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Item Seroprevalence, Genetic Diversity, and Drug Resistance of Hepatitis B Virus among Gravid Women Attending Antenatal Clinic in Saretho Health Centre, Garissa, Kenya(Kenyatta University, 2025-10) Mwangome, Lawi EmmanuelThe Hepatitis B Virus remains one of the global infectious diseases of public health concern. It is estimated that 2 billion people are infected worldwide with about 1.2 million mortality being reported yearly. Gravid women are considered a vulnerable group due to their immune suppression hence posing a risk for vertical transmission to their newborns. However, HBV disease burden and circulating HBV strains causing this endemic infections among gravid women remains elusive, in Garissa. Therefore, this study was aimed at determining seroprevalence, of HBV, genetic diversity, and drug resistance among gravid women attending Saretho Health Centre at Dadaab in Garissa.A cross-sectional study was conducted. A total of 186 consenting gravid women were recruited using systematic random sampling design. The study participants were recruited consecutively during the period between August to October 2023. A structured questionnaire was administered and demographic data; that includes age, level of education, marital status, ear piercing, tattooing, female genital mutilation (FGM), history of undergoing a caesarean section, history of blood transfusion, and dental procedure collected.About, 5ml venous blood was collected in EDTA tubes and screened for AntiHBs, AntiHBc, AntiHBe, HBsAg, and HBe-sero using Lumiquick HBV 5 panel kit according to the manufacturers instructions. The HBV positive samples viral DNA was extracted from separated plasma using the GeneProof pathogen free DNA isolation kit (Gene Proof, Czech Republic) as per the manufacturer’s instructions. The partial HBV pol gene was amplified and directly sequenced using Sanger sequencer platform. The genarated HBV sequences were phylogenetically analysed using MEGAx software.In addition, the HBV sequences were also analysed for drug resistance mutations using Insilico HBV drug resistance database. The demographic data was analyzed using SPSS version 19 and frequency tables generated. The sero-prevalence markers for HBV was presented in percentage and tabulated. Two tailed chi-square tests with significance set at p value of < 0.05 was used to compare the association between socio-demographic factors, serological markers and HBV infection stages across the study participants. Overall 8.6% prevalence was detected. Marital Status, level of education, history of undergoing FGM, having Ear piercing were risk factors associated with HBV infection (p < 0.05) while Age, history of; blood transfusion, caesarean section, dental procedures, tattoo, having liver disease or having family history of liver diseases (p > 0.05), were not risk factors associated with HBV infection. From the analysis, 19(10.2%) were immune to HBV infection, 6(3.2%) acute infection, 11(5.9%) on HBV recovery, 8(4.3%) were on chronic stage and 5(2.7%) had occult HBV. After the confirmation of HBV DNA by Gel electrophoresis, 9 samples were successful amplified, purified and sequenced. The phylogenetic analysis of HBV sequences revealed that seven (7) isolates were classified as HBV genotype A while two (2) isolates belonged to genotype D. The study found high overall drug resistance prevalence of 77.8%. Five participants harbored cross-resistance mutations to Lamivudine, Entacavir, and Telbivudine. Two had additional resistance to Adefovir and Entacavir, while no drug resistance mutations associated with tenofovir. Two participants had no detectable resistance mutations.This study suggests need for utilisation of HBV -5 panel seromarkers in HBV testing for early detection, infection staging and effective treatment. HBV genotype A predominates among pregnant women in Dadaab, with a high prevalence of drug resistance mutations. Continuous genotype surveillance is essential to monitor viral evolution and resistance dynamics. Based on observed cross-resistance, combined therapy with Tenofovir and Lamivudine is recommended for effective HBV managementItem Prevalence, Genetic Diversity and Risk Factors Associated with Hepatitis B Infection among Women Attending Antenatal Clinic at St. Orsola Hospital, Tharaka Nithi County, Kenya(Kenyatta University, 2025-07) Njuguna, Joseph KamauThere is a dearth of information on the impacts of hepatitis B virus (HBV) because it is rarely screened for in prenatal profiles in many facilities especially in Tharaka Nithi County. The transmission of Hepatitis B virus (HBV) occurs in the uterus through trans-placental, childbirth, and during newborn care. The likelihood of transmission is influenced by the presence of HBV markers in the mother where the risk is decreased if she is positive for HBsAg test result but rose if she has a positive HBsAg and HBeAg test result. Therefore, this study was carried out to determine the prevalence, genetic diversity and the associated risk factors for hepatitis B virus infection among expectant mothers seeking ANC at St. Orsola Hospital. A total of 385 pregnant mothers who were enrolled from September to December 2021 participated in a cross-sectional study. Blood samples were collected and examined for the presence of HBsAg and to determine the HBV risk of perinatal transmission, the positive sample for HBsAg were tested for HBsAg, HBsAb, HBeAg, HBeAb, HBcAb using five panel kit. The viral DNA was extracted from HBsAg positive samples, partial HBV-pol gene was amplified in nested PCR, directly sequenced using the Big Dye chain terminator method using ABI 3730xl DNA Analyzer. The obtained sequences were then scrutinized and assembled using BioEdit software v7.1.1 and subjected to multiple sequence alignment by MUltiple Sequence Comparison by Log- Expectation (MUSCLE). Phylogenetic relationships were estimated using Maximum likelihood-based inference of phylogenetic trees with Smart Model Selection (PhyML+SMS). From the analysis, the prevalence of HBV among pregnant womem was 25 (6.5%). Among these (25 pregnant women); 19 (76%) were inactive carrier, 4 (16%) chronically infected, 1 (4%) at recovery HBV and 1 (4%) at occult HBV. From the SPSS analysis, age (χ2= 13.55, p = 0.019), education (χ2= 44.53, p = 0.000), liver problems (χ2= 5.724, p = 0.017) and HIV (χ2= 6.267, p = 0.012) were associated with risk to HBV infection. From the phylogenetic analysis, the HBV genotype that was in circulation was genotype A, 11(100%). The detected prevalence of HBV in Tharaka Nithi region indicated possible increasing trends in HBV infection with age, education, liver problem and HIV being the associated risk factors, and HBV genotype A being the most predominate genotype in circulation. In order to control the spread of the virus there is need to identify cases both during antenatal as well as postnatal care, raise the risk awareness, track HBV genotypes and offer treatment for positive cases and HBV immunization for negative as well as all women of childbearing ageItem Therapeutic Promise of Aqueous Extract of Portulaca oleracea L.: Antioxidant and Anti-Inflammatory Effects(Kenyatta University, 2025-08) Wanderi, Gladys WamaithaOxidative stress is an imbalance in which oxidants exceed antioxidants in the body's defense system. Several chronic diseases, including rheumatoid arthritis, cardiovascular disorders and cancer are caused by oxidative stress. Inflammation refers to biological responses caused by oxidative stress, toxic substance, irradiation and pathogens. Synthetic antioxidant and anti-inflammatory drugs already on the market are linked to adverse effects, necessitating the need for an alternative medicinal approach. Portulaca oleracea is used by communities living in Embu County to manage inflammation. Nevertheless, the scientific data to confirm this claim was lacking. This study aimed to assess in vitro antioxidant and ex vivo anti-inflammatory effects, including qualitative phytochemical analysis of Portulaca oleracea. Fresh plant sample was obtained from Embu County, Kenya. The sample was air-dried, milled, macerated with water and then freeze dried to obtain a solid extract. The 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, H2O2 radical scavenging, ferric reducing antioxidant power (FRAP), total phenolic content (TPC) and total flavonoid content (TFC) were among the antioxidant assays that were performed according to standard methods. The antioxidant assays used the extract at concentrations of 7, 15, 31, 62, 125, 250, 500 and 1000 µg/ml. In antioxidant assays, ascorbic acid was utilized as the standard. The standards that were used in TFC and TPC assays were rutin and gallic acid, respectively. The ex vivo anti- inflammatory assays included hypotonicity-induced hemolysis, heat-induced hemolysis, albumin denaturation and anti-proteinase activity. Indomethacin was utilized as reference drug in the ex vivo antiinflammatory assays. The extract and reference drug used concentrations of 7, 15, 31, 62, 125, 250, 500 and 1000 µg/ml. Standard procedures were used to conduct a qualitative phytochemical analysis. Analyzed data was summarized using mean and the standard error of the mean. Statistical differences between the different concentrations were evaluated using one-way analysis of variance and Tukey's multiple comparisons. Effects of ascorbic acid/Indomethacin and the extract were compared statistically using independent T-test. If p value was <0.05, statistical results were deemed significant. This study found that Purslane oleracea extract possesses potent in vitro antioxidant effect through FRAP, as well as DPPH radical scavenging and H2O2 radical scavenging activities. The extract also revealed considerable amount of TPC and TFC, which are linked with antioxidant effects. The extract also demonstrated ex vivo anti-inflammatory effect via inhibitions of: hypotonicity-induced hemolysis, heat-induced hemolysis, albumin denaturation, as well anti-proteinase activity. A concentration- dependent response was seen in the extract's in vitro antioxidant and ex vivo anti- inflammatory activities. For instance, at the highest concentration of extract(1000 µg/ml), the extract had its highest percentage inhibition on heat-induced hemolysis (72.65%) and its lowest inhibitory percentage (27.14%) at the lowest concentration of(7µg/ml) Phytocompounds including flavonoids, alkaloids, steroids, saponins, terpenoids, cardiac glycosides, tannins, and phenolic acids were detected in the extract according to a qualitative phytochemical analysis. These phytocompounds were linked to the two activities mentioned in this study. The current study concluded that the extract possesses potent in vitro antioxidant and ex vivo antiinflammatory effects. The study recommends that the aqueous extract of Purslane oleracea can be used to develop alternative anti- inflammatory and antioxidant agents.Item Exploring the Population Structure and Genetic Diversity of Moringa oleifera Using DArTseq-Derived SNP Markers(Kenyatta University, 2025-11) Ndalo, JantorMoringa oleifera is a versatile tree native to the foothills of the Himalayas and now naturalized in the tropics. Moringa is nutritionally significant owing to its high nutrient and antioxidant content. Despite its increasing use as a fodder crop, wood fuel, medicine, an anticoagulant and a potential source of biodiesel, the genetic diversity of Moringa across the tropics remains a subject of intense investigation. Previous studies have used hybridization-based methods such as microsatellites which have not fully resolved its genetic diversity. In this study, genetic diversity and structure of 95 accessions of Moringa from tropical regions were analyzed using single nucleotide polymorphisms. Genomic DNA was extracted from 19 provenances collected from Africa, Caribbean and Southeast Asia. 3968 SNP markers were identified using DArTSEQ technology, which combines complexity reduction methods with next-generation sequencing. These were culled to a final set of 1913 informative markers that were then used for population structure and genetic diversity analysis. Unweighted neighbour joining phylogeny and principal coordinate analysis revealed four distinct clusters related to the geographic origin: Caribbean (Haiti/Jamaica) and East African (Kenya/Tanzania) were identified to be a subset of the West African (Mali/Ghana) population while the Southern African (Malawi) segregated distinctly. Philippines samples clustered separately and farthest as expected. Analysis of molecular variance revealed high gene flow within populations (77 %) compared to among populations (23 %). Bayesian modelling in structure with best k being two still distinctly segregated the Southern African (Malawi) population from the other African regions suggesting a distinct introduction. The significant admixture of individuals noted in structure is typical of unnatural introductions possibly through anthropogenic events. This study highlights the power of SNP markers from DArTSEQ technology in elucidating the genetic structure and molecular diversity of Moringa oleifera. Malawi and Philippines being the most diverse should be considered as candidates for conservation improvement and utilization since they have higher ecosystem functioning. The discovered SNPs enable genome-wide association studies to accelerate marker-assisted breeding. These results too have implications for germplasm collection, improvement, conservation, utilization strategies and policies. Further research utilizing advanced genomic tools will enhance our knowledge of Moringa oleifera and support its sustainable utilization for various applications.Item Analysis of Mating System and Gene Flow Patterns of Melia volkensii within Clonal Seed Orchard in Kibwezi Using Microsatellites(Kenyatta University, 2025-09) Rotich, Kipkoech JaphetMelia volkensii (M. volkensii) is an indigenous tree species that grows and develops well in Kenyan Arid and semi-arid lands (ASALs). There has been a drastic decline in the M. volkensii population because of the overexploitation and uncontrolled harvesting of the natural stands where large and best trees are utilized for charcoal and timber, creating a huge demand for quality planting materials. Melia volkensii improvement programme began in 2012 to address the sharp decline in their genetic diversity, provide farmers with improved seeds for commercial plantations in dry lands and produce drought-tolerant and fast-growing trees adaptable to ASALs. Scions from the best M. volkensii, also known as candidate plus trees (CPTs), were collected to establish the first generation of clonal seed orchard to increase the breeding population and genetic resources of M. volkensii. The distributed materials from a tree seed orchard should always be of the recommended genetic quality with no or minimal contamination from unimproved wild stands surrounding the orchard. Therefore there is a need to determine the level and patterns of gene flow among the elite trees grown in a seed orchard to maintain random outcrossing in order to minimize loss of diversity. The study was carried out using the M. volkensii trees grown at the Kenya Forestry Research Institute seed orchard in Kibwezi in Makueni County. In total, 15 populations which comprised of 618 M. volkensii trees consisting of four hundred and twenty three open pollinated progenies from ten clones, ninety eight candidate plus trees and ninety seven individuals from the orchard background population were studied. Genomic DNA was isolated by CTAB method and amplified by multiplex PCR reactions using primers previously developed by Hanaoka et al., 2012. The amplified DNA fragments were screened by capillary electrophoresis on the ABI 3500 genetic analyzer. Parameters of genetic diversity were determined using GenAlEx 6.503; MLTR program was used to determine the mating system in the orchard based on the mixed mating model. The population had a mean heterozygosity of 0.712, inbreeding coefficient of -0.035, fixation index of 0.068, a high number of migrants (Nm = 3.952), with high single (1.014) and multi-locus (1.2) estimates of the outcrossing rates. This indicates an exclusive out-crossing mating system and existence of gene flow in M. volkensii, possibly promoting inter-breeding and genetic diversity among the trees in Kibwezi seed orchard, which is vital for their future survival. Paternity analysis implicitly assigned 334 out of 423 progenies (78.96%) to 77 out of 98 potential (78.57%) seed orchard clones, with the unassigned 89 progenies (21.04 %) not matching any of the 98 seed orchard clones thought to be derived from the background population. The panmictic design of the seed orchard and flowering synchrony with the background population could have contributed to the pollen introgression in the orchard therefore regular studies should be done across the other blocks of the orchard to find out the extent of contamination and then come up with suitable mitigation which might include thinning and a review of the current isolation distance of 200 metres between the orchard and the background population to ensure the integrity of the seed sourceItem Isolation and Characterization of L-Asparaginase Producing Endophytic Fungi Inhabiting Prunus africana and Periploca linearifolia(Kenyatta University, 2025-09) Cheruiyot, Dennis KipngenohThe clinical use of L-Asparaginase derived from bacterial sources has been hindered by various challenges, including toxicity and repression. This has prompted the exploration of alternative sources, particularly eukaryotic microorganisms like fungi, in an effort to enhance the safety and effectiveness of therapeutic ASNase. In this study, endophytic fungi isolated from medicinal plants, Periploca linearifolia (Apocynacease family) and Prunus africana (Rosaceae family), were investigated for their potential as a source of novel ASNase for therapeutic applications. These isolates were screened for L-Asparaginase production using the plate assay method on modified Czapex dots agar medium. L-Asparaginase activity of the fungal endophytes was determined using the nesslerization method. Identification of the fungal endophytes was performed using morphological characteristics and DNA barcoding with ITS sequencing, followed by BLAST analysis. Additionally, a phylogenetic tree was constructed using MEGA version X software. Twenty-four percent of the fungal endophytes exhibited positive reaction for L-ASNase activity and were identified as Penicillium ubiquetum, Penicillium pancosmium, Phoma sp, Penicillium. crustosum, Fusarium sporotrichioides, Cercospora canescens, Penicillium commune, septoria sp, Fusarium solani, and Colletotrichum sydowii. The fungal endophytes exhibited significant variation in production of L-asparaginase under the inflence of time of incubation and pH. It was observed that the fungal endophytes showed L-asparaginase activity at different day of incubation with Penicillium ubiquetum (2.63±0.47UI/mL), Penicillium pancosmium (1.44±0.1UI/mL), Phoma sp (2.6±0.47UI/mL), Penicillium crustosum (3.80±0.37 UI/mL), Penicillium commune (2.52±0.29 UI/mL), Fusarium sporotrichioides (3.47±0.24 UI/mL), Cercospora canescen (2.24±0.12 UI/mL) showed highest enzyme activity on the 6th day of incubation. Septoria sp and Colletotrichum sydowii exhibited best L-asparaginase activity of 12.6±0.81UI/mL and 4.06±0.23 UI/mL on the 9th day of incubation, respectively. While Fusarium solani showed atmost L-asparaginase activity of 12.4±1.12 UI/mL on the 12th day of incubation. In addition, the ten identified fungal endophytes records the highest activity at pH range 5.0-6.0 with Fusarium solani recording the highest enzyme activity of (6.14±0.01 UI/mL) at pH 6.0. The study revealed that fungal endophytes inhabiting plants with medicinal properties are potential source of L-Asparaginase. Among the fungal isolates, Fusarium solani and Septoria sp. showed the highest ASNase activity under optimized conditions (pH 5-6, incubation 9-12 days), indicating their potential as safer alternative to bacterial L-Asparaginase for anticancer therapy.Item Bioethanol Production from Dilute Acid-Pretreated Rice and Sorghum Biomass via Enzymatic Hydrolysis and Fermentation(Kenyatta University, 2025-09) Nyang’au, Agatha KemuntoThe world has a massive energy need, and bioethanol is a viable clean energy substitute for the fast-depleting fossil fuel supply. Large volumes of crop leftovers generated and left in the field for burning can be used in an affordable, dependable, and steady way thanks to production of bioethanol from lignocellulose biomass. However, because of the variations in lignocellulosic biomass, biochemical composition and lignin’s recalcitrance, producing ethanol from it is still difficult. This study evaluated the effects of pre-treating selected agro wastes with dilute acid on ethanol yields via microbial hydrolysis and fermentation. Nerica husk (NH), Nerica straw (NS), Basmati 370 husk (BH), Basmati 370 straw (BS), sorghum from KALRO plot 8 (SP08) and Sorghum from KALRO plot 17 (SP17) were used in this study. Biomass samples were dried to a constant moisture content, milled into fine powder, and treated at 121oC for 60 min with sulphuric acid (1.2%(w/w) or 2.25%(w/w) at a solid to liquid ratio of 1:10. This was followed by enzyme hydrolysis using cellulase from Aspergillus niger at 5% substrate loading. High performance liquid chromatography (HPLC) with a reverse phase column and refractive index detector was used to evaluate the resultant sugars. The cellulase hydrolysed substrate solution was fermented with Saccharomyces cerevisiae, and the alcohol production was measured by HPLC. An analysis of the statistics was done through the analysis of variance (ANOVA), considering a 95% confidence level using SPSS software. Simple sugars including glucose, sucrose, maltose, and specific sugars such as xylose, arabinose, and mannose were detected, with glucose being the sugar that was found to be most prevalent in all samples. Glucose yields were consistently higher in samples pre-treated with 2.25%(w/w) dilute sulphuric acid than in biomass samples pre-treated with 1.2%(w/w) sulphuric acid, which yielded between 12.8%(w/v) and 26.7%(w/v) glucose across all biomass samples. In contrast, cellulase hydrolysis after 2.25%(w/w) acid pre-treatment, yielded 32.3%(w/w), 30.6%(w/w), 31.6%(w/w), 30.3%(w/w), 29.3%(w/w), and 13.4%(w/w) glucose from NH, NS, BH, BS, SP08, and SP17 samples, respectively. Biomass samples pre-treated with 2.25%w/w dilute acid and subjected to microbial fermentation produced ethanol ranging from 5.8%(v/v) to 8.9%(v/v). These findings demonstrate that 2.25%(w/w) sulphuric acid pre-treatment significantly enhances the release of fermentable sugars, particularly glucose from selected agro-wastes, supporting their potential as viable low-cost feedstocks for sustainable bioethanol production in KenyaItem Fungal Spore Air Pollution: Seasonal Concentration, Diversity and Antifungal Resistance in Nairobi City County, Kenya(Kenyatta University, 2025-11) Kipchumba, Kiprop VincentPoor air quality is associated with cardiovascular and respiratory diseases including, allergies, obstructive lung diseases, cancer, and even reduced life expectancy. According to WHO data, approximately 92% of the global population is exposed to air pollution, causing up to 6.5 million mortalities. Understanding and subsequent management of microbial air pollution have been a main focus for research. Several studies have reported various effects of Particulate matter (PM10) on human health. However, limited information is available on the effects of airborne fungi on human health. Studies focusing on evaluating fungal air quality in urban environments to identify biological health risks and provide necessary information for control are limited. This work aims to determine fungal diversity and concentrations in the atmospheric air of Nairobi, Kenya, towards determining fungal air quality. Nonrandomized sampling design was adopted, where sampling sites were categorized into 4 zones: (1) Traffic zones, i.e., roundabouts and major roads; (2) Commercial zones; (3) Recreation zones; Waste dumping zones. A total of 384 samples were collected; out of these, 192 samples were collected during the dry season (January to March), remaining 192 samples were sampled during wet seasons (June to July). Temperature, humidity, and wind speed data were recorded using the Accuweather mobile Application. The identified fungal isolates were enumerated using the Omelyansky formula (2013). Culture-dependent techniques were adopted for fungal identification and characterization. Moreover, their potential pathogenicity was tested by subjecting the isolates to temperature tolerance, hemolytic, and protease tests. Antifungal susceptibility tests were performed using the CLSI M38-A2 broth microdilution method against 3 azole antifungals; [fluconazole (FCZ), voriconazole (VCZ), and itraconazole (ITZ)], which are commonly dispensed antifungals. The relationship between the fungal concentration and meteorological parameters was analyzed using multiple regression and Pearson correlation. The wet season had the highest number of fungal spores (5318.88 CFU m− 3 ) compared to the dry season (1929.58 CFU m− 3 ). Consequently, we identified 502 isolates across two seasons; 16 genera and 38 species comprising Ascomycota 426(89.31%), Basidiomycota 21(4.40%), Deuteromycota 17(3.56%), Muromycota 7(1.47%) and Zycomycota 6(1.26%). The most isolated fungal species included Candida (17.13%), followed by Penicillium 66(13.15%), Fusarium 62(12.35%), Aspergillus 61(12.15%), and, Cladosporium 60(11.95%). Temperature, humidity, and windspeed significantly affected airborne fungal concentration (p=.000), (p=.0280), and (p=.000), respectively. Pearson correlation analysis showed that temperature negatively correlated with the fungal concentration significantly (p=.000). Humidity had significant positive correlation with fungal concentration (p=.001) while the wind speed negatively correlated with the fungal concentration significantly (p=.000). A total of 33/58(56.89%) fungal displayed growth at 37°C. Extracellular proteases production was evident in 15/58(25.86%) isolates. After hemolysis, 12(20.69%) isolates were capable of beta (complete) hemolysis, 39(67.24%) showed alpha (partial) hemolysis and 7(12.07%) displayed gamma or no hemolysis. Among the characterized isolates, most of the airborne fungal isolates tested were susceptible to voriconazole and itraconazole. However, resistance against fluconazole was observed among 4/18 (22.22%) of all the isolates tested. Therefore, our findings provide insightful information about the concentration of airborne fungi in relation to human activities, location in relation to weather patterns in Nairobi. It highlights the significance of fungal spore pollution antifungal resistance and their significance in the burden of respiratory conditions and climate changeItem Phytochemical and Elemental Composition, Ameliorative Potential and Safety of Aqueous Extracts of Selected Medicinal Plants against Pyrexia, Inflammation and Pain(Kenyatta University, 2025-10) Chumba, Careen IhazanoPrunus africana and Melia azedarach are traditionally used in Kakamega County, Kenya, for the management of fever, pain, and inflammation. However, their efficacy and safety remain scientifically unverified. Establishing preliminary data on these plants is important to guide further research and inform their safe use. Hence, this study’s purpose was to assess the antipyretic, anti-inflammatory and antinociceptive activity and safety of Prunus africana and Melia azedarach of aqueous leaf extracts in animal models. Fresh leaves of both plants were processed into aqueous extracts. Antipyretic activity was tested using turpentine-induced fever, while anti-inflammatory and antinociceptive effects were assessed using the formalin model. For each study, the animals were split into six groups each comprising of six animals: positive, normal and negative controls and three experimental groups for extract doses of 50, 100 and 150 mg/kg body weight administered orally. Diclofenac (15 mg/kg) served as the positive control. Acute toxicity was examined at single doses of 450-2000 mg/kg for fourteen days, while sub-acute toxicity was assessed at 150–450 mg/kg for four weeks with hematological, biochemical, and organ weight analyses. Phytochemical and mineral composition of the extracts was also determined. Both extracts demonstrated antipyretic and antinociceptive effects at all tested doses. Melia azedarach exhibited anti-inflammatory activity across doses, whereas Prunus africana lacked activity at the highest dose (150 mg/kg). Acute and sub-acute exposure produced some dose-dependent changes in body weight, relative organ weights, and hematological and biochemical parameters, though no severe toxicity was observed at the tested levels. Phytochemical analysis revealed flavonoids, phenols, alkaloids, and amino acids, while trace element analysis identified thirteen minerals in concentrations below recommended daily allowances. This study provides preliminary pharmacological and toxicological evidence supporting the traditional use of Prunus africana and Melia azedarach in managing fever, pain, and inflammation. The extracts demonstrated biological activity, though acute and sub-acute studies produced physiological changes that warrant caution. The new knowledge contributed by this study is the first experimental demonstration of both efficacy and safety profiles of aqueous leaf extracts of these plants in animal models, alongside identification of their phytochemical and mineral constituents. These findings support further mechanistic and long-term studies, including clinical evaluation, before safe therapeutic use in humans can be confirmed.Item Prevalence, Genetic Diversity and Drug Resistance of Hepatitis B Virus among Hiv-Infected Patients Attending Kisii Teaching and Referral Hospital, Kisii County, Kenya(Kenyatta University, 2025-06) Njeru, Phinehas Guthua MugoThe Hepatitis B Virus (HBV) infections continue to pose a global public health concern. The emergence of liver cirrhosis and liver cancer incidences have been increasing. HBV co-infection with HIV-1 has been on an upward trajectory, exacerbating the accompanying severe complications that include liver cirrhosis and, eventually, cancer that could lead to mortalities. Based on the shared transmission routes of HBV and HIV infections and the upsurge of incidences of infections associated with these viral infections, the need to confirm the status of disease burden in the country, particularly Kisii County, is inevitable. This study was conducted to assess the prevalence, genetic diversity, and drug resistance of HBV among HIV-infected patients at Kisii Teaching and Referral Hospital in Kisii County, Kenya. A cross-sectional study was conducted, and participants were randomly recruited. Administration of a structured questionnaire was conducted, and demographic data was acquired from 400 consenting eligible HIV-infected patients. Blood samples were drawn, and HBV infection HBsAg serostatus was confirmed. The samples confirmed to be HBsAg-positive were isolated, and viral DNA was extracted using the Qiagen Viral DNA Mini Kit, following the manufacturer's guidelines. The HBV–pol gene was then amplified and directly sequenced using the automated ABI 377 DNA sequencer (Applied Biosystem, Foster City, USA). The produced sequences were phylogenetically analysed using the Molecular Evolutionary Genetics Analysis (MEGA X version 10.4) software. The risks associated with HBV infections were statistically analyzed using two-way ANOVA. Of the 400 individuals who participated in this study, 221(55.2%) were female and 179 (44.8%) were male, all aged between 18 and 69 with an average age of 40.09 years. Majority of the study particpants (301/400) had tertiary levels of education. Age, gender and marital status were identified as significant risk factors associated with HBV infections. The overall prevalence of 11.75% (47/400) HBV-HBsAg was detected in this study. The analysis of the phylogenetic relationships of the 47 samples revealed that all sequences were of HBV genotype A. HBV nucleos(t)ide drug resistance mutations; rt1814V (1), rt180FSQ rt202L/E, I169K/L, rtV173K/G (2), rt202H/F/K (3), 180Q/S/F (3), and rt181G (4) were detected in 4 (8.5%) patients. This study, therefore, confirms that HBV genotype A is the most predominant in the country, with a low proportion of HBV-HIV co-infected patients being infected with drug-resistant strains. In addition, this study shows that in order to entirely suppress infections in co-infected individuals with HIV and HBV, dual antiviral therapy is required.Item Cardioprotective and Anti-Atherosclerotic Effects of Solanum Incanum (Linnaeus.) and Rhamnus Prinoides Extracts in Animal Models(Kenyatta University, 2025-03) Mburu, Stephen NgigiCardio protection is a mechanism that serve to protect the heart and its vessels from injury, diseases or malfunction. In Kenya, plant material extracts have been applied as a remedy in diseases such as, hepatitis, malaria etc. Nonetheless, use of these traditional remedies gathers a compendium of risks to consumers ascribed to scantiness of information on safety and inclusive of their antihyperlipidemic ability. Application 10% methanol and normal saline was used to reconstitute the materials. Mature Albino Wistar rats three months old were fed with HCHF diet (10% egg York (5.6g/bw),10% lard (5.6g/bw),0.2% cholic acid (0.112g/bw) and 0.59% propylthiouracil (0.28g/bw), for 28 days. Onset of 28th day, the rats were euthanized and bioassays done. Body weights and organ weights were recorded. For cardiotonic studies,10 New Zealand male rabbits were used. They were injected with 1000 units of heparin to avoid clot formation. Chest was opened through cardiac thoracotomy and heart placed in a dish containing Tyrode solution. This was followed by Langerdorff method using a kymograph for ionotropic and chronotropic effects. In toxicity studies, male mice of age 6-7 weeks were given oral doses of plant extract for 28 days of the experiment. On 29th day of the experiment, animals were sacrificed through cardiac puncture and blood sample collected for biochemical assays. Mice’s were ruminated with rodent pellets and water adlipitum. OECD 407 precepts were followed when conducting toxicity studies. One way ANOVA was used in data analysis. This was followed by Tukey as post hoc and statistical significance at P<0. 05.Both plant extracts exhibited positive ionotropic and negative chronotropic effects. R. prinoides extracts had significant reduction on total percent changes of the heart rate. Significance reduction on low density lipoproteins and total cholesterol was exhibited by both plant extracts, following a high cholesterol high fat diet (HCHF). Total body weights were significantly reduced. Extracts of S. incanum showed presence of saponins, alkaloids, glycosides, flavonoids, terpenoids, steroids and phenolics. Extracts of R. prinoides displayed presence of phenolics, glycosides, terpenoids, alkaloids steroids and saponins. Further investigation should be done to quantify the number of glycosides present in both plant extractsItem Phytochemical Profile, in Silico Molecular Docking Analysis and Anti-Cervical Cancer Effects of Rhamnus Prinoides and Grewia Villosa Extracts(Kenyatta University, 2025-07) Kamau, Sally WambuiGlobally, cancer is the biggest cause of illness and mortality. Cancer comes second in prevalence in non-communicable disease in Kenya, after cardiovascular diseases. Cervical cancer is the leading cause of deaths in Kenya, resulting in as much as 11% of all cancer-related deaths. Presently there are several ways to treat cervical cancer: hysterectomy, radiation therapy, and chemotherapy. Chemotherapy is the most often utilized treatment because in Kenya, cervical cancer is typically diagnosed in its advanced stages. Although effective, chemotherapy is plagued by a myriad of challenges including severe side effects that greatly diminish the quality of living for the affected patients, the prohibitive cost of medical treatment and development of chemo-resistance to the chemotherapeutic drugs. Plant derived products are a feasible alternative in alleviating some of the challenges facing chemotherapy, especially in cervical cancer cases. Historically, Rhamnus prinoides and Grewia villosa plants have been utilized to cure and manage cancer and inflammatory illnesses. This study was undertaken to evaluate the phytochemical profile, the selective anti-proliferative activity of the extracts from R. prinoides and G. villosa root barks and their effects in limiting cell migration in vitro. In accordance with standard procedures, the 3- (4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium (MTT) method was utilized to determine the anti-proliferative effects of the extracts in vitro, the in vitro scratch assay was used to determine the effects of the extracts in limiting cervical cancer cell migration while gas chromatography/mass spectrometry analysis was employed to identify extract specific compounds. The probable targets for the compounds found in the active extracts were identified using a variety of online databases and applications, and Pyrx software was utilized for molecular docking. R. prinoides ethyl acetate extract exhibited the most anti-proliferative effect having an IC50 value of 77.87 µg/ml while G. villosa ethyl acetate extract having an IC50 value of 100.70 µg/ml, similarly, exhibited the highest anti-proliferative effect among the extracts from G. villosa. The ethyl acetate extracts of both plants also had the highest selectivity indices with the R. prinoides extract having 4.40 and the G. villosa extract having a selectivity index of 2.48. The ethyl acetate extracts were also shown to inhibit cell migration in vitro with the IC50 concentration having the highest inhibitory effect after 48 hours. Phenols, triterpenoids, hydrocarbons, alkaloids, fatty acid esters were identified in the crude, hexane and ethyl acetate extracts of R. prinoides and G. villosa. 2,6,10-trimethyltetradecane and Benzene_1-methylundecyl compounds in the ethyl acetate extract of G. villosa and squalene, 3,3a,6,6-tetramethyl-4,5,5a,7,8,9-hexahydro-1H-cyclopenta[i]indene and Olean-12-en-3.beta.-ol,acetate compounds in the ethyl acetate extract of R. prinoides interacted with various oncogenic proteins with high binding affinity energies (<-4 kcal/mol). Network pharmacological analysis revealed that the compounds interacted with various proteins from key oncogenic pathways including the PI3K/Akt signaling pathway, carbon pathways in cancer and the EGFR tyrosine kinase resistance pathway. The ethyl acetate extracts of both plants upregulated TP53 mRNA levels while concurrently downregulating EGFR, ERBB2, and AKT1 mRNA levels. Additionally, the ethyl acetate extract of R. prinoides upregulated Bax mRNA levels while downregulating Bcl-2 and NF-kB mRNA levels, while the ethyl acetate extract of G. villosa upregulated Caspase 3 levels. In conclusion, the results from this study demonstrate the potential of Grewia villosa and Rhamnus prinoides extracts against cervical cancer in vitro and lay a solid foundation into further studies using the plant extracts for the development of drugs in cervical cancer therapy.Item Bioethanol Production by Saccharomyces Cerevisiae Using Lignocellulose Substrates Saccharified by Fungal Isolates from Karura Forest Reserve, Nairobi County, Kenya(Kenyatta University, 2025-01) Kamande, Stephen MwanikiLignocellulose from plant biomass is the most available organic compound in nature that can be used by the microbes for the cellulases production, reducing sugars and bioethanol. However, its recalcitrant to hydrolysis and use of lignocellulolytic enzymes to convert this plant biomass into fermentable sugars and for biofuel production is paramount. Push for clean environment and renewable energy is health concerns emanating from fossil fuels The main goal of the study was to to investigate bioethanol production by saccharomyces cerevisiae using lignocellulose substrates saccharified by fungal isolates from karura forest reserve, nairobi county, kenya. A total of 20 of fungal samples were obtained from Karura forest reserve growing on decaying biomass based on their morphological variation. Six fungi from collected sample were selected after screening using 1% CMC- congo red agar for cellulolytic activities based on zonal inhibition and the isolates selected for the study. Characterization by molecular technique (ITS1 and ITS4 primers) was used and biological sequences analyzed using BLAST algorim and MEGA II software to identify the six isolates, as Xylaria sp. km01, Nemania sp. km02, Xylaria sp. km03, Cyathus sp. KM04, Podoscypha bolleana km05 and Podoscypha petalodes km06. The phylogenetical analysis revealed divergence of isolated fungi and classified them as either ascomycota or basidiomycota. The six isolates were cultured for cellulases production and enzymes used for saccharification under SSF process. Data obtained were recorded in triplicates and statistically analyzed using one-way ANOVA at P ≤ 0.05 significant level on R software. Any significant differences in the factors affecting enzyme and ethanol production was determined by Tukey's HSD Post Hoc test. Effect of time of incubation was investigated and maize cobs substrate produced the highest cellulase activity. Xylaria sp.km01 recorded the maximum FPase activity at 16.7±0.34 IU/ml on the 9th day of incubation. Xylaria sp. km03 produced the highest exoglucanase activity at 8.32±0.23 IU/ml while P. petalodes km06 produced the highest endoglucanase activity at 28.7±1.2 IU/ml on the 6th day of incubation. Podosycpha boleana km05 produced the highest β-glucosidase activity at 6468±210 IU/g on the 12th day of incubation. Effect of pretreatment on substrates was also investigated and maize cobs produced the highest cellulase activity. Xylaria sp.km01 produced the highest FPase at 20.1±1.31 IU/ml, exoglucanase activity at 9.35±0.77 IU/ml and endoglucanase activity 35.8±1.19 IU/ml while P. boleana km05 produced the highest β-glucosidase activity at 5111±101 IU/g when pretreated with 0.1M HCl at 121oc for 15 min. Saccharification and Fermentation of maize cob substrate of low and high loading concentration (4%,8%,18% and 20%). Hydrolysis by cellulase of P. petalodes km06 recorded the maximum of 10.63±0.70 g/l reducing sugars with 8%, whereas cellulase of P. bolleana km05 and Saccharomyces cerevisiae produced higher bioethanol of 37.3±0.72 g/l with 20% during fermentation period at 72 hours and 96 hours respectively. These findings show that both cellulolytic enzymes and bioethanol can be produced from local microbes using agro waste and the technology harnessed for creating income. Maize cobs, therefore performed as the best substrate for cellulases and bioethanol productionItem Isolation and Characterization of Polycyclic Aromatic Hydrocarbons-degrading Bacteria from Mangrove Habitat’s Sediments in Makupa Creek, Mombasa County, Kenya(Kenyatta University, 2025-06) Mshai, Mlaghui FlorahIn humans and animals, polycyclic aromatic hydrocarbons (PAHs) have a long and notorious history of being recognized as potent endocrine system disruptors, cancers, and mutagens. Their lipophilic nature and the unique chemical structure of fused aromatic rings allow them to disseminate swiftly throughout the environment. The biological degradation of PAHs is the natural ecosystem primary remediation mechanism, where microorganisms are essential to PAH metabolism. The objective of the study was to isolate, characterize and identify bacteria capable of degrading PAHs from sediment samples collected in a mangrove habitat. Twelve sediment samples were collected from various sections within the mangrove region of Makupa Creek, Mombasa, County. Anthracene and Naphthalene-supplemented marine agar were used to isolate the bacteria that broke down PAHs. Biochemical assays were conducted to assess the activities of amylase, oxidase, and catalase. Molecular methods to identify the isolated bacterium were achieved by amplifying the 16S rRNA followed by sequencing using dye terminator technique. BLAST and the RDP's SeqMatch technique were used to search the NCBI database using sequence data. ClustalW 1.6 program was then used to align the 16S rRNA gene sequence. Determination of isolates' evolutionary connection was achieved using a maximum likelihood algorithm on MEGA 6 software. Twenty-one of the 44 bacterial samples isolated from the sediments were viable. The isolates had anthracene and naphthalene degradation efficiencies ranging from 93.8% to 99.5% and 79.1% to 99.39%, respectively. Biochemical tests showed that all isolates were positive for the catalase test, while 90% and 95% had oxidase and amylase activity, respectively. The genomic DNA from each bacterial isolate was extracted. The bacterial universal primers 27F and 1492R were then used to amplify the 16S rRNA gene, yielding an amplicon of about 1500 bp. Compared to the other isolates, S3B01, S2A01 A, and S1A01 produced less DNA. Blast searches indicated that the isolates shared a sequence similarity index of between 81% - 100% with those of other existing taxon, 60% of which were Pseudomonas and the rest were Bacillus, Ralstonia, Enterobacter, and Exiguobacterium. Ten isolates had a similarity score of less than 97% with other species, indicating that they are novel strains. The prominence of Pseudomonas reinforces its significance in PAH degradation. Furthermore, the emergence of unclassified isolates suggests the exciting possibility of novel bacterial strains that can be targeted for developing anti-pollution agents. In conclusion Mangrove sediments from Makupa Creek, Mombasa County, harbor diverse bacteria capable of degrading PAHs, particularly naphthalene and anthracene. The enzymatic; catalase, amylase, oxidase activity of these isolates supported microbial degradation. The 16S rRNA analysis identified Pseudomonas, Bacillus, Ralstonia, Enterobacter, and Exiguobacterium spp as the key hydrocarbon-degrading genera. The presence of other genera undocumented isolates suggested the presence of potentially novel strains. There is need therefore, to develop the bacterial consortia from Makupa Creek sediments for hydrocarbon bioremediation.Item Determination of Bacterial Profiles in Preferred and Non-Preferred Oviposition Sites of Anopheles Arabiensis in Kwale County, Kenya(Kenyatta University, 2025-02) Gachoki, Daniel MuriukiMalaria remains a signifianct global health challenge, with Africa bearing a disproportionate burden. In Kenya, Anopheles arabiensis has emerged as a key malaria vector, particularly in coastal regions, following shifts in vector dynamics due to control measures. While bacteria in oviposition sites are known to influence mosquito egg-laying choices, the precise roles of these microbial communities in attracting or repelling An. arabiensis are not fully elucidated. This study aimed to characterize physicochemical parameters and bacterial communities in preferred and non-preferred oviposition sites of An. arabiensis in Kwale County, Kenya, and to evaluate the role of these bacteria in mediating oviposition. The study had three objectives: (i) To determine the physicochemical characteristics of Anopheles arabiensis larval habitats; (ii) To identify bacterial profiles in oviposition sites of Anopheles arabiensis in malaria-endemic regions of Kwale County; and (iii) To evaluate the role of bacterial communities in attracting Anopheles arabiensis mosquitoes to oviposition sites. The study identified distinct larval habitats, with preferred sites exhibiting significantly higher An. arabiensis larval densities (M >10 larvae/dip) compared to non-preferred sites (M < 10 larvae/dip) (F (1, 84) = 740.229, p<.001). Habitat type also significantly influenced larval density (F (2, 84) = 81.246, p<.001), with rain pools supporting the highest densities (M = 33.33 larvae/dip) and proving significantly more favourable than hoofprints and swamps (p<.001 for both comparisons). Physicochemical analysis revealed significant differences: preferred sites had higher mean temperatures (M = 33.77 °C, SD = 0.85 vs. M = 31.50 °C, SD = 0.96; t(4) = 3.053, p = .038), higher electrical conductivity (M = 1289.33 µS/cm, SD = 194.74 vs. M = 542.67 µS/cm, SD = 115.98; t(4) = 5.076, p = .005), higher total dissolved solids (M = 581.67 mg/L, SD = 82.78 vs. M = 273.33 mg/L, SD = 58.38; t(4) = 5.272, p = .006), and a lower pH (M = 7.10, SD = 0.15 vs. M = 8.03, SD = 0.40; t(4) = -3.837, p = .019) compared to non-preferred sites. Bacterial populations were isolated, and 16S rRNA gene sequencing revealed distinct profiles: Enterobacter species predominated in preferred sites, while Plualibacter species were more common in non-preferred sites. Bioassays demonstrated a significant preference for bacterial isolates from preferred sites (Mann-Whitney U = 0.000, p = .003). Specifically, Enterobacter sp. strain CDB3 (from a preferred site) elicited the highest mean number of eggs (M = 126.00, SD = 11.53) and an Oviposition Actrivity Index (OAI) of 0.84. Conversely, Pluralibacter gergoviae strain PGBM32 and an uncultured bacterium clone (both from non-preferred sites) attracted no eggs (OAI = -1.00). These findings highlight that specific physicochemical conditions and associated bacterial communities, particularly Enterobacter species, significantly attract An. arabiensis for oviposition, whereas others, like certain Pluralibacter species, may act as deterrents. This research underscores the potential for developing novel, microbe-based “push-pull” strategies for sustainable malaria vector control, to control mosquito breeding behaviours. This study suggests eco-friendly bactericides can reduce mosquito egg laying by removing attractant bacteria, aiding malaria vector control in malaria-prone areas.Item Genetic Diversity of Rhizobia and Non-Rhizobial Endophytes Associated with Desmodium Species in Push-Pull Cropping Systems in Western Kenya(Kenyatta University, 2025-01) Hassan, Adan IsackDesmodium species used as companion crops in push-pull technology (PPT) are known to preserve soil biodiversity, deter pests and suppress Striga sp. weed. While the above-ground aspects of PPT have been well investigated and documented, Desmodium root nodule microorganisms remain unexplored. This study investigated the shifts in root nodule microbiome and the effect associated with soil physico-chemical properties of Desmodium incanum (AID), Desmodium intortum (GLD) and Desmodium uncinatum (SLD) used in PPT. Soil and Desmodium-root nodule samples were collected from selected PPT farms in Homabay, Siaya, Vihiga and Kisumu counties in Western Kenya. Healthy and unbroken root nodules were selected and crushed. Afterwards, gDNA was extracted, and sequenced for bacterial and fungal diversity. Soil characteristics, including micro and macronutrients, as well as soil texture, were also analysed. The study revealed that AID exhibited better physico-chemical properties as compared to GLD and SLD, particularly in pH, nitrogen, phosphorous, potassium, and organic carbon. Each Desmodium species exhibited a unique microbe composition, with a major shift in fungi communities as opposed to bacteria. Over 98% of the sequences identified belonged to Bradyrhizobium genus across all Desmodium species and locations. Within the Bradyrhizobium genus, several species were detected, namely Bradyrhizobium liaoningense, Bradyrhizobium japonicum and Phenylobacterium spp., which were more enriched in AID as compared to SLD and GLD. Enterobacter kobei, Variovorax paradoxus, Mycobacterium neoaurum and Streptomyces griseorubiginosus, were only associated with SLD, while Labrys neptuniae was only associated with GLD. Analysis of root nodule mycobiome revealed Fusarium as the most abundant fungal genus although with varying abundances across the treatments. Fusarium spp. was more enriched in both AID and SLD as compared to GLD whereas Clonostachys spp. and Fusarium sacchari were more enriched in GLD as compared to AID and SLD. Fusarium solani was more enriched in AID whereas Sistotrema spp. and Poaceascoma spp. were more enriched in SLD. Additionally, the study also identified three arbuscular mycorrhiza fungi in Desmodium root nodules namely Funneliformis geosporum, Scutellospora reticulata and Racocetra crispa which are recognized for various plant growth-promoting abilities. While a more pronounced shift was observed for fungal community compositions compared to bacteria, no significant differences were detected in alpha diversity of fungal and bacterial communities among the three Desmodium species. Similarly, beta diversity was not significantly different among the three Desmodium species (P > 0.05). Despite the shifts in metabolic pathways among the three Desmodium species, significant differences were only observed in the sequences responsible for energy biosynthesis (GLYCOLYSIS-E-D, PWY-3001 and GLUCONEO-PWY). However, energy and amino acid biosynthesis pathways were significantly higher in SLD compared to AID and GLD (P < 0.05). Therefore, it is likely that the root nodules of the three Desmodium species host comparable microbes reflecting shared symbiotic partner selection and adaptability among the three Desmodium species to the local environment. Their abundance may be useful in generating effective inocula for use in different habitats. Subsequent experiments are warranted to evaluate the impact of the microbes on general plant growth, paving the way for sustainable agricultural practices.Item Production and Characterization O Cellulolytic Enzymus Ox Fusarium Solawi, Hypoxplon Sp., Podoscypha Petalodes and Fusarium Oxpsporium 1solated from Decaying Tree Trunks(Kenyatta University, 2023-03) Kioko, Emice MinooLignocellulosic biomass such as agro-waste is a geographically abundant source of renewable energy, showing enormous potential to contribute to escalating energy demands. Improving the industrial economics of cellulase production remains a significant hurdle, thus enhancing the yield of cellulase production and the catalytic efficiency of cellulases is the key targets for research and development. The present work focused on analysis of fungi for cellulase activity and studied the effect of pre-treatment and nitrogen sources on the fermentation process of said fungi. Fungi were collected from Kenyatta University environs and Congo red was used to select for significant biomass degrading fungi colonies. The cultures obtained were used for identification of the fungi via molecular techniques and were found to be Fusarium solani, Hypoxylon sp., Podoscypha petalodes and Fusarium oxysporam. SSF was carried out using three substrates; rice husks, Sugarcane bagasse and maize cobs. Composition analysis of the substrates was conducted and Sugarcane bagasse had the highest cellulose and hemicellulose composition of the 3 substrates as well as the least lignin composition. Composition of pre-treated substrates showed that the most significant breakdown of cellulose in sugarcane bagasse, maize cobs and rice husks was recorded when the substrates were pre-treated with 0.5M HCL at 121°C for 15 minutes while the most significant breakdown of hemicellulose and lignin was observed when the substrates were pre-treated with 0.5M NaOH 121°C for 15 minutes. Nitrogen composition was also determined and showed Sugarcane bagasse and maize cobs had comparably high nitrogen levels while rice husks had the least amount of nitrogen. The substrates were divided to three; untreated, pre-treated -and supplemented with nitrogen sources. For the untreated, the substrates were used as they were. For the pre-treated, the substrates were exposed to either acidic or alkaline pH at varying temperatures. For the nitrogen sources, the substrates were supplemented with four different nitrogen sources. The obtained crude enzyme extracts were then used to assay for cellulase enzyme activity. The selected fungi were seen to have varying levels of cellulase activity under different conditions with Fusarium solani and Hypoxylon sp. having higher enzyme production than Podoscypha petalodes and Fusarium oxysporum. The 4 fungi had highest enzyme production on different days with sugarcane bagasse had maximum Fpase, endoglucanase and exoglucanase activities were observed mainly on the 3¢ and 6™ day of incubation while maize cobs and rice husks enzyme activity peaks were from the 12* to the 18™ days of incubation. B- glucosidase consistently peaked from the 12* to the 18 day for all the fungi. Sugarcane bagasse, maize cobs and rice husks pre-treated with 0.5M NaOH produced the highest amount of Fpase, endoglucanase and exoglucanase at 121°C for 15 minutes at 15 psi. Pre-treatment of the substrates with 0.5M HCI did not elicit high enzyme production except for p-glucosidase. - glucosidase production where the substrates were pre-treated with 0.5M HCI favored mild temperatures for prolonged periods 90°C for 2 hours conditions over 121°C for 15 minutes at 15 psi conditions. Nitrogen supplementation had an effect on cellulase activities of the 4 fungi. Organic nitrogen sources were seen to elicit higher cellulase activities compared with inorganic sources. Organic nitrogen sources had the highest cellulase production with Yeast extract being in the lead followed closely by Urea then peptone. Ammonium nitrate had the lowest cellulase production across the board. Of the three substrates used, Sugarcane bagasse consistently elicited the highest amount of cellulase enzymes by the four fungi selected followed by maize cobs while rice husks performed the poorest.Item Molecular Characterization of African Bush Mango (Irvingia Species) Using Diversity Arrays Technology(Kenyatta University, 2023-05) Jepkemboi , SylviaIr\:ingiu is a genus of trees in the Irvingiaceae family endemic to West Africa, Central Al and Southeast Asia. Two closely related species; Irvingia gabonensis and (: vingia wombolu are indigenous to West and Central Afiica and are of high economic importance owing to their valuable kernels. They grow wild in tropical forests and are also -planlcd in agroforestry systems as windbreaks near coffee plantations. The two species are commonly referred to as bush mango which have several uses in various fields such as, traditional medicine, drug adjuncts, weight loss, cloth dye, food, cosmetics, timber and firewood. Local communities consume bush mango kernels with their day-to-day food and also trade them in local and international markets. This has led to massive fruit collection and subsequent decline in regeneration leading to potential loss of genetic diversity. Conservation of these species is imperative in order to avoid genetic erosion in the wild and to maintain a sustainable use in agroforestry. The main objective of this study was to evaluate the genetic diversity and population structure of Irvingia species; I gabonensis, I. wombolu and I. robur using single nucleotide polymorphisms (SNPs) markers of accessions from Nigeria, Cameroon and Gabon held at the Word Agroforestry (International Center for Research in Agroforestry, ICRAF) field genebanks. Diversity arrays technology with sequencing (DArTseq) was used to discover SNPs in DNA samples representing 340 Irvingia accessions. The SNPs were used to determine the measures of genetic diversity, analysis of molecular variance (AMOVA) and population structure using various software; GenAlEx, Arlequin, MSA, PHYLIP, and STRUCTURE. 3,170 SNPs revealed a relatively low genetic diversity in accessions held at the ICRAF genebank as shown by the gene diversity (He = 0.24) and proportion of polymorphic loci (P = 63.28%). Populations from Cameroon and Nigeria had the highest genetic diversity than Gabon. AMOVA indicated that much of the genetic variation was preserved within individuals (70%) while low variations existed among individuals and among populations, 19% and 11% respectively. Cluster analyses by STRUCTURE and Neighbor Joining tree showed a close relationship of I gabonensis accessions from Cameroon with Nigeria and Gabon. Nigerian and Gabonese . gabonensis accessions were rarely clustered together, suggesting differentiation by evolution. Most I wombolu and I robur accessions clustered separately from I. gabonensis although some 1. wom_bvlu were mixed with /, gabonensis accessions thus showing some extent of species delineation. Cluster analyses were consistent with Principal coordinates analysis (PCoA). Collection of more seeds from natural forests of Cameroon and Nigeria should be considered for the enrichment of genetic diversity of current collections at ICRAF genebanks. The wider geographic range of bush mango should also be represented in the genebanlg to capture a broader genotypic diversity. DArTseq basec! SNPs are suitable for‘ genetic dlvers_uy analysis in /rvingia, and the highly polymorphic markers can be'l‘\sed in future breeding studies of bush mango for nutrition, yield and environmental resilience.Item Characterization of Circulating Hepatitis B Virus Genotypes among Inmates and Low Risk Voluntary Blood Donors in Garissa County, Kenya(Kenyatta University, 2023-12) Odallo, Vincent BahatiHepatitis B virus (HBV) infection is a life-threatening infection that attacks the liver and can cause both acute and chronic disease. This creates a high risk of death from cirrhosis and liver cancer. Hepatitis B infection poses a major health concern globally. It is estimated that in 2019, about 296 million people had been chronically infected with HBV globally and about 820, 000 deaths from hepatocellular carcinoma and cirrhosis were reported. In Kenya, HBV prevalence stands at chronic states of intermediate range (5-7%) and high (>8%) with regional variations. Garissa County carries a high HBV infection risk with a reported prevalence of 14.1% in pregnant women attending antenatal care (ANC) clinics. This study sought to determine the seroprevalence and circulating Hepatitis B virus genotypes among the prisoners and compare it with that of the surrounding general population at Garissa County Referral Hospital in Garissa, Kenya. A total of 130 in-mates and 130 voluntary blood donors were randomly sampled in this study and a questionnaire used to collect data on their socio-demographic characteristics. Blood was then collected in plain vacutainers and the resulting serum tested for Hepatitis B surface antigen (HBsAg) using a rapid test strip. HBV DNA was then extracted from the serum and a 930bp region of the overlapping HBV P/S gene amplified and sequenced using Sanger method. Logistic regression was used to evaluate socio-demographic factors associated with HBV seropositivity. Resulting HBV DNA sequences were manually edited, assembled into contigs and then aligned. Genotype identity of the aligned sequences was initially made using the Geno2pheno [hbv] 2.0 online data base. The aligned sequences from this study and genotype specific sequences in Genbank were then used to infer phylogenetic relationships of the local strains. The Geno2pheno [hbv] 2.0 online data base was further used to identify mutations in the samples associated with diagnostic failure and vaccine failure (in the S gene) and antiviral resistance (in the P gene). Majority of the study participants were males (86.9% among inmates and 95.4% among blood donors. Majority (76.2%) of the in-mates and of the donors (83.1%) were aged between 20-40 years while majority (51.4 % of the donors and 81.5% of in mates) had only a primary school level of education. HBV seroprevalence was significantly higher among in-mates compared to blood donors. Out of the total number of in-mates tested, 7 (5.4%) were HBYV seropositive. Conversely, among blood donors 4 (3.1 %) were seropositive. There was a significant association between HBV seropositivity and gender among both the blood donors and inmates. Out of the 22 HBV-DNA positive samples, genotype D was the most prevalent among both the in-mates and blood donors (81.8%). Genotype A sub-genotype Al was only detected among the in-mate population (18.2%). All the genotype D sequences were found to be either D/A or D/E recombinants. HBsAg escape mutations associated with diagnostic failure were noted among both study populations. As a pioneer study on HBV in Kenyan prisons, the current study confirms the categorization of in-mates as HBV high risk populations. The dominance of HBV genotype D is a novel finding as studies in other regions of the country have identified genotype A as the most prevalent. To control spread of HBV infection, serological testing should be followed up with PCR testing methods to avoid diagnostic failure. Further, mutation analysis should be considered before initiating treatment of HBV infection to curb antiviral resistance.Item Antibacterial, Antioxidant, Phytochemical Profile and Toxicological Effects of Aqueous Extract of Rhaphiolepis Bibas (Lour.)(Kenyatta University, 2023-05) Waweru, Kariuki IbrahimAbstract