Shifts in species dominance related to spatial assemblages and variation in environmental parameters in a tropical mangrove estuary.

A shift in species dominance in the mangrove microalgae community in Cross River Estuary System (CRES), Nigeria, was carried out during the wet season to highlight the microalgae structure, identify potential indicators, and evaluate the water quality variation. Plankton samples were collected at sixteen selected sampling sites along the river. Diatoms showed the highest number of species (240 species), contributing more than 70% of the total microalgae abundance. Cluster analysis of the microalgae community delimits the CRES into three sections; upper (UCRS), middle (MCRS), and lower (LCRS) communities. The spatial shift in the microalgae community showed that the green algae (Eudorina elegans and Hylotheca dissiliens) dominated the UCRS communities, while diatoms dominated the MCRS (Polymyxus coronalis and Actinocyclus normanii) and LCRS (A. normanii and A. octonarius). The principal component analysis showed that the UCRS was influenced by turbidity and nitrate, while the MCRS and LCRS were characterized by phosphate, electrical conductivity, and salinity/total dissolved solids. The similarity percentage (SIMPER) analysis showed that Surirella tenera and Hylotheca dissiliens contributed >3.5% inter site dissimilarity between the UCRS and LCRS microalgae community. The redundancy analysis revealed that some microalgae species such as Odontella mobiliensis, Coscinodiscopsis jonesiana, A. normanii, and A. octonarius responded positively to salinity change and ammonia concentration in the estuary, while S. tenera, P. coronalis, Bacillaria paxilifer, Navicula transitans, Cyclotella meneghiniana, Humidophila contenta, Melosira granulata, Aulacoseira herzogii, Eudorina elegans, H. dissiliens, Mougeotia sp., and Dinobryon sertularia responded positively to turbidity, nitrate, and phosphate concentration. This study illustrates that CRES inhabit rich biodiversity of microalgae which some taxa could be used as indicators of the environmental changes in marine waters.

Antimicrobial analysis of honey against Staphylococcus aureus isolates from wound, ADMET properties of its bioactive compounds and in-silico evaluation against dihydropteroate synthase.

BACKGROUND: One of the main challenges of wound healing is infection with multi-drug resistant (MDR) bacteria such as Staphylococcus aureus. The spectrum of antibiotics used to treat them is declining; thus, there is a need for alternatives. Our study was designed to evaluate the antimicrobial properties of honey, its pharmacokinetics (ADMET) properties and in-silico analysis of its bioactive compounds against dihydropteroate synthase of S. aureus using trimethoprim as control. METHODS: Standard protocols were employed in collection and preparation of samples, generation of canonical strings, and conduction of microbiological analyses. Bioactive compounds' ADMET properties were evaluated using the SWISSADME and the MCULE toxicity checker tools. The MCULE one-click docking tool was used in carrying out the dockings. RESULTS: The gas chromatography-mass spectrophotometry revealed twenty (20) bioactive compounds and was dominated by sugars (> 60%). We isolated a total of 47 S. aureus isolates from the wound samples. At lower concentrations, resistance to trimethoprim (95.74 to 100.00%) was higher than honey (70.21 to 96.36%). Only seven (7) isolates meet Lipinski's rule of five and ADMET properties. The docking scores of the bioactive compounds ranged from -3.3 to -4.6 while that of trimethoprim was -6.1, indicating better binding or interaction with the dihydropteroate synthase. The bioactive compounds were not substrates to P450 cytochrome enzymes (CYP1A2, CYP2CI9 and CYP2D6) and p-glycoprotein, indicating better gastrointestinal tract (GIT) absorption. CONCLUSION: The favourable docking properties shown by the bioactive compounds suggest they could be lead compounds for newer antimetabolites for management of MDR S. aureus.

Assessment of Lead (Pb) Remediation Potential of Senna obtusifolia in Dareta Village, Zamfara, Nigeria.

BACKGROUND: Environmental contamination by lead (Pb) and other toxic metals is of significant environmental and human health concern. Heavy metals are not readily eliminated by degradation, and thus remediation of contaminated media (soil, sediment and water/sludge) requires the outright removal or cleanup of these metals. Evaluation of the performance and cost efficiency of various remediation methods has led to the development of bioremediation as an inexpensive, innovative and environmentally friendly cleanup strategy. OBJECTIVES: The present study was designed to assess the Pb remediation potential of wild Senna obtusifolia (Sicklepod), in Dareta Village, Zamfara, Nigeria. METHODS: Soil and Senna obtusifolia samples were collected from established plots and Pb content was determined using a Shimadzu atomic absorption spectrophotometer (model AA-6800, Japan) after wet digestion. RESULTS: The mean concentrations of Pb (mg/kg) in soil, roots, stems and leaves, respectively, were 130.68±5.2, 61.33±17.86, 66.64±18.10 and 173.39±13.73 for plot 1, 287.84±6.5, 69.42±11.62, 123.4±3.67 and 294.28±4.38 for plot 2, 315.73±4.13, 68.42±10.22, 86.89±6.08 and 290.61±7.47 for plot 3, 396.86±5.48, 91.64±2.87, 150.58±2.21 and 282.53±5.69 for plot 4 and 264.23±8.02, 72.71±2.18, 124.60±2.27 and 282.40±3.79 for plot 5. Average values for the translocation factor, bioaccumulation factor and bioconcentration factor were 3.65±0.66, 1.01±0.23 and 0.29±0.10, respectively. DISCUSSION: Soil Pb levels in the present study were found to be within the United States Environmental Protection Agency (USEPA) standards and the Dutch Intervention Values for Pb in soil. Lead content of Senna obtusifolia leaves was found to be higher than the Pb content of the stem and root, indicating relatively low restriction and the efficiency of internal transport of the toxic metal from the roots towards the aerial parts. High translocation and bioaccumulation factors indicate that the plant has vital characteristics for phytoextraction of Pb. The mean Pb concentration of Senna obtusifolia leaves was found to be far above Codex general standards and the European Union (EU) maximum levels for Pb in leafy vegetables. CONCLUSIONS: The study concludes that wild Senna obtusifolia has significant characteristics for phytoextraction of Pb and that consumption of Senna obtusifolia leaves from the study area would pose a serious risk of Pb intoxication. COMPETING INTERESTS: The authors declare no competing financial interests.