Bio-chemistry/Bio-medical

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Characterization and classification of clay minerals for potential applications in Rugi Ward, Kenya
(African Journal of Environmental Science and Technology, 2016-11) Ombaka,Ochieng
The applications of various clayey minerals are related to their structural, physical and chemical characteristics. The physical and chemical properties of the clayey minerals dictate their utilization in the process industries and beneficiation required before usage. The study aimed at establishing the potentiality of clayey minerals from the study area, and the possibility of exploring and exploiting them in order to spur industrial development and promote economic self reliance of Kenya as a nation. The plasticity, particle size, surface area, chemical and mineralogy composition, morphological, thermal analysis and other physical properties were studied using various techniques. The clay samples composed of albite (5-16.7%), kaolinite (11.4-36.2%), microcline (15.2-35.3%), quartz (24.3-68.1%), hornblende (7.6% in samples from Ngamwa only), and other mineral impurities in small amounts. Ngamwa clayey materials consist of high impurities of chemical oxides such as TiO2, MnO, MgO and Fe2O3. Generally, quartz and iron were the major impurities present in the samples from the concerned sites. The findings shows that clayey minerals from the study area can be exploited for commercial production of ceramic products after beneficiation using low cost and environmental friendly techniques in order to reduce the levels of iron, quartz, and other impurities to acceptable levels.
Sequential Extraction as Novel Approach to Compare 12 Medicinal Plants From Kenya Regarding Their Potential to Release Chromium, Manganese, Copper, and Zinc
(Biological Trace Element Research, 2017-07-21) Mogwasi, R.; Zor, S.; Kariuki, D. K.; Getenga, M. Z.; Nischwitz, V
This study is focusing on a novel approach to screen a large number of medicinal plants from Kenya regarding their contents and availability of selected metals potentially relevant for treatment of diabetes patients. For this purpose, total levels of zinc, chromium, manganese, and copper were determined by flame atomic absorption spectrometry and inductively coupled plasma mass spectrometry as well as BCR sequential extraction to fractionate the elemental species in anti-diabetic medicinal plants collected from five natural locations in two sub counties in Nyamira County, Kenya. Solanum mauense had the highest zinc level of 123.0 ± 3.1 mg/kg while Warburgia ugandensis had the lowest level of 13.9 ± 0.4 mg/kg. The highest level of copper was in Bidens pilosa (29.0 ± 0.6 mg/kg) while the lowest was in Aloe vera (3.0 ± 0.1 mg/kg). Croton macrostachyus had the highest manganese level of 1630 ± 40 mg/kg while Clerodendrum myricoides had the lowest (80.2 ± 1.2 mg/kg). The highest level of chromium was in Solanum mauense (3.20 ± 0.06 mg/kg) while the lowest (0.04 ± 0.01 mg/kg) were in Clerodendrum myricoides and Warburgia ugandesis among the medicinal plants from Nyamira and Borabu, respectively. The levels of the elements were statistically different from that of other elements while the level of a given element was not statistically different in the medicinal plants from the different sub counties. Sequential extraction was performed to determine the solubility and thus estimate the bioavailability of the four investigated essential and potentially therapeutically relevant metals. The results showed that the easily bioavailable fraction (EBF) of chromium, manganese, zinc, and copper ranged from 6.7 to 13.8%, 4.1 to 10%, 2.4 to 10.2%, and 3.2 to 12.0% while the potentially bioavailable fraction (PBF) ranged from 50.1 to 67.6%, 32.2 to 48.7%, 23.0 to 41.1%, and 34.6 to 53.1%, respectively. Bidens pilosa, Croton macrostachyus, Ultrica dioica, and Solanum mauense medicinal plants used to treat diabetes by 80 % of the herbalists in Nyamira County were found to be rich in chromium, manganese, copper, and zinc. The EBF of zinc, manganese, and chromium constitutes adequate amounts recommended for daily intake not exceeding the ADI and delivered a low percentage of RDA when estimating daily intake during therapy from typically applied doses. The plants did not show any significant differences at p < 0.05 in terms of concentrations of the elements between the two study areas though the levels of the different elements were statistically significant. Another major observation was that high total levels of the metals in a given plant did not necessarily translate to high bioavailable levels, and hence the need to determine bioavailable form as it is the one accessible to the patient.
Establishment of Reference Ranges for Liver Biochemistry Tests in Children in Meru County, Kenya
(Biochem Anal Biochem, an open access journal, 2018-02-05) Munene, Rhoda Kainyu; Njagi ENM,; George O; Kiruki S
This study was aimed at determining the reference range values for eight liver function parameters that are routinely analyzed in the clinical chemistry laboratory of Meru Level 5 Hospital. The study was cross-sectional, population-based and carried out on the young population of ages one to seventeen years in Meru County, Kenya. A total of 768 samples were collected from the volunteers who participated in the study. Out of these, 740, comprising 360 females and 380 males that were found to be free from HIV, Hepatitis B and syphilis were used to construct the reference ranges. DRI - CHEM NX 500I Clinical Chemistry analyzer (Fujifilm, Europe) was used to analyze eight biochemical parameters. Determination of reference ranges was done in order to estimate the lower 2.5 and upper 97.5 percentiles of the distribution by use of parametric methods. The determined percentiles were considered the lower and upper reference limits respectively. Significant sex differences were observed in children reference values for total protein. Other parameters (alkaline phosphatase, gamma glutamyl transferase, direct bilirubin, total bilirubin, albumin, alanine aminotransferase, aspartate aminotransferase) did not show significant sex dependent differences. In conclusion, the findings of this study provide sex-specific reference range values for children from Meru County in Kenya. The study recommends the health care practitioners and facilities in the region under study to adopt the new reference values developed and for other regions in Kenya to carry out a similar study to determine their own
Assessment of Water Quality in Boreholes and Wells in Waa Location, Kwale County - Kenya
(Journal of Scientific and Engineering Research, 2017) Kilwake J. Wanjala; Mwakio, Tole; Musundi, Sammy
Water from boreholes and dug wells is extensively used in Kwale County, especially by rural communities living away from established market centers, where piped water is commonly available. The study aimed to assess the quality of water in boreholes and dug wells found in Waa location of Kwale County – Kenya. Selection of the boreholes and dug wells was carried out using purposive sampling and simple random sampling. All the seventy one boreholes and wells in Waa location were visited and inspected to determine their sanitary condition and functionality. Twenty eight samples of water that were collected in duplicate from 14 boreholes and dug wells (30% of total number) were analyzed for faecal coliform (Escherichia. coli), total coliform count, pH, total dissolved solids, turbidity, colour, total hardness, salinity, chloride content, electrical conductivity, total alkalinity, Ca2+ and Mg2+ using 3M PetrifilmTM method, pH meter, HACH digital titrator, Total dissolved solids/Conductivity meter, and DR 2000 (HACH) spectrophotometer at KIMAWASCO laboratory. The study revealed that 32% of the boreholes and dug wells have either permanently or temporarily failed to discharge good quality drinking water to the local community reliably. This state has been attributed to negligence from the relevant authorities and agencies in terms of water quality monitoring and low level of community involvement in the development of these water projects. The County government of Kwale and water resource providers should build the capacity of the community in water resource management, introduce desalination and water treatment plants to provide safe drinking piped water.
Isolation and Molecular Characterization of Soil Bacteria Capable of Degrading Chlorpyrifos and Diuron Pesticides
(Journal of Applied & Environmental Microbiology, 2018) Mirenga E.O,; Korir J.C,; Kimosop S.J ,; Orata, F; Getenga Z.M
The pesticides Chlorpyrifos and Diuron have been extensively used in sugarcane farming for several years in spite of their known harmful effects. The aim of this study was to isolate hlorpyrifos and Diuron- degrading bacteria from exposed agricultural soil in the Nzoia River Drainage Basin and characterize the isolated bacteria by analyzing the 16S rRNA nucleotide sequence. The isolates could be potential candidates for use in bioremediation protocols. One soil isolate was found capable of degrading Chlorpyrifos and another was found capable of degrading Diuron. 16S rRNA gene sequences of the two isolates were deposited in GenBank and assigned the Accession Numbers MG517447 and MG517448 respectively. Sequence analysis of the two isolates using BLASTN and phylogenetic analysis revealed that the isolate capable of utilizing Chlorpyrifos as the sole carbon source was Kosakonia oryzae strain Ola 51, while the isolate capable of utilizing Diuron as the sole carbon source was Pseudomonas aeruginosa strain M-1. Kosakonia oryzae strain Ola 51 and Pseudomonas aeruginosa strain M-1 are thus potential candidates for use in bioremediation protocols for soils contaminated with Chlorpyrifos and Diuron, respectively.
Salmonella enterica Serovar Typhimurium Interacts with CD209 Receptors To Promote Host Dissemination and Infection
(American Society for Microbiology, 2019-07-23) Ye, Chenglin; Li, Qiao; Li, Xinyi; Park, Chae Gyu; He, Yingxia; Zhang, Yingmiao; Wu, Bicong; Xue, Ying; Yang, Kun; Lv, Yin; Ying, Xiao-Ling; Ding, Hong-Hui; Cai, Huahua; Alkraiem, Ayman Ahmad; Njiri, Olivia; Tembo, John; Huang, Hong-Ping; Li, An-Yi; Gong, Jianping; Qin, Jichao; Cheng, Bing; We, Xiang; Sun, Ziyong; Zhang, Shu-Sheng; Zhang, Pei; Zheng, Guo-Xing; Li, Wei; Kan, Biao; Yan, Meiying; Xiding, Xiamu; Huo, Xixiang; Huo, Xixiang; Peng, Hua; Fu, Yangxin; Klena, John D.; Skurnik, Mikael; Jiang, Ling-Yu; Chen, Tie
Salmonella enterica serovar Typhimurium, a Gram-negative bacterium, can cause infectious diseases ranging from gastroenteritis to systemic dissemination and infection. However, the molecular mechanisms underlying this bacterial dissemination have yet to be elucidated. A study indicated that using the lipopolysaccharide (LPS) core as a ligand, S. Typhimurium was able to bind human dendritic cell-specific intercellular adhesion molecule-3-grabbing nonintegrin (hCD209a), an HIV receptor that promotes viral dissemination by hijacking antigen-presenting cells (APCs). In this study, we showed that S. Typhimurium interacted with CD209s, leading to the invasion of APCs and potentially the dissemination to regional lymph nodes, spleen, and liver in mice. Shielding of the exposed LPS core through the expression of O-antigen reduces dissemination and infection. Thus, we propose that similar to HIV, S. Typhimurium may also utilize APCs via interactions with CD209s as
Loss of the virulence plasmid by Shigella sonnei promotes its interactions with CD207 and CD209 receptors
(Journal of Medical Microbiology, 2021) Wu, Bi-cong; Olivia, Njiri A.; Tembo, John Mambwe; He, Ying-xia; Zhang, Ying-miao; Xue, Ying; Ye, Cheng-lin; Lv, Yin; Li, Wen-jin; Jiang, Ling-Yu; Huo, Xi-xiang; Sun, Zi-yong; Chen, Zhong-ju; Qin, Ji-chao; Li, An-yi; Park, Chae Gyu; Klena, John D.; Ding, Hong-hui; Chen, Tie
Introduction. Shigella sonnei, the cause of bacillary dysentery, belongs to Gram-negative enteropathogenic bacteria. S. sonnei contains a 210kb virulence plasmid that encodes an O-antigen gene cluster of LPSs. However, this virulence plasmid is frequently lost during replication. It is well-documented that after losing the O-antigen and becoming rough strains, the Gramnegative bacteria may express an LPS core on its surface. Previous studies have suggested that by using the LPS core, Gram-negative bacteria can interact with several C-type lectin receptors that are expressed on antigen-presenting cells (APCs). Hypothesis/Gap Statement. S. sonnei by losing the virulence plasmid may hijack APCs via the interactions of LPS-CD209/ CD207. Aim. This study aimed to investigate if the S. sonnei rough strain, by losing the virulence plasmid, interacted with APCs that express C-type lectins of human CD207, human CD209a and mouse CD209b. Methodology. SDS-PAGE silver staining was used to examine the O-antigen expression of S. sonnei WT and its rough strain. Invasion assays and inhibition assays were used to examine the ability of S. sonnei WT and its rough strain to invade APCs and investigate whether CD209 and CD207 are receptors for phagocytosis of rough S. sonnei. Animal assays were used to observe the dissemination of S. sonnei. Results. S. sonnei did not express O-antigens after losing the virulence plasmid. The S. sonnei rough strain invades with APCs, including human dendritic cells (DCs) and mouse macrophages. CD209 and CD207 are receptors for phagocytosis of rough S. sonnei. Expression of the O-antigen reduces the ability of the S. sonnei rough strain to be disseminated to mesenteric lymph nodes and spleens. Conclusion. This work demonstrated that S. sonnei rough strains – by losing the virulence plasmid – invaded APCs through interactions with CD209 and CD207 receptors.
Genetic and phenotypic diversity of microsymbionts nodulating promiscuous soybeans from diferent agro-climatic conditions
(Springer Open, 2022) Mburu, Simon W.; Koskey, Gilbert; Njeru, Ezekiel M.; Ombori, Omwoyo; Maingi, John; Kimiti, Jacinta M.
Background: Global food supply is highly dependent on feld crop production that is currently severely threatened by changing climate, poor soil quality, abiotic, and biotic stresses. For instance, one of the major challenges to sustainable crop production in most developing countries is limited nitrogen in the soil. Symbiotic nitrogen fxation of legumes such as soybean (Glycine max (L.) Merril) with rhizobia plays a crucial role in supplying nitrogen sufcient to maintain good crop productivity. Characterization of indigenous bradyrhizobia is a prerequisite in the selection and development of efective bioinoculants. In view of this, bradyrhizobia were isolated from soybean nodules in four agro-climatic zones of eastern Kenya (Embu Upper Midland Zone, Embu Lower Midland Zone, Tharaka Upper Midland Zone, and Tharaka Lower Midland Zone) using two soybean varieties (SB8 and SB126). The isolates were characterized using biochemical, morphological, and genotypic approaches. DNA fngerprinting was carried out using 16S rRNA gene and restricted by enzymes HaeIII, Msp1, and EcoRI.
Genetic and phenotypic diversity of selected Kenyan mung bean (Vigna radiata L. Wilckzek) genotypes
(Springer Open, 2021) Mwangi, J.W.; Okoth, O.R.; Kariuki, M.P.; Piero, N.M.
Background: Mung bean is a pulse crop principally grown in the tropic and subtropic parts of the world for its nutrient-rich seeds. Seven mung beans accessions from Eastern Kenya were evaluated using thirteen phenotypic traits. In addition, 10 SSR markers were used to determine their genetic diversity and population structure. This aimed at enhancing germplasm utilization for subsequent mung bean breeding programs. Results: Analysis of variance for most of the phenology traits showed significant variation, with the yield traits recording the highest. The first three principal components (PC) explained 83.4% of the overall phenotypic variation, with the highest (PC1) being due to variation of majority of the traits studied such as pod length, plant height, and seeds per pod. The dendogram revealed that the improved genotypes had common ancestry with the local landraces. The seven mung beans were also genotyped using 10 microsatellite markers, eight of which showed clear and consistent amplification profiles with scorable polymorphisms in all the studied genotypes. Genetic diversity, allele number, and polymorphic information content (PIC) were determined using powermarker (version 3.25) and phylogenetic tree constructed using DARWIN version 6.0.12. Analysis of molecular variance (AMOVA) was calculated using GenALEx version 6.5. A total of 23 alleles were detected from the seven genotypes on all the chromosomes studied with an average of 2.875 across the loci. The PIC values ranged from 0.1224 (CEDG056) to 0.5918 (CEDG092) with a mean of 0.3724. Among the markers, CEDG092 was highly informative while the rest were reasonably informative except CEDG056, which was less informative. Gene diversity ranged from 0.1836 (CEDG050) to 0.5102 (CDED088) with an average of 0.3534. The Jaccards dissimilarity matrix indicated that genotypes VC614850 and N26 had the highest level of dissimilarity while VC637245 and N26 had lowest dissimilarity index. The phylogenetic tree grouped the genotypes into three clusters as revealed by population structure analysis (K = 3), with cluster III having one unique genotype (VC6137B) only. AMOVA indicated that the highest variation (99%) was between individual genotype. In addition, marker traits association analysis revealed 18 significant associations (P < 0.05). Conclusion: These findings indicate sufficient variation among the studied genotypes that can be considered for germplasm breeding programs.
Effects of 2,4-D and Hexazinone Application on soil Dehydrogenase activity on Sugarcane Cultivated Soils in Nzoia Sugarcane Plantations, pp 361-371.
(2020-10)
Diversity of flowering plants, pollinators and microbial activity was assessed in five farms of Nzoia Sugar Company and one outgrower farm in Western Kenya. The overarching study objective was to determine differences in species diversity in the sugar farms using agrochemicals and those not using. To sample flowering plants, transects were laid along sugar farms with quadrats 20 m apart. Sweep nets captured fauna flying or attached to the flora. Microbial activities were assessed following application of 2,4 D and Hexazinone in soil from an outgrower farm (OGF) where these herbicides had not been applied before. Microbial activity expressed as formazan concentration following triphenyltetrazolium chloride (TTC) reduction in total Dehydrogenase activity (DHA) test. Results indicated that outgrower farm had higher flowering plant species richness than the sugar farms although diversity of both flowering plants and flower visitors in the sugar farms was higher. Results indicated that hexazinone significantly (p<0.05) increased microbial activity in soils to a high of 172.945 ug g-1 following 7 days incubation while 2,4-D suppressed microbial activity to less than 2 ug g-1 in first three days of incubation. From this study, it is recommended that bee pastures composed of plants frequently visited by bees should be left to grow around farms to increase pollinators and bee hotel structures for cavity nesting bees erected in agro-ecosystems. Use of pesticides on farms should be minimised and integrated weeds and pest management promoted to increase pollinators and beneficial fauna.
Phenotypic Diversity Studies on Selected Kenyan and Tanzanian Rice (Oryzasativa L) Genotypes Based on Grain and Kernel Traits
(2015) Mawia Musyoki A 1*; Wambua, Kioko F. 1; Agyirifo, Daniel 1; Nyamai, Wavinya D. 1; Matheri, Felix 1; Langat, Chemtai R. 1; Njagi, Mwenda S. 1; Arika, Arika W. 1; Gaichu, Muthee D. 1; Ngari, Ngithi L. 1; Ngugi, Piero M.1; Karau, Muriira G. 2
Phenotypic characterization of rice (Oryza sativa L.) provides useful information regarding preservation of diversity and selection of parental genotypes with superior traits in plant breeding program. The main objective of the present study was to characterize 13 selected rice genotypes from Kenya and Tanzania based on 7 grain and kernel traits. Minitab 15.0 software was used to analyze data. The 7 traits showed highly significant differences among the improved and local landraces. A dendrogram was constructed from data set of mean values of grain and kernel traits and showed two super clusters; I and II. Principal component analysis revealed that all the seven quantitative traits significantly influenced the variation in these genotypes.
Nephrotoxicity effects of Khat (Catha edulis) on mice when administered orally
(2017-03) Kimutai, Rogers; Gitonga, Godfrey
Renal problems are currently on increase worldwide. Some factors suspected to be the cause of the renal problems are drug abuse. Hence, this study investigated possible renal toxicity effect of Khat in male albino mice. Khat alkaloids were extracted from fresh Khat shoots and leaves. The Khat extract were administered orally through intubation. Accordingly, forty- five albino mice (20 – 25g) were distributed randomly into nine groups (n = 5). Negative controls (NCs) received purely distilled water. Positive controls (PCs) received indomethacin at a dosage of 2mg/Kg/day as a twice dose per day. Test groups received Khat extract administered in combination of 2ml tea, 2ml water, 2ml milk, 2ml coffee, 2ml coke, 2g patico sweet and 2g groundnut. To each test group Khat extract was administered at a dosage of 2000mg/Kg/day for four weeks. Blood samples were collected from all animals for biochemical analysis after four weeks which included the renal function tests such as serum creatinine and blood urea nitrogen levels. The histological and cytological studies were done using H&E staining technique. There was an increased level of renal biochemical markers in all albino mice serum exposed to Khat extract. There was a significant different between levels of renal biochemical enzymes biomarkers at p<0.05. There were signs of adverse effects of Khat on kidney of mice
In vivo Safety of Dichloromethane-Methanolic Extract of Allium sativum in Normal Mice.
(2017) Kariuki D. M., D. M.*; Gaichu, D. M. .; Mburu, D. N.; Ngugi, M. P.
The indiscriminate use of Allium sativum in treatment of various diseases can pose a great danger to various body functions. Assessment of the effect of the extract on haematological and biochemical parameters can be used to explain the blood, liver and kidney related functions. Sub-chronic toxicity evaluation was done by orally administering extracts dissolved in 1% DMSO, using a drenching syringe in doses of 100, 500, 1000 and 200 mg/kg body weights of extract for 28 days. The control group was given DMSO at the same frequency and period. The body weights of both treated and control rats was recorded before, during and at the end of the experiment. The results of this study showed that dichloromethane-Methanolic extract of A. sativum induced significant increase in the levels of red blood cell, haemoglobin and haematocrit across the 100, 500, 1000 and 2000 mg/kg. bw dose levels (p > 0.05). The total and differential white blood cell counts also increased significantly at all dose levels (p<0.05). The dichloromethane-Methanolic extract of A. sativum caused a significant increase in the levels of liver functions profiles across the 100, 500 and 2000 mg/kg.bw dose levels (p <0.05). Qualitative phytochemical screening confirmed the presence of various phytochemicals which included alkaloids, flavonoids, steroids, saponins, cardiac glycosides and phenolics. These phytochemicals are understood to play a major role in gene expression, erythropoietin stimulatory, thrombopoietic stimulatory, immune-stimulatory and enzyme activities. Flavonoids, cardiac glycosides and alkaloids are also responsible for the increase in the red blood cell count through their antioxidant properties. Conversely, an increase in saponins may result to a decrease in red blood cell indices. It was therefore concluded that the plant extract, subject to various stipulated assays, is safe at particular doses as indicated by changes in haematological parameters. On the other hand, the study also shows that the plant extract is not safe at high doses as indicated by change in the liver and kidney parameters which showed hepatotoxicity and nephrotoxicity respectively.
Phytochemical screening and antipyretic activities of dichloromethanemethanolic leaf and stem bark extracts of Ximenia americana in rat models
(2017-07) Gaichu, Daniel; Musyoki, Mawia A .; Gitonga, Godfrey; Ngugi, Mathew P.; Mburu, David
Introduction: In most parts of Africa, Ximenia americana is used in folklore to treat various disorders such as oedema, pain, fever, helminthiasis, diarrhoea, burns among other diseases. This study tested the antipyretic activities of dichloromethane-methanolic (DCM-MeOH) stem bark and leaf extracts of X. Americana in rats. Qualitative phytochemical screening was also done to evaluate the presence of alkaloids, flavonoids, steroids, saponins, cardiac glycosides, phenolics and terpenoids in the extract. Methods: The plant materials were collected from Mbeere North sub-county, Embu county, Kenya. Methanol and dichloromethane in the ratio of 1:1 was used to extract the active compounds. Two to three months old male Wister rats were employed for the antipyretic studies. Animals were divided into six groups of five rats each: Normal, negative, reference and three experimental groups (50, 100 and 150 mg/kg body weight). Pyrexia was induced experimentally using turpentine. The experimental groups were treated with predetermined dose quantities of prepared extracts. Aspirin was used as the reference drug. Data were analyzed using one-way analysis of variance (ANOVA). Results: The extracts from the leaves lowered rectal temperature by 0.45% to 2.11% while the stem bark extracts lowered rectal temperature in the range of 0.71% to 2.13%. Aspirin lowered the rectal temperature in the range of 0.74% and 1.67%. Qualitative phytochemical screening showed presence of alkaloids, flavonoids, saponins, cardiac glycosides, phenolics and terpenoids in the extract. Conclusion: DCM-MeOH leaf and stem bark extracts of X. Americana is effective in management of fever and therefore it can be explored as a possible bio-resource in the development of herbal antipyretic medicines.
Anti-inflammatory activities of dichloromethane-methanolic leaf and stem bark extracts of Ximenia americana in mice models
(2020) Gaichu, Daniel M.1; Nthiga, Peter M. 1; Kariuki, Duncan M. 1; Ngugi, Matthew P. 1; Mburu, David N. 1
Introduction: Ximenia americana is a highly branched shrub mainly found in tropics of Asia, Africa, New Zealand, Central and South America among others. In most parts of Africa, X. americana is used in folklore to treat various disorders such as oedema, pain, fever, helminthiasis, diarrhea and burns among others. There is no published data on anti-inflammatory activities of organic extracts of X. americana. It is against this background that this research was carried out. The study tested for the anti-inflammatory activities of dichloromethane-methanolic (DCMMeOH) leaf and stem bark extracts of X. americana in rats. Methods: The plant materials were collected from Mbeere North sub-county, Embu county, Kenya. Methanol and dichloromethane in the ratio of 1:1 was used to extract the active compounds. Five to 6 weeks old Swiss Albino mice were employed for the anti-inflammatory studies. Animals were divided into 6 groups of 5 mice each: normal, negative, reference and three experimental groups (50, 100 and 150 mg/kg body weight). Inflammation was induced experimentally using carrageenan. The experimental groups were treated with predetermined dose quantities of prepared extracts. Diclofenac was used as the reference drug. Data was analyzed using one-way analysis of variance (ANOVA). Results: The extracts from the leaves reduced hind paw circumference by between 0.91% and 16.90% while the stem bark extracts reduced hind paw circumference by between 5.84% and 29.00%. Diclofenac reduced right hind paw circumference by 1.32%-29.60%. Qualitative phytochemical screening showed presence of alkaloids, flavonoids, steroids, saponins, cardiac glycosides, phenolics and terpenoids in the extract. Conclusion: The study established that the DCM-MeOH leaf and stem bark extracts of X. americana is effective in management of inflammation and therefore it can be explored as a possible bio-resource in the development of herbal medicines.
Antibiotic resistance in the sediments of a second order stream passing through agricultural farm land: Njoro river, Kenya
(2018) Itotia, Tabitha Kavuli; Muia, Anastasia; Kiruki, S.K.; Getenga, Z.
Abstract A significant proportion of the population living along River Njoro depend on direct river use to carry out domestic activities. Antibiotic pollutants in wastes of treated farm animals that have not undergone any disinfection and sewage treatment processes pose a significant environmental health risk. The current study investigated the presence of total antibiotic resistant bacteria to a range of antibiotics used in the treatment of infectious diseases that may find their way into water and sediments in the river. This was done by culturing samples on nutrient agar media amended with various types of antibiotics. The study showed significant (P< 0.05) spatial variations in total bacteria resistant to chroramphenical, tetracycline, ampicillin and streptomycin antibiotics. Faecal pollution in river Njoro can transmit various diarrhoea pathogens as well as being a reservoir for antibiotic resistant genes that can be transmitted to consumers through water.
Occurrence of Pathogenic Bacteria Harboring Antibiotic Resistant Genes in River Njoro in Nakuru County
(2018) Itotia, T. K. 1; Muia, A. W. 2; Kiruki, S. K. 3; Getenga, Z. 3
Njoro River drains an agricultural catchment whose main livelihood activities are livestock rearing and employment in light industries. The limited quantities of piped water supplies coupled with inadequate sanitary facilities experienced in the area can contribute to the spread of antibiotic resistance from antibiotic use in agriculture and human. The objective of the current study was to isolate common waterborne enteric pathogens and test them for antibiotic resistance on some commonly used antibiotics. The organisms that were found to be resistant were also tested for the presence resistant genes. This was done by filtering known quantities of water through membrane filters and plating them on selective and differential media and these were tested for sensitivity to antibiotics. Isolates that showed antibiotic resistance were tested for the presence of tetracycline (Tet A), Sulfamethoxazole (Sul2) genes class 1 intergrase gene and SXT element resistance genes using PCR with appropriate primers. Pathogens including E. coli strains, Salmonella spp, Vibrio cholera and V. parahaemolyticus were recorded in this study. Sulfamethoxazole (Sul2) genes were detected in Klebsiella pneumonia, Klebsiella oxytoca isolates and Entero- aggregative strains of E. coli. Tetracycline (tet A) genes were detected in ETEC and EAEC pathogenic strains of E.coli. Class 1 integrase was detected in an EAEC strain. The SXT (int) element was not detected in any of the isolates tested.
Bacteriological quality and diarrhoeagenic pathogens on River Njoro and Nakuru Municipal water, Kenya
(2011-09) Kiruki, Silas 1*; Limo, Kiprop Moses1; Mwaniki, Njagi Eliud Nyaga 2; Okemo, Paul Owuor 3
Waterborne diarrhoeal pathogens are considered a re-emerging threat and are responsible for considerable morbidity and mortality, especially in developing countries. The objective of this study was to determine bacteriological quality, biochemical oxygen demand and presence of diarrhoeagenic pathogens in water samples collected from River Njoro and Nakuru Municipal water. A total of 432 samples were tested, 216 from River Njoro and 216 from Nakuru Municipal water. Bacteria indicator numbers (arithmetic mean MPN/ml) varied from 24.4 (source) to >2700.0 (midstream) for total coliforms and 3.6 (source) to 1880.0 (midsream) for faecal coliforms in River Njoro. There was a consistent increase in bacteria loading as the river flowed from the source (Nessuit) to downstream sites. The biochemical oxygen demand (BOD) ranged from 2.0 mg/L at the source of the river to 44.0 mg/L at Njoro bridge. The frequency of enteropathogenic bacteria isolated in 216 samples collected from River Njoro were; Aeromonas hydrophila 52%, Hafnia alvei 29.2%, Salmonella typhimurium 18%, Salmonella typhi 17%,Enteroaggregative Escherichia coli 9.2%, Necrotoxigenic E. coli 7.4% and Enteropathogenic E. coli 3.2%. Only H. alvei 4.6% and A. hydrophila 6.5% were isolated from Nakuru Municipality water and no enteropathogens were detected at Nakuru town centre, Kiti and Milimani estates. River Njoro has been found to be heavily contaminated with indicator bacteria, organic material and diarrhoegenic pathogens. This suggests need to educate people regarding good health practices, proper waste disposal, boiling drinking water and seek alternative sources of drinking water in the study area.
Analysis of Microbial Quality of Drinking Water in Njoro Sub-county, Kenya
(2019-10) Kirianki, Philip; Othira, J.O.; Kiruki, Silas;
Drinking water should be free of microbial pathogens so as to be regarded as potable water and safe for drinking. However, water is prone to fecal contaminants which are the sources of gastrointestinal illnesses. In Njoro Sub-county, river Njoro and rain water are the primary sources of water which also reduces during dry seasons. Other water sources include boreholes, dams, springs and wells while in other cases, the residents store water in household storage containers for future uses. In this study, various water sources and water stored in different containers in Njoro Sub-County was analyzed for its microbial quality. Various microbial parameters such as total viable colony counts (TVCC), total coliforms (TC) and fecal coliforms (FC) were evaluated by use of the culture methods. Most of the water sources were contaminated. TVCC ranged from 0.47 to 1.76 CFU/1mL in water sources and 0.48 to 2.04 CFU/1mL in domestic storage containers. TC was in the range of between 0.30 to 1.89 CFU/100mL in water sources and 0.59 to 2.47 CFU/100mL in domestic storage containers. The mean FC in water sources ranged from 0.10 to 1.68 CFU/100mL and from 0.81 CFU/100mL domestic storage containers. Therefore frequent water testing should be performed by water authorities as recommended by WHO. At households, the people should employ various water treatment methods and practice safe water handling so as to avoid gastrointestinal infections.
Establishment of Reference Ranges for Liver Biochemistry Tests in Children in Meru County, Kenya
(2018-01) Kainyu, R. M; Njagi, Eliud N. M.; George, O.; Kiruki, S.
This study was aimed at determining the reference range values for eight liver function parameters that are routinely analyzed in the clinical chemistry laboratory of Meru Level 5 Hospital. The study was cross-sectional, population-based and carried out on the young population of ages one to seventeen years in Meru County, Kenya. A total of 768 samples were collected from the volunteers who participated in the study. Out of these, 740, comprising 360 females and 380 males that were found to be free from HIV, Hepatitis B and syphilis were used to construct the reference ranges. DRI - CHEM NX 500I Clinical Chemistry analyzer (Fujifilm, Europe) was used to analyze eight biochemical parameters. Determination of reference ranges was done in order to estimate the lower 2.5 and upper 97.5 percentiles of the distribution by use of parametric methods. The determined percentiles were considered the lower and upper reference limits respectively. Significant sex differences were observed in children reference values for total protein. Other parameters (alkaline phosphatase, gamma glutamyl transferase, direct bilirubin, total bilirubin, albumin, alanine aminotransferase, aspartate aminotransferase) did not show significant sex dependent differences. In conclusion, the findings of this study provide sex-specific reference range values for children from Meru County in Kenya. The study recommends the health care practitioners and facilities in the region under study to adopt the new reference values developed and for other regions in Kenya to carry out a similar study to determine their own reference values.

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