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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 extracts.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 IbrahimAbstractItem In Vivo Activities of Methanol Extract of Solanum Incanum and Urtica Massaica on Aspirin Induced Ulcers and Gastrointestinal Motility(Kenyatta University, 2023-04) Assefa, Selamawit AtilawPeptic ulcer affects millions people around the world and the number is increasing annually. About 10-20% of these patients are diagnosed with ulcer, among these 14% !mve perforated peptic ulcer. Currently there are several anti-ulcer medications which are in use to treat ulcer. However, these drugs have adverse side effects and most of them are not affordable. Traditionally plants are used to treat ulcer; this medication is common and affordable. Solanum incanum and Urtica massaica are among the plants which are used to treat stomach related ailment in East African. However, there is no report on their effect on the gastric or duodenal ulcers as well as the gastrointestinal motility. Therefore, the main objective of this study was to establish whether the methanol extract of S. incanum root and U. massaica leaves can reverse aspirin induced ulcer in rats as well as their effect on GIT motility using isolated rabbit jejunum. Gastric hemorrhagic lesion was induced using 200 mg/kg of aspirin with 2.0 ml of 40% ethanol. The lesions were then observed using a dissecting microscope to score the damage taking in to consideration the number of the lesions per stomach. The Mohr method was carried out to measure chloride ion concentration and the pH of each stomach content was measured using pH meter. To determine the GIT activity, segments of rabbit jejunum were suspended in an organ bath connected to the kymograph. . incanum root extract and U. massaica leaves were effective against gastric mucosal lesions conferring healing through reduction of gastric acidity. The total chloride was significantly (p<0.05) reduced with administration of the doses of S. incanum extracts. The group of rats treated with Cimetidine showed significant reduction of ulcerations with 60.4 £ 4.48 which was comparable with the S. incanum and U. massaica treated groups. The root extract of S. incanum at dose 50 mg, 100 mg and 200 mg induced jejunal relaxation. All the extracts of U. massaica compared with both the vehicle and acetylcholine had no effect. Qualitative phytochemical screening of U. massaica showed presence of alkaloids, flavonoids, saponins and tannins while that of S. incanum root extract revealed presence of alkaloids, flavonoids, phenolics, glycosides, saponins, anthraquinones and tannins. The findings of this study are in support of traditional uses of these plants for management of ulcerItem Antibacterial, antioxidant activities, acute toxicity effect and phytochemical profile of ethanol extracts of selected plant species grown in Tanzania(Kenyatta University, 2023-04) Mavanza, Spora AloyceAbstractItem Production and Characterization of Cellulolytic Enzymes of Fusarium Solani, Hypoxylon Sp., Podoscypha Petalodes and Fusarium Oxysporum Isolated from Decaying Tree Trunks(Kenyatta University, 2023-03) Kioko, Emice MinooLignocellulosic biomass such as agro-waste is o geographically abundant source of renewable energy, showing enormous potential to contribule to escalating energy demands. Improving the industrial cconomics of cellulase production remains a significant hurdle, thus enhancing the yicld 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 uscd 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.SM 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 cither 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 B-glucosidase. B- 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 In Vivo Activities of Methanol Extract Of Solanum Incanum and Urtica Massaica On Aspirin Induced Ulcers And Gastrointestinal Motility(Kenyatta University, 2023-04) Assefa, Selamawit AtilawPeptic ulcer affects millions people around the world and the number is increasing annually. About 10-20% of these patients are diagnosed with ulcer, among these 14% !mve perforated peptic ulcer. Currently there are several anti-ulcer medications which are in use to treat ulcer. However, these drugs have adverse side effects and most of them are not affordable. Traditionally plants are used to treat ulcer; this medication is common and affordable. Solanum incanum and Urtica massaica are among the plants which are used to treat stomach related ailment in East African. However, there is no report on their effect on the gastric or duodenal ulcers as well as the gastrointestinal motility. Therefore, the main objective of this study was to establish whether the methanol extract of S. incanum root and U. massaica leaves can reverse aspirin induced ulcer in rats as well as their effect on GIT motility using isolated rabbit jejunum. Gastric hemorrhagic lesion was induced using 200 mg/kg of aspirin with 2.0 ml of 40% ethanol. The lesions were then observed using a dissecting microscope to score the damage taking in to consideration the number of the lesions per stomach. The Mohr method was carried out to measure chloride ion concentration and the pH of each stomach content was measured using pH meter. To determine the GIT activity, segments of rabbit jejunum were suspended in an organ bath connected to the kymograph. . incanum root extract and U. massaica leaves were effective against gastric mucosal lesions conferring healing through reduction of gastric acidity. The total chloride was significantly (p<0.05) reduced with administration of the doses of S. incanum extracts. The group of rats treated with Cimetidine showed significant reduction of ulcerations with 60.4 £ 4.48 which was comparable with the S. incanum and U. massaica treated groups. The root extract of S. incanum at dose 50 mg, 100 mg and 200 mg induced jejunal relaxation. All the extracts of U. massaica compared with both the vehicle and acetylcholine had no effect. Qualitative phytochemical screening of U. massaica showed presence of alkaloids, flavonoids, saponins and tannins while that of S. incanum root extract revealed presence of alkaloids, flavonoids, phenolics, glycosides, saponins, anthraquinones and tannins. The findings of this study are in support of traditional uses of these plants for management of ulcer.Item In Vivo Activities of Methanol Extract Of Solanum Incanum and Urtica Massaica on Aspirin Induced Ulcers and Gastrointestinal Motility(Kenyatta University, 2023-04) Assefa, Selamawit AtilawAbstractItem Determination of Cellulase Activity of Phleobiopsis Sp., Penicillium Shearii, Phacoacremonium Rubrigenum and Clonostachys Sp. Cultured On Various Plant Biomass Substrates(Kenyatta University, 2023-07) Jobita, Christine IchiaCellulose being the most accessible organic compound in nature can be broken down to produce biofuels. The enzyme that is responsible for breaking down cellulose into glucose is referred to as cellulase. This study was aimed at isolation, identification and characterization of cellulase producing fungi from a decaying tree trunk, determining the effect of incubation time on cellulase production using untreated maize cobs, rice husks and sugarcane bagasse by solid state fermentation and determining the effect of pretreated maize cobs, sugarcane bagasse and rice husks as Penicillium shearii produced the highest total cellulase activity (FPase) and exoglucanase enzymes at 36.1+£0.14IU/ml and 22.9+0.14IU/ml respectively. Phaeoacremonium rubrigenum produced the highest endoglucanase activity at by Phlebiopsis sp. at 6.17+0.041U/; h 5 sp. 6. i ‘ml and 25.1+0.611U/ml, respectivel gI}l0051dase activity Wwas - highest in Phlebiopsis sp. when maize cobs wgre ;l)::trye'atfd . This s}udy reveals that Phlebiopsis sp., Penicillium sheariiItem Toxicity of Methanolic Extracts Of Caesalpinia Volkensii(Harms) and Vernonia Lasiopus (O. Hoffman) In Rat Models(Kenyatta University, 2018-03) Ndile, Michacel MusilaItem Determination of Antibiotic Drug Residues in Cow Milk from Nyandarua, Meru, and Kiambu Counties(Kenyatta University, 2024-06) Odeny, Bonnita AluochThe cases of antimicrobial resistance (AMR) are on the rise globally and will soon be considered a global health emergency. The rise has been associated with the misuse, underuse, or overuse of antibiotics. A report released by the United Nations (UN) Ad hoc Interagency Coordinating Group on Antibiotics Resistance in 2019 revealed that around 700,000 individuals lose their lives each year because of drug-resistant microbial infections. A new UN report warns that if timely action is not taken, this number could skyrocket, reaching 10 million deaths each year by 2050. One of the contributing factors to the growing resistance to antibiotics in humans is veterinary antibiotics residues found in food of animal origin. Antibiotic residues enter the human systems when farmers do not adhere to the drug withdrawal period of the livestock after treatment, feeding livestock with antibiotics contaminated feed and excessive use of antibiotics to promote animal growth. This study was conducted to establish the presence and quantity of antibiotics drug residues in milk from cattle sampled from Nyandarua, Meru and Kiambu counties in Kenya. Milk samples were collected from selected dairy farms. To determine the sample size, 1-sample binomial proportion equation for simple random sampling of 4% desired precision and 95% confidence interval. The milk sample was received at the Kenya Bureau of Standards (KEBS) biochemical laboratories for analysis. They were screened for the presence of sulfonamides, tetracyclines, and beta-lactams using the Charm ROSA TRIO™ test. Quantification of these antibiotics was done using LC-MS/MS chromatographic method. The results showed that tetracyclines were the most prevalent, followed by beta-lactams, and sulfonamides were the least prevalent. Among the beta-lactams, dicloxacillin was the most prevalent at 9.3%, followed by penicillin and cloxacillin at 3.7% each, and nafcillin at 0.9%. Oxacillin was not detected. Among the tetracyclines, demeclocycline and tigecycline were the most prevalent at 10.3% each, followed by oxytetracycline at 9.3%, chlortetracycline at 7.5%, and doxycycline at 3.7%. Sulfaquinoxaline was the only type of sulfonamide antibiotic that was detected at 0.9%. The levels of beta-lactams in milk from Kiambu were 2.89 µg/kg for penicillin, 3.78 µg/kg for oxacillin, and 5.21 µg/kg for nafcillin. The levels in milk from Nyandarua were 11.09 µg/kg for cloxacillin and 17.16 µg/kg for dicloxacillin. The levels of tetracyclines in milk from Nyandarua were 68.77 µg/kg for oxytetracycline, 88.77 µg/kg for chlortetracycline, 106.41 µg/kg for demeclocycline, and 88. µg/kg for tigecycline. Milk from the three counties had significantly high levels of all sulfonamide antibiotics except sulfamerazine, sulfapyridine, and quinoxaline. Sulfamerazine was the only sulfonamide antibiotic that was not found in milk from all the counties. About 3% of the milk in Kiambu and Nyandarua were found to have penicillin levels above the maximum residue limit (MRL), 5% of milk in Meru had cloxacillin levels above MRL, and 10.5% of milk from Meru and Nyandarua had dicloxacillin above the MRL. These findings suggest that there is an urgent need to control the use of antibiotics in animal management in order to curb antimicrobial resistance (AMR).