Browsing by Author "Maingi, John"

Now showing 1 - 8 of 8
  • Thumbnail Image
    Item
    Analysis of the Effects of Di-Electric Heating on Common Food Bacterial Pathogens: Evaluation Based on Antibiotic Susceptibility and Infective Doses
    (2013-08) Okemo, P. O.; Luvanda, M. K.; Maingi, John; Yang, E.
    In this study, various food samples (n=73) artificially infected by food borne disease pathogens ( Escherichia coli,Staphylococcus aureus, Shigella flexneri and Salmonellaenterica spp. paratyphi) were exposed to microwave radiation at different powers (P-00, P-20, P-40, P-60, P-80) and time periods (2 min, 4 min, 6 min, 8 min).The degree of inactivation was estimated by measuring the colony forming units formed in culture before and after exposure of samples to radiation. The data showed that microwave radiation produced a 1-2 log reduction when infected food samples were processed. Initial seeded bacterial numbers (>3.0 x 104) were reduced significantly (P<0.05). The most effective power-time combination for bacteria inactivation was 8 minutes at P-80 (1180W) where bacteria numbers were very low (<1.0 x 103); whereas the least effective power-time combination for bacteria inactivation was 2 minutes at P-20 (295W) where bacteria numbers remained at (>3.0 x 104). The study shows that microwave radiation reduces infective doses of bacteria but does not have any significant effect on their antibiotic susceptibility patterns.
  • Thumbnail Image
    Item
    Antimicrobial susceptibility patterns of bacteria associated with upper respiratory tract infections in Kitui, Kenya
    (2018-01) Mutinda, Josphat; Maingi, John; Kebira, Anthony
    Background:This study aimed at determining the prevalence of bacterial agents causing upper respiratory tract infections and their susceptibility patterns to commonly used antibiotics among outpatients in Kitui District Hospital. Methods: A total of 237 throat swabs were collected between November, 2012 to April, 2013 and innoculated onto Blood agar, MacCkonkey agar and Chocolate agar then incubated at 37 oC for 24 hours. Colony morphology and standard biochemical tests were performed for identification and confirmation of the isolates based on their Gram staining and cultural characteristics. Antimicrobial sensitivity patterns of the bacteria to antibiotics was determined by Kirby-Bauer disc diffusion technique. P values of _ 0.05 were considered to have clinical and epidemiological significance. Results: Pathogens were isolated in 95.4 % of the samples collected’ out of this, 5% were mixed cultures involving Candia albicans and either viridans group streptococci or Staphylococcus aureus. Bacteria isolated were S. aureus with the highest prevalence (44.3%), followed by viridans group streptococci (32.5 %) and Streptococcus pyogenes (13.5%). Resistance of bacterial pathogens to antibiotics in Kitui district hospital was highest in viridians group streptococci (48.2 %) followed by Staphylococcus aureus (40.5%) while Streptococcus pyogenes had the least resistance (28.1 %) and there were no cases of multi-drug resistance. Conclusion: The rate of antibiotic resistance was significantly high and proper interventions should be put in place by the relevant government ministry to prevent these infections and their complications.
  • Thumbnail Image
    Item
    Effect of trichoderma asperellum on growth of rhizobium leguminosarum in vitro
    (2016) Kamau, Esther Waithira; Kariuki, George M.; Maingi, John
    Trichoderma asperellum has been fronted as a biocontrol agent of root-knot nematodes on tomato and French beans in Kenya. Research on the effect of T. asperellum on growth of Rhizobium species is lacking yet the two interact within the rhizosphere particularly when T. asperellum is applied as a biocontrol agent. Legume roots and Rhizobium species have symbiotic relationship resulting in biological nitrogen fixation. The plant supplies carbon for the energy-dependent reduction of nitrogen and protects the oxygen-sensitive nitrogenase enzyme. Nitrogen is an important primary nutrient element in plant physiology and is a key factor in agricultural production. Trichoderma spp. is increasingly being used as a biological control agent against soil-borne pathogens. The type of interaction between Trichoderma spp. and Rhizobium spp. could affect nodulation and the symbiotic nitrogen fixation process. In this study, the type of interaction between Trichoderma spp. and Rhizobium spp. was established by culturing them on yeast extract mannitol agar (YEMA) which was found to support the growth of both organisms. The effect of T. asperellum on growth of Rhizobium spp. was evaluated by dual culture technique. The means for the radial growth of Rhizobium spp. in presence of T. asperellum were highly significant ( p=0.00). The growth on day 3 was the highest with a mean growth of 29.93 mm followed by the growth on day 5 with a mean of 16.53 mm. There was no rhizobial growth visible on day 7. The in vitro research output indicated that T. asperellum inhibited the growth of Rhizobium spp. by 49.7 to 100 % between day 3 and day 7. The results of this study point towards an antogonistic effect of the biocontrol agent T. asperellem on the beneficial Rhizobium spp and should be further investigated.
  • Thumbnail Image
    Item
    The efficacy of some medicinal plants used locally within Transmara west, Narok County, Kenya against selected Enterobacteria and Candida
    (International Organization of Scientific Research, 2017) Nyang’au, Hesbon Omwoyo; Maingi, John; Kebira, Anthony
    The bacterial family Enterobacteriaceae and fungal genus Candida have continued to be a great challenge worldwide including resistance to antibiotics and relapse of infections mediated by them. Among these organisms, Salmonella typhi, Shigella species, Klebsiella pneumoniae and Escherichia coli strains have emerged as the most frequent cause of diarrheal illnesses which account for an annual mortality rate of 4.6 million people worldwide and many other infections. Candida albicans has been reported as a causative agent of all types of candidiasis. In the present study, the efficacy of plants commonly used plants in Transmara west, Kenya against these microbes was investigated. An ethnobotanical survey using semi-structured questionnaire was done. Plant extracts were obtained through methanolic extraction. Antimicrobial susceptibility assay was done using Kirby Bauer disk diffusion technique. Minimum inhibitory Concentration (MIC), Minimum Bactericidal Concentration (MBC) for the bacterial test stains and Minimum Fungicidal Concentration (MFC) for C. albicans were determined using microtitre broth dilution method. Phytochemical tests were done using standard procedures. The study validates the ethno-medicinal use of Pterolobium stellatum, Rhamnus prinoides, Phyllanthus urinaria, Carissa edulis, Clutia abyssinica, Clerodendrum rotundifolium, Clerodendron myricoides and Dovyalis abyssinica and recommends consideration for the use of the studied plants as possible sources of antimicrobial agents in the development of drugs for treatment of Enterobacteria and Candida related infections.
  • Thumbnail Image
    Item
    Elucidating the potential of native rhizobial isolates to Improve biological nitrogen fixation and growth of common bean and soybean in smallholder farming systems of Kenya
    (Hindawi Publishing Corporation, 2016) Ouma, Ernest Wandera; Asango, Anne Mercy; Maingi, John; Njeru, Ezekiel Mugendi
    Identification of effective indigenous rhizobia isolates would lead to development of efficient and affordable rhizobia inoculants. These can promote nitrogen fixation in smallholder farming systems of Kenya. To realize this purpose, two experiments were conducted under greenhouse conditions using two common bean cultivars; Mwezi moja (bush type) and Mwitemania (climbing type) along with soybean cultivar SB 8. In the first experiment, the common bean cultivars were treated with rhizobia inoculants including a consortium of native isolates, commercial isolate (CIAT 899), a mixture of native isolates and CIAT 899, and a control with no inoculation. After 30 days, the crop was assessed for nodulation, shoot and root dry weights, and morphological features. In the second experiment, soybean was inoculated with a consortium of native isolates, commercial inoculant (USDA 110), and a mixture of commercial and native isolates. Remarkably, the native isolates significantly (𝑝 < 0.001) increased nodulation and shoot dry weight across the two common bean varieties compared to the commercial inoculant, CIAT 899.Mixing of the native rhizobia species and commercial inoculant did not show any further increase in nodulation and shoot performance in both crops. Further field studies will ascertain the effectiveness and efficiency of the tested indigenous isolates
  • Thumbnail Image
    Item
    Genetic Characterization of Rhizosphere Bacteria that Inhabit Common Bean Nodules in Western Kenya Soils
    (OMICS International, 2017) Wekesa, Clabe; Muoma, John; Ombori, Omwoyo; Maingi, John; Okun, Daniel; Juma, Kelvin; Okoth, Patrick; Wamalwa, Emily; Kollenberg, Mario; Mauti, Eliakim
    Background: With the increasing world population, there is increasing demand for food. This has led to overuse of agricultural farms causing reduced soil fertility and accumulation of phytopathogens. Inorganic fertilizers and pesticides have been extensively used in response to these challenges. Extensive integration of inorganic fertilizers and pesticides in the farming system has contributed to soil and water pollution worsening the eutrophication in rivers lake waters. Alternative farming methods are therefore necessary to address this problem. Recent studies have found that rhizobacteria that colonize nodules of leguminous plants are capable of increasing yield and health of the tested plants. Their plant growth promoting ability depends on the rhizobacteria type, soil properties, and climatic conditions. The aim of this study, therefore, was to genetically characterize rhizobacteria that closely associate with common bean nodules by analyzing the nucleotide sequence of 16SrRNA gene. Results: The 16SrRNA gene analysis revealed that common bean nodule associated bacteria in Western Kenya soils are genetically diverse as indicated by the evolutionary genetic distances. Not even organisms in the same species had zero genetic distance though they formed independent groups on the phylogenetic tree. The isolates belonged to the genus Pseudomonas, Providencia, Rhizobia, Klebsiella, Enterobacter, Delfitia and Acinetobacter as identified through nucleotide BLAST at the NCBI GenBank database. Conclusion: Rhizobacteria that colonize common bean nodules are genetically diverse. Those found in this study may be adaptable to Western Kenya soils and further tests are required to determine their plant growth promoting efficiency.
  • Thumbnail Image
    Item
    Impact of Community Strategy Package on Uptake of Reproductive Tract Infections Health Services Among Young Street Females in the Municipality of Eldoret, Kenya
    (Elsevier, 2023) Wanyoro, Anthony; Maingi, John; Nyamari, Jackim; Ng'ang'a, Murima; Maritim, C Violet
    Background: Despite the intervention of free medical care services for street children by a dedicated clinic in Eldoret municipality, health care service of young street females (YSFs) is still deficient. The present study aimed to evaluate the impact of the community strategy package on the uptake of reproductive tract infections (RTI) health services among the target population. Materials and methods: A pre-test-post-test quasi-experimental with a qualitative and quantitative approach was applied among the YSFs aged 10–24 years. The study used structured questionnaires and key informant interviews to collect data from the respondents. Results: The study enrolled a total of 77 young street females in Eldoret municipality. A significantly higher proportion of respondents reportedly first sought treatment for RTI at a health facility after the implementation of the community strategy package (97.1%) when compared to the proportion of respondents who first sought treatment at a health facility in the pre-intervention phase (51.0%)(p＜0.001). Early seeking of treatment improved significantly after the introduction of the intervention; 72.0% and 94.1% of the respondents sought treatment early during the pre-intervention and post-intervention phase, respectively (p ¼ 0.011). Conclusion: The study recommends the adoption of the community strategy as an intervention to increase the uptake of RTIs health services and promotion of the reproductive health of young street females
  • Thumbnail Image
    Item
    Leveraging the Complex Interplay between Arbuscular Mycorrhizal Fungi, Seasonal Dynamics, and Genotypic Diversity to Optimize Maize Productivity in Semi-Arid Agroecosystems
    (Heliyon, 2024-09) Kipkorir, Koech; Koskey, Gilbert; Njeru, Ezekiel Mugendi; Maingi, John
    Maize production under low-input agricultural systems in semi-arid areas of Sub-Saharan Africa faces significant challenges, primarily stemming from the synergistic impacts of climate vari ability and suboptimal agronomic practices. Harnessing soil microbiota, particularly arbuscular mycorrhizal fungi (AMF), represents a pivotal strategy for bolstering low-input systems. However, their functional utility is contingent upon their compatibility with the prevailing environmental conditions and biotic interactions. This study examines the influence of two distinct AMF in oculants on the growth and yield attributes of diverse maize genotypes across varying seasons within semi-arid regions of Kenya. We hypothesized that AMF inoculants exhibit differential adaptability to varying environmental sites and seasons, and their interaction will enhance the provision of key ecosystem services important for maize production. Field experiments were conducted in three semi-arid Counties (Tharaka-Nithi, Embu, and Kitui) during the 2019/2020 cropping seasons. A randomized complete block design with three replications and three treat ments was adopted. Treatments consisted of Rhizatech (a commercial AMF inoculant), a con sortium of AMF isolates (Rhizophagus irregularis and Funneliformis mosseae), and a non-inoculated control. In season one, notable interaction effects were observed for both site × maize genotype (p = 0.0007) and site × AMF inoculation (p < 0.0001), whereby Duma 43 genotype had the highest yield in Embu (11.93 t ha− 1 ) and Kitui (11.76 t ha− 1 ) counties, and Rhizatech and con sortium inoculation consistently led to elevated grain yields across all three genotypes in Kitui, surpassing non-inoculated controls. AMF inoculation notably augmented phosphorus (P) uptake, with Rhizatech demonstrating a 79.7 % increase and consortium showing a 38.7 % increase in shoot P content compared to control plants in season 1. These findings highlight the complex interplay between AMF effectiveness, seasonal variations, and maize diversity. Further research is needed to elucidate the underlying mechanisms driving these seasonal shifts, allowing for opti mized AMF inoculation strategies for improved maize performance under diverse conditions.