Maasai Mara University

This study aimed at preparing and assessing the potential of cow dung biochar (CDB) in adsorption of selected pesticides (tebuconazole, λ-cyhalothrin and α-cypermethrin) and polycyclic aromatic hydrocarbons (PAHs) (naphthalene, phenanthrene and anthracene) from water.CDB was prepared by low temperature pyrolysis (300-350°C) and characterized for surface morphol., composition, crystallinity, phases and thermal properties before assessing its adsorption efficacy at different conditions, isotherm models and regeneration capacity for the target pesticides and PAHs.The morphologies of the samples indicated an amorphous structurewith -OH groups.The composite char had four phases of amorphous, transition, composite and turbostratic char phase while depicting high thermally stability.The adsorption capacities ranged between 78 and 91%.The optimal adsorption conditions were 20°C at a pH range of 4.0-8.0 for 30 min.Temkins adsorption was the most favored model.Chemisorption was exhibited for all sorbates except λ-cyhalothrin while following both pseudo-first order and Akrami-Erovich models.The adsorption processes were spontaneous under room temperature conditions.The adsorbents had an adsorption capacity of 63-80% for the third adsorption cycle indicating they would be regenerated successfully.As a matter of fact, the prepared CBD showed potential for removal of the chem. pollutants removal.

The Winam Gulf in the Kenyan region of Lake Victoria experiences prolific, year-round cyanobacterial harmful algal blooms (cyanoHABs) which pose threats to human, livestock, and ecosystem health. To our knowledge, there is limited molecular research on the gulf’s cyanoHABs, and thus, the strategies employed for survival and proliferation by toxigenic cyanobacteria in this region remain largely unexplored. Here, we used metagenomics to analyze the Winam Gulf’s cyanobacterial composition, function, and biosynthetic potential. Dolichospermum was the dominant bloom-forming cyanobacterium, co-occurring with Microcystis at most sites. Microcystis and Planktothrix were more abundant in shallow and turbid sites. Metagenome-assembled genomes (MAGs) of Dolichospermum harbored nitrogen fixation genes, suggesting diazotrophy as a potential mechanism supporting the proliferation of Dolichospermum in the nitrogen-limited gulf. Over 300 biosynthetic gene clusters (BGCs) putatively encoding the synthesis of toxins and other secondary metabolites were identified across the gulf, even at sites where there were no visible cyanoHAB events. Almost all BGCs identified had no known synthesis product, indicating a diverse and novel biosynthetic repertoire capable of synthesizing harmful or potentially therapeutic metabolites. Microcystis MAGs contained mcy genes encoding the synthesis of hepatotoxic microcystins which are a concern for drinking water safety. These findings illustrate the spatial variation of bloom-forming cyanobacteria in the Winam Gulf and their available strategies to dominate different ecological niches. This study underscores the need for further use of genomic techniques to elucidate the dynamics and mitigate the potentially harmful effects of cyanoHABs and their associated toxins on human, environmental, and economic health.

The Winam Gulf (Kenya) is a vital resource that experiences prolific cyanobacterial harmful algal blooms (cyanoHABs). Bloom-forming cyanobacteria produce cyanotoxins, threatening human and environmental health, recreation, and fishing. However, cyanotoxin production in the gulf has not been linked to a specific type of cyanobacteria. We used DNA sequencing of whole microbial communities to track the species of cyanobacteria present across the gulf and investigate the genes responsible for synthesis of known and novel toxins. Our results reveal Dolichospermum as the main bloom-forming cyanobacteria in the gulf, often co-occurring with high abundance of toxigenic Microcystis. Over 300 unique gene clusters were found, with most predicted to encode the synthesis of uncharacterized molecules. These results provide initial insights into the diverse biosynthetic potential encoded by cyanobacteria in the Winam Gulf and underscore the need to further elucidate and investigate the effects of known and novel molecules produced in cyanoHABs in this region.

Data are sparse on the epidemiological picture of Taenia saginata taeniasis in Kenya. Infections are underreported, and their persistence nonetheless negatively impacts the beef industry. Populations vulnerable to taeniasis in the developing world are commonly burdened with other intestinal parasites, ubiquitous in unsanitary environments. This study aimed to estimate the occurrence of human taeniasis in Narok County, Kenya, and screen for the presence of other intestinal parasitic infections. A community‐based survey was conducted in five pastoral wards, and stool samples, mainly from adults, subjected to multiple diagnostic tests. One sample tested positive for Taenia spp. by coproantigen enzyme‐linked immunosorbent assay (0.3%, 95% CI, 0–1.6, n  = 360), and all samples tested negative on multiplex copro‐polymerase chain reaction targeting the cytochrome c oxidase subunit 1 gene and copromicroscopy. Microscopy ( n  = 361) additionally identified Entamoeba histolytica / dispar / moshkovskii at a prevalence of 15.5% (95% CI, 12.1–19.6), Giardia spp. at 5.3% (95% CI, 3.4–8.1), Hymenolepis spp. at 1.1% (95% CI, 0.4–2.8), and hookworm at 0.3% (95% CI, 0–1.6). Grazing livestock near the homestead (< 2 km) and a formal education background were associated with a reduced likelihood of Giardia spp. infection (AOR 0.07, 95% CI 0–0.36, p = 0.011, and AOR 0.06, 95% CI 0.01–0.50, p = 0.014, respectively). Our findings suggest a very low prevalence of human taeniasis in the population. The occurrence of other pathogenic zoonotic intestinal parasites highlights a public health concern and calls for a One Health approach in the enhancement of hygiene initiatives.