Browsing by Author "Muhanguzi, Dennis"

Now showing 1 - 8 of 8
  • Thumbnail Image
    Item
    Analysis of Genetic Diversity of Banana Weevils (Cosmopolites sordidus) (Coleoptera: Curculionidae) Using Transcriptome-Derived Simple Sequence Repeat Markers
    (Journal of Economic Entomology, 2022) Milton, Ali; Muhanguzi, Dennis; Male, Allan; Kajubi, Ali; Buah, Stephen; Kubiriba, Jerome; Tumuhimbise, Robooni
    The banana weevil, Cosmopolites sordidus (Germar) (Coleoptera: Curculionidae) is an economically important insect pest of bananas. It causes up to 100% yield losses and substantial lifespan reduction in bananas. Advances in genomics, proteomics, and sequencing technologies have provided powerful pathways to genotyping disastrous pests such as C. sordidus. However, such technologies are often not available to the majority of rural subtropical African banana growers and pest control managers. This study was therefore motivated by the need to create cheap and easily accessible C. sordidus genotyping methods that could be deployed by banana pest control managers to the benefit of C. sordidus control programs in the tropics where such advanced technologies are not readily accessible. We used an in-house C. sordidus transcriptome from the an-ongoing study from which we mined an array of simple sequence repeat (SSR) markers. Of these, six highly polymorphic transcriptome-derived SSR markers were used to successfully genotype within and among banana weevil population genetic diversity of 12 C. sordidus populations collected from four bananagrowing agro-ecological zones (AEZs) in Uganda. The developed transcriptome-derived SSR markers can be used by researchers in population genetics for characterization of the C. sordidus and identification of new genes that are linked to traits of particular interest. The significant genetic diversity revealed in C. sordidus provides pertinent information for integrated pest management strategies.
  • Thumbnail Image
    Item
    Factors That Influence Pig Production In Central Uganda - Case Study Of Nangabo Sub-County, Wakiso District
    (Vet World, 2012) Muhanguzi, Dennis; Lutwama, Vincent; Mwiine, Frank Norbert
    To study the factors affecting pig production in Nangabo Sub-County, Wakiso District, Central Uganda. A total of 11% (1350/12783) of all households in the Nangabo Sub-County kept pigs. Theth systematic sampling technique was used to complete the list of all pig farming households. This was done by taking 10 farming household until 10% of all the farming households were sampled. Atotal of 135 farmers were interviewed with semistructured questionnaire. Questionnaire data was entered into Microsoft Excel worksheet and trans-ferred into Statistical Package for Social Scientists. Results indicated that 49.6 % of the pigs were raised in the semi-intensive system while 31%, 12% and 8% of the farmers kept pigs on intensive, tethering and free range rearing systems respectively. Farmers that raised their pigs on what is hereby referred to as semi-intensive and intensive management systems allowed their pigs up to five and two hours of open foraging respectively. Ninety eight percent of the farmers provided housing to their pigs and the commonest pig houses were local mud houses and a few of them were tree shades. Majority of farmers (85.2%) watered their pigs at least once a day. The major factors limiting pig production were; diseases and parasites mainly helminthosis and African swine fever (ASF). Others included; high costs of inputs, lack of capital, unstable availability of feed resources, inadequate advisory services and feed price fluctuation (maize bran, sow and weaner), lack of good quality breeding stock, poor and unorganized marketing, lack of enough land, high costs of veterinary medicines and inability to keep records. Additionally, lack of enough water and uncontrolled pig movement grossly limited the pig production in Wakiso district. Most Ugandans keep their pigs in periurban areas of Uganda. It was however, noted that there were important limitations for pig production in the country. To improve pig production and reduce animal protein deficit, knowledge on constraints to pig production was important to inform pig sector promotion stakeholders.Limitations to pig farming including parasites and diseases, ASF, nutritional deficiencies, high cost of inputs like building materials, drugs and veterinary services, inadequate capital and failure of farmers to access credit services,expensive feeds among others were identified and should be addressed to meet national animal protein requirements.
  • Thumbnail Image
    Item
    Genetic diversity of aflatoxin-producing Aspergillus flavus isolated from groundnuts in selected agroecological zones of Uganda
    (BMC microbiology, 2020) Acur, Amos; Arias, Renée S.; Odongo, Steven; Tuhaise, Samuel; Ssekandi, Joseph; Muhanguzi, Dennis; Adriko, John; Buah, Stephen; Kiggundu, Andrew
    Background Aspergillus is the main fungal genus causing pre- and post-harvest contamination of groundnuts. Aspergillus flavus belongs to section Flavi, a group consisting of both the aflatoxigenic species (A. flavus, A. parasiticus and A. nomius) and non-aflatoxigenic species (A. oryzae, A. sojae and A. tamarii). Aflatoxins are food-borne toxic secondary metabolites produced by Aspergillus species, causing hepatic carcinoma and stunting in children and are the most toxic carcinogenic mycotoxins ever identified. Despite the well-known public health problems associated with aflatoxicosis in Uganda, information about the genetic diversity of the main aflatoxin causing fungus, Aspergillus flavus in this country is still limited. Results A cross-sectional survey was therefore carried out in three main groundnut-growing agro-ecological zones (AEZs) of Uganda; West Nile farming system, Lake Kyoga basin mixed farming system and Lake Victoria basin farming system. This was to assess the genetic diversity of A. flavus and to establish the contamination rates of groundnuts with Aspergillus species at pre- and post-harvest stages. Out of the 213 A. flavus isolates identified in this study, 96 representative isolates were fingerprinted using 16 insertion/deletion microsatellite markers. Data from fingerprinting were analyzed through Neighbor Joining while polymorphism was determined using Arlequin v 3.5. The pre- and post-harvest contamination rates were; 2.5% and 50.0% (West Nile farming system), 55.0% and 35.0% (Lake Kyoga basin mixed farming system) and 32.5% and 32.5% (Lake Victoria basin farming system) respectively. The Chi-square test showed no significant differences between pre- and post-harvest contamination rates among AEZs (p = 0.199). Only 67 out of 96 isolates produced suitable allele scores for genotypic analysis. Analysis of genetic diversity showed higher variation within populations than among populations. Two major clusters (aflatoxigenic and non-aflatoxigenic isolates) were identified as colonizing groundnuts at pre- and postharvest stages. Conclusions These findings provide a first insight on the existence of non-aflatoxigenic strains of A. flavus in Uganda. These strains are potential candidates for developing local Aspergillus biocontrol agent.
  • Thumbnail Image
    Item
    Invasive Cattle Ticks in East Africa: Morphological and Molecular Confirmation of The Presence of Rhipicephalus Microplus in South‑Eastern Uganda
    (Parasites & Vectors, 2020) Muhanguzi, Dennis; Byaruhanga, Joseph; Amanyire, Wilson; Ndekezi, Christian; Ochwo, Sylvester; Nkamwesiga, Joseph; Mwiine, Frank Norbert; Tweyongyere, Robert; Fourie, Josephus; Madder, Maxime; Schetters, Theo; Horak, Ivan; Juleff, Nick; Jongejan, Frans
    Rhipicephalus microplus, an invasive tick species of Asian origin and the main vector of Babesia species, is considered one of the most widespread ectoparasites of livestock. The tick has spread from its native habitats on translocated livestock to large parts of the tropical world, where it has replaced some of the local populations of Rhipicephalus decoloratus ticks. Although the tick was reported in Uganda 70 years ago, it has not been found in any subsequent surveys. This study was carried out to update the national tick species distribution on livestock in Uganda as a basis for tick and tick-borne disease control, with particular reference to R. microplus.The study was carried out in Kadungulu, Serere district, south-eastern Uganda, which is dominated by small scale livestock producers. All the ticks collected from 240 cattle from six villages were identified microscopically. Five R. microplus specimens were further processed for phylogenetic analysis and species confirmation.The predominant tick species found on cattle was Rhipicephalus appendiculatus (86.9 %; n = 16,509). Other species found were Amblyomma variegatum (7.2 %; n = 1377), Rhipicephalus evertsi (2.3 %; n = 434) and R. microplus (3.6 %; n = 687). Phylogenetic analysis of the 12S rRNA, 16S rRNA and ITS2 gene sequences of R. microplus confirmed the morphological identification.It is concluded that R. microplus has replaced R. decoloratus in the sampled villages in Kadungulu sub-county, since the latter was not any longer found in this area. There is currently no livestock movement policy in force in Uganda, which could possibly limit the further spread of R. microplus ticks. Future surveys, but also retrospective surveys of museum specimens, will reveal the extent of distribution of R. microplus in Uganda and also for how long this tick has been present on livestock without being noticed.
  • Thumbnail Image
    Item
    Molecular characterization of non‐polio enteroviruses isolated from acute flaccid paralysis patients in Uganda
    (Journal of Medical Virology, 2021) Tushabe, Phionah; Howard, Wayne; Bwogi, Josephine; Birungi, Molly; Eliku, James P.; Kakooza, Proscovia; Bukenya, Henry; Namuwulya, Prossy; Gaizi, Joseph; Tibanagwa, Mayi; Kabaliisa, Theopista; Mulindwa, Julius; Muhanguzi, Dennis; Suchard, Melinda; Gumede, Nicksy; Bakamutumaho, Barnabas
    Enteroviruses (EVs) are RNA viruses that can cause many clinical syndromes including acute flaccid paralysis (AFP). Within the global polio laboratory network, EVs are categorized either as polioviruses or non‐polio enteroviruses (NPEVs). Specific NPEVs have been described in polio‐like residual paralytic events in AFP patients. Retrospective analysis of 112 NPEV isolates from AFP patients was performed and thirty one NPEV types were identified of which 91% were Enterovirus B and 9% were Enterovirus A species. The NPEVs were distributed across the country with most patients in the eastern region (41/89; 46.1%). The highest proportion of patients were children less than 5 years (77/89; 86.5%) and male patients were more common (54/89; 60.7%). Echovirus 11 (11/89; 12.4%) was frequently observed and phylogenetic analysis of these sequences revealed high diversity. Coxsackievirus B5 (CV‐B5), CV‐B6, E21, and EV‐B69 were only seen in patients with residual paralysis. Analyses of the EV‐A71 sequence indicated a unique genogroup.
  • Thumbnail Image
    Item
    Prevalence of sweetpotato viruses in Acholi sub-region, northern Uganda
    (Current plant biology, 2019) Wokoracha, Godfrey; Edema, Hilary; Muhanguzi, Dennis; Echodu, Richard
    The purpose of the study was to identify different viruses infecting sweetpotato and the level of co-infection and spatial distribution of the viruses within the Acholi sub-region of northern Uganda. Multiplex PCR was used to screen and determine level of co-infection in 380 sweetpotato plants. The PCR scores were computed to give overall frequency of occurrence of different viruses. The spatial distribution of viruses was represented on an ArcGIS map. Of all screened samples, 24% (92/380) were infected with at least one virus. Sweetpotato feathery mottle virus (65/92), sweetpotato chlorotic fleck virus (17/92) and sweetpotato mild mottle virus (8/92) were the most frequent viruses detected. Of sampled fields, 74% (28/38) had at least one virus-infected sweetpotato plant. The four viruses detected are the major viruses causing significant yield losses in major sweetpotato growing regions of Uganda and East Africa. The findings of limited distribution and low prevalence of the viruses in the region indicate it causes less burden to sweetpotato production in the sub-region compared with other parts of Uganda.
  • Thumbnail Image
    Item
    Seroprevalence of contagious bovine pleuropneumonia (CBPP) in cattle from Karamoja region, North-eastern Uganda
    (BioMed Central Ltd, 2024-03) Tweyongyere, Robert; Nkamwesiga, Joseph; Etiang, Patrick; Mugezi, Israel; Wamala, Henry; Wasswa, Auther Tamale; Kamusiime, Maureen; Ainebyoona, Solomon; Abizera, Harriet; Mwiine, Frank Norbert; Muhanguzi, Dennis
    Background Contagious bovine pleuropneumonia [CBPP] is a transboundary animal disease of cattle caused by Mycoplasma mycoides subsp. mycoides [Mmm]. CBPP causes severe economic losses to livestock producers in sub-Saharan Africa mainly due to high mortality, morbidity, reduction in productivity as well as livestock trade restrictions. This study aimed at determining seroprevalence of Mmm in cattle from Karamoja region, north-eastern Uganda; data that are required to design and implement risk based CBPP control program. Methods We randomly collected blood samples from 2,300 cattle spread across Karamoja region. Serum was extracted and screened for antibodies against Mycoplasma mycoides subsp. mycoides [Mmm] using the competitive enzyme linked immunosorbent assay [cELISA]. Results A quarter [25.4%; 95% CI: 23.7-27.3] of the screened cattle [n = 2,300] were sero-positive for Mmm. Amudat and Kaabong districts recorded the lowest [12.3%] and highest [30.7%] Mmm seroprevalence respectively. Increasing age, overnight stay in cattle kraals and location [certain districts, villages, herds and sub counties] of the cattle herds, the factors that promote animal commingling, were the most significant risk factors of seroconversion with Mmm. Conclusion Results from this study indicated a higher seroprevalence of Mmm in Karamoja region cattle herds. This could be due to the increased frequency of CBPP outbreaks in recent years. To be effective, CBPP vaccination programs should target high risk herds along the international borders and other hotspot areas [e.g., parishes or sub counties] where cattle commingling is high. Keywords: Karamoja region, Uganda, Seroprevalence, CBPP, cELISA, Cattle
  • Thumbnail Image
    Item
    Systemic and cerebrospinal fluid immune and complement activation in Ugandan children and adolescents with long-standing nodding syndrome: A case-control study
    (Epilepsia Open, 2021) Ogwang, Rodney; Muhanguzi, Dennis; Mwikali, Kioko; Anguzu, Ronald; Nutman, Thomas B.; Newton, Charles R.; Idro, Richard
    Nodding syndrome is a poorly understood epileptic encephalopathy characterized by a unique seizure type—head nodding—and associated with Onchocerca volvulus infection. We hypothesized that altered immune activation in the cerebrospinal fluid (CSF) and plasma of children with nodding syndrome may yield insights into the pathophysiology and progression of this seizure disorder. We conducted a case-control study of 154 children (8 years or older) with long-standing nodding syndrome and 154 healthy age-matched community controls in 3 districts of northern Uganda affected by nodding syndrome. Control CSF samples were obtained from Ugandan children in remission from hematological malignancy during routine follow-up. Markers of immune activation and inflammation (cytokines and chemokines) and complement activation (C5a) were measured in plasma and CSF using ELISA or Multiplex Luminex assays. O volvulus infection was assessed by serology for anti–OV-16 IgG levels. The mean (SD) age of the population was 15.1 (SD: 1.9) years, and the mean duration of nodding syndrome from diagnosis to enrollment was 8.3 (SD: 2.7) years. The majority with nodding syndrome had been exposed to O volvulus (147/154 (95.4%)) compared with community children (86/154 (55.8%)), with an OR of 17.04 (95% CI: 7.33, 45.58), P < .001. C5a was elevated in CSF of children with nodding syndrome compared to controls (P < .0001). The levels of other CSF markers tested were comparable between cases and controls after adjusting for multiple comparisons. Children with nodding syndrome had lower plasma levels of IL-10, APRIL, CCL5 (RANTES), CCL2, CXCL13, and MMP-9 compared with community controls (P < .05 for all; multiple comparisons). Plasma CRP was elevated in children with nodding syndrome compared to community children and correlated with disease severity.