Plant Species in the Folk medicine of Kit Mikayi Region, Western Kenya

An ethnobotanical survey of medicinal plants used in Kit Mikayi area of Western Kenya was carried out in 2007. The area is adjacent to Lake Victoria, the second largest fresh water lake in the world. Being a shrine, an ethnobotanical survey was conducted with the aim of documenting the local plants of economic value which have over time attracted both local and foreign visitors. Thirty-seven species were documented, and their use values and informant consensus factors were determined. The results were considered as important in defining conservation priorities as well as for further investigation of the identified plants for possible pharmacological applications

In vitro antifungal activity of methanolic extracts of different Senna didymobotrya (Fresen.) H.S. Irwin & Barneby plant parts

Background: Herbal medicines have been in use for many years and remain widespread in developing countries; whereas, the use of complementary alternative medicine is on the increase in developed countries. Senna didymobotrya is important for its medicinal benefits among most communities in treating a wide range of ailments.Materials and methods: Plants were collected from a cluster in Siaya, Nandi and Nakuru counties (Kenya). Stem bark, root bark, leaves, flowers and immature pods were obtained; air-dried and ground into fine powder. Methanol was used to extract the plant extracts. The extracts were reconstituted in water and incorporated into growth media to obtain 0%, 2.5%, 5%, 7.5% and 10%. Bioassays were carried out on T. tonsurans (ATCC 28942) and C. albicans (14053). The growth of cultures on the plates was measured over a period of sixteen days. The area under disease progress stairs was determined and subjected to ANOVA and comparison of means using LSD.Results: Results indicated that the growth of C. albicans was not significantly affected by the plant extracts. Growth of T. tonsurans was completely inhibited by immature pods extract at 10%, the leaves and flowers extracts inhibited the growth at 7.5%. The stem and root bark extracts inhibited growth at low dosages of 2.5- 5 %.Conclusion: There is need to carry out research on root and stem barks to identify the active phytochemicals that contribute to their high efficacies. On species conservation, harvesting of roots may lead to depletion of S. didymobotrya.Keywords: Senna didymobotrya, ringworms, candidiasis, tinea capiti

Distribution and origin of suspended matter and organic carbon pools in the Tana River Basin, Kenya

We studied patterns in organic carbon pools and their origin in the Tana River Basin (Kenya), in February 2008 (dry season), September–November 2009 (wet season), and June–July 2010 (end of wet season), covering the full continuum from headwater streams to lowland mainstream sites. A consistent downstream increase in total suspended matter (TSM, 0.6 to 7058 mg l−1) and particulate organic carbon (POC, 0.23 to 119.8 mg l−1) was observed during all three sampling campaigns, particularly pronounced below 1000m above sea level, indicating that most particulate matter exported towards the coastal zone originated from the mid and low altitude zones rather than from headwater regions. This indicates that the cascade of hydroelectrical reservoirs act as an extremely efficient particle trap. Although 7Be / 210Pbxs ratios/age of suspended sediment do not show clear seasonal variation, the gradual downstream increase of suspended matter during end of wet season suggests its origin is caused by inputs of older sediments from bank erosion and/or river sediment resuspension. During wet season, higher TSM concentrations correspond with relatively young suspended matter, suggesting a contribution from recently eroded material.With the exception of reservoir waters, POC was predominantly of terrestrial origin as indicated by generally high POC : chlorophyll a (POC : Chl a) ratios (up to 41 000). Stable isotope signatures of POC ( 13CPOC) ranged between −32 and −20‰and increased downstream, reflecting an increasing contribution of C4-derived carbon in combination with an expected shift in 13C for C3 vegetation towards the more semi-arid lowlands. 13C values in sediments from the main reservoir (−19.5 to −15.7 ‰) were higher than those found in any of the riverine samples, indicating selective retention of particles associated with C4 fraction. Dissolved organic carbon (DOC) concentrations were highest during the end of wet season (2.1 to 6.9 mg l−1), with stable isotope signatures generally between −28 and −22 ‰. A consistent downstream decrease in % organic carbon (%OC) was observed for soils, riverine sediments, and suspended matter. This was likely due to better preservation of the organic fraction in colder high altitude regions, with loss of carbon during downstream spiraling. 13C values for soil and sediment did not exhibit clear altitudinal patterns, but values reflect the full spectrum from C3-dominated to C4-dominated sites. Very low ratios of organic carbon to mineral surface area (OC : SA) were found in reservoir sediments and suspended matter in the lower Tana River, indicating that these are stable OC pools which have undergone extensive degradation. Overall, our study demonstrates that substantial differences occur in both the quantities and origin of suspended sediments and organic carbon along the river profile in this tropical river basin, as well as seasonal differences in the mechanisms causing such variations.Peer reviewe

ETHNOBOTANICAL STUDY OF MEDICINAL PLANTS USED BY SABAOTS OF MT. ELGON KENYA.

Though the majority of people in Kenya and at Kopsiro Division in particular, rely on ethnomedicinal plant species to manage human ailments, the indigenous knowledge largely remains undocumented. Therefore, an ethnobotanical study was conducted on medicinal plant species used to manage human ailments at Kopsiro Division Mt. Elgon District Kenya. The objectives were to identify and document plants traditionally used for medicinal therapy by the Sabaots, to find out the method used for preparing and administering the drugs and to find out the conservation practices for the medicinal plants. Observations and semi-structured interviews were used to gather ethnobotanical data. 107 plants belonging to 56 families were identified and reported to be of medicinal value to the locals. Roots (47.3%) were the most frequently used parts of the plant followed by the bark (23.35%) then leaves (22.75%). The whole plant (1.8%), seed (1.2%), fruit (1.2%), sap (1.2%), flower (0.6%) and wood (0.6%) are least used in that order. The study revealed other hitherto undocumented medicinal plant species that may be new records for treating various ailments. Traditional medicine in Kopsiro division offers cheap, accessible and convenient remedy that suits the traditional lifestyle of the local community in comparison to the conventional medicine. Most medicinal plant species reported in this study were found to be under threat and this calls for urgent conservation measures so as to maximize the sustainable use of these vital resources in the study area

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

Carbon sources supporting a diverse fish community in a tropical coastal ecosystem (Gazi Bay, Kenya)

Interlinked mangrove–seagrass ecosystems are characteristic features of many tropical coastal areas, where they act as feeding and nursery grounds for a variety of fishes and invertebrates. The autotrophic carbon sources supporting fisheries in Gazi bay (Kenya) were studied in three sites, two located in the tidal creeks flowing through extensive mangrove forests, another site located in the subtidal seagrass meadows, approximately 2.5 km away from the forest. Carbon and nitrogen stable isotope composition of 42 fish species, 2 crustacean species and a range of potential primary food sources (e.g., mangroves, seagrasses and epiphytes, macroalgae) were analysed. There was considerable overlap in the δ13C signatures between fish (−16.1 ± 2.1‰), seagrasses (−15.1 ± 3.0‰), seagrass epiphytes (−13.6 ± 3.3‰), and macroalgae (−20.4 ± 3.1‰). Nevertheless, the signatures for most primary producers were sufficiently distinct to indicate that the dominant carbon sources for fish were mainly derived from the seagrass and their associated epiphytic community, and possibly macroalgae. Mangrove-derived organic matter contributes only marginally to the overall fish food web. Carbon supporting these fish communities was derived directly through grazing by herbivorous and some omnivorous fishes, or indirectly through the benthic food web. Fishes from the mangrove creeks had distinctly lower δ13C signatures (−16.8 ± 2.0‰) compared to those collected in the adjacent seagrass beds (−14.7 ± 1.7‰). This indicated that these habitats were used as distinct sheltering and feeding zones for the fishes collected, with minimal degree of exchange within the fish communities despite their regular movement pattern.