Factors associated with bacterial contamination of shallow well water sources. Case Study of Juja hostels Kiambu County

The use of water from polluted water sources poses numerous public health challenges in developing countries. The ultimate purpose of any solid and liquid waste management plan is to mitigate environmental pollution; these goals become unachievable in the absence of a participatory approach to integrated waste management. This study sought to determine the extent of underground pollution of groundwater sources in Juja Town. Sanitary inspection and water quality analysis are complementary and valuable tools for characterizing and protecting water safety. The quality of the shallow wells is of great importance because it is used for consumption in Juja hostels. A two-stage cluster sampling strategy was adopted to obtain a representative sample size. Data collection involved the administration of questionnaires and field observation checklists, and E. coli levels present in the water were determined by the number of positive tubes in the table of computation of most probable number (MPN). Results showed that the predominant types of waste disposal practices observed in Juja were septic tank systems (77%) for liquid waste and private collection (87.3%) for solid waste methods. Sixty-eight per cent of the water samples were found to be positive (they exceeded the WHO (2004) maximum permissible load of 0.01/100 ml for drinking water. Three sanitary risk factors had a statistically significant effect on the dependent variable: the distance of the septic tank from the well on the level of water contamination (0.016), the liquid waste management plan (0.039), and the fitness of the water well cover on the level of water contamination (0.024). Shallow well water sources are unsuitable for use in food processing and drinking due to the presence of E. coli bacteria. The consequences of consuming contaminated water can be expensive to treat. Water from wells in Juja is contaminated with E. coli levels ranging from <3 - >1000 MPN/g, indicating fecal contamination in the area's underground water sources

Potential use of rhizobial bacteria as promoters of plant growth for increased yield in landraces of African cereal crops

Rhizobia form root nodules that fix nitrogen (N2) in symbiotic legumes. Extending the ability of these bacteria to fix N2 in non-legumes such as cereals would be a useful technology for increased crop yields among resource-poor farmers. Although some inoculation attempts have resulted in nodule formation in cereal plants, there was no evidence of N2 fixation. However, because rhizobia naturally produce molecules (auxins, cytokinins, abscicic acids, lumichrome, rhiboflavin, lipo-chito-oligosaccharides and vitamins) that promote plant growth, their colonization and infection of cereal roots would be expected to increase plant development, and grain yield. We have used light, scanning, and transmission electron microscopy to show that roots of sorghum and millet landraces from Africa were easily infected by rhizobial isolates from five unrelated legume genera. With sorghum, in particular, plant growth and phosphorus (P) uptake were significantly increased by rhizobial inoculation, suggesting that field selection of suitable rhizobia/cereal combinations could increase yields and produce fodder for livestock production

An assessment of rhizobial infection, metabolite release and growth response in agriculturally important legume and cereal crops

Includes bibliographical references (leaves 149-180).Reports on the natural and laboratory infection of cereals by rhizobium provided the impetus to embark on research using African landraces of sorghum and millet to study their interaction with rhizobia. Seven strains of root-nodule bacteria (namely Rhizobium GHR2, Bradyrhizobium japonicum Tal 110, Sinorhizobium meliloti strain 1, Rhizobium leguminosarum bv. viceae Cn6, R. leguminosarum bv. viceae strain 30, Rhizobium NGR234 and Azorhizobium caulinodans ORSS71, hereafter referred to as ""rhizobia"") that fix N2, were used to study rhizobial effects on sorghum and millet seedlings grown aseptically in Leonard jars with Yz strength Hoagland nutrient solution containing 1 mM KN03

Diagnosis of Bacterial Vaginosis and evaluation of associated factors: Comparable findings using Hay/ Ison’s and Nugent’s Scoring System

Although Nugent’s criterion is considered as the gold standard for the diagnosis of bacterial vaginosis (BV), the method requires an experienced slide reader and considerable time and skill. We compared Hay/ Ison and Amsel with Nugent’s scoring criteria to determine the prevalence and corelates for BV among women of reproductive age attending reproductive health related clinics (family planning, post-natal and sexually transmitted Infection - STI) at Mbagathi County Referral Hospital in Nairobi. Vaginal specimens were collected from 201 consenting women, presenting with or without the vaginal symptoms of vaginitis. BV was diagnosed using Hay/ Ison, Amsel and Nugent’s method while factors corelates were gathered using structured interviews. Sensitivity, specificity, and predictive values for positive and negative test were calculated for both Hay/ Ison and Amsel methods using Nugent criteria as the gold standard. Corelates for BV in this population were evaluated against the three methods. There were 66 cases (32.8%) of BV by Amsel’s method, 79 cases (39.3%) of BV by Hay/ Ison’s Criteria and 72 (35.8%) cases by the Nugent’s method. Using Nugent criteria as the gold standard, the concordant, sensitivity, specificity, positive and negative predictive values of tests were. Amsel: 77.1%, 63.9%, 84.5%, 80.7% and 69.7% respectively, and Hay/ Ison: 96.5%, 100%, 94.6%, 100% and 91.1% respectively. Evaluating the performance of Hay/ Ison test against Amsel criteria, the standard method for clinical diagnosis; offered no improvement in sensitivity 72.7%, specificity 77.1%, NPV 85.3% and PPV 60.8% when compared to Nugent’s score. Factors independently associated with BV infection included. For all the three tests: Presence of clue cells; Nugent and Hay/ Ison methods: education level, marital status and positive for whiff tests: For Nugent and Amsel criteria: Presence of vaginal discharge and for Hay/ Ison test: condom use. Attributes of socio-demographic and sexual hygiene and behavior contributes to high prevalence of BV among women in the capital city of Kenya. The Hay/ Ison’s method shows good agreement with the Nugent criteria and can be recommended as a stand-alone alternative assay to Nugent’s criteria or as a confirmatory test for BV in this population. Key words: Nugent, Amsel and Hay/ Ison method Bacterial Vaginosis, Test performance, Correlates, Women of Reproductive Age, Western Kenya

Potential use of rhizobial bacteria as promoters of plant growth for increased yield in landraces of African cereal crops

Rhizobia form root nodules that fix nitrogen (N2) in symbiotic legumes. Extending the ability of these bacteria to fix N2 in non-legumes such as cereals would be a useful technology for increased crop yields among resource-poor farmers. Although some inoculation attempts have resulted in nodule formation in cereal plants, there was no evidence of N2 fixation. However, because rhizobia naturally produce molecules (auxins, cytokinins, abscicic acids, lumichrome, rhiboflavin, lipo-chito-oligosaccharides and vitamins) that promote plant growth, their colonization and infection of cereal roots would be expected to increase plant development, and grain yield. We have used light, scanning, and transmission electron microscopy to show that roots of sorghum and millet landraces from Africa were easily infected by rhizobial isolates from five unrelated legume genera. With sorghum, in particular, plant growth and phosphorus (P) uptake were significantly increased by rhizobial inoculation, suggesting that field selection of suitable rhizobia/cereal combinations could increase yields and produce fodder for livestock production. Key Words: Rhizobia, N2 fixation, plant growth, sorghum, millet African Journal of Biotechnology Vol.3(1) 2004: 1-

Genotypes of Candida albicans from Stool Samples of HIV Sero Positive and HIV Negative Individuals in Nairobi, Kenya

Candida albicans is one of the commonest opportunistic yeast pathogens that infect both healthy and immune-compromised individuals. Currently there are five recognized genotypes of C. albicans based on the 25 rDNA gene. Different genotypes of C. albicans have been shown to differ in their virulence and susceptibility to antifungal drugs and, thus accurate identification of the infecting genotype is essential for guiding antifungal therapy. The aim of the study was to determine the genotypes of C. albicans from stool samples of HIV sero positive and HIV negative individuals and ascertain whether there is an association between HIV status and genotype distribution. A total of forty four (44) Candida albicans isolates from the stool samples of 28 HIV sero positive patients attending an outpatient HIV/AIDS management clinic and 16 HIV negative individuals attending a hospitality industry support program at Kenya Medical Research Institute (KEMRI) were genotyped using PCR primer pairs that span the transposable intron region of the 25S rDNA. Genotype A C. albicans was the most prevalent type (61.4%) followed by genotype C (11.4%) and genotype B (4.5%). Genotype B C. albicans was not isolated from HIV negative individuals. There was no significant difference in the genotype distribution of C. albicans isolates from HIV sero positive and HIV negative individuals (p=0.304). Ten (22.7%) C. albicans isolates could not be genotyped using the transposable region primers an indication of possible new genotypes. Genotype A is the most predominant C. albicans isolate both in HIV sero positive and HIV negative individuals and there is no predilation of any genotype to HIV infected. There is a possibility of new genotypes of C. albicans and sequence analysis may be warranted. Keywords: Genotypes, C. albicans, stool, HIV, Kenya

Cultural Characterization of Fungi Isolated From Oil Contaminated Soils

Application of Fungi for effective removal of hydrocarbon contamination from soil is being considered as the better option when it comes to biodegradation. Other method like physical and chemical bioremediation leads to production of toxic compounds and these methods are not cost effective. In the present study, soil samples from four different oil contaminated soils were assessed for any recovery of fungi present. Cultural characterization was used as preliminary identification using keys.  Initial isolation from the oil contaminated soil was done using potato dextrose agar.  Colonies were observed and characterized morphologically. The isolates were grown at varied temperatures and pH. Eight fungal isolates were recovered from polluted soils namely, Trichoderma viride, Trichoderma spirale, Neosartorya pseudofischeri, Neosartorya aureola, Aspergillus flavus, Aspergillus terreus, Penicillium griseofulvum and Trichoderma longibrachiatum.  The optimum growth temperature range for the eight fungi was 30oC and 40oC.  There was no growth at 50oC for all isolates except some slight growth by Aspergillus flavus.  Optimum growth at pH 7 and pH 9 and poor growth at pH 5 was noted. This study will contribute to the database on locally available fungal diversity and their ecology. Keywords.  Fungi, Bioremediation, oil contamination, biodegradatio

Prevalence of gastric mucosal interleukin-1 polymorphisms in Kenyan patients with advanced gastric cancer

Helicobacter pylori is the main cause of peptic ulceration, distal gastric adenocarcinoma, and gastric lymphoma.1 Worldwide, gastric cancer is the second most common malignancy in men and women.1 According to data from the Nairobi Cancer Registry, gastric cancer is the fourth most common malignancy in adult males and the fifth most common in adult females. However, this may not represent the true situation because of under-reporting of cases. In the development of gastric cancer, environmental factors such as smoking, diet and, in particular, infection with H. pylori are significant.1 Based on epidemiological studies, the International Agency for Research on Cancer (IARC) identified H. pylori as a ‘group 1 agent (definite carcinogen)’.2 H. pylori infection can result in decreased acid secretion with subsequent mucosal atrophy and intestinal metaplasia.1 Another precondition for mucosal atrophy is autoimmunity against parietal cells, which can mimic classic autoimmune gastritis with the presence of various autoantibodies in up to 40% of H. pylori-infected individuals.1 The occurrence of intestinal metaplasia, for which a relationship with gastric cancer is strongly suggested, has been demonstrated in approximately 60% of patients with H. pylori infection.1 The metaplasia may then progress to gastric cancer, especially to tumours of the intestinal type.1 Findings by Uemura et al. support the importance of these histological findings as a precancerous condition in H. pyloriassociated gastritis.3 However, only a minority of H. pyloriinfected patients develop gastric cancer, which underscores the notion that the host genetic background could be of critical importance. Data strongly suggest that the susceptibility to infection from H. pylori is mainly conferred by genes involved in inflammatory processes following colonisation with H. pylori.1 Chronic gastritis is characterised by the release of pro-inflammatory cytokines such as interleukin-1β (IL-1β) or tumour-necrosis factor alpha (TNFα), which are potent inhibitors of gastric acid secretion.1 Advanced-stage gastric cancer has been repeatedly associated with polymorphisms of the IL-1 gene cluster on chromosome 2q, which contains 3 related genes within a 430 kb region (IL-1A, IL-1B, and IL-1RN), encoding for IL-1α , IL-1β, and the endogenous receptor antagonist IL-1ra, respectively. It was hypothesised that genetic differences within these genes could influence the immune response against pathogens such as H. pylori and the development of premalignant histological alterations in the gastric mucosa.1 In patients with advanced-stage gastric cancer, an increased frequency of the IL-1B-31C and IL-1B-511T alleles and the uncommon IL-1B-31C/IL-1B-511T haplotype was demonstrated. In addition, the IL-1RN*2 allele and the homozygous genotype IL-1RN*2/2 were found in increased prevalence in gastric cancers.1 Subsequent studies confirmed these genetic associations.1 El-Omar et al. genotyped patients with gastric cancer according to tumour localisation (cardia v. non-cardia) and oesophageal cancers (adenocarcinomas v. squamous cell carcinomas) for various polymorphisms of genes encoding for pro- and anti-inflammatory cytokines.4 They described an increased risk for non-cardia gastric cancer in carriers of the IL-1B-511T allele, IL-1RN*2 homozygotes, carriers of the TNF-A-308A allele and the haplotype IL-10- 1082A/-819T/-592A. The cumulative risk depends on the number of high-risk alleles or genotypes per patient.4 A previous study confirmed the risk increase for development of gastric carcinoma in carriers of multiple proinflammatory genotypes.1 The alleles IL-1RN*2 and IL-1B-511T are associated with increased synthesis of the proinflammatory cytokine IL-1ß, and the allele TNFA-308A results in an increased production of the proinflammatory cytokine TNF.

INFLUENCE OF SOIL FERTILITY AMENDMENT PRACTICES ON EX-SITU UTILISATION OF INDIGENOUS ARBUSCULAR MYCORRHIZAL FUNGI AND PERFORMANCE OF MAIZE AND COMMON BEAN IN KENYAN HIGHLANDS

Arbuscular Mycorrhizal Fungi (AMF) are important in agriculture and have received attention as they are considered a part of an active and diverse soil biological community essential for increasing the sustainability of agricultural systems. However, most of agricultural practices have a negative impact on AMF association and agricultural soils are AMF impoverished. Interventions to replenish AMF include re-introduction through inoculation or manipulation of existing AMF to increase density. A major problem with inoculation is that there is possible competition with native (indigenous) AMF species. Indigenous AMF will be more adapted to the soil environment than introduced strains but with conflicting results on the effects of AMF inoculation on crop yield, more field studies for different ecological areas are required. The objective of the study was to compare the effect of inoculating crops with indigenous AMF applied applied singly or combined with other Soil Fertility Amendment Practices (SFAP) on root colonisation and subsequent performance of maize (Zea mays L.) and common bean (Phaseolus vulgaris L.). Analysis was also done on the best soil amendment practice that encourages crop colonisation by AMF. This was tested under field experiment and compared with control treatment (no soil amendment practice) and three other soil fertility amendment practices used singly or in combination with AMF; (1) MAVUNO (macro- and micronutrients and secondary nutrients) fertilizer, and (2) Calcium Ammonium Nitrate (CAN) and Triple Super Phosphate (TSP) (3) cattle manure. Maize and bean performances were determined and compared between the treatments for a period of two consecutive seasons with the experiment replicated in two benchmark sites of Embu district (highlands of central Kenya) and Taita-Taveta district (coastal highlands). Soils at Embu have high soil pH than at Taita which results in low phosphorus levels and possible micronutrients deficiencies. Even though no significant differences were observed from root colonisation by AMF with application of SFAP, significant differences were observed at the crop yield. Bean crop was more responsive to AMF inoculation than maize in terms of yield. Combination of AMF inoculant with other organic and inorganic fertilizers resulted in higher crop yield compared to AMF applied singly. Thus, utilisation of indigenous AMF species has potential to constitute an environmentally friendly method of soil fertility amendment over time to improve maize and bean production potential of small-scale holders but consideration should be done on the local soil nutrients conditions, other soil fertility amendment practices in use and the targeted crop