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Dagaa fish hydrolysate (DFH) and dagaa protein hydrolysate (DPH) were prepared from dagaa using Alcalase enzyme. Proximate, mineral analysis, and potential use of DFH and DPH in microbial media wer...

To search for new alkaliphilic cellulases and to improve their efficiency on crystalline cellulose through molecular engineering Two novel cellulases, BpGH9 and BpGH48, from a Bacillus pumilus strain were identified, cloned and biochemically characterized. BpGH9 is a modular endocellulase belonging to the glycoside hydrolase 9 family (GH9), which contains a catalytic module (GH) and a carbohydrate-binding module belonging to class 3 and subclass c (CBM3c). This enzyme is extremely tolerant to high alkali pH and remains significantly active at pH 10. BpGH48 is an exocellulase, belonging to the glycoside hydrolase 48 family (GH48) and acts on the reducing end of oligo-β1,4 glucanes. A truncated form of BpGH9 and a chimeric fusion with an additional CBM3a module was constructed. The deletion of the CBM3c module results in a significant decline in the catalytic activity. However, fusion of CBM3a, although in a non native position, enhanced the activity of BpGH9 on crystalline cellulose. A new alkaliphilic endocellulase BpGH9, was cloned and engineered as a fusion protein (CBM3a-BpGH9), which led to an improved activity on crystalline cellulose.

The study was undertaken to explore the nutritive potential of cassava leaves and Azolla as supplementary source of crude protein to cattle fed on either mixed range grass hay or Bracharia Mulato II. Two experiments were carried out, the first was the determination of the biomass yield of Azolla, its relative growth rate and doubling time while the second was a feeding trial to determine the performance of small East African Shorthorned Zebu heifers of similar age and weight. The heifers (four each) were randomly assigned to six treatments in the feeding trial that ran for 16 weeks. The doubling time for Azolla was 5 days while the relative growth rate was 0.15 g/g/day. The chemical analysis indicated that Azolla is rich in crude protein (18.8%) and minerals (3.29% calcium, 2.66% potassium and 0.15% phosphorus and other minerals in trace levels). All the supplemented groups showed more weekly weight gains ranging from 0.75 to 1.11 kg per day more than the control. Overall, the treatment with Azolla or cassava showed slightly higher but insignificant increases in weight gains. Azolla and cassava leaves can therefore be considered as potential feed for livestock. Key words: Arid and range lands, cattle, doubling time, relative growth rate.

BackgroundHepatitis B is becoming a growing public health problem in Kenya. To combat the threat, HBV vaccination should be recommended, particularly for individuals who are not covered by the national immunization program. Vaccination provides sero-protection rates approaching 95% among healthy adults after completing the three-dose vaccination course, but decreases to 87% among those who receive only two doses, emphasizing the importance of completing the three-dose vaccination course. However, data on adult adherence to HBV multi-dose vaccines in Sub-Saharan Africa are limited, despite the fact that this information is critical for prevention. As a result, more research on HBV vaccine dose completion is required. The purpose of this study is to estimate the prevalence of hepatitis B virus infection among out-patient clinic attendees in Nairobi, Kenya, as well as to identify beneficiaries of free vaccination and barriers to completing the recommended vaccine doses.MethodsBetween July 30thand September 30th, 2015, 2644 outpatient clinic attendees aged ≥ 4 were recruited from three hospitals in Nairobi County, Kenya: Mama Lucy, Riruta, and Loco. Self-administered questionnaires were used to collect socio-demographic information, and blood samples were tested for hepatitis B surface antigen (HBsAg) using the KEMRI HEPCELL Rapid® (Hepatitis B Detection kit) test kit. Individuals who tested negative for HBsAg were given a free course of three doses of HBV vaccine. The vaccination register provided information on the number of doses administered.ResultsThe average age of the study population was 31.4 years (range: 4–66), with females accounting for 59.2%. 1.82% (48/2644) of the participants tested positive for HBsAg. Among the 2596 individuals eligible for vaccination, 66% (1720/2596) received at least one dose, and 51.8% (1345/2596) received all three doses. Vaccination acceptance increased with age, with older patients more likely to return for subsequent dose (OR>1 for second and third dose). Unavailability and failure to contact client were cited as significant (pConclusionThe prevalence of HBV infection among outpatient clinic attendees highlights the importance of expanding HBV immunization programs in Kenya. However, given the low vaccination completion rate, there is a need for public awareness of the vaccine’s importance in preventing HBV and HBV-related complications.

We present the draft genome sequence of Fusarium equiseti strain K3, a fungus isolated from a hexachlorocyclohexane (HCH)-contaminated soil (Kitengela, Kenya). The 37.88-Mb draft genome sequence consists of 206 contigs, 12,311 predicted protein-coding sequences, and 261 tRNA sequences. This genome sequence contributes to our understanding of fungal-bacterial interactions during hexachlorocyclohexane degradation.

Common bean (Phaseolus vulgaris L.) is a vital legume used as human food, source of cash income, feed for livestock, and it increases the fertility of soil by its ability to fix nitrogen. The aim of this research was to determine the genetic diversity and population structure of 40 common bean germplasm cultivated in Kenya, using peroxidase gene (POX)-based molecular markers. The loci analyzed showed high diversity and amplified 624 alleles, ranging from 3 to 9 on every locus, with an average of 7.20. The PIC of the POX markers varied from 0.6204 to 0.9110, with an average of 0.7677. The range of the observed heterozygosity was from 0.6667 to 0.9150 with a mean of 0.7945, while the values of the mean genetic diversity ranged from 0.3072 to 0.4425 with a mean of 0.3972. The UPGMA phenogram separated the genotypes into two main genetic clusters, and the genotypes showed no grouping by geographical origins. The highest value of genetic variation was observed between the genotypes obtained from Western, Rift valley and Central regions of Kenya. Population structure analysis grouped the germplasm into 7 gene pools and showed that the genotypes have a common genetic lineage. AMOVA revealed higher genetic diversity (99%) within population than among population (1%), and this offers a reliable base for the design of genetic improvement schemes. Results of the present study can be used in future breeding programs and for the genetic improvement in common bean.

The development of novel anti-infectives against Kinetoplastids pathogens targeting proteins is a big problem occasioned by the antigenic variation in these parasites. This is also a global concern due to the zoonosis of these parasites, as they infect both humans and animals. Therefore, we need not only to create novel antibiotics, but also to speed up the development pipeline for these antibiotics. This may be achieved by using novel drug targets for Kinetoplastids drug discovery. In this study, we focused our attention on motifs of rRNA molecules that have been created using homology modeling. The RNA is the most ambiguous biopolymer in the kinetoplatid, which carries many different functions. For instance, tRNAs, rRNAs, and mRNAs are essential for gene expression both in the pro-and eukaryotes. However, all these types of RNAs have sequences with unique 3D structures that are specific for kinetoplastids only and can be used to shut down essential biochemical processes in kinetoplastids only. All these features make RNA very potent targets for antibacterial drug development. Here, we combine in silico methods combined with both computational biology and structure prediction tools to address our hypothesis. In this study, we outline a systematic approach for identifying kinetoplastid rRNA-ligand interactions and, more specifically, techniques that can be used to identify small molecules that target particular RNA. The high-resolution optimized model structures of these kineoplastids were generated using RNA 123, where all the stereochemical conflicts were solved and energies minimized to attain the best biological qualities. The high-resolution optimized model’s structures of these kinetoplastids were generated using RNA 123 where all the stereochemical conflicts were solved and energies minimized to attain the best biological qualities. These models were further analyzed to give their docking assessment reliability. Docking strategies, virtual screening, and fishing approaches successfully recognized novel and myriad macromolecular targets for the myxobacterial natural products with high binding affinities to exploit the unmet therapeutic needs. We demonstrate a sensible exploitation of virtual screening strategies to 18S rRNA using natural products interfaced with classical maximization of their efficacy in phamacognosy strategies that are well established. Integration of these virtual screening strategies in natural products chemistry and biochemistry research will spur the development of potential interventions to these tropical neglected diseases.

The ability of many insects to thrive on wood, foliage, and detritus has stimulated an interest on the potential use of gut microbial flora of such species as a bioresource for industrial conversion of cheap cellulosic material into bioproducts. In this study, the capacity of intestinal flora from the gut of Schistocerca gregaria to degrade cellulose model compound was investigated. Two Bacillus species were isolated, their cellulose degradation capacity determined by zone clearance assay on agar plates and later identified by 16S rDNA gene sequencing. The two isolates had relatively high cellulolytic activity with ICA (Index Cellulolytic Activities) values of 1.146 ± 0.109 and 0.8442 ± 0.09203, and were identified as Bacillus safensis strain MED1 and Bacillus safensis strain CACO respectively. The 16S rDNA sequences were deposited to GenBank under accession numbers JQ 837242.1 and JQ 837243.1.

The banana aphid,Pentalonia nigronervosa, is the sole insect vector of banana bunchy top virus (BBTV), the causal agent of banana bunchy top disease. The aphid acquires and transmits BBTV while feeding on infected banana plants. RNA interference (RNAi) enables the generation of pest and disease-resistant crops, however, its effectiveness relies on the identification of pivotal gene sequences to target and silence. Acetylcholinesterase (AChE) is an essential enzyme responsible for the hydrolytic metabolism of the neurotransmitter acetylcholine in animals. In this study, the AChE gene of the banana aphid was targeted for silencing by RNAi through transgenic expression of AChE dsRNA in banana and plantain plants. The efficacy of dsRNA was first assessed using an artificial feeding assay. In vitro aphid feeding on a diet containing 7.5% sucrose, and sulfate complexes of trace metals supported aphid growth and reproduction. When AChE dsRNA was included in the diet, a dose of 500 ng/μL was lethal to the aphids. Transgenic banana cv. Cavendish Williams and plantain cvs. Gonja Manjaya and Orishele expressing AChE dsRNA were regenerated and assessed for transgene integration and copy number. When aphids were maintained on elite transgenic events, there was a 67.8%, 46.7%, and 75.6% reduction in aphid populations growing on Cavendish Williams, Gonja Manjaya, and Orishele cultivars, respectively, compared to those raised on nontransgenic control plants. These results suggest that RNAi targeting an essential aphid gene could be a useful means of reducing both aphid infestation and potentially the spread of the disease they transmit.

Jackfruit (Artocarpus heterophyllus Lam.) is an underutilized fruit tree crop in East Africa. Despite its importance for food and nutritional security, only limited information exists on the extent of genetic variability among Ugandan and Kenyan jackfruit populations. This study was aimed at analyzing the extent of genetic diversity in jackfruit germplasm from selected regions of Kenya and Uganda. A total of 30 mature fruit samples were collected randomly from three districts (Kampala, Wakiso and Mbale) in Uganda and five counties (Siaya, Kwale, Mombasa, Busia, and Murang’a) in Kenya. Genetic characterization was using six simple sequence repeat (SSR) and nine sequence-related amplified polymorphism (SRAP) markers. The results revealed that 62.50% of the loci for SSR and 82.14% for SRAP markers were polymorphic. The average polymorphism information contentwas 0.48 for SSR and 0.56 for SRAP markers. The Jaccard’s similarity coefficient ranged from 0.55 to 1.0 for SSR and from 0.33 to 0.93 for SRAP markers, indicating considerable genetic diversity among jackfruit germplasm. Based on combined SSR and SRAP data, analysis of molecular variance revealed greater genetic diversity within the populations (76%) than among the eight populations (24%). Dendrogram and principal coordinate analysis separated the germplasm into two clusters, with several intermediates. The germplasm distribution among the clusters and sub-clusters was not associated with the geographical region. The significant genetic variability existing in Ugandan and Kenyan jackfruit germplasm can be used to improve jackfruit through breeding. The substantial genetic diversity should enable jackfruit breeders to develop high-yielding varieties with improved quality traits.

Nile perch (Lates niloticus) is a major fish species in East Africa and its processing produces sufficient amounts of by-products containing significant amounts of long-chain polyunsaturated fatty acids (PUFAs). Due to the health benefits associated with PUFAs, they can be incorporated into commonly consumed foods such as yoghurt. This study is aimed at developing an omega-3-rich functional yoghurt and evaluating its quality and acceptability. Omega-3-rich fish oils were obtained from Nile perch fat pads in the presence and absence of a commercial food grade enzyme Alcalase. Recovery of omega-3-rich fish oil was done by centrifugation at 1000 × g at room temperature. The peroxide value (PV), anisidine value (AV), total oxidation (TOTOX), and free fatty acids (FFA) were some of the quality parameters investigated. Natural yoghurt (150 ml) was prepared and spiked with 3.5 g of omega-3-rich Nile perch oil. To mask the fishy flavor and taste, four different flavors were used and sensory evaluation of the yoghurt samples was performed. The liberation of Nile perch fish oil in the absence of Alcalase gave better yield (60.7% wet weight), while the use of Alcalase gave lower yields (48.3% wet weight). Assessment of the quality of the extracted fish oils showed that all parameters were within the required limits. Sensory characterization by a panel of students showed that passion and strawberry flavors were the most liked with mean values of 4.65 and 4.625, respectively. This study revealed that substantial amounts of omega-3-rich fish oil can be extracted from Nile perch fish pads in the absence of exogenous enzymes. Fortification of yoghurt with omega-3-rich Nile perch fish oils is an approach towards increasing omega-3 intake within the Kenyan population and globally.

Banana bunchy top disease (BBTD) is one of the world's most destructive viral diseases of banana and plantain, causing up to 100% yield loss in severe cases. The disease is vectored by banana aphids (Pentalonia nigronervosa) and carried long distances through the movement of infected plant materials. The banana aphids harboring banana bunchy top virus (BBTV) present in banana producing regions are the sole vector and the most efficient method of transmitting the virus to the healthy plants. Controlling the spread of BBTD has been very challenging since no known banana germplasm is immune to BBTV. The disease can be managed with the use of virus‐free planting material and roguing. However, once BBTD is established in the field, it is very difficult to eradicate or manage it. Therefore, a more sustainable way of controlling the disease is developing host plant resistance against the virus and the vector. Biotechnological strategies via RNA interference (RNAi) could be used to target the banana aphid as well as BBTV to reduce virus‐associated yield losses of banana and plantain, which feed over 500 million people around the world. This review discusses the status of BBTD and perspectives on effective RNAi technologies for controlling BBTV and the vector, banana aphid, transmitting the virus as sustainable management of the disease., Banana bunchy top disease (BBTD) is one of the world's most destructive viral disease of banana and plantain causing up to 100% yield loss in severe cases. Biotechnological strategies via RNAi could be used to target banana aphid as well as__banana bunchy top virus__(BBTV) to reduce virus‐passociated yield losses of banana and plantain, which feed over 500 million people around the world. This review discusses the status of BBTD and perspectives on effective RNAi technologies for controlling BBTV and the vector, banana aphid, transmitting the virus as management of the disease.

To search for new alkaliphilic cellulases and to improve their efficiency on crystalline cellulose through molecular engineering RESULTS: Two novel cellulases, BpGH9 and BpGH48, from a Bacillus pumilus strain were identified, cloned and biochemically characterized. BpGH9 is a modular endocellulase belonging to the glycoside hydrolase 9 family (GH9), which contains a catalytic module (GH) and a carbohydrate-binding module belonging to class 3 and subclass c (CBM3c). This enzyme is extremely tolerant to high alkali pH and remains significantly active at pH 10. BpGH48 is an exocellulase, belonging to the glycoside hydrolase 48 family (GH48) and acts on the reducing end of oligo-β1,4 glucanes. A truncated form of BpGH9 and a chimeric fusion with an additional CBM3a module was constructed. The deletion of the CBM3c module results in a significant decline in the catalytic activity. However, fusion of CBM3a, although in a non native position, enhanced the activity of BpGH9 on crystalline cellulose.A new alkaliphilic endocellulase BpGH9, was cloned and engineered as a fusion protein (CBM3a-BpGH9), which led to an improved activity on crystalline cellulose.

Background The demand for a carbohydrate driven economy coupled with the abundant cellulosic biomass has driven the search for cellulases that can be applied for the utilization of the cellulosic biomass.Context of the study Of special focus for our study is cotton, which is the preferred textile fiber given its favorable high quality. In addition, sugar, which is an important feedstock for several chemical industries, can be readily produced from cellulosic biomass. Purpose of the studyWe therefore sought to characterize cellulases from favorable ecosystems in order to gauge the validity of their inclusion in cellulosic biomass industrial utilization. ConclusionWe have shown the production of saccharides from cellulosic biomass (cotton and filter paper). Further, we established the stability of the cellulases in 40% (v/v) organic solvents; propanol, methanol, ethanol. In addition, the enzymes showed tolerance to the accumulation of sugars. Moreover, the cellulase enzymes were most stable at pH 6 and demonstrated a wide activity temperature range of 20°-80°C. Optimal cellulase activity was recorded at 60°C confirming the thermophilic nature of the enzymes. Brief SummaryThis validates and shows the potential of these enzymes in co-expression bio-factories and applications requiring high sugar yields Potential ImplicationsThis work adds to the study on the activity of the pure extracted cellulases from this microorganism under review at the journal of applied Biochemistry and Biotechnology. These findings substantiate the potential inclusion of either this microorganism or its isolated/extracted enzymes in the industrial processing of cellulosic biomass including but not limited to cotton and paper.

Banana and plantain are among the foremost staple food crops providing food and livelihood to over 500 million people in tropical countries. Despite the importance, their production is hampered due to several biotic and abiotic stresses. Plant tissue culture techniques such as somatic embryogenesis and genetic transformation offer a valuable tool for genetic improvement. Identification and quantification of phytochemicals found in banana and plantain are essential in optimizing in vitro activities for crop improvement. Total antioxidants, phenolics, flavonoids, and tannins were quantified in various explants obtained from the field, as well as in vitro plants of banana and plantain cultivars. The result showed genotypic variation in the phytochemicals of selected cultivars. The embryogenic cell suspensions were developed for three farmer-preferred plantain cultivars, Agbagba, Obino l&rsquo, Ewai, and Orishele, using different MS and B5-based culture media. Both culture media supported the development of friable embryogenic calli (FEC), while MS culture media supported the proliferation of fine cell suspension in liquid culture media. The percentage of FEC generated for Agbagba, Obino l&rsquo, Ewai, and Orishele were 22 &plusmn, 24%, 13 &plusmn, 28%, and 9 &plusmn, 16%, respectively. Cell suspensions produced from FECs were successfully transformed by Agrobacterium-mediated transformation with reporter gene constructs and regenerated into whole plants.

Banana bunchy top virus (BBTV) is one of the world’s invasive species. Banana aphid (Pentalonia nigronervosa) is found in all banana producing areas and it is the insect pest known to transmit BBTV causing banana bunchy top disease (BBTD) in bananas and plantains (Musa spp.) and can cause a significant yield loss of up to 100% in severe cases. Controlling the spread of BBTD has been very challenging since there is no known endogenous gene in the Musa germplasm that could confer resistance to BBTV. Excessive dependence on insecticides for disease control is detrimental to the environment and off-target-organisms. The objective of this study was to use RNA interference (RNAi) targeting the acetylcholinesterase (AChE) gene in banana aphid to develop resistance against aphids in farmer preferred plantain cultivars. This could help sustain smallholder farmers in areas where BBTD is an epidemic. To achieve this, plantain cultivars were initiated using plant tissue culture techniques and rapidly multiplied using Temporary Immersion Bioreactor. This was followed by generation of embryogenic cell suspension (ECS), Agrobacterium-mediated transformation of banana and plantain ECS using a RNAi plasmid construct and molecular characterization of putative transgenic lines. Agro-infected ECS of banana and plantain cultivars were regenerated on selective medium and produced several transgenic lines. Molecular characterization confirmed the presence of transgene in about 80% transgenic lines. Preliminary glasshouse screening of transgenic lines showed reduction in population of banana aphids in comparison to control non-transgenic plants. This is the first report on using RNAi targeting AChE gene for developing transgenic plantain that are resistant to banana aphids.

Frequently, forensic entomology is applied in the use of insect maggots for the identification of specimens or remains of humans. Maggot crop analysis could be valuable in criminal investigations when maggots are found at a crime scene and a corpse is absent. Human short tandem repeat (STR) has previously been used to support the association of maggots to a specific corpse but not in the period at which the body has been decomposing. The aim of this research was to assess the time period for successful STR analyses of human DNA from third instar maggots (Protophormia terraenovae) obtained from decomposing human corpses as well as to investigate the human DNA turnover and degradation in the maggot crop after they are removed from food and/or are fed on a beef (a new/different) food source. Results showed that the amount of human DNA recovered from maggots decreased with time in all cases. For maggots fed on beef, the human DNA could only be recovered up to day two and up to day four for the starved maggots. STR analyses of human DNA from maggots’ crop content using 16 loci generated profiles that matched those of reference samples although some of the alleles were not amplifiable therefore generating partial profiles for the samples starved for 4 days and those fed on beef. This may be due to nuclease activity present in the gut of larvae that may have caused degradation of DNA and consequently reduction in DNA yield. It was possible to identify the decomposing body using STRs as markers.

Cellulolytic microorganisms such as fungi and bacteria are responsible for much of the cellulose degradation in soils. Despite the vast number of cellulase producers, there is a deficiency of microorganisms that can produce significant amount of the three components of a cellulase system. i.e. CMCases, exoglucanases and β-glucosidases to efficiently degrade cellulose to fermentable products. Soil samples were collected from two sites of the Kenyan Rift valley; Hell’s gate National Park and a geothermal well in Eburru hill at depths of 155 m, 156 m and 157 m. Isolation of cellulolytic bacteria was carried out using minimal media supplemented with 1% CMC. Isolates obtained were characterized using both morphological and molecular methods. A quantitative cellulolytic test was carried out to select the isolate with the highest specific activity. Additionally the cell-free supernatant was used for functional studies to determine the isolate’s cellulase system components, optimum temperature, pH and time stability. Phylogenetic analyses indicated that all isolates associated mainly with members of the Bacillus licheniformis. All isolates were capable of utilizing CMC, avicel and Cellobiose as their sole carbon sources. Isolate 3 from a depth of 156 m in the well was identified as Bacillus licheniformis strain vic and selected for further functional studies. This isolate was found to bear the three enzyme components of a cellulase system. A cell free extract was noted to hydrolysecellobiose, Avicel and CMC with enzyme specific activities of 0.46878 U/mg, 0.18784 U/mg and 0.13571 U/mg respectively. Optimum temperature for activity measured over 60 minutes was found to be 60oC with relatively high activity at both 70oC and 80oC. The optimum pH at the predetermined optimum temperature was found to be pH 5. The crude enzyme extract was stable for eight hours of incubation at 60oC and pH 5 retaining 92.2% of its activity. This makes B.licheniformis strain vic a quite attractive isolate for potential application in industries.

Symbiotic nitrogen fixing Rhizobium species have been reported to trigger induced resistance reactions that are inhibitive to aboveground antagonists. We tested the hypothesis that root infection by nitrogen-fixing Rhizobium triggers enzyme-mediated induced resistance reactions, which lead to the production of defensive compounds that suppress aboveground colonization by foliar pests. An experiment was conducted using common bean Phaseolus vulgaris, comprising of factorial treatments of Rhizobium inoculation (with or without), C. lindemuthianum (with or without) and soil type (solarized and non-solarized). Anthracnose disease incidence was higher in plants under dual inoculation with C. lindemuthianum and Rhizobium than in plants inoculated with C. lindemuthianum alone (p 0.05). Soil pH, organic carbon and the concentration of nutrients (N, P, Na, Ca, Mg, Zn, Cu) in solarized soil were higher than in non-solarized soil, while Fe and K were lower. There was no evidence to support induced resistance since anthracnose disease was high in Rhizobium inoculated plants. High disease incidence without reduction in plant growth can be interpreted as host plant tolerance. In conclusion, Rhizobium infection of common bean enhances the production of N-based nutritive compounds, while limiting the production of C-based organic compounds associated with plant resistance, thereby promoting host plant suitability to C. lindemuthianum, and possibly enhancing host plant tolerance to the pathogen.

Proximate composition analysis for crude lipid content, crude protein content, moisture content, total ash content and dry weight of Dagaa (Rastrineobola argentea): a small pelagic fish which constitutes one of the main fish species in Lake Victoria was determined from selected beaches: Paga, Dunga, Rota, Usari and Nduru around Lake Victoria-Kenya. This was done with a view to provide nutritional data to guide food processing, industrial exploitation, preservation and consumption of the fish. On a wet weight basis (wwb), proximate composition values were established as crude protein content, kjedahl and biuret (19.1 - 21.7% and 1.93 - 5.80 mg/ml respectively), lipid content by Dyer and Bligh and Soxhlet (3.87 - 7.78 and 1.77 - 3.40% respectively), ash content (1.88 - 4.38%), ash content on a dry weight basis was (10 - 14.58%) and moisture content of (72.83 - 76.90%). Analysis of these results showed that there were significant differences (p 2%) based on Dyer and Bligh method. The high protein, ash and lipid content of Dagaa make it a nutritionally dense fish. Key words: Dagaa, Lake Victoria, proximate composition.

Warburgia ugandensis is an important African medicinal tree. The species population has shown a high genetic differentiation in the Kenya's Rift Valley. Nine populations were analysed by Bulk Segregant Analysis employing Random Amplified Polymorphic DNA marker technique to identify regional differentiation-linked markers within and across Kenyan Rift Valley. Five primers showed putative East and West genetic differentiation. Diagnostic markers were isolated, cloned, sequenced and compared with Genbank sequences using BLAST algorithms. Three, (WarburgiaIC15E, WarburgiaIC55E and WarburgiaIC28W) sequences showed homology to plant and bacterial-like chromosomal sequences with low E-values. Sequence alignment indicated conserved protein domains of plants and bacteria-like sequences. Phylogenetic analysis revealed high rates of genetic distances (H" 0.8) and a low rate of disparity indices of (0), suggesting some evolutionary forces behind demographic differentiation. These imply that genetic differentiation observed might be due to genetic mutants in certain domains of chromosome that may have some implication on genome functionality.

Warburgia ugandensis is an important medicinal tree species in Eastern Africa used to treat several ailments. Wild populations are under great threat due to unsustainable harvesting for medicines and indiscriminate felling of trees for timber and firewood. There is an urgent need for developing and implementing conservation strategies of this species and information on genetic structure is a crucial input. Analysis of molecular variance (AMOVA), which employed 141 AFLP markers revealed most genetic variation to be among individuals within populations (59%, P< 0.0001), but variation among populations (41%, P< 0.0001) was highly significant as well. Constrained ordination analysis illustrating the relationship among populations showed a clear distinction between W. ugandensis from Uganda and western Kenya and other W. ugandensis populations. No correspondence was shown in some cases on pair-wise genetic distances and geographic distances among populations. These findings suggested that conservation strategies for the species in Kenya should place relatively more emphasis on the revealed genetic structuring within the country.

For the isolation of gene space representative sequence elements, a new methodology—high C+G patch (HCGP) filtration—has been developed using rice as a model. The method is based on the fragmentation of the genomic DNA by methylation-sensitive HpaII and MspI restriction endonucleases having exclusively G/C base pair-containing recognition sites. These enzymes fragment the genome at high C+G content and hypomethylated regions. Cloning fragments spanning such regions in close vicinity (200–2,000 bp) revealed that about 60% of the clones represented gene space sequences resulting in twofold enrichment of these sequences, which is close to the theoretical maximum in rice.

Background CCR5 antagonists have clinically been approved for prevention or treatment of HIV/AIDS. Countries in Sub-Saharan Africa with the highest burden of HIV/AIDS are due to adopt these regimens. However, HIV-1 can also use CXCR4 as a co-receptor. There is hence an urgent need to map out cellular tropism of a country’s circulating HIV strains to guide the impending use of CCR5 antagonists. Objectives To determine HIV-1 coreceptor usage among patients attending a comprehensive care centre in Nairobi, Kenya. Methods Blood samples were obtained from HIV infected patients attending the comprehensive care centre, Kenyatta National Hospital in years 2008 and 2009. The samples were separated into plasma and peripheral blood mononuclear cells (PBMCs). Proviral DNA was extracted from PBMCs and Polymerase Chain reaction (PCR) done to amplify the HIV env fragment spanning the C2-V3 region. The resultant fragment was directly sequenced on an automated sequencer (ABI, 3100). Co-receptor prediction of the env sequences was done using Geno2pheno[co-receptor], and phylogenetic relationships determined using CLUSTALW and Neighbor Joining method. Results A total of 67 samples (46 treatment experienced and 21 treatment naive) were successfully amplified and sequenced. Forty nine (73%) sequences showed a prediction for R5 tropism while 18(27%) were X4 tropic. Phylogenetic analysis showed that 46(69%) were subtype A, 11(16%) subtype C, and 10(15%) subtype D. No statistical significant associations were observed between cell tropism and CD4+ status, patient gender, age, or treatment option. There was a tendency for more X4 tropic strains being in the treatment experienced group than the naive group: Of 46 treatment experiencing participants, 14(30%) harboured X4, compared with 4(19%) of 21 of the treatment-naïve participants, the association is however not statistically significant (p = 0.31). However, a strong association was observed between subtype D and CXCR4 co- receptor usage (p = 0.015) with 6(60%) of the 10 subtype D being X4 tropic and 4(40%) R5 tropic. Conclusion HIV-1 R5 tropic strains were the most prevalent in the study population and HIV infected patients in Kenya may benefit from CCR5 antagonists. However, there is need for caution where subtype D infection is suspected or where antiretroviral salvage therapy is indicated.