24-h microfilarial periodicity of Mansonella perstans
(Springerlink: Parasitology Research, 2008-12-24) Asio, Santa Maria; Simonsen, Paul E.; Onapa, Ambrose W.
The Mansonella perstans microfilarial (mf) periodicity in peripheral blood was analysed in a group of 32 healthy individuals from an endemic community in Uganda. The majority of individuals had maximum mf intensity during the first and minimum during the last 12 h of the day. Mean mf ratios (i.e. time-specific counts in relation to mean count for the individual) indicated a weak but significant diurnal periodicity with peak intensity around 0800 h. Trigonometric analysis of the ratios, assuming a harmonic wave pattern of periodicity, gave a periodicity index of 11.1 and a peak time of 0645 h. The higher mf intensities in the early morning appeared to coincide with the preferred biting hour of the vectors. The observed weak pattern of mf periodicity indicates that the sampling time of blood specimens for diagnosis will have only minor effect on diagnostic sensitivity.
Mansonella perstans filariasis in Africa
(Elsevier: Acta Tropica, 2011-09) Simonsen, Paul E.; Onapa, Ambrose W.; Asio, Santa Maria
Mansonella perstans is a vector-borne human filarial nematode, transmitted by tiny blood-sucking flies (biting midges). It is widespread in many parts of Sub-Saharan Africa and also occurs in parts of Central and South America. Despite the commonness of this parasite very few studies have been carried out on its epidemiology and on the morbidity resulting from it, and only few thorough drug trials have been conducted to look for effective and suitable drugs and drug regimens for treatment and control. Here, we review currently available knowledge on M. perstans infections in Africa, including documented aspects of biology, vectors, transmission, diagnosis, epidemiology, morbidity and treatment. It is concluded that there is an urgent need for more research on this widespread but greatly neglected infection in order to properly assess its public health significance and as a background for identifying and recommending optimal means and strategies for treatment and control.
How water exchange and seasonality affect the eutrophication of Murchison bay, lake Victoria
(Elsevier: Limnologica, 2015-07) Luyiga, Suzan; Haande, Sigrid; Semyalo, Ronald P.; Kizito, Yusuf S.; Miyingo-Kezimbira, Anne; Brettum, Pål; Solheim, Anne Lyche; Odong, Robinson; Asio, Santa Maria; Jensen, Knut Helge; Larsson, Petter
Murchison Bay in the Northern part of Lake Victoria has for decades received a daily wastewater load of 0.2% of its volume from Kampala City, through the Nakivubo channel. In spite of this, the Water Treatment Works abstracts raw water from this bay and has been able to produce drinking water of sufficient quality for the capital. This study monitored various physical−chemical components within the bay during 2000−2003 to understand the processes responsible for the acceptable quality of raw water. Four sampling stations were located along a transect from the channel mouth towards the open lake. Results showed that the wastewater did not accumulate in the bay, instead was already strongly diluted 2.5 km from the channel mouth. This caused an abrupt reduction in conductivity and the concentrations of the nutrients total phosphorus (Tot-P), orthophosphate (PO4-P) and total nitrogen (Tot-N). Inshore−offshore exchange of water was mediated by flows from daily and sub-daily water level fluctuations and wind-driven currents. As a daily average, 2% of the Murchison Bay flowed in and out and the incoming wastewater was diluted 9.7 times. During the dry season from June to August (D2), when the weather was influenced by the south-east monsoon, the thermal stratification in the main lake disappeared and cooler and deoxygenated water from deeper depths entered the bay influencing its water quality. The daily flushing of water in and out of the bay due to water level variation was identified as the main factor diluting the bay water.
A randomised, double-blind field trial of ivermectin alone and in combination with albendazole for the treatment of Mansonella perstans infections in Uganda
(Oxford Academic: Transactions of The Royal Society of Tropical Medicine and Hygiene, 2009-03-01) Asio, Santa Maria; Simonsen, Paul E.; Onapa, Ambrose W.
The effect of a single dose of ivermectin alone (150–200 μg/kg body weight) or in combination with albendazole (total of 400 mg) in Mansonella perstans infection was assessed in a randomised, double-blind field trial in two endemic communities in Mukono and Luwero districts of Uganda. No side effects were observed or reported during the first 7 days after treatment. The effect on microfilaraemia was analysed among individuals with ≥20 microfilariae (mf) per 100 μl of blood at baseline, who took the treatment and who attended follow-up examinations at 6 months and 12 months after treatment (48 and 46 in Mukono and 48 and 40 in Luwero for the ivermectin and combination treatment, respectively). In both communities, the combination treatment appeared slightly more effective than ivermectin alone, but the difference was not statistically significant. Both drug regimens were more effective in Luwero than in Mukono, probably owing to different diets in the two areas. However, in general both treatment regimens in both communities had limited effect on microfilarial intensities, and only one individual (given combination treatment in Luwero) was mf-negative at 6 months and 12 months after treatment. [ClinicalTrials.gov identifier
Mansonella perstans filariasis in Uganda: patterns of microfilaraemia and clinical manifestations in two endemic communities
(Oxford Academic: Transactions of The Royal Society of Tropical Medicine and Hygiene, 2009-03-01) Asio, Santa Maria; Simonsen, Paul E.; Onapa, Ambrose W.
Surveys for Mansonella perstans infection and potentially related clinical manifestations were undertaken in two endemic communities in Mukono and Luwero districts of Uganda where no other human filarial infections are transmitted. A sensitive and accurate counting chamber method was used for quantifying microfilaraemia in 100 μl of finger-prick blood. Among 575 and 991 examined individuals aged ≥1 year in the two communities, the overall microfilariae (mf) prevalence was significantly higher in Mukono (76.5%) than in Luwero (57.7%). As early as age 1–4 years, 40.6% and 20.5% of the children were mf-positive. Prevalences increased rapidly with increasing age to reach 89.2% and 81.4% in the 15–19 years age group and then remained high in subsequent age groups. The geometric mean mf intensity among mf-positive individuals was slightly higher in the Mukono community (32.4 mf/100 μl) than in the Luwero community (29.9 mf/100 μl), and this parameter increased with age in both communities. No obvious associations were observed between various clinical parameters and M. perstans microfilaraemia in any of the study communities. The observed patterns of microfilaraemia and the lack of obvious visible clinical manifestations suggest that the host's regulatory responses are downregulated in M. perstans infections. [ClinicalTrials.gov identifier:
Response of endemic Clarias species’ life-history biometrics to land use around the papyrus-dominated Mpologoma riverine wetland, Uganda
(Taylor&Francis Online: African Journal of Aquatic Science, 2014-10-02) Ssanyu, GA; Kipkemboi, J; Mathooko, JM; Balirwa, J
The Mpologoma River wetland is highly negatively impacted by rice growing and yet it provides habitat to endemic Clarias species that are important to the wetland fishery. Variations in life-history biometrics of small Clarias species at various wetland sites in relation to land-use changes within the wetland were studied in 2012. Four sites exposed to different land uses were sampled for vegetation, water quality and small Clarias species’ life-history biometrics. Water conductivity was significantly higher at the highly disturbed site, ranging from 140 to 480 µS cm−1. Limiting nutrient levels, particularly phosphorus, were higher at the least disturbed sites. Two small Clarias species were identified. Mean total length and weight of Clarias liocephalus, the most abundant species (66%), were 16.81 cm (SD 4.03) and 33.77 g (SD 19.63), respectively, whilst those for Clarias alluaudi (34%) were 17.83 cm (SD 4.49) and 39.94 g (SD 22.99), respectively. Mean total length, weight and fecundity of both species were significantly higher at the highly disturbed sites than at the least disturbed sites. Habitat disturbance intensities due to land use conferred population-level benefits such as higher values of life-history biometrics of Clarias species at the highly disturbed sites in the wetland.

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