Promise Osariemen AIWEKHOE

Clay minerals are naturally occurring fine-grained materials composed primarily of hydrous aluminum silicates, formed through the prolonged weathering and hydrothermal alteration of feldspathic rocks under diverse environmental conditions. This study was aimed at investigating the synergetic effect of Ubiaja clay and Uzala black clay and their antibacterial properties against clinical isolates. The clays were collected from Edo State, Nigeria and investigated for parameters such as pH, electrical conductivity, total dissolved solids, chloride, nitrate, sulphate, phosphate, organic carbon, and metal content. Antimicrobial assays were conducted using the agar disc diffusion method, while minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) were determined through serial dilution techniques. Results revealed that Uzala black clay exhibited stronger antimicrobial activity than Ubiaja clay, attributed to its higher organic matter and iron content. The combined sample demonstrated synergistic enhancement, showing the lowest MIC (25 mg/mL) and highest inhibition zones (up to 4.2 mm), particularly against Escherichia coli and Pseudomonas aeruginosa. Physicochemical data showed that Ubiaja clay had higher mineralization, whereas Uzala black clay was richer in redox-active components, both contributing to their antibacterial potency. The clays also inhibited multidrug-resistant isolates that exhibited resistance to β-lactam antibiotics but sensitivity to fluoroquinolones and aminoglycosides. The findings suggest that locally sourced clays possess promising antimicrobial potential and could serve as cost-effective complementary agents in managing infections, especially in regions affected by antibiotic resistance.