Microplastic pollution (MP) in marine environments around the globe is severe and insufficient precautions have yet to be taken for its prevention. The focus of this study was on quantifying MPs from beach sediment and seawater samples and identifying their distributions and types along the western coast of Sri Lanka from the Kelani River estuary to the Mahaoya estuary. Nine sites along this 42 km stretch were selected, and random sampling was employed to collect a minimum of eight sediment samples from each site between October and December 2021. Water samples were also collected, parallel to the sediments, from the ocean surface. FTIR analysis revealed that most of the MPs found were polyethylene (PE), polypropylene (PP), polystyrene (PS), polyethylene terephthalate (PET), and phenol formaldehyde resin. The mean abundance of MPs varied from 2.0 ± 0.6 items/L to 161.0 ± 15.7 items/L in water samples and from 3.0 ± 0.3 items/m² to 656.0 ± 34.5 items/m² in sediment samples. The MPs found were identified in different shapes as fragments (80.2%), pellets (14.9%), fibers (2.7%), and foams (2.5%). Analysis revealed that the beach sediments were contaminated with PS, phenol formaldehyde resin, PET, PP, and PE, while the surface seawater was dominated by phenol formaldehyde resin, PS, PP, and PE.

Microplastic pollution (MP) in marine environments around the globe is severe and enough precautions have not been taken so far for its prevention. The focus of this study is to quantify MPs from beach sediment and seawater samples and to identify their distribution and types along the western coast of Sri Lanka from the Kelani River estuary to the Mahaoya estuary. Nine sites along this 42 km stretch were selected and random sampling was employed to collect a minimum of 8 sediment samples from each site between October and December 2021. Water samples were also collected, parallel to the sediments, from the ocean surface. FTIR analysis revealed that most of the MPs found were polyethylene(PE), polypropylene(PP), polystyrene(PS), polyethylene terephthalate(PET), and phenol formaldehyde resin. The mean abundance of MPs varied from 2.0 ± 0.6 items/L to 161.0 ± 15.7 items/L in water samples and, from 3.0 ± 0.3 items/m2 to 656.0 ± 34.5 items/m2 in sediment samples. The MPs found were identified in different shapes as fragments (80.2%), pellets (14.9%), fibers (2.7%) and foams (2.5%). Analysis revealed that the beach sediments were contaminated with PS, phenol formaldehyde resin, PET, PP and PE, while surface seawater is dominated by phenol formaldehyde resin, PS, PP and PE.

Gallium-based antimicrobials have historically shown their strongest activity against Gram-negative pathogens, particularly P. aeruginosa, while exhibiting limited efficacy against S. aureus. Here, we demonstrate that ligand design can profoundly alter the antibacterial spectrum of gallium complexes. Among six structurally distinct Ga(III) complexes evaluated, gallium tris(8-hydroxyquinolinate), Ga(8HQ)₃, emerged as the only compound displaying potent anti-staphylococcal activity. Ga(8HQ)₃ exhibited low MIC values (2.5-5.0 μg/mL) against methicillin-susceptible S. aureus (MSSA), methicillin-resistant S. aureus (MRSA), vancomycin-intermediate S. aureus (VISA), and multiple clinical isolates, and demonstrated rapid bactericidal activity with MBC/MIC ratios ≤2. The complex also effectively inhibited MRSA biofilm formation and restored susceptibility of a mupirocin-resistant MRSA strain, reducing the mupirocin MIC by 64-fold. The crystallographic, computational, and biological data together support a mechanistic model in which ligand coordination enhances intracellular gallium delivery. Consistent with this model, Ga(8HQ)₃ produced substantially greater intracellular gallium accumulation than gallium nitrate, accompanied by increased oxidative stress and membrane permeabilization. In serial-passage studies, Ga(8HQ)₃ exhibited a low propensity for resistance development and retained activity against mupirocin-resistant MRSA, indicating minimal cross-resistance.,Collectively, these findings demonstrate that rational ligand selection can reprogram the biological behavior of gallium complexes, transforming a traditionally anti-Gram-negative metallodrug platform into a potent anti-staphylococcal agent and identifying Ga(8HQ)₃ as a promising candidate for treating drug-resistant and biofilm-associated S. aureus infections.