Browsing by Author "Wahome, Caroline Nyawira"
Item Banana Rhizosphere Microbial Diversity, Low-Cost Tissue Culture Bananas (Musa spp.) Micropropagation, Genetic Fidelity and Acclimatization Using Arbuscular Mycorrhizal Fungi(Kenyatta University, 2024-05) Wahome, Caroline NyawiraBanana production in Kenya predominantly involves smallholder farmers, yet current yields fall short of meeting local and international market demands due to constraints faced by these farmers among them being soil health and lack of clean planting materials. To address this issue, the study assessed banana cultivation practices in Kisii, Nyamira, and Embu counties, aiming to understand strengths and challenges within these regions. In this study, rhizospheric soil physicochemical properties and the diversity of microbial communities was assessed, shedding light on soil health status. Furthermore, the efficacy of a cost-effective micro-propagation technique for local banana cultivars was determined, considering contamination susceptibility and acclimatization efficacy of arbuscular mycorrhizal fungi on micropropagated banana plantlets. The study revealed a reliance on ineffective traditional propagation methods, with over 30% of the smallholder farmers facing a banana seedlings shortage. The soil physic-chemical parameters indicated signs of degradation, with low pH and nutrient deficiencies raising concerns with Embu County having the lowest pH measured (4.43). Soil metagenomic studies by NGS showed that proteobacteria and basidiomycota were the two most prevalent bacterial and fungus divisions, respectively. Based on the Shannon diversity indices, the highest bacterial and fungal community diversity was in soil samples obtained from Embu County and Kisii County respectively. To evaluate efficacy using low cost tissue culture technology, selected banana cultivars were utilized and results indicated the highest survival rate of 100 % in Kiganda, Muraru and Kienyeji banana cultivars established in BAP and IAA. Ng’ombe cultivar best responded to low cost micropropagation with the highest shoot establishment (80.5 %) and shoot emergence rates (75.5 %) producing the highest number of shoots per culture (10.61). To investigate clonal fidelity of the tissue culture plantlets Inter Simpler Sequence Repeats (ISSR) and the research demonstrated genetic homogeneity in banana seedlings generated via low cost tissue culture to the mother plant. During the micropropagation process the presence of bacterial and fungal contaminants in the tissue culture laboratory was noted with the most predominant bacterial and fungal contaminants being Microccoccus luteus and Cladosporium sp respectively. Additionally, broad-spectrum antimicrobial agents nalidixic acid (30 µg) and carbendazim+ triadimefom (0.3 µg and 0.6 µg) exhibited 100% inhibition rates against these contaminants. To determine the response of the micropropagated plantlets to AMF acclimatization, it was observed that Kiganda cultivar responded best to Rhizophagus irregularis which showed the highest recorded biomass at 0.97. There is need to emphasize collaborative efforts among various stakeholders in establishing sustainable practices. Additionally, low-cost TC is a viable tool for producing disease-free seedlings and intergrating antimicrobial agents is recommended to minimize contamination risks. Finally, the use of AMF treatment in acclimatization with further research needed for validation across different agroecological conditions. These recommendations aim to enhance productivity, sustainability, and resilience in banana farming systems.Item Contamination Levels of Groundwater, Antimicrobial Resistance Patterns, Plasmid Profiles and Chlorination Efficacy in Ongata Rongai, Kajiado North County, Kenya(2014-02-17) Wahome, Caroline Nyawira; Okemo, P. O.; Nyamache, A. K.Water contamination is a serious threat to human health especially if the contaminant is from sewage. Ground water is increasingly used as a water source in urban settlements due to limited sources of fresh surface water. This has increased the vulnerability of underground water sources to sewage and waste water contamination and therefore exposing the population to infections by various water borne pathogens such as bacteria, viruses and protozoa. Exposure to these bacteria coupled with the rising incidences of antimicrobial resistance in various bacterial species has made patient management a great challenge. Ongata Rongai was chosen for this study because it represents the current state of the impact of unregulated urbanization and population pressure on natural resources. In the present study, the microbial quality of several boreholes, used by residents of Ongata Rongai, Kajiado North County was assessed to determine their safety for human consumption and to highlight the potential occurrence of water-borne diseases. The microbiological quality of the water sources was performed using the heterotrophic plate count (HPC) method and Most Probable Number (MPN) technique, while standard culture methods were used for bacteria isolation. Efficacy of water disinfection using 1% NaOCl was also assessed. The results obtained indicated that the water quality of the boreholes was poor over the study period. Indicator organisms which include typical coliforms and fecal coliforms were present exceeding the acceptable maximum limits prescribed by the World Health Organization and the Kenya Bureau of Standards. Heterotrophic plate Count (HPC) yielded counts as high as 5.64x104 (±1.77x104) CFU’s per milliliter and there was no significant difference among the total counts (p=0.320 at p>0.05)) from the four sampling sites. The coliforms counts were as high as 1.12x102 (±8.8x101) MPN/100ml with no significance (p=0.483 at p>0.05) among the counts from the sampling sites. Numerous organisms that are potential enteric pathogens such as Vibrio sp, Salmonella sp., Shigella sp., P. aeruginosa and E. coli were isolated from the water samples. There was high incidences of resistance to many antibiotics particularly Sulfamethoxazole (98.5%), kanamycin (95.3%) and ampicillin (87.5%). The most active antibiotics were chloramphenicol with resistance level of 45.4% and streptomycin (59.4%). All the isolates responded to disinfection by 1% NaOCl although Vibrio sp. and P. aeruginosa required double the recommended dosage. Plasmid profile studies revealed that multi-drug resistant isolates did contain plasmids varying in number from 1 to 3 and also in size ranging from 3.5 kb to 11.5 kb . There was a notable relatedness among the plasmid profiles from the isolates which might be an indication that resistance to certain antibiotics might be plasmid mediated. The study indicates that water from the studied boreholes was not suitable for human consumption and may pose a serious threat to the health of consumers and therefore calls for urgent intervention. On-site treatment of water at all ground water outlets is a viable short term solution. High levels of antibiotic resistance are of concern in the management of infections caused by these organisms. Further studies are needed to identify the sources of contamination in order to curb the negative effect of contaminated water.Item Microbial quality and antibiotic resistant bacterial pathogens isolated from groundwater used by residents of Ongata Rongai, Kajiado North County, Kenya(International Formulae Group, 2014-02) Okemo, P. O.; Wahome, Caroline Nyawira; Nyamache, A. K.Groundwater represents an important source of drinking water and its quality is currently threatened by a combination of over-abstraction and microbiological and chemical contamination. Nairobi, Kenya and its environs is plagued with un-planned dwelling residential settlements, with limited potable water sources which are often contaminated by bacterial pathogens. This coupled with increased incidences of antibiotic resistance among the pathogens is alarming. This study used the MPN technique to determine indicator organisms, and the agar diffusion method to determine resistance in isolated pathogenic bacteria. The total coliforms values recorded were as high as 1.12x102 (±8.8x101) MPN/100 ml, fecal coliform loads were 8.63(±7.01) MPN/100 ml for the shopping centre. Total bacterial counts values recorded were as high as 5.64x104 (±1.77x104) CFU/ml at the shopping centre. Numerous organisms that are potential enteric pathogens such as Vibrio sp, Salmonella sp., Shigella sp., P. aeruginosa and E. coli were isolated from the water samples. There was high resistance to many antibiotics particularly sulphamoxazole (98.5%), kanamycin (95.3%) and ampicillin (87.5%). The most active antibiotics were chloramphenicol with resistance level of 45.4% and streptomycin (59.4%). The study indicates that water from the studied boreholes was not suitable for human consumption and therefore calls for urgent intervention. There is a high likelihood that congestion and lack of proper waste and waste water management is responsible for contamination of aquifers in this region.