Browsing by Author "Nakavuma, Jesca"
Now showing 1 - 10 of 10
Results Per Page
Sort Options
Item Antifungal activity of flavonoids isolated from Monanthotaxis littoralis against mycotoxigenic fungi from maize(American Journal of Chemistry and Application, 2014) Chepkirui, Clara; Matasyoh, Josphat C.; Wagara, Isabel N.; Nakavuma, JescaThis study evaluated the antifungal activity of a mixture of two closely related flavonoids namely 3, 7, 5’- trihydroxy anthocynidines and 3, 5-dihydroxy-7-methoxy anthocynidines isolated from Monanthotaxis littoralis (Annonaceae) against mycotoxigenic fungi from three genera (Aspergillus, Fusarium and Penicillium) isolated from maize samples. Dry leaves of Monanthotaxis littoralis was extracted with methanol, suspended in water and extracted with ethyl acetate. Column chromatography and Preparative Thin Layer Chromatography (PTLC) was used to purify the compounds. 1D and 2D NMR and Mass Spectroscopy were used to elucidate the structures of the compounds isolated. The extent of inhibition of fungal growth was dependent on the concentration of the flavonoids. The highest activity of the flavonoids was that against Aspergillus ochraceus with inhibition zone of 20.17 mm and MIC of 1 mg/ml. The activity of the flavonoids against the mycotoxigenic fungi had Minimum Inhibitory Concentration (MIC) values ranging from 1 mg/ml to 4 mg/ml. These results show that the two flavonoids from M. littoralis have antifungal activities against fungi that are the producers of poisonous mycotoxins found in foods. These compounds are potential antimicrobials that can be used in food preservation systems to inhibit the growth of moulds and retard subsequent mycotoxin productionItem Brucellosis: Community, Medical and Veterinary Workers’ Knowledge, Attitudes, and Practices in Northern Uganda(Int J One Health, 2017) Nabirye, Harriet Muloki; Erume, Joseph; Nasinyama, George William; Kungu, Joseph Morison; Nakavuma, Jesca; Ongeng, Duncan; Owiny, David OkelloThis study aimed at determining the knowledge, attitudes, and practices of the community, medical and veterinary workers regarding brucellosis.A cross-sectional study was conducted at selected health facilities in Apac, Gulu, Lira, and Pader districts of Northern Uganda using a standardized questionnaire. A total of 251 patients testing positive for brucellosis using the Brucella plate agglutination test, 59 medical and 29 veterinary workers were studied. Chi-square test at 95% confidence level was used to analyze data.Only 8% patients, 15.3% medical, and 21.4% veterinary workers were knowledgeable on transmission methods and symptoms for brucellosis and knowledge differed according to the level of education among patients (p=0.001), medical (p=0.001), and veterinary workers (p=0.012). Over 80% patients, medical and veterinary workers had a positive attitude. Only 8% patients, 13.6% medical, and 7.1% veterinary workers had good practices regarding brucellosis control. Poor knowledge, poor practices, and positive attitude provide an opportunity for health education and policy formulation for the control of brucellosis. The prevalence studies of human and animal brucellosis are recommended to determine the magnitude of the problem.Item The in vitro Efficacy of Two Microbial Strains and Physicochemical Effects on their Aflatoxin Decontamination in Poultry Feeds(2020) Tebetyo, Zakia; Bogere, Paul; Nabulime, Margaret M.; Kaaya, Archileo N.; Gnonlonfin, Benoit; Ntale, Mohammed; Nakavuma, JescaContamination of animal feeds with aflatoxigenic fungi is a challenge to livestock farmers worldwide. Aflatoxins are very toxic fungal metabolites that are associated with carcinogenic, mutagenic, teratogenic, and estrogenic effects. The toxins affect animal productivity and may lead to deaths, causing enormous economic losses. Aflatoxin decontamination is a challenge to the feed industry, despite the several approaches available. This study investigated the efficacy of two microbial isolates, Bacillus spp (B285) and Yeast strain (Y833), in reducing Aflatoxin concentration in poultry feeds in comparison with a commonly used commercial chemical binder, Bentonite. The influence of the poultry feed matrix, pH, and temperature on the aflatoxin reducing activity by the two microorganisms was also explored. Results: The in vitro studies showed that the two microorganisms and the chemical binder reduced aflatoxins by over 74% of the original concentration. The chemical binder registered the highest reduction at 93.4%; followed by Y833 (83.6%), then the combination of Y833 and B285 (77.9%); and lastly B285 (74.9%). There was no significant (p>0.05) influence of temperature on the toxin reducing capacity of all the agents tested. The pHs 4.5 and 6.5 did not have a significant effect on the performance of both chemical binder and biological agents, however, the former performed better at pH 6.5 with 95% aflatoxin reduction compared to the microorganisms. The aflatoxin reducing activity was lower in presence of feeds compared to that in Phosphate Buffered Saline except for Y833 where no difference was observed. Conclusions: Although the feed components affected the aflatoxin reducing capacity of the test materials, the chemical binder was more effective than the microbial agents. Yeast strain was more effective than the bacterial strain in reducing the aflatoxin levels, however, both are promising strategies for countering the aflatoxin challenges in animal feeds. In response to the advocacy for use of biological control agents, there is need for more investigations to establish the safety of the microorganisms, the mechanism of decontamination and safety of the products; the optimum concentrations that can reduce aflatoxins in feeds to permissible levels and the effect of the toxin contamination levels on microbial efficiency.Item Mycobacteriophages Exhibit Antibiofilm Activity at High Multiplicities of Infection(2022) Ssengooba, Willy; Kamya, Deus; Nakavuma, Jesca; Achan, Beatrice; Semanda, JosephBiofilm formation has been shown to be a very effective survival mechanism used by many bacteria pathogens, including Mycobacterium tuberculosis (Mtb). However, unlike other bacteria, mycobacterial biofilms tend to be very rich in lipids, and this accords them much more resilience than their carbohydratebased counterparts’. Mycobacteriophage therapy, as an up-and-coming technology, is envisaged to revolutionize the treatment of tuberculosis (TB), particularly involving antibiotic-resistant Mtb. Antibiofilm activity, therefore, is a highly sought-after characteristic of mycobacteriophages intended for therapeutic use. Here we investigated the in-vitro activity of a three-phage cocktail against biofilms of forty-six clinically isolated Mtb using the MBEC biofilm device. We demonstrate that multiplicity of infection and the age of the biofilms are significant determinants of phage antibiofilm activity. Furthermore, based on our host range data, we hypothesize that mycobacteriophages might have a preference for Mtb hosts from pulmonary infection sites compared to those from extrapulmonary sites. If accurate, this finding could have profound implications for both diagnostic and therapeutic applications of mycobacteriophages. Overall, our findings demonstrate the antibiofilm potential of mycobacteriophages and continue to endorse mycobacteriophage therapy as a treatment alternative to our failing antibiotic arsenal. We recommend further investigations to; understand the basis of the observed host preference in mycobacteriophages, evaluate combinatorial therapy of phages and antibiotics, and screen the phages for undesirable genes.Item Perceptions about mercury and lead in fish consumed in Lake Albert fishing communities Uganda(Cogent Food & Agriculture, 2016) Tamale, Andrew; Ejobi, Francis; Muyanja, Charles; Naigaga, Irene; Nakavuma, Jesca; Ocaido, Micheal; Katuhoire, Anne; Amulen, DeborahFish consumption is a lifestyle in fishing communities influenced by individual and communal perceptions. However, information about individual perceptions about fish consumption in the vulnerable fishing community in a developing country is lacking. Without this study, the benefits of fish consumption in a vulnerable community may not be realized. Data collection was executed using key informant interviews and survey structured questionnaires. The key informants include fisheries, community development, veterinary, community and environmental officers. The household heads were the respondents. The Qualitative data was organized and queried using QSR Nvivo 10 and quantitative data analyzed with SPSS version 22. The perceived benefits of eating fish are health, income, nutrition and manhood. The perceived risks are Stigma and ill health. The factors increasing fish consumption are heedless of fish consumption benefits (p = 0.041) and household size i.e. number of adults more than seven (p = 0.020). Those decreasing are methods of preparation of fish i.e. boiling and frying (p = 0.019 and p = 0.010) and oblivious about organizations dealing with fishing activities (p = 0.029). An awareness campaign is needed to demystify the health benefits and fallacies of fish consumption. The knowledge on individual perceptions associated with fish consumption will increase fish consumption but with fewer risksItem Performance of Cryptococcal Antigen Lateral Flow Assay Using Saliva in Ugandans with CD4 ,<100(PloS one, 2014) Kwizera, Richard; Nguna, Joyce; Kiragga, Agnes; Nakavuma, Jesca; Rajasingham, Radha; Boulware, David R.; Meya, David B.Cryptococcal meningitis can best be diagnosed by cerebrospinal fluid India ink microscopy, cryptococcal antigen detection, or culture. These require invasive lumbar punctures. The utility of cryptococcal antigen detection in saliva is unknown. We evaluated the diagnostic performance of the point-of-care cryptococcal antigen lateral flow assay (CrAg LFA) in saliva.We screened HIV-infected, antiretroviral therapy naïve persons with symptomatic meningitis (n = 130) and asymptomatic persons with CD4+<100 cells/µL entering into HIV care (n = 399) in Kampala, Uganda. The diagnostic performance of testing saliva was compared to serum/plasma cryptococcal antigen as the reference standard.The saliva lateral flow assay performance was overall more sensitive in symptomatic patients (88%) than in asymptomatic patients (27%). The specificity of saliva lateral flow assay was excellent at 97.8% in the symptomatic patients and 100% in asymptomatic patients. The degree of accuracy of saliva in diagnosing cryptococcosis and the level of agreement between the two sample types was better in symptomatic patients (C-statistic 92.9, κ-0.82) than in asymptomatic patients (C-statistic 63.5, κ-0.41). Persons with false negative salvia CrAg tests had lower levels of peripheral blood CrAg titers (P<0.001).There was poor diagnostic performance in testing saliva for cryptococcal antigen, particularly among asymptomatic persons screened for preemptive treatment of cryptococcosis.Item Physiochemical properties and antibacterial activity of silver nanoparticles green synthesized by Camellia sinensis and Prunus africana extracts(2021) Ssekatawa, Kenneth; Byarugaba, Denis; Kato, Charles; Nakavuma, Jesca; Wampande, Eddie; Ejobi, Francis; Maaza, Malik; Sackey, Juliet; Kirabira, John; Nxumalo, EdwardAntibiotics have been the nucleus of chemotherapy since their discovery and introduction into the healthcare system in the 1940s. They are used routinely not only to treat bacterial infections but also to prevent infections in patients with compromised immune systems and enhancing growth in livestock. However, resistance to last-resort antibiotics used in the treatment of MDR infections has been reported worldwide. Therefore, the aim of this study was to evaluate green synthesized nanomaterials such as AgNPs as alternatives to antibiotics. UV Vis Spectroscopy surface plasmon resonance peaks for AgNPs were obtained between 417 to 475nm. XRD analysis generated 4 peaks for both PAE and CSE biosynthesized AgNPs positioned at 2θ angles of 38.2˚, 44.4˚, 64.5˚, and 77.4˚ corresponding to crystal planes (111), (200), (220) and (311) respectively. DLS registered mean zeta potential of + 6.3mV and + 0.9mV for PAE and CSE biosynthesized nanoparticles respectively. FTIR spectra exhibited bands corresponding to different organic functional groups confirming capping of AgNPs by PAE and CSE phytochemicals. FESEM imaging showed that AgNPs were spherical with average size distribution ranging from 10 to 19nm. Biosynthesized AgNPs exhibited maximum growth inhibitory zones of 21mm with MIC and MBC of 125μg/ml and 250μg/ml respectively against carbapenem resistant bacteria.Item Prevalence and risk factors for brucellosis in prolonged fever patients in post-conflict Northern Uganda(African Health Sciences, 2018) Muloki, Harriet N.; Erume, Joseph; Owiny, David O.; Kungu, Joseph M.; Nakavuma, Jesca; Ogeng, Duncan; Nasinyama, George W.Background: Brucellosis is a disease with significant public and economic implications but strategies for controlling this disease remain problematic. Objectives: This study sought to determine the sero-prevalence of brucellosis in prolonged fever patients and to identify modifiable risk factors for the infection in humans in post conflict Northern Uganda. Methods: The study employed a cross-sectional method among prolonged fever patients who had visited selected health facilities in the study districts in Northern Uganda. Sero-prevalence of brucellosis was calculated for i-ELISA IgG/IgM. A structured questionnaire was used to obtain data on possible risk factors for brucellosis. Associations between sero-prevalence and risk factors were measured using the Odds Ratio. Results: Brucellosis was confirmed in 18.7% of the 251 patients that tested positive for the disease, with the rapid Brucella Plate Agglutination Test, and ages 10-84 years (median age 47+0.86). Sex (p = 0.001; OR 3.79; 95% CI 1.75 - 8.24), rearing livestock (p < 0.005; OR 8.44; 95% CI 2.84-25.03) and consumption of unpasteurised milk (p = 0.023; OR 2.57; 95% CI 1.14-5.80) were factors associated with brucellosis. Conclusion: Control of brucellosis in animals, training and sensitisation of the community on brucellosis is needed to stimulate action on human brucellosis control.Item Retrospective Analysis of Archived Pyrazinamide Resistant Mycobacterium tuberculosis Complex Isolates from Uganda—Evidence of Interspecies Transmission(Microorganisms, 2019) Wanzala, Sylvia I.; Nakavuma, Jesca; Travis, Dominic; Kia, Praiscillia; Ogwang, Sam; Waters, Wade R.; Thacker, Tyler; Johnson, Timothy; Hadi, Syeda A.; Sreevatsan, SrinandThe contribution of Mycobacterium bovis to the proportion of tuberculosis cases in humans is unknown. A retrospective study was undertaken on archived Mycobacterium tuberculosis complex (MTBC) isolates from a reference laboratory in Uganda to identify the prevalence of human M. bovis infection. A total of 5676 isolates maintained in this repository were queried and 136 isolates were identified as pyrazinamide resistant, a hallmark phenotype of M. bovis. Of these, 1.5% (n = 2) isolates were confirmed as M. bovis by using regions of di erence PCR analysis. The overall size of whole genome sequences (WGSs) of these two M. bovis isolates were ~4.272 Mb (M. bovis Bz_31150 isolated from a captive chimpanzee) and 4.17 Mb (M. bovis B2_7505 from a human patient), respectively. Alignment of these genomes against 15 MTBC genome sequences revealed 7248 single nucleotide polumorphisms (SNPs). Theses SNPs were used for phylogenetic analysis that indicated a strong relationship between M. bovis and the chimpanzee isolate (Bz_31150) while the other M. bovis genome from the human patient (B2_7505) analyzed did not cluster with any M. bovis or M. tuberculosis strains. WGS analysis also revealed multidrug resistance genotypes; these genomes revealed pncA mutations at positions H57D in Bz_31150 and B2_7505. Phenotypically, B2_7505 was an extensively drug-resistant strain and this was confirmed by the presence of mutations in the major resistance-associated proteins for all anti-tuberculosis (TB) drugs, including isoniazid (KatG (S315T) and InhA (S94A)), fluoroquinolones (S95T), streptomycin (rrs (R309C)), and rifampin (D435Y, a rare but disputed mutation in rpoB). The presence of these mutations exclusively in the human M. bovis isolate suggested that these occurred after transmission from cattle. Genome analysis in this study identified M. bovis in humans and great apes, suggesting possible transmission from domesticated ruminants in the area due to a dynamic and changing interface, which has created opportunity for exposure and transmission.Item Risk estimates for children and pregnant women exposed to mercury-contaminated Oreochromis niloticus and Lates niloticus in Lake Albert Uganda(Cogent Food & Agriculture, 2016) Tamale, Andrew; Ejobi, Francis; Muyanja, Charles; Naigaga, Irene; Nakavuma, Jesca; Ocaido, Micheal; Kato, Drago; Sente, Celsus; Amulen, Deborah; Rumbeiha, WilsonExposure to mercury contaminated fish predisposes populations particularly children and pregnant women to various health hazards including neurotoxicity, reproductive abnormalities and cognitive disorders. Earlier studies in the Lake Albert community have demonstrated the presence of mercury in Nile tilapia and Nile perch. However, the risk estimates for vulnerable groups such as Children and pregnant women is not well documented. Secondary data-set from previous studies were employed comprising family household size and fish consumption history, fish consumption quantity and frequency and mercury levels in fish species in comparison with FAO/WHO guidelines. Data collected was used to establish the hazard quotients (HQs) for the vulnerable group and the general population. A risk model was developed using iRISK to demonstrate the Disability Adjusted Life Years (DALYs) for eating different parts of the fish (muscle and bellyfat). HQ values (HQ = 2.05) above one for the vulnerable group were realized especially with Nile perch muscle. The highest DALYs (0.111) was obtained with tilapia muscle consumption. The study outcome reveals that vulnerable populations are at risk of non-carcinogenic complications. Therefore, there is a need for sensitization of the community especially the vulnerable groups about risks associated with consuming mercury-contaminated fish.