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Item Bacterial Diversity and their Association with Anchocerca Volvulus Infection in Simulium Flies in Northern Uganda(Unpublish Dissertation_Gulu University, 2024) Lakot, AmeridaABSTRACT Onchocerciasis, also known as river blindness, is a chronic and debilitating neglected tropical disease resulting from recurrent infections with the parasitic filarial worm Onchocerca volvulus. This disease is transmitted by blackflies (Simulium species) and poses significant health challenges to affected populations. To date, vector control of blackflies has largely relied on chemical insecticides, an approach that has several drawbacks. There is a pressing need for alternative biological strategies for vector control, one potential approach being the use of 'probiotic' bacteria to modify the physiology of the vector's gut, thereby creating an environment that is hostile to pathogens. This study aimed to survey the bacterial communities in the guts of blackflies from onchocerciasis foci in northern Uganda to identify species with the potential to interrupt onchocerciasis transmission. Simulium flies (n=534) were collected from five sites in Nwoya, Pader, Amuru and Moyo districts in Northern Uganda. The flies were extracted using the SDS method and tests for O. volvulus infection were done using nested PCR. Twenty-five infected flies and forty-seven non-infected Simulium flies were then run for 16s metagenomic PCR using the 16S Barcoding Kit. The library was then subjected to nanopore sequencing. The sequencing identified 12 bacterial phyla with Proteobacteria as the predominant with a relative abundance of 89.7%. The most abundant genera were Enterobacter with 21.4% out of the 149 bacterial genera identified. The bacterial diversity across the sampled districts were significantly different basing on the Shannon index (p=0.26). Eight bacterial genera were significantly associated with flies infected with O. volvulus: Peptoniphilus (p=0.009), Vogesella (p=0.029), Aquabacterium (p=0.018), Curvibacter (P=0.034), Paucibacter (P=0.004), Massilia (P=0.011), Mannheimia (p=0.011) and Shimwellia (P=0.036). On the other hand, six bacterial genera were identified to be predominantly associated with uninfected status. These included Enterococcus (p= 0.03), Citrobacter (p=0.043), Haemophilus (p=0.037), Shewanella (p=0.035), Halotalea (p=0.020) and Zymobacter (p=0.018). The study identified eight novel bacterial genera linked to O. volvulus infection and six associated with non-infection in Simulium flies. Antibacterial drugs could be developed to target the infection-associated genera, while symbiotic bacteria in non-infected flies could be modified to produce molecules against O. volvulus. Further research is needed to understand the physiological mechanisms of these bacteria, which could lead to effective biocontrol strategies.Item FRUIT FLY INFESTATION AND ITS IMPACT ON MANGO (Mangifera indica . L.) PRODUCTION IN OYAM DISTRICT, UGANDA(Gulu University, 2016) Odyomo PatrickWorldwide, fruit fly infestation is a major constraint to mango production. In Oyam district northern Uganda. mango fruits drop on the ground due to fruit fly attack. This is disheartening and frustrates efforts to diversify agriculture. Despite the overwhelming economic importance of mangoes, efforts to assess the impact of fruit flies (Diptera: Tephritidae) have been minimal. In this study, the fruit fly species causing damage and their damage level on mango fruits and local perspectives on the pest were assessed. Matured mango fruits were collected from purposively selected 30 trees belonging to I 0 mango varieties between May and July 2011. assessed for fruit fly damage and incubated individually Knowledge and perceptions of smallholder's growers and fruit vendors on the fruit fly pest and their management practices were sought by use of semi-structured questionnaires and focus group discussions respectively. Bactrocera invadens and Ceratitis rosa Wft.! identified as the fruit fly species causing damage on mango fruits. Bactrocera invadens was the most abundant (99.4%).The percentage median levels of damage varied from 7.56 to 84.34 among the mango varieties. The most damaged mango varieties were Ddodo'Atik'. Gleen and Alphonso. whereas the least damaged were Ddodo'lndia' and Ddodo·Totol'. The infestation index for B invadens was 53.42 adults/kg infested fruit and for C rosa was 0.3 adults/kg infested fruit. The general knowledge about the fruit fly pest and the damage its cause was limited among the mango growers and fruit vendors. The results of this study indicate that B mvadens is the main species causing high damage and economic loss on mango fruits in Oyam district. The results further suggest that there is no proper management of fruit flies by mango stakeholders. This highlights the need to make the management of mango fruit fly pest a high priority in all the agricultural, marketing and developmental plans.