35 research outputs found

    Population Levels of Indigenous Bradyrhizobia Nodulating Promiscuous Soybean in two Kenyan Soils of the Semi-arid and Semi-humid Agroecological Zones

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    Soybeans grown in Africa have been selected to nodulate effectively with indigenous Bradyrhizobium spp. populations since Bradyrhizobium japonicum populations are considered absent or in very low numbers in African soils. The major objective of this study was to estimate total population of Bradyrhizobia specific to soybean in two agro-ecologically different study sites, Kiboko in Makueni District, Southeast Kenya (semi-arid to arid conditions) and Kaguru in Meru District, East Kenya (semi-humid climate) . The population of the indigenous rhizobia specific to soybeans was determined using the Most Probable Number (MPN) plant infection technique. In these experiments, the total Bradyrhizobia populations, the population sizes of taxonomically defined slow-growing Bradyrhizobia specific to soybean and the population sizes of Bradyrhizobia spp. specific to tropical Glycine Cross (TGx) varieties were determined for the two study sites. Cowpea, Vigna unguiculata, cultivar Ken Kunde I was used to estimate the total Bradyrhizobia spp. population. Clark soybean, Glycine max, was used to estimate the population sizes of taxonomically defined slow-growing Bradyrhizobia spp. specific to soybean while a TGx genotype, SB12-TGx1869-31E was used to determine the population sizes of Bradyrhizobia spp. specific to TGx varieties. The results of the MPN counts indicated that the total Bradyrhizobia population in Kiboko was between 2.59x104 and 1.89x105. The population size of taxonomically defined slowgrowing Bradyrhizobia in Kiboko was between 2.59x102 and 1.89x103 cells per gram of soil sample while the approximate Bradyrhizobia population specific to TGx genotype was between 7.81x102 and 5.67x103 cells per gram of soil. In Kaguru, the approximate total Bradyrhizobia population was between 1.04x102 and 7.56x103 cells per gram of soil. The population size of taxonomically defined slow-growing Bradyrhizobia was between 1.33x102 and 9.72x102 cells per gram of soil while the approximate Bradyrhizobia population specific toTGx genotype was between 2.37x102 and 1.73x103 per gram of soil. These populations were adequate to give satisfactory results on nodulation and nitrogen fixation in the two study sites

    Analysis of small ruminants’ pastoral management practices as risk factors of peste des petits ruminants (PPR) spread in Turkana District, Kenya

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    Peste des petits ruminants (PPR) is an emerging viral disease spreading throughout Kenya and East Africa causing major losses in the small stock. This study is an attempt to evaluate small stock management practices in Turkana pastoral system, Kenya as predictors of PPR outbreaks. Information on the social practices and the occurrence of PPR outbreaks was obtained by participatory techniques. The small stock management practices, evaluated as factors, in a previous study were simultaneously analyzed with seasons and administrative divisions as the independent risk factors for the presence or absence of PPR outbreaks in 142 Adakars (villages) as the dependent variable. Analyses were carried out for the years 2009 and 2010 combined as one data set and considered as longitudinal repeated data. In the analyses, the presence or absence of PPR outbreaks was the dependent variable. Data were further analyzed separately disaggregated by season where the presence or absence of PPR outbreaks in a season was considered as the dependent variable. All analyses utilized multivariable logistical regression analyses. In the longitudinal analysis, season was the only significant factor associated with PPR outbreak. Disaggregating the data by season revealed that certain seasonal-specific livestock management activities increased the risk of reporting PPR outbreaks: (1) sharing water sources leading to social aggregation of young stock in one point (Factor 3) (odds ratio (OR) = 2.0) in season 2 (wet season) of 2009; (2) sick dams left to nurse their young kids/lambs (Factor 7) (OR=1.62) in the same season in 2010. The finding of diverse risk factors in the same seasons across years suggests temporal heterogeneity in the distribution and occurrence of the determinants of PPR in the Turkana ecosystem. The study discusses the implications of these findings on disease control

    Water-Borne Bacterial Pathogens in Surface Waters of Nairobi River and Health Implications to Communities Downstream Athi River

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    ABSTRACT The quality of surface water in Nairobi River and the adjacent river Athi was assessed to ascertain whether it meets local and international microbiological standards for safe human consumption. Standard bacteriological techniques were used to describe bacteria content from water samples collected from the two confluent sources. The waters were highly contaminated with human pathogenic bacteria. The most dominant bacteria in combined waters of the two rivers was Escherichia col

    Antimicrobial resistance genes in Salmonella and Escherichia coli isolates from chicken droppings in Nairobi, Kenya

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    Abstract Objective Increase in antimicrobial resistance is a threat to health sector globally. Surveillance on the spread and emergence of antimicrobial resistance is therefore invertible. This study investigated prevalence of Salmonella and Escherichia coli, molecularly characterized their antimicrobial resistance patterns and spread among resistant isolates from chicken droppings. Results A total of 150 chicken households were selected randomly within Nairobi and fresh chicken droppings collected. Salmonella and Escherichia coli were isolated and antimicrobial susceptibility test carried out. Beta-lactamase genes and class 1 integrons were determined among amoxicillin resistant isolates. Isolates carrying TEM gene were further subjected to (GTG)5 PCR genotyping. Of the analysed samples, 57% and 12% contained Escherichia coli and Salmonella respectively. Most of the isolates were susceptible to the tested antibiotics with exemption of 53% of the isolates that were resistant to amoxicillin. The isolates were detected with TEM (46%), CTX-M (18%) resistance genes and class 1 integrons (25%). The study reveals presence of beta-lactamase genes and class 1 integrons across Salmonella and Escherichia coli isolates from droppings of reared chicken. Therefore, the wide distribution of chicken and their fecal waste is likely to increase development of antibiotic resistance

    Banana Production Trends, Cultivar Diversity, and Tissue Culture Technologies Uptake in Kenya

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    Banana (Musa acuminate L) is the world’s most widely known and distributed fruit and is a great contributor to food security in the developing world. However, many limiting factors affect banana farming, which cut across sociodemographic factors and agronomic and management practices. The current study was carried in three counties, including Kisii, Nyamira, and Embu. The study aimed to assess agronomic practices, banana production practices (main banana cultivars, source of planting materials), market information, and awareness of tissue culture bananas. Sample size was determined using the Snedecor and Cochran formula, and data were collected using structured questionnaires, observation, and face to face interviews from 90 smallholder farmers. Data obtained were analysed using Statistical Package for Social Sciences (SPSS) version 22.0, and Microsoft Excel was used to generate tables and graphs. Results indicated that banana production in Kisii, Nyamira, and Embu were limited by several factors including pests and diseases, limited access to quality disease-free planting materials, access to extension services, especially in Kisii and Nyamira, as well as access to agrochemicals. Declining production as well as limited market access also adversely affected production in these regions. Most farmers chose cultivars according to the availability of planting materials, suitability to the region, productivity, as well as market demand. The most predominant cultivar in Kisii and Nyamira was the Ng’ombe which was planted by about 90% and 73.3% of the respondents, respectively. In Embu, the most common cultivar was Israel and was planted by 96% of the respondents. More than 50% of the farmers in Kisii, Nyamira, and Embu cited lack of awareness of tissue-cultured bananas. None of the respondents in the study sites carried out any value addition processes on bananas thus limiting exploitation of a major revenue source. There was low adoption of tissue-cultured banana cultivation with the highest recorded number of respondents growing tissue-cultured banana reported in Embu (36%), followed by Kisii (10%) and lastly Nyamira (3.3%), as well as limited knowledge of tissue culture technology in three counties with 60% of the respondents in Kisii, Nyamira, and Embu indicating limited knowledge of the tissue-cultured banana varieties. This could potentially lead to a decline in production due to the use of potentially diseased planting materials. Creating awareness with the aid of relevant authorities on the potential benefits of utilizing disease-free tissue-cultured bananas and adopting low-cost tissue culture technology will significantly boost banana production in these regions and the country as a whole. The results of this study could be used by relevant stakeholders to increase banana productivity in the study areas

    Risk factors associated with occurrence of nematodes in free range pigs in Busia District, Kenya

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    Nematode infections are a serious constraint to pig production, especially where free range pig keeping is practiced. This study investigated the epidemiology of nematodes in free range pigs in Busia District, Kenya. Three hundred and six pigs from 135 farms were sampled for faeces that were analysed for nematode eggs per gram (EPG) of faeces using the McMaster technique. The nematode eggs were also identified to genus and species based on morphology. A questionnaire on risk factors was also administered to the pig owners. The overall prevalence and mean nematode EPG were 84.2% and 2,355, respectively. The nematode eggs were identified as those belonging to Oesophagostomum spp. (75%), Strongyloides ransomi (37%), Ascaris suum (18%), Metastrongylus spp. (11%), Trichuris suis (7%) and Physocephalus sexalatus (3%). The prevalence of nematodes was positively correlated (p < 0.05) with the amount of rainfall in the division of the pigs' origin (all nematodes except S. ransomi). The prevalence of nematodes was also associated with the age of the pigs. A lower burden of nematodes was associated (p < 0.05) with a history of deworming (A. suum) and the provision of night housing (S. ransomi and Metastrongylus spp.). In conclusion, this study has provided information on nematode infections and the associated risk factors for free range pigs in Busia District, which can be used when implementing integrated control measures
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